[1/3] clk: arm: sunxi: Add a new clock driver for sunxi SOCs

Commit Message

Emilio López Jan. 22, 2013, 6:12 a.m. UTC

This commit implements the base CPU clocks for sunxi devices. It has
been tested using a slightly modified cpufreq driver from the
linux-sunxi 3.0 tree.

Additionally, document the new bindings introduced by this patch, and drop
the (now unused) old sunxi clock driver.

Idling:
    / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
    /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
    30000000
    /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
    60000000
    /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
    60000000
    /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
    60000000
    /sys/kernel/debug/clk/osc24M/pll1/clk_rate
    60000000
    /sys/kernel/debug/clk/osc24M/clk_rate
    24000000
    /sys/kernel/debug/clk/osc32k/clk_rate
    32768

After "yes >/dev/null &":
    / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
    /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
    84000000
    /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
    168000000
    /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
    336000000
    /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
    1008000000
    /sys/kernel/debug/clk/osc24M/pll1/clk_rate
    1008000000
    /sys/kernel/debug/clk/osc24M/clk_rate
    24000000
    /sys/kernel/debug/clk/osc32k/clk_rate
    32768

Signed-off-by: Emilio López <[e-mail]>
---
 Documentation/devicetree/bindings/clock/sunxi.txt |  47 ++++
 drivers/clk/Makefile                              |   2 +-
 drivers/clk/clk-sunxi.c                           |  30 ---
 drivers/clk/sunxi/Makefile                        |   5 +
 drivers/clk/sunxi/clk-factors.c                   | 175 ++++++++++++++
 drivers/clk/sunxi/clk-factors.h                   |  25 ++
 drivers/clk/sunxi/clk-fixed-gate.c                | 152 +++++++++++++
 drivers/clk/sunxi/clk-fixed-gate.h                |  13 ++
 drivers/clk/sunxi/clk-sunxi.c                     | 265 ++++++++++++++++++++++
 9 files changed, 683 insertions(+), 31 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/clock/sunxi.txt
 delete mode 100644 drivers/clk/clk-sunxi.c
 create mode 100644 drivers/clk/sunxi/Makefile
 create mode 100644 drivers/clk/sunxi/clk-factors.c
 create mode 100644 drivers/clk/sunxi/clk-factors.h
 create mode 100644 drivers/clk/sunxi/clk-fixed-gate.c
 create mode 100644 drivers/clk/sunxi/clk-fixed-gate.h
 create mode 100644 drivers/clk/sunxi/clk-sunxi.c

Comments

Gregory CLEMENT Feb. 5, 2013, 11:18 a.m. UTC | #1

Hi Emilio,

I don't have this hardware by I have a few remarks regarding the way
you use the CCF, see my comments inline.
Mike, don't hesite to correct me if I am wrong.

On 01/22/2013 07:12 AM, Emilio López wrote:
> This commit implements the base CPU clocks for sunxi devices. It has
> been tested using a slightly modified cpufreq driver from the
> linux-sunxi 3.0 tree.
> 
> Additionally, document the new bindings introduced by this patch, and drop
> the (now unused) old sunxi clock driver.
> 
> Idling:
>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>     30000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/clk_rate
>     24000000
>     /sys/kernel/debug/clk/osc32k/clk_rate
>     32768
> 
> After "yes >/dev/null &":
>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>     84000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>     168000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>     336000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>     1008000000
>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>     1008000000
>     /sys/kernel/debug/clk/osc24M/clk_rate
>     24000000
>     /sys/kernel/debug/clk/osc32k/clk_rate
>     32768
> 
> Signed-off-by: Emilio López <[e-mail]>
> ---
>  Documentation/devicetree/bindings/clock/sunxi.txt |  47 ++++
>  drivers/clk/Makefile                              |   2 +-
>  drivers/clk/clk-sunxi.c                           |  30 ---
>  drivers/clk/sunxi/Makefile                        |   5 +
>  drivers/clk/sunxi/clk-factors.c                   | 175 ++++++++++++++
>  drivers/clk/sunxi/clk-factors.h                   |  25 ++
>  drivers/clk/sunxi/clk-fixed-gate.c                | 152 +++++++++++++
>  drivers/clk/sunxi/clk-fixed-gate.h                |  13 ++
>  drivers/clk/sunxi/clk-sunxi.c                     | 265 ++++++++++++++++++++++
>  9 files changed, 683 insertions(+), 31 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/sunxi.txt
>  delete mode 100644 drivers/clk/clk-sunxi.c
>  create mode 100644 drivers/clk/sunxi/Makefile
>  create mode 100644 drivers/clk/sunxi/clk-factors.c
>  create mode 100644 drivers/clk/sunxi/clk-factors.h
>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.c
>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.h
>  create mode 100644 drivers/clk/sunxi/clk-sunxi.c
> 
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> new file mode 100644
> index 0000000..446c5ca
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> @@ -0,0 +1,47 @@
> +Device Tree Clock bindings for arch-sunxi
> +
> +This binding uses the common clock binding[1].
> +
> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +Required properties:
> +- compatible : shall be one of the following:
> +	"allwinner,sunxi-osc-clk" - for a gatable oscillator
> +	"allwinner,sunxi-pll1-clk" - for the main PLL clock
> +	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
> +	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
> +	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
> +	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
> +
> +Required properties for all clocks:
> +- reg : shall be the control register address for the clock.
> +- clocks : shall be the input parent clock(s) phandle for the clock, except for
> +	the root gatable oscillator clock where it is not present
> +- #clock-cells : from common clock binding; shall be set to 0.
> +
> +Additionally, the gatable oscillator clock requires:
> +- clock-frequency : shall be the frequency of the oscillator.
> +
> +
> +For example:
> +
> +osc24M: osc24M {
> +	#clock-cells = <0>;
> +	compatible = "allwinner,sunxi-osc-clk";
> +	reg = <0x01c20050 0x4>;
> +	clock-frequency = <24000000>;
> +};
> +
> +pll1: pll1@01c20000 {
> +	#clock-cells = <0>;
> +	compatible = "allwinner,sunxi-pll1-clk";
> +	reg = <0x01c20000 0x4>;
> +	clocks = <&osc24M>;
> +};
> +
> +cpu: cpu@01c20054 {
> +	#clock-cells = <0>;
> +	compatible = "allwinner,sunxi-cpu-clk";
> +	reg = <0x01c20054 0x4>;
> +	clocks = <&osc32k>, <&osc24M>, <&pll1>;
> +};
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index ee90e87..129afed 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -20,7 +20,7 @@ endif
>  obj-$(CONFIG_MACH_LOONGSON1)	+= clk-ls1x.o
>  obj-$(CONFIG_ARCH_U8500)	+= ux500/
>  obj-$(CONFIG_ARCH_VT8500)	+= clk-vt8500.o
> -obj-$(CONFIG_ARCH_SUNXI)	+= clk-sunxi.o
> +obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
>  obj-$(CONFIG_ARCH_ZYNQ)		+= clk-zynq.o
>  
>  # Chip specific
> diff --git a/drivers/clk/clk-sunxi.c b/drivers/clk/clk-sunxi.c
> deleted file mode 100644
> index 0e831b5..0000000
> --- a/drivers/clk/clk-sunxi.c
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -/*
> - * Copyright 2012 Maxime Ripard
> - *
> - * Maxime Ripard <[e-mail]>
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License as published by
> - * the Free Software Foundation; either version 2 of the License, or
> - * (at your option) any later version.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> - * GNU General Public License for more details.
> - */
> -
> -#include <linux/clk-provider.h>
> -#include <linux/clkdev.h>
> -#include <linux/clk/sunxi.h>
> -#include <linux/of.h>
> -
> -static const __initconst struct of_device_id clk_match[] = {
> -	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
> -	{}
> -};
> -
> -void __init sunxi_init_clocks(void)
> -{
> -	of_clk_init(clk_match);
> -}
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> new file mode 100644
> index 0000000..8e773be
> --- /dev/null
> +++ b/drivers/clk/sunxi/Makefile
> @@ -0,0 +1,5 @@
> +#
> +# Makefile for sunxi specific clk
> +#
> +
> +obj-y += clk-sunxi.o clk-factors.o clk-fixed-gate.o
> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
> new file mode 100644
> index 0000000..428b47d
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-factors.c
> @@ -0,0 +1,175 @@
> +/*
> + * Copyright (C) 2013 Emilio López <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * Adjustable factor-based clock implementation
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/string.h>
> +
> +#include <linux/delay.h>
> +
> +#include "clk-factors.h"
> +
> +/*
> + * DOC: basic adjustable factor-based clock that cannot gate
> + *
> + * Traits of this clock:
> + * prepare - clk_prepare only ensures that parents are prepared
> + * enable - clk_enable only ensures that parents are enabled
> + * rate - rate is adjustable.
> + *        clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
> + * parent - fixed parent.  No clk_set_parent support
> + */
> +
> +struct clk_factors {
> +	struct clk_hw hw;
> +	void __iomem *reg;
> +	struct clk_factors_config *config;
> +	void (*get_factors) (u32 *rate, u8 *n, u8 *k, u8 *m, u8 *p);
> +	spinlock_t *lock;
> +};
> +
> +#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
> +
> +#define SETMASK(len, pos)		(((-1U) >> (31-len))  << (pos))
> +#define CLRMASK(len, pos)		(~(SETMASK(len, pos)))
> +#define FACTOR_GET(bit, len, reg)	(((reg) & SETMASK(len, bit)) >> (bit))
> +
> +#define FACTOR_SET(bit, len, reg, val) \
> +	(((reg) & CLRMASK(len, bit)) | (val << (bit)))
> +
> +static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
> +					     unsigned long parent_rate)
> +{
> +	u8 n, k, p, m;
> +	u32 reg;
> +	unsigned long rate;
> +	struct clk_factors *factors = to_clk_factors(hw);
> +	struct clk_factors_config *config = factors->config;
> +
> +	/* Fetch the register value */
> +	reg = readl(factors->reg);
> +
> +	/* Get each individual factor */
> +	n = FACTOR_GET(config->nshift, config->nwidth, reg);
> +	k = FACTOR_GET(config->kshift, config->kwidth, reg);
> +	m = FACTOR_GET(config->mshift, config->mwidth, reg);
> +	p = FACTOR_GET(config->pshift, config->pwidth, reg);
> +
> +	/* Calculate the rate */
> +	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
> +
> +	return rate;
> +}
> +
> +static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
> +				   unsigned long *parent_rate)
> +{
> +	struct clk_factors *factors = to_clk_factors(hw);
> +	factors->get_factors((u32 *)&rate, NULL, NULL, NULL, NULL);
> +
> +	return rate;
> +}
> +
> +static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
> +				unsigned long parent_rate)
> +{
> +	u8 n, k, m, p;
> +	u32 reg;
> +	struct clk_factors *factors = to_clk_factors(hw);
> +	struct clk_factors_config *config = factors->config;
> +	unsigned long flags = 0;
> +
> +	factors->get_factors((u32 *)&rate, &n, &k, &m, &p);
> +
> +	if (factors->lock)
> +		spin_lock_irqsave(factors->lock, flags);
> +
> +	/* Fetch the register value */
> +	reg = readl(factors->reg);
> +
> +	/* Set up the new factors */
> +	reg = FACTOR_SET(config->nshift, config->nwidth, reg, n);
> +	reg = FACTOR_SET(config->kshift, config->kwidth, reg, k);
> +	reg = FACTOR_SET(config->mshift, config->mwidth, reg, m);
> +	reg = FACTOR_SET(config->pshift, config->pwidth, reg, p);
> +
> +	/* Apply them now */
> +	writel(reg, factors->reg);
> +
> +	/* delay 500us so pll stabilizes */
> +	__delay((rate >> 20) * 500 / 2);
> +
> +	if (factors->lock)
> +		spin_unlock_irqrestore(factors->lock, flags);
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops clk_factors_ops = {
> +	.recalc_rate = clk_factors_recalc_rate,
> +	.round_rate = clk_factors_round_rate,
> +	.set_rate = clk_factors_set_rate,
> +};
> +
> +/**
> + * clk_register_factors - register a factors clock with
> + * the clock framework
> + * @dev: device registering this clock
> + * @name: name of this clock
> + * @parent_name: name of clock's parent
> + * @flags: framework-specific flags
> + * @reg: register address to adjust factors
> + * @config: shift and width of factors n, k, m and p
> + * @get_factors: function to calculate the factors for a given frequency
> + * @lock: shared register lock for this clock
> + */
> +struct clk *clk_register_factors(struct device *dev, const char *name,
> +				 const char *parent_name,
> +				 unsigned long flags, void __iomem *reg,
> +				 struct clk_factors_config *config,
> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
> +						      u8 *m, u8 *p),
> +				 spinlock_t *lock)
> +{
> +	struct clk_factors *factors;
> +	struct clk *clk;
> +	struct clk_init_data init;
> +
> +	/* allocate the factors */
> +	factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
> +	if (!factors) {
> +		pr_err("%s: could not allocate factors clk\n", __func__);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	init.name = name;
> +	init.ops = &clk_factors_ops;
> +	init.flags = flags;
> +	init.parent_names = (parent_name ? &parent_name : NULL);
> +	init.num_parents = (parent_name ? 1 : 0);
> +
> +	/* struct clk_factors assignments */
> +	factors->reg = reg;
> +	factors->config = config;
> +	factors->lock = lock;
> +	factors->hw.init = &init;
> +	factors->get_factors = get_factors;
> +
> +	/* register the clock */
> +	clk = clk_register(dev, &factors->hw);
> +
> +	if (IS_ERR(clk))
> +		kfree(factors);
> +
> +	return clk;
> +}
> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
> new file mode 100644
> index 0000000..a24c889
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-factors.h
> @@ -0,0 +1,25 @@
> +#ifndef __MACH_SUNXI_CLK_FACTORS_H
> +#define __MACH_SUNXI_CLK_FACTORS_H
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +
> +struct clk_factors_config {
> +	u8 nshift;
> +	u8 nwidth;
> +	u8 kshift;
> +	u8 kwidth;
> +	u8 mshift;
> +	u8 mwidth;
> +	u8 pshift;
> +	u8 pwidth;
> +};
> +
> +struct clk *clk_register_factors(struct device *dev, const char *name,
> +				 const char *parent_name,
> +				 unsigned long flags, void __iomem *reg,
> +				 struct clk_factors_config *config,
> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
> +						      u8 *m, u8 *p),
> +				 spinlock_t *lock);
> +#endif
> diff --git a/drivers/clk/sunxi/clk-fixed-gate.c b/drivers/clk/sunxi/clk-fixed-gate.c
> new file mode 100644
> index 0000000..b16eda5
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-fixed-gate.c
> @@ -0,0 +1,152 @@
> +/*
> + * Copyright (C) 2013 Emilio López <[e-mail]>
> + *
> + * Based on drivers/clk/clk-gate.c,
> + *
> + * Copyright (C) 2010-2011 Canonical Ltd <[e-mail]>
> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * Fixed rate, gated clock implementation
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/string.h>
> +
> +#include "clk-fixed-gate.h"
> +
> +/**
> + * DOC: fixed rate clock which can gate and ungate it's ouput
> + *
> + * Traits of this clock:
> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
> + * enable - clk_enable and clk_disable are functional & control gating
> + * rate - rate is always a fixed value.  No clk_set_rate support
> + * parent - fixed parent.  No clk_set_parent support
> + */
> +

This file seems to be a copy and past of clk-fixed-rate.c and
clk-gate.c (as explained in your header). The purpose of the common
clock framework was to reduce code duplication not increase it! :)

The current way to achieve what you want is to declare two clock:
one fixed-rate and one gateable.

In this case your fixed clock will only be use by the gateable
one. Latter thecomposite clk may be a solution, if you really want to
only deal with one clock.

You could remove this file and its header, do a little change in the
dtsi with something like this:

osc24M_fixed: osc24M_fixed {
	#clock-cells = <0>;
	compatible = "fixed-clock";
	clock-frequency = <24000000>;
};

osc24M osc24M {
	#clock-cells = <0>;
	compatible = "allwinner,sunxi-osc-clk"
	reg = <0x01c20050 0x4>;
	clocks = <&osc24M_fixed>;
};

And modify sunxi_osc_clk_setup() as below


[...]

> +
> +static void __init sunxi_osc_clk_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	void *reg;
> +	u32 rate;
> +
> +	reg = of_iomap(node, 0);

here you retrieve the name of the parent clock:

	clk = of_clk_get(np, 0);
	if (!IS_ERR(clk)) {
		parent_name = __clk_get_name(clk);
		clk_put(clk);
	}

We don't anymore to get the clock-frequency
> +
> +	if (of_property_read_u32(node, "clock-frequency", &rate))
> +		return;
> +

And here instead of clk_register_fixed_gate you can use the
clk_register_gate as below:
> +	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
> +				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
> +				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
> +
	clk = clk_register_gate(NULL, clk_name, parent_name,
			CLK_IGNORE_UNUSED, reg, SUNXI_OSC24M_GATE, 0, &clk->lock);

> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +
> +/**
> + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
> + * PLL1 rate is calculated as follows
> + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
> + * parent_rate is always 24Mhz
> + */
> +
> +static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
> +{
> +	u8 div;
> +
> +	/* Normalize value to a 6M multiple */
> +	div = *freq / 6000000;
> +	*freq = 6000000 * div;
> +
> +	/* we were called to round the frequency, we can now return */
> +	if (n == NULL)
> +		return;
> +
> +	/* m is always zero for pll1 */
> +	*m = 0;
> +
> +	/* k is 1 only on these cases */
> +	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
> +		*k = 1;
> +	else
> +		*k = 0;
> +
> +	/* p will be 3 for divs under 10 */
> +	if (div < 10)
> +		*p = 3;
> +
> +	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
> +	else if (div < 20 || (div < 32 && (div & 1)))
> +		*p = 2;
> +
> +	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
> +	 * of divs between 40-62 */
> +	else if (div < 40 || (div < 64 && (div & 2)))
> +		*p = 1;
> +
> +	/* any other entries have p = 0 */
> +	else
> +		*p = 0;
> +
> +	/* calculate a suitable n based on k and p */
> +	div <<= *p;
> +	div /= (*k + 1);
> +	*n = div / 4;
> +}
> +
> +/**
> + * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
> + */
> +
> +struct clk_factors_config pll1_config = {
> +	.nshift = 8,
> +	.nwidth = 5,
> +	.kshift = 4,
> +	.kwidth = 2,
> +	.mshift = 0,
> +	.mwidth = 2,
> +	.pshift = 16,
> +	.pwidth = 2,
> +};
> +
> +static void __init sunxi_pll1_clk_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char *parent;
> +	void *reg;
> +
> +	reg = of_iomap(node, 0);
> +
> +	parent = of_clk_get_parent_name(node, 0);
> +
> +	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
> +				   reg, &pll1_config, sunxi_get_pll1_factors,
> +				   &clk_lock);
> +
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +
> +/**
> + * sunxi_cpu_clk_setup() - Setup function for CPU mux
> + */
> +
> +#define SUNXI_CPU_GATE		16
> +#define SUNXI_CPU_GATE_WIDTH	2
> +
> +static void __init sunxi_cpu_clk_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
> +	void *reg;
> +	int i = 0;
> +
> +	reg = of_iomap(node, 0);
> +
> +	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
> +		i++;
> +
> +	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
> +			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
> +			       0, &clk_lock);
> +
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +
> +/**
> + * sunxi_divider_clk_setup() - Setup function for simple divider clocks
> + */
> +
> +#define SUNXI_DIVISOR_WIDTH	2
> +
> +struct div_data {
> +	u8 div;
> +	u8 pow;
> +};
> +
> +static const __initconst struct div_data axi_data = {
> +	.div = 0,
> +	.pow = 0,
> +};
> +
> +static const __initconst struct div_data ahb_data = {
> +	.div = 4,
> +	.pow = 1,
> +};
> +
> +static const __initconst struct div_data apb0_data = {
> +	.div = 8,
> +	.pow = 1,
> +};
> +
> +static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
> +					   u8 power_of_two)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char *clk_parent;
> +	void *reg;
> +
> +	reg = of_iomap(node, 0);
> +
> +	clk_parent = of_clk_get_parent_name(node, 0);
> +
> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
> +				   reg, shift, SUNXI_DIVISOR_WIDTH,
> +				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
> +				   &clk_lock);
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +/* Matches for of_clk_init */
> +static const __initconst struct of_device_id clk_match[] = {
> +	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
> +	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
> +	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
> +	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
> +	{}
> +};
> +
> +/* Matches for divider clocks */
> +static const __initconst struct of_device_id clk_div_match[] = {
> +	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
> +	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
> +	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
> +	{}
> +};
> +
> +static void __init of_sunxi_divider_clock_setup(void)
> +{
> +	struct device_node *np;
> +	const struct div_data *data;
> +	const struct of_device_id *match;
> +
> +	for_each_matching_node(np, clk_div_match) {
> +		match = of_match_node(clk_div_match, np);
> +		data = match->data;
> +		sunxi_divider_clk_setup(np, data->div, data->pow);
> +	}
> +}
> +
> +void __init sunxi_init_clocks(void)
> +{
> +	/* Register all the simple sunxi clocks on DT */
> +	of_clk_init(clk_match);
> +
> +	/* Register divider clocks */
> +	of_sunxi_divider_clock_setup();
> +}
> 

Regards,

Emilio López Feb. 8, 2013, 10:38 a.m. UTC | #2

Hello Gregory,

El 05/02/13 08:18, Gregory CLEMENT escribió:
> Hi Emilio,
> 
> I don't have this hardware by I have a few remarks regarding the way
> you use the CCF, see my comments inline.
> Mike, don't hesite to correct me if I am wrong.
> 
> On 01/22/2013 07:12 AM, Emilio López wrote:
>> This commit implements the base CPU clocks for sunxi devices. It has
>> been tested using a slightly modified cpufreq driver from the
>> linux-sunxi 3.0 tree.
>>
>> Additionally, document the new bindings introduced by this patch, and drop
>> the (now unused) old sunxi clock driver.
>>
>> Idling:
>>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>>     30000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/clk_rate
>>     24000000
>>     /sys/kernel/debug/clk/osc32k/clk_rate
>>     32768
>>
>> After "yes >/dev/null &":
>>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>>     84000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>>     168000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>>     336000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>>     1008000000
>>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>>     1008000000
>>     /sys/kernel/debug/clk/osc24M/clk_rate
>>     24000000
>>     /sys/kernel/debug/clk/osc32k/clk_rate
>>     32768
>>
>> Signed-off-by: Emilio López <[e-mail]>
>> ---
>>  Documentation/devicetree/bindings/clock/sunxi.txt |  47 ++++
>>  drivers/clk/Makefile                              |   2 +-
>>  drivers/clk/clk-sunxi.c                           |  30 ---
>>  drivers/clk/sunxi/Makefile                        |   5 +
>>  drivers/clk/sunxi/clk-factors.c                   | 175 ++++++++++++++
>>  drivers/clk/sunxi/clk-factors.h                   |  25 ++
>>  drivers/clk/sunxi/clk-fixed-gate.c                | 152 +++++++++++++
>>  drivers/clk/sunxi/clk-fixed-gate.h                |  13 ++
>>  drivers/clk/sunxi/clk-sunxi.c                     | 265 ++++++++++++++++++++++
>>  9 files changed, 683 insertions(+), 31 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/clock/sunxi.txt
>>  delete mode 100644 drivers/clk/clk-sunxi.c
>>  create mode 100644 drivers/clk/sunxi/Makefile
>>  create mode 100644 drivers/clk/sunxi/clk-factors.c
>>  create mode 100644 drivers/clk/sunxi/clk-factors.h
>>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.c
>>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.h
>>  create mode 100644 drivers/clk/sunxi/clk-sunxi.c
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> new file mode 100644
>> index 0000000..446c5ca
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -0,0 +1,47 @@
>> +Device Tree Clock bindings for arch-sunxi
>> +
>> +This binding uses the common clock binding[1].
>> +
>> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
>> +
>> +Required properties:
>> +- compatible : shall be one of the following:
>> +	"allwinner,sunxi-osc-clk" - for a gatable oscillator
>> +	"allwinner,sunxi-pll1-clk" - for the main PLL clock
>> +	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
>> +	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
>> +	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
>> +	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
>> +
>> +Required properties for all clocks:
>> +- reg : shall be the control register address for the clock.
>> +- clocks : shall be the input parent clock(s) phandle for the clock, except for
>> +	the root gatable oscillator clock where it is not present
>> +- #clock-cells : from common clock binding; shall be set to 0.
>> +
>> +Additionally, the gatable oscillator clock requires:
>> +- clock-frequency : shall be the frequency of the oscillator.
>> +
>> +
>> +For example:
>> +
>> +osc24M: osc24M {
>> +	#clock-cells = <0>;
>> +	compatible = "allwinner,sunxi-osc-clk";
>> +	reg = <0x01c20050 0x4>;
>> +	clock-frequency = <24000000>;
>> +};
>> +
>> +pll1: pll1@01c20000 {
>> +	#clock-cells = <0>;
>> +	compatible = "allwinner,sunxi-pll1-clk";
>> +	reg = <0x01c20000 0x4>;
>> +	clocks = <&osc24M>;
>> +};
>> +
>> +cpu: cpu@01c20054 {
>> +	#clock-cells = <0>;
>> +	compatible = "allwinner,sunxi-cpu-clk";
>> +	reg = <0x01c20054 0x4>;
>> +	clocks = <&osc32k>, <&osc24M>, <&pll1>;
>> +};
>> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
>> index ee90e87..129afed 100644
>> --- a/drivers/clk/Makefile
>> +++ b/drivers/clk/Makefile
>> @@ -20,7 +20,7 @@ endif
>>  obj-$(CONFIG_MACH_LOONGSON1)	+= clk-ls1x.o
>>  obj-$(CONFIG_ARCH_U8500)	+= ux500/
>>  obj-$(CONFIG_ARCH_VT8500)	+= clk-vt8500.o
>> -obj-$(CONFIG_ARCH_SUNXI)	+= clk-sunxi.o
>> +obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
>>  obj-$(CONFIG_ARCH_ZYNQ)		+= clk-zynq.o
>>  
>>  # Chip specific
>> diff --git a/drivers/clk/clk-sunxi.c b/drivers/clk/clk-sunxi.c
>> deleted file mode 100644
>> index 0e831b5..0000000
>> --- a/drivers/clk/clk-sunxi.c
>> +++ /dev/null
>> @@ -1,30 +0,0 @@
>> -/*
>> - * Copyright 2012 Maxime Ripard
>> - *
>> - * Maxime Ripard <[e-mail]>
>> - *
>> - * This program is free software; you can redistribute it and/or modify
>> - * it under the terms of the GNU General Public License as published by
>> - * the Free Software Foundation; either version 2 of the License, or
>> - * (at your option) any later version.
>> - *
>> - * This program is distributed in the hope that it will be useful,
>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> - * GNU General Public License for more details.
>> - */
>> -
>> -#include <linux/clk-provider.h>
>> -#include <linux/clkdev.h>
>> -#include <linux/clk/sunxi.h>
>> -#include <linux/of.h>
>> -
>> -static const __initconst struct of_device_id clk_match[] = {
>> -	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
>> -	{}
>> -};
>> -
>> -void __init sunxi_init_clocks(void)
>> -{
>> -	of_clk_init(clk_match);
>> -}
>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> new file mode 100644
>> index 0000000..8e773be
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/Makefile
>> @@ -0,0 +1,5 @@
>> +#
>> +# Makefile for sunxi specific clk
>> +#
>> +
>> +obj-y += clk-sunxi.o clk-factors.o clk-fixed-gate.o
>> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
>> new file mode 100644
>> index 0000000..428b47d
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-factors.c
>> @@ -0,0 +1,175 @@
>> +/*
>> + * Copyright (C) 2013 Emilio López <[e-mail]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * Adjustable factor-based clock implementation
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/err.h>
>> +#include <linux/string.h>
>> +
>> +#include <linux/delay.h>
>> +
>> +#include "clk-factors.h"
>> +
>> +/*
>> + * DOC: basic adjustable factor-based clock that cannot gate
>> + *
>> + * Traits of this clock:
>> + * prepare - clk_prepare only ensures that parents are prepared
>> + * enable - clk_enable only ensures that parents are enabled
>> + * rate - rate is adjustable.
>> + *        clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
>> + * parent - fixed parent.  No clk_set_parent support
>> + */
>> +
>> +struct clk_factors {
>> +	struct clk_hw hw;
>> +	void __iomem *reg;
>> +	struct clk_factors_config *config;
>> +	void (*get_factors) (u32 *rate, u8 *n, u8 *k, u8 *m, u8 *p);
>> +	spinlock_t *lock;
>> +};
>> +
>> +#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
>> +
>> +#define SETMASK(len, pos)		(((-1U) >> (31-len))  << (pos))
>> +#define CLRMASK(len, pos)		(~(SETMASK(len, pos)))
>> +#define FACTOR_GET(bit, len, reg)	(((reg) & SETMASK(len, bit)) >> (bit))
>> +
>> +#define FACTOR_SET(bit, len, reg, val) \
>> +	(((reg) & CLRMASK(len, bit)) | (val << (bit)))
>> +
>> +static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
>> +					     unsigned long parent_rate)
>> +{
>> +	u8 n, k, p, m;
>> +	u32 reg;
>> +	unsigned long rate;
>> +	struct clk_factors *factors = to_clk_factors(hw);
>> +	struct clk_factors_config *config = factors->config;
>> +
>> +	/* Fetch the register value */
>> +	reg = readl(factors->reg);
>> +
>> +	/* Get each individual factor */
>> +	n = FACTOR_GET(config->nshift, config->nwidth, reg);
>> +	k = FACTOR_GET(config->kshift, config->kwidth, reg);
>> +	m = FACTOR_GET(config->mshift, config->mwidth, reg);
>> +	p = FACTOR_GET(config->pshift, config->pwidth, reg);
>> +
>> +	/* Calculate the rate */
>> +	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>> +
>> +	return rate;
>> +}
>> +
>> +static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
>> +				   unsigned long *parent_rate)
>> +{
>> +	struct clk_factors *factors = to_clk_factors(hw);
>> +	factors->get_factors((u32 *)&rate, NULL, NULL, NULL, NULL);
>> +
>> +	return rate;
>> +}
>> +
>> +static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
>> +				unsigned long parent_rate)
>> +{
>> +	u8 n, k, m, p;
>> +	u32 reg;
>> +	struct clk_factors *factors = to_clk_factors(hw);
>> +	struct clk_factors_config *config = factors->config;
>> +	unsigned long flags = 0;
>> +
>> +	factors->get_factors((u32 *)&rate, &n, &k, &m, &p);
>> +
>> +	if (factors->lock)
>> +		spin_lock_irqsave(factors->lock, flags);
>> +
>> +	/* Fetch the register value */
>> +	reg = readl(factors->reg);
>> +
>> +	/* Set up the new factors */
>> +	reg = FACTOR_SET(config->nshift, config->nwidth, reg, n);
>> +	reg = FACTOR_SET(config->kshift, config->kwidth, reg, k);
>> +	reg = FACTOR_SET(config->mshift, config->mwidth, reg, m);
>> +	reg = FACTOR_SET(config->pshift, config->pwidth, reg, p);
>> +
>> +	/* Apply them now */
>> +	writel(reg, factors->reg);
>> +
>> +	/* delay 500us so pll stabilizes */
>> +	__delay((rate >> 20) * 500 / 2);
>> +
>> +	if (factors->lock)
>> +		spin_unlock_irqrestore(factors->lock, flags);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct clk_ops clk_factors_ops = {
>> +	.recalc_rate = clk_factors_recalc_rate,
>> +	.round_rate = clk_factors_round_rate,
>> +	.set_rate = clk_factors_set_rate,
>> +};
>> +
>> +/**
>> + * clk_register_factors - register a factors clock with
>> + * the clock framework
>> + * @dev: device registering this clock
>> + * @name: name of this clock
>> + * @parent_name: name of clock's parent
>> + * @flags: framework-specific flags
>> + * @reg: register address to adjust factors
>> + * @config: shift and width of factors n, k, m and p
>> + * @get_factors: function to calculate the factors for a given frequency
>> + * @lock: shared register lock for this clock
>> + */
>> +struct clk *clk_register_factors(struct device *dev, const char *name,
>> +				 const char *parent_name,
>> +				 unsigned long flags, void __iomem *reg,
>> +				 struct clk_factors_config *config,
>> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
>> +						      u8 *m, u8 *p),
>> +				 spinlock_t *lock)
>> +{
>> +	struct clk_factors *factors;
>> +	struct clk *clk;
>> +	struct clk_init_data init;
>> +
>> +	/* allocate the factors */
>> +	factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
>> +	if (!factors) {
>> +		pr_err("%s: could not allocate factors clk\n", __func__);
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	init.name = name;
>> +	init.ops = &clk_factors_ops;
>> +	init.flags = flags;
>> +	init.parent_names = (parent_name ? &parent_name : NULL);
>> +	init.num_parents = (parent_name ? 1 : 0);
>> +
>> +	/* struct clk_factors assignments */
>> +	factors->reg = reg;
>> +	factors->config = config;
>> +	factors->lock = lock;
>> +	factors->hw.init = &init;
>> +	factors->get_factors = get_factors;
>> +
>> +	/* register the clock */
>> +	clk = clk_register(dev, &factors->hw);
>> +
>> +	if (IS_ERR(clk))
>> +		kfree(factors);
>> +
>> +	return clk;
>> +}
>> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
>> new file mode 100644
>> index 0000000..a24c889
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-factors.h
>> @@ -0,0 +1,25 @@
>> +#ifndef __MACH_SUNXI_CLK_FACTORS_H
>> +#define __MACH_SUNXI_CLK_FACTORS_H
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/clkdev.h>
>> +
>> +struct clk_factors_config {
>> +	u8 nshift;
>> +	u8 nwidth;
>> +	u8 kshift;
>> +	u8 kwidth;
>> +	u8 mshift;
>> +	u8 mwidth;
>> +	u8 pshift;
>> +	u8 pwidth;
>> +};
>> +
>> +struct clk *clk_register_factors(struct device *dev, const char *name,
>> +				 const char *parent_name,
>> +				 unsigned long flags, void __iomem *reg,
>> +				 struct clk_factors_config *config,
>> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
>> +						      u8 *m, u8 *p),
>> +				 spinlock_t *lock);
>> +#endif
>> diff --git a/drivers/clk/sunxi/clk-fixed-gate.c b/drivers/clk/sunxi/clk-fixed-gate.c
>> new file mode 100644
>> index 0000000..b16eda5
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-fixed-gate.c
>> @@ -0,0 +1,152 @@
>> +/*
>> + * Copyright (C) 2013 Emilio López <[e-mail]>
>> + *
>> + * Based on drivers/clk/clk-gate.c,
>> + *
>> + * Copyright (C) 2010-2011 Canonical Ltd <[e-mail]>
>> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[e-mail]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * Fixed rate, gated clock implementation
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/err.h>
>> +#include <linux/string.h>
>> +
>> +#include "clk-fixed-gate.h"
>> +
>> +/**
>> + * DOC: fixed rate clock which can gate and ungate it's ouput
>> + *
>> + * Traits of this clock:
>> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
>> + * enable - clk_enable and clk_disable are functional & control gating
>> + * rate - rate is always a fixed value.  No clk_set_rate support
>> + * parent - fixed parent.  No clk_set_parent support
>> + */
>> +
> 
> This file seems to be a copy and past of clk-fixed-rate.c and
> clk-gate.c (as explained in your header). The purpose of the common
> clock framework was to reduce code duplication not increase it! :)

I agree, I am not much of a fan of code duplication :)

> The current way to achieve what you want is to declare two clock:
> one fixed-rate and one gateable.

I don't like this solution much however, because the software
representation does not accurately match (1:1) the hardware then.

> In this case your fixed clock will only be use by the gateable
> one. Latter thecomposite clk may be a solution, if you really want to
> only deal with one clock.

The composite clock lacks fixed rate support from what I saw on the patches.

So, right now I can think of three possibilities:
1) Use two separate clocks as Gregory suggests, and ignore the
non-accurate representation.
2) Extend composite to support fixed rate and use that.
3) Extend gate to support fixed rate and use that.

I think going with 1) will be best for now, and we can then decide and
work on getting it improved with 2) or 3)

> You could remove this file and its header, do a little change in the
> dtsi with something like this:
> 
> osc24M_fixed: osc24M_fixed {
> 	#clock-cells = <0>;
> 	compatible = "fixed-clock";
> 	clock-frequency = <24000000>;
> };
> 
> osc24M osc24M {
> 	#clock-cells = <0>;
> 	compatible = "allwinner,sunxi-osc-clk"
> 	reg = <0x01c20050 0x4>;
> 	clocks = <&osc24M_fixed>;
> };
> 
> And modify sunxi_osc_clk_setup() as below
> 
> 
> [...]
> 
>> +
>> +static void __init sunxi_osc_clk_setup(struct device_node *node)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	void *reg;
>> +	u32 rate;
>> +
>> +	reg = of_iomap(node, 0);
> 
> here you retrieve the name of the parent clock:
> 
> 	clk = of_clk_get(np, 0);
> 	if (!IS_ERR(clk)) {
> 		parent_name = __clk_get_name(clk);
> 		clk_put(clk);
> 	}
> 
> We don't anymore to get the clock-frequency
>> +
>> +	if (of_property_read_u32(node, "clock-frequency", &rate))
>> +		return;
>> +
> 
> And here instead of clk_register_fixed_gate you can use the
> clk_register_gate as below:
>> +	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
>> +				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
>> +				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
>> +
> 	clk = clk_register_gate(NULL, clk_name, parent_name,
> 			CLK_IGNORE_UNUSED, reg, SUNXI_OSC24M_GATE, 0, &clk->lock);
> 
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +
>> +/**
>> + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
>> + * PLL1 rate is calculated as follows
>> + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>> + * parent_rate is always 24Mhz
>> + */
>> +
>> +static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
>> +{
>> +	u8 div;
>> +
>> +	/* Normalize value to a 6M multiple */
>> +	div = *freq / 6000000;
>> +	*freq = 6000000 * div;
>> +
>> +	/* we were called to round the frequency, we can now return */
>> +	if (n == NULL)
>> +		return;
>> +
>> +	/* m is always zero for pll1 */
>> +	*m = 0;
>> +
>> +	/* k is 1 only on these cases */
>> +	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
>> +		*k = 1;
>> +	else
>> +		*k = 0;
>> +
>> +	/* p will be 3 for divs under 10 */
>> +	if (div < 10)
>> +		*p = 3;
>> +
>> +	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
>> +	else if (div < 20 || (div < 32 && (div & 1)))
>> +		*p = 2;
>> +
>> +	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
>> +	 * of divs between 40-62 */
>> +	else if (div < 40 || (div < 64 && (div & 2)))
>> +		*p = 1;
>> +
>> +	/* any other entries have p = 0 */
>> +	else
>> +		*p = 0;
>> +
>> +	/* calculate a suitable n based on k and p */
>> +	div <<= *p;
>> +	div /= (*k + 1);
>> +	*n = div / 4;
>> +}
>> +
>> +/**
>> + * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
>> + */
>> +
>> +struct clk_factors_config pll1_config = {
>> +	.nshift = 8,
>> +	.nwidth = 5,
>> +	.kshift = 4,
>> +	.kwidth = 2,
>> +	.mshift = 0,
>> +	.mwidth = 2,
>> +	.pshift = 16,
>> +	.pwidth = 2,
>> +};
>> +
>> +static void __init sunxi_pll1_clk_setup(struct device_node *node)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	const char *parent;
>> +	void *reg;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	parent = of_clk_get_parent_name(node, 0);
>> +
>> +	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
>> +				   reg, &pll1_config, sunxi_get_pll1_factors,
>> +				   &clk_lock);
>> +
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +
>> +/**
>> + * sunxi_cpu_clk_setup() - Setup function for CPU mux
>> + */
>> +
>> +#define SUNXI_CPU_GATE		16
>> +#define SUNXI_CPU_GATE_WIDTH	2
>> +
>> +static void __init sunxi_cpu_clk_setup(struct device_node *node)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
>> +	void *reg;
>> +	int i = 0;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
>> +		i++;
>> +
>> +	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
>> +			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
>> +			       0, &clk_lock);
>> +
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +
>> +/**
>> + * sunxi_divider_clk_setup() - Setup function for simple divider clocks
>> + */
>> +
>> +#define SUNXI_DIVISOR_WIDTH	2
>> +
>> +struct div_data {
>> +	u8 div;
>> +	u8 pow;
>> +};
>> +
>> +static const __initconst struct div_data axi_data = {
>> +	.div = 0,
>> +	.pow = 0,
>> +};
>> +
>> +static const __initconst struct div_data ahb_data = {
>> +	.div = 4,
>> +	.pow = 1,
>> +};
>> +
>> +static const __initconst struct div_data apb0_data = {
>> +	.div = 8,
>> +	.pow = 1,
>> +};
>> +
>> +static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
>> +					   u8 power_of_two)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	const char *clk_parent;
>> +	void *reg;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	clk_parent = of_clk_get_parent_name(node, 0);
>> +
>> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
>> +				   reg, shift, SUNXI_DIVISOR_WIDTH,
>> +				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
>> +				   &clk_lock);
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +/* Matches for of_clk_init */
>> +static const __initconst struct of_device_id clk_match[] = {
>> +	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
>> +	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
>> +	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
>> +	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
>> +	{}
>> +};
>> +
>> +/* Matches for divider clocks */
>> +static const __initconst struct of_device_id clk_div_match[] = {
>> +	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
>> +	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
>> +	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
>> +	{}
>> +};
>> +
>> +static void __init of_sunxi_divider_clock_setup(void)
>> +{
>> +	struct device_node *np;
>> +	const struct div_data *data;
>> +	const struct of_device_id *match;
>> +
>> +	for_each_matching_node(np, clk_div_match) {
>> +		match = of_match_node(clk_div_match, np);
>> +		data = match->data;
>> +		sunxi_divider_clk_setup(np, data->div, data->pow);
>> +	}
>> +}
>> +
>> +void __init sunxi_init_clocks(void)
>> +{
>> +	/* Register all the simple sunxi clocks on DT */
>> +	of_clk_init(clk_match);
>> +
>> +	/* Register divider clocks */
>> +	of_sunxi_divider_clock_setup();
>> +}
>>
> 
> Regards,
> 

@Mike and anyone else reading: do you have any other comments before I
send a v2 series?


Thanks for the review,

Emilio

Gregory CLEMENT Feb. 8, 2013, 11:33 a.m. UTC | #3

Hi Emilio,

This is the last part of my review, I didn't takt time to review the
whole patch the last time. As usual, my comments are inline

On 01/22/2013 07:12 AM, Emilio López wrote:

> This commit implements the base CPU clocks for sunxi devices. It has
> been tested using a slightly modified cpufreq driver from the
> linux-sunxi 3.0 tree.
> 
> Additionally, document the new bindings introduced by this patch, and drop
> the (now unused) old sunxi clock driver.
> 
> Idling:
>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>     30000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>     60000000
>     /sys/kernel/debug/clk/osc24M/clk_rate
>     24000000
>     /sys/kernel/debug/clk/osc32k/clk_rate
>     32768
> 
> After "yes >/dev/null &":
>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>     84000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>     168000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>     336000000
>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>     1008000000
>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>     1008000000
>     /sys/kernel/debug/clk/osc24M/clk_rate
>     24000000
>     /sys/kernel/debug/clk/osc32k/clk_rate
>     32768
> 
> Signed-off-by: Emilio López <[e-mail]>
> ---
>  Documentation/devicetree/bindings/clock/sunxi.txt |  47 ++++
>  drivers/clk/Makefile                              |   2 +-
>  drivers/clk/clk-sunxi.c                           |  30 ---
>  drivers/clk/sunxi/Makefile                        |   5 +
>  drivers/clk/sunxi/clk-factors.c                   | 175 ++++++++++++++
>  drivers/clk/sunxi/clk-factors.h                   |  25 ++
>  drivers/clk/sunxi/clk-fixed-gate.c                | 152 +++++++++++++
>  drivers/clk/sunxi/clk-fixed-gate.h                |  13 ++
>  drivers/clk/sunxi/clk-sunxi.c                     | 265 ++++++++++++++++++++++
>  9 files changed, 683 insertions(+), 31 deletions(-)
>  create mode 100644 Documentation/devicetree/bindings/clock/sunxi.txt
>  delete mode 100644 drivers/clk/clk-sunxi.c
>  create mode 100644 drivers/clk/sunxi/Makefile
>  create mode 100644 drivers/clk/sunxi/clk-factors.c
>  create mode 100644 drivers/clk/sunxi/clk-factors.h
>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.c
>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.h
>  create mode 100644 drivers/clk/sunxi/clk-sunxi.c
> 
> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
> new file mode 100644
> index 0000000..446c5ca
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
> @@ -0,0 +1,47 @@
> +Device Tree Clock bindings for arch-sunxi
> +
> +This binding uses the common clock binding[1].
> +
> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +Required properties:
> +- compatible : shall be one of the following:
> +	"allwinner,sunxi-osc-clk" - for a gatable oscillator
> +	"allwinner,sunxi-pll1-clk" - for the main PLL clock
> +	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
> +	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
> +	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
> +	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
> +
> +Required properties for all clocks:
> +- reg : shall be the control register address for the clock.
> +- clocks : shall be the input parent clock(s) phandle for the clock, except for
> +	the root gatable oscillator clock where it is not present
> +- #clock-cells : from common clock binding; shall be set to 0.
> +
> +Additionally, the gatable oscillator clock requires:
> +- clock-frequency : shall be the frequency of the oscillator.
> +
> +
> +For example:
> +
> +osc24M: osc24M {
> +	#clock-cells = <0>;
> +	compatible = "allwinner,sunxi-osc-clk";
> +	reg = <0x01c20050 0x4>;
> +	clock-frequency = <24000000>;
> +};
> +
> +pll1: pll1@01c20000 {
> +	#clock-cells = <0>;
> +	compatible = "allwinner,sunxi-pll1-clk";
> +	reg = <0x01c20000 0x4>;
> +	clocks = <&osc24M>;
> +};
> +
> +cpu: cpu@01c20054 {
> +	#clock-cells = <0>;
> +	compatible = "allwinner,sunxi-cpu-clk";
> +	reg = <0x01c20054 0x4>;
> +	clocks = <&osc32k>, <&osc24M>, <&pll1>;
> +};
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index ee90e87..129afed 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -20,7 +20,7 @@ endif
>  obj-$(CONFIG_MACH_LOONGSON1)	+= clk-ls1x.o
>  obj-$(CONFIG_ARCH_U8500)	+= ux500/
>  obj-$(CONFIG_ARCH_VT8500)	+= clk-vt8500.o
> -obj-$(CONFIG_ARCH_SUNXI)	+= clk-sunxi.o
> +obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
>  obj-$(CONFIG_ARCH_ZYNQ)		+= clk-zynq.o
>  
>  # Chip specific
> diff --git a/drivers/clk/clk-sunxi.c b/drivers/clk/clk-sunxi.c
> deleted file mode 100644
> index 0e831b5..0000000
> --- a/drivers/clk/clk-sunxi.c
> +++ /dev/null
> @@ -1,30 +0,0 @@
> -/*
> - * Copyright 2012 Maxime Ripard
> - *
> - * Maxime Ripard <[e-mail]>
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License as published by
> - * the Free Software Foundation; either version 2 of the License, or
> - * (at your option) any later version.
> - *
> - * This program is distributed in the hope that it will be useful,
> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> - * GNU General Public License for more details.
> - */
> -
> -#include <linux/clk-provider.h>
> -#include <linux/clkdev.h>
> -#include <linux/clk/sunxi.h>
> -#include <linux/of.h>
> -
> -static const __initconst struct of_device_id clk_match[] = {
> -	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
> -	{}
> -};
> -
> -void __init sunxi_init_clocks(void)
> -{
> -	of_clk_init(clk_match);
> -}
> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
> new file mode 100644
> index 0000000..8e773be
> --- /dev/null
> +++ b/drivers/clk/sunxi/Makefile
> @@ -0,0 +1,5 @@
> +#
> +# Makefile for sunxi specific clk
> +#
> +
> +obj-y += clk-sunxi.o clk-factors.o clk-fixed-gate.o
> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
> new file mode 100644
> index 0000000..428b47d
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-factors.c
> @@ -0,0 +1,175 @@
> +/*
> + * Copyright (C) 2013 Emilio López <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * Adjustable factor-based clock implementation
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/string.h>
> +
> +#include <linux/delay.h>
> +
> +#include "clk-factors.h"
> +
> +/*
> + * DOC: basic adjustable factor-based clock that cannot gate
> + *
> + * Traits of this clock:
> + * prepare - clk_prepare only ensures that parents are prepared
> + * enable - clk_enable only ensures that parents are enabled
> + * rate - rate is adjustable.
> + *        clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
> + * parent - fixed parent.  No clk_set_parent support
> + */
> +
> +struct clk_factors {
> +	struct clk_hw hw;
> +	void __iomem *reg;
> +	struct clk_factors_config *config;
> +	void (*get_factors) (u32 *rate, u8 *n, u8 *k, u8 *m, u8 *p);
> +	spinlock_t *lock;
> +};
> +
> +#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
> +
> +#define SETMASK(len, pos)		(((-1U) >> (31-len))  << (pos))
> +#define CLRMASK(len, pos)		(~(SETMASK(len, pos)))
> +#define FACTOR_GET(bit, len, reg)	(((reg) & SETMASK(len, bit)) >> (bit))
> +
> +#define FACTOR_SET(bit, len, reg, val) \
> +	(((reg) & CLRMASK(len, bit)) | (val << (bit)))
> +
> +static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
> +					     unsigned long parent_rate)
> +{
> +	u8 n, k, p, m;
> +	u32 reg;
> +	unsigned long rate;
> +	struct clk_factors *factors = to_clk_factors(hw);
> +	struct clk_factors_config *config = factors->config;
> +
> +	/* Fetch the register value */
> +	reg = readl(factors->reg);
> +
> +	/* Get each individual factor */
> +	n = FACTOR_GET(config->nshift, config->nwidth, reg);
> +	k = FACTOR_GET(config->kshift, config->kwidth, reg);
> +	m = FACTOR_GET(config->mshift, config->mwidth, reg);
> +	p = FACTOR_GET(config->pshift, config->pwidth, reg);
> +
> +	/* Calculate the rate */
> +	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
> +
> +	return rate;
> +}
> +
> +static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
> +				   unsigned long *parent_rate)
> +{
> +	struct clk_factors *factors = to_clk_factors(hw);
> +	factors->get_factors((u32 *)&rate, NULL, NULL, NULL, NULL);
> +
> +	return rate;
> +}
> +
> +static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
> +				unsigned long parent_rate)
> +{
> +	u8 n, k, m, p;
> +	u32 reg;
> +	struct clk_factors *factors = to_clk_factors(hw);
> +	struct clk_factors_config *config = factors->config;
> +	unsigned long flags = 0;
> +
> +	factors->get_factors((u32 *)&rate, &n, &k, &m, &p);
> +
> +	if (factors->lock)
> +		spin_lock_irqsave(factors->lock, flags);
> +
> +	/* Fetch the register value */
> +	reg = readl(factors->reg);
> +
> +	/* Set up the new factors */
> +	reg = FACTOR_SET(config->nshift, config->nwidth, reg, n);
> +	reg = FACTOR_SET(config->kshift, config->kwidth, reg, k);
> +	reg = FACTOR_SET(config->mshift, config->mwidth, reg, m);
> +	reg = FACTOR_SET(config->pshift, config->pwidth, reg, p);
> +
> +	/* Apply them now */
> +	writel(reg, factors->reg);
> +
> +	/* delay 500us so pll stabilizes */
> +	__delay((rate >> 20) * 500 / 2);
> +
> +	if (factors->lock)
> +		spin_unlock_irqrestore(factors->lock, flags);
> +
> +	return 0;
> +}
> +
> +static const struct clk_ops clk_factors_ops = {
> +	.recalc_rate = clk_factors_recalc_rate,
> +	.round_rate = clk_factors_round_rate,
> +	.set_rate = clk_factors_set_rate,
> +};
> +
> +/**
> + * clk_register_factors - register a factors clock with
> + * the clock framework
> + * @dev: device registering this clock
> + * @name: name of this clock
> + * @parent_name: name of clock's parent
> + * @flags: framework-specific flags
> + * @reg: register address to adjust factors
> + * @config: shift and width of factors n, k, m and p
> + * @get_factors: function to calculate the factors for a given frequency
> + * @lock: shared register lock for this clock
> + */

Do you have other "factors" clock than sunxi-pll1-clk?
On your patch I only see this clock using this, and the way
you pass a function  and a the config struct seems to me
overcomplicated for a sinlge clock.

> +struct clk *clk_register_factors(struct device *dev, const char *name,
> +				 const char *parent_name,
> +				 unsigned long flags, void __iomem *reg,
> +				 struct clk_factors_config *config,
> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
> +						      u8 *m, u8 *p),
> +				 spinlock_t *lock)
> +{
> +	struct clk_factors *factors;
> +	struct clk *clk;
> +	struct clk_init_data init;
> +
> +	/* allocate the factors */
> +	factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
> +	if (!factors) {
> +		pr_err("%s: could not allocate factors clk\n", __func__);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	init.name = name;
> +	init.ops = &clk_factors_ops;
> +	init.flags = flags;
> +	init.parent_names = (parent_name ? &parent_name : NULL);
> +	init.num_parents = (parent_name ? 1 : 0);
> +
> +	/* struct clk_factors assignments */
> +	factors->reg = reg;
> +	factors->config = config;
> +	factors->lock = lock;
> +	factors->hw.init = &init;
> +	factors->get_factors = get_factors;
> +
> +	/* register the clock */
> +	clk = clk_register(dev, &factors->hw);
> +
> +	if (IS_ERR(clk))
> +		kfree(factors);
> +
> +	return clk;
> +}
> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
> new file mode 100644
> index 0000000..a24c889
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-factors.h
> @@ -0,0 +1,25 @@
> +#ifndef __MACH_SUNXI_CLK_FACTORS_H
> +#define __MACH_SUNXI_CLK_FACTORS_H
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +
> +struct clk_factors_config {
> +	u8 nshift;
> +	u8 nwidth;
> +	u8 kshift;
> +	u8 kwidth;
> +	u8 mshift;
> +	u8 mwidth;
> +	u8 pshift;
> +	u8 pwidth;
> +};
> +
> +struct clk *clk_register_factors(struct device *dev, const char *name,
> +				 const char *parent_name,
> +				 unsigned long flags, void __iomem *reg,
> +				 struct clk_factors_config *config,
> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
> +						      u8 *m, u8 *p),
> +				 spinlock_t *lock);
> +#endif
> diff --git a/drivers/clk/sunxi/clk-fixed-gate.c b/drivers/clk/sunxi/clk-fixed-gate.c
> new file mode 100644
> index 0000000..b16eda5
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-fixed-gate.c
> @@ -0,0 +1,152 @@
> +/*
> + * Copyright (C) 2013 Emilio López <[e-mail]>
> + *
> + * Based on drivers/clk/clk-gate.c,
> + *
> + * Copyright (C) 2010-2011 Canonical Ltd <[e-mail]>
> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * Fixed rate, gated clock implementation
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/io.h>
> +#include <linux/err.h>
> +#include <linux/string.h>
> +
> +#include "clk-fixed-gate.h"
> +
> +/**
> + * DOC: fixed rate clock which can gate and ungate it's ouput
> + *
> + * Traits of this clock:
> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
> + * enable - clk_enable and clk_disable are functional & control gating
> + * rate - rate is always a fixed value.  No clk_set_rate support
> + * parent - fixed parent.  No clk_set_parent support
> + */
> +
> +struct clk_fixed_gate {
> +	struct clk_hw hw;
> +	u8            bit_idx;
> +	u8            flags;
> +	unsigned long fixed_rate;
> +	void __iomem  *reg;
> +	spinlock_t    *lock;
> +};
> +
> +#define to_clk_fixed_gate(_hw) container_of(_hw, struct clk_fixed_gate, hw)
> +
> +static void clk_fixed_gate_endisable(struct clk_hw *hw, int enable)
> +{
> +	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
> +	unsigned long flags = 0;
> +	u32 reg;
> +
> +	if (gate->lock)
> +		spin_lock_irqsave(gate->lock, flags);
> +
> +	reg = readl(gate->reg);
> +
> +	if (enable)
> +		reg |= BIT(gate->bit_idx);
> +	else
> +		reg &= ~BIT(gate->bit_idx);
> +
> +	writel(reg, gate->reg);
> +
> +	if (gate->lock)
> +		spin_unlock_irqrestore(gate->lock, flags);
> +}
> +
> +static int clk_fixed_gate_enable(struct clk_hw *hw)
> +{
> +	clk_fixed_gate_endisable(hw, 1);
> +
> +	return 0;
> +}
> +
> +static void clk_fixed_gate_disable(struct clk_hw *hw)
> +{
> +	clk_fixed_gate_endisable(hw, 0);
> +}
> +
> +static int clk_fixed_gate_is_enabled(struct clk_hw *hw)
> +{
> +	u32 reg;
> +	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
> +
> +	reg = readl(gate->reg);
> +
> +	reg &= BIT(gate->bit_idx);
> +
> +	return reg ? 1 : 0;
> +}
> +
> +static unsigned long clk_fixed_gate_recalc_rate(struct clk_hw *hw,
> +						unsigned long parent_rate)
> +{
> +	return to_clk_fixed_gate(hw)->fixed_rate;
> +}
> +
> +static const struct clk_ops clk_fixed_gate_ops = {
> +	.enable = clk_fixed_gate_enable,
> +	.disable = clk_fixed_gate_disable,
> +	.is_enabled = clk_fixed_gate_is_enabled,
> +	.recalc_rate = clk_fixed_gate_recalc_rate,
> +};
> +
> +/**
> + * clk_register_fixed_gate - register a fixed rate,
> + * gate clock with the clock framework
> + * @dev: device that is registering this clock
> + * @name: name of this clock
> + * @parent_name: name of this clock's parent
> + * @flags: framework-specific flags for this clock
> + * @reg: register address to control gating of this clock
> + * @bit_idx: which bit in the register controls gating of this clock
> + * @lock: shared register lock for this clock
> + */
> +struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
> +				    const char *parent_name,
> +				    unsigned long flags, void __iomem *reg,
> +				    u8 bit_idx, unsigned long fixed_rate,
> +				    spinlock_t *lock)
> +{
> +	struct clk_fixed_gate *gate;
> +	struct clk *clk;
> +	struct clk_init_data init;
> +
> +	/* allocate the gate */
> +	gate = kzalloc(sizeof(struct clk_fixed_gate), GFP_KERNEL);
> +	if (!gate) {
> +		pr_err("%s: could not allocate fixed gated clk\n", __func__);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	init.name = name;
> +	init.ops = &clk_fixed_gate_ops;
> +	init.flags = flags | CLK_IS_BASIC;
> +	init.parent_names = (parent_name ? &parent_name : NULL);
> +	init.num_parents = (parent_name ? 1 : 0);
> +
> +	/* struct clk_fixed_gate assignments */
> +	gate->fixed_rate = fixed_rate;
> +	gate->reg = reg;
> +	gate->bit_idx = bit_idx;
> +	gate->lock = lock;
> +	gate->hw.init = &init;
> +
> +	clk = clk_register(dev, &gate->hw);
> +
> +	if (IS_ERR(clk))
> +		kfree(gate);
> +
> +	return clk;
> +}
> diff --git a/drivers/clk/sunxi/clk-fixed-gate.h b/drivers/clk/sunxi/clk-fixed-gate.h
> new file mode 100644
> index 0000000..29d9ed3
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-fixed-gate.h
> @@ -0,0 +1,13 @@
> +#ifndef __MACH_SUNXI_CLK_FIXED_GATE_H
> +#define __MACH_SUNXI_CLK_FIXED_GATE_H
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +
> +struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
> +				    const char *parent_name,
> +				    unsigned long flags, void __iomem *reg,
> +				    u8 bit_idx, unsigned long fixed_rate,
> +				    spinlock_t *lock);
> +
> +#endif
> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
> new file mode 100644
> index 0000000..cb587a0
> --- /dev/null
> +++ b/drivers/clk/sunxi/clk-sunxi.c
> @@ -0,0 +1,265 @@
> +/*
> + * Copyright 2013 Emilio López
> + *
> + * Emilio López <[e-mail]>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation; either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/clk-provider.h>
> +#include <linux/clkdev.h>
> +#include <linux/clk/sunxi.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +
> +#include "clk-factors.h"
> +#include "clk-fixed-gate.h"
> +
> +static DEFINE_SPINLOCK(clk_lock);
> +
> +/**
> + * sunxi_osc_clk_setup() - Setup function for gatable oscillator
> + */
> +
> +#define SUNXI_OSC24M_GATE	0
> +
> +static void __init sunxi_osc_clk_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	void *reg;
> +	u32 rate;
> +
> +	reg = of_iomap(node, 0);
> +
> +	if (of_property_read_u32(node, "clock-frequency", &rate))
> +		return;
> +
> +	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
> +				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
> +				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
> +
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +
> +/**
> + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
> + * PLL1 rate is calculated as follows
> + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
> + * parent_rate is always 24Mhz
> + */
> +
> +static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
> +{
> +	u8 div;
> +
> +	/* Normalize value to a 6M multiple */
> +	div = *freq / 6000000;
> +	*freq = 6000000 * div;
> +
> +	/* we were called to round the frequency, we can now return */
> +	if (n == NULL)
> +		return;
> +
> +	/* m is always zero for pll1 */
> +	*m = 0;
> +
> +	/* k is 1 only on these cases */
> +	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
> +		*k = 1;
> +	else
> +		*k = 0;
> +
> +	/* p will be 3 for divs under 10 */
> +	if (div < 10)
> +		*p = 3;
> +
> +	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
> +	else if (div < 20 || (div < 32 && (div & 1)))
> +		*p = 2;
> +
> +	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
> +	 * of divs between 40-62 */
> +	else if (div < 40 || (div < 64 && (div & 2)))
> +		*p = 1;
> +
> +	/* any other entries have p = 0 */
> +	else
> +		*p = 0;
> +
> +	/* calculate a suitable n based on k and p */
> +	div <<= *p;
> +	div /= (*k + 1);
> +	*n = div / 4;
> +}
> +
> +/**
> + * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
> + */
> +
> +struct clk_factors_config pll1_config = {
> +	.nshift = 8,
> +	.nwidth = 5,
> +	.kshift = 4,
> +	.kwidth = 2,
> +	.mshift = 0,
> +	.mwidth = 2,
> +	.pshift = 16,
> +	.pwidth = 2,
> +};
> +
> +static void __init sunxi_pll1_clk_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char *parent;
> +	void *reg;
> +
> +	reg = of_iomap(node, 0);
> +
> +	parent = of_clk_get_parent_name(node, 0);
> +
> +	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
> +				   reg, &pll1_config, sunxi_get_pll1_factors,
> +				   &clk_lock);
> +
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +
> +/**
> + * sunxi_cpu_clk_setup() - Setup function for CPU mux
> + */
> +
> +#define SUNXI_CPU_GATE		16
> +#define SUNXI_CPU_GATE_WIDTH	2
> +
> +static void __init sunxi_cpu_clk_setup(struct device_node *node)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
> +	void *reg;
> +	int i = 0;
> +
> +	reg = of_iomap(node, 0);
> +
> +	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
> +		i++;
> +
> +	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
> +			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
> +			       0, &clk_lock);
> +
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +
> +/**
> + * sunxi_divider_clk_setup() - Setup function for simple divider clocks
> + */
> +
> +#define SUNXI_DIVISOR_WIDTH	2
> +
> +struct div_data {
> +	u8 div;
> +	u8 pow;
> +};
> +
> +static const __initconst struct div_data axi_data = {
> +	.div = 0,
> +	.pow = 0,
> +};
> +
> +static const __initconst struct div_data ahb_data = {
> +	.div = 4,
> +	.pow = 1,
> +};
> +
> +static const __initconst struct div_data apb0_data = {
> +	.div = 8,
> +	.pow = 1,
> +};

Can't you read this from a register?

If not then this 3 clocks are good candidates for my patch:
"clk: add DT fixed-factor-clock binding support"
http://www.spinics.net/lists/arm-kernel/msg191522.html

It was not merged by lack of user, but it will be pretty simple to me
to rebase it on top of 3.8-rc6

So if it is really an informatilon you can only get from the datasheet,
you will be able to just declare it in the DTS.

> +
> +static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
> +					   u8 power_of_two)
> +{
> +	struct clk *clk;
> +	const char *clk_name = node->name;
> +	const char *clk_parent;
> +	void *reg;
> +
> +	reg = of_iomap(node, 0);
> +
> +	clk_parent = of_clk_get_parent_name(node, 0);
> +
> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
> +				   reg, shift, SUNXI_DIVISOR_WIDTH,
> +				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
> +				   &clk_lock);
> +	if (clk) {
> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +		clk_register_clkdev(clk, clk_name, NULL);
> +	}
> +}
> +
> +
> +/* Matches for of_clk_init */
> +static const __initconst struct of_device_id clk_match[] = {
> +	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
> +	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
> +	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
> +	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
> +	{}
> +};
> +
> +/* Matches for divider clocks */
> +static const __initconst struct of_device_id clk_div_match[] = {
> +	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
> +	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
> +	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
> +	{}
> +};
> +
> +static void __init of_sunxi_divider_clock_setup(void)
> +{
> +	struct device_node *np;
> +	const struct div_data *data;
> +	const struct of_device_id *match;
> +
> +	for_each_matching_node(np, clk_div_match) {
> +		match = of_match_node(clk_div_match, np);
> +		data = match->data;
> +		sunxi_divider_clk_setup(np, data->div, data->pow);
> +	}
> +}
> +
> +void __init sunxi_init_clocks(void)
> +{
> +	/* Register all the simple sunxi clocks on DT */
> +	of_clk_init(clk_match);
> +
> +	/* Register divider clocks */
> +	of_sunxi_divider_clock_setup();
> +}
>

Gregory CLEMENT Feb. 8, 2013, 11:43 a.m. UTC | #4

On 02/08/2013 11:38 AM, Emilio López wrote:
[Snip]

>>> +
>>
>> This file seems to be a copy and past of clk-fixed-rate.c and
>> clk-gate.c (as explained in your header). The purpose of the common
>> clock framework was to reduce code duplication not increase it! :)
> 
> I agree, I am not much of a fan of code duplication :)
> 
>> The current way to achieve what you want is to declare two clock:
>> one fixed-rate and one gateable.
> 
> I don't like this solution much however, because the software
> representation does not accurately match (1:1) the hardware then.

I don't see as a problem: we just split this clock in logical
components. It allows a better reusability of the components.

> 
>> In this case your fixed clock will only be use by the gateable
>> one. Latter thecomposite clk may be a solution, if you really want to
>> only deal with one clock.
> 
> The composite clock lacks fixed rate support from what I saw on the patches.
> 
> So, right now I can think of three possibilities:
> 1) Use two separate clocks as Gregory suggests, and ignore the
> non-accurate representation.
> 2) Extend composite to support fixed rate and use that.
> 3) Extend gate to support fixed rate and use that.
> 
> I think going with 1) will be best for now, and we can then decide and
> work on getting it improved with 2) or 3)

I agree.

> 
>> You could remove this file and its header, do a little change in the
>> dtsi with something like this:
>>
>> osc24M_fixed: osc24M_fixed {
>> 	#clock-cells = <0>;
>> 	compatible = "fixed-clock";
>> 	clock-frequency = <24000000>;
>> };
>>
>> osc24M osc24M {
>> 	#clock-cells = <0>;
>> 	compatible = "allwinner,sunxi-osc-clk"
>> 	reg = <0x01c20050 0x4>;
>> 	clocks = <&osc24M_fixed>;
>> };
>>
>> And modify sunxi_osc_clk_setup() as below
>>
>>
>> [...]
>>
>>> +
>>> +static void __init sunxi_osc_clk_setup(struct device_node *node)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	void *reg;
>>> +	u32 rate;
>>> +
>>> +	reg = of_iomap(node, 0);
>>
>> here you retrieve the name of the parent clock:
>>
>> 	clk = of_clk_get(np, 0);
>> 	if (!IS_ERR(clk)) {
>> 		parent_name = __clk_get_name(clk);
>> 		clk_put(clk);
>> 	}
>>
>> We don't anymore to get the clock-frequency
>>> +
>>> +	if (of_property_read_u32(node, "clock-frequency", &rate))
>>> +		return;
>>> +
>>
>> And here instead of clk_register_fixed_gate you can use the
>> clk_register_gate as below:
>>> +	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
>>> +				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
>>> +				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
>>> +
>> 	clk = clk_register_gate(NULL, clk_name, parent_name,
>> 			CLK_IGNORE_UNUSED, reg, SUNXI_OSC24M_GATE, 0, &clk->lock);
>>
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +
>>> +/**
>>> + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
>>> + * PLL1 rate is calculated as follows
>>> + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>>> + * parent_rate is always 24Mhz
>>> + */
>>> +
>>> +static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
>>> +{
>>> +	u8 div;
>>> +
>>> +	/* Normalize value to a 6M multiple */
>>> +	div = *freq / 6000000;
>>> +	*freq = 6000000 * div;
>>> +
>>> +	/* we were called to round the frequency, we can now return */
>>> +	if (n == NULL)
>>> +		return;
>>> +
>>> +	/* m is always zero for pll1 */
>>> +	*m = 0;
>>> +
>>> +	/* k is 1 only on these cases */
>>> +	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
>>> +		*k = 1;
>>> +	else
>>> +		*k = 0;
>>> +
>>> +	/* p will be 3 for divs under 10 */
>>> +	if (div < 10)
>>> +		*p = 3;
>>> +
>>> +	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
>>> +	else if (div < 20 || (div < 32 && (div & 1)))
>>> +		*p = 2;
>>> +
>>> +	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
>>> +	 * of divs between 40-62 */
>>> +	else if (div < 40 || (div < 64 && (div & 2)))
>>> +		*p = 1;
>>> +
>>> +	/* any other entries have p = 0 */
>>> +	else
>>> +		*p = 0;
>>> +
>>> +	/* calculate a suitable n based on k and p */
>>> +	div <<= *p;
>>> +	div /= (*k + 1);
>>> +	*n = div / 4;
>>> +}
>>> +
>>> +/**
>>> + * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
>>> + */
>>> +
>>> +struct clk_factors_config pll1_config = {
>>> +	.nshift = 8,
>>> +	.nwidth = 5,
>>> +	.kshift = 4,
>>> +	.kwidth = 2,
>>> +	.mshift = 0,
>>> +	.mwidth = 2,
>>> +	.pshift = 16,
>>> +	.pwidth = 2,
>>> +};
>>> +
>>> +static void __init sunxi_pll1_clk_setup(struct device_node *node)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	const char *parent;
>>> +	void *reg;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	parent = of_clk_get_parent_name(node, 0);
>>> +
>>> +	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
>>> +				   reg, &pll1_config, sunxi_get_pll1_factors,
>>> +				   &clk_lock);
>>> +
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +
>>> +/**
>>> + * sunxi_cpu_clk_setup() - Setup function for CPU mux
>>> + */
>>> +
>>> +#define SUNXI_CPU_GATE		16
>>> +#define SUNXI_CPU_GATE_WIDTH	2
>>> +
>>> +static void __init sunxi_cpu_clk_setup(struct device_node *node)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
>>> +	void *reg;
>>> +	int i = 0;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
>>> +		i++;
>>> +
>>> +	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
>>> +			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
>>> +			       0, &clk_lock);
>>> +
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +
>>> +/**
>>> + * sunxi_divider_clk_setup() - Setup function for simple divider clocks
>>> + */
>>> +
>>> +#define SUNXI_DIVISOR_WIDTH	2
>>> +
>>> +struct div_data {
>>> +	u8 div;
>>> +	u8 pow;
>>> +};
>>> +
>>> +static const __initconst struct div_data axi_data = {
>>> +	.div = 0,
>>> +	.pow = 0,
>>> +};
>>> +
>>> +static const __initconst struct div_data ahb_data = {
>>> +	.div = 4,
>>> +	.pow = 1,
>>> +};
>>> +
>>> +static const __initconst struct div_data apb0_data = {
>>> +	.div = 8,
>>> +	.pow = 1,
>>> +};
>>> +
>>> +static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
>>> +					   u8 power_of_two)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	const char *clk_parent;
>>> +	void *reg;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	clk_parent = of_clk_get_parent_name(node, 0);
>>> +
>>> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
>>> +				   reg, shift, SUNXI_DIVISOR_WIDTH,
>>> +				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
>>> +				   &clk_lock);
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +/* Matches for of_clk_init */
>>> +static const __initconst struct of_device_id clk_match[] = {
>>> +	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
>>> +	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
>>> +	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
>>> +	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
>>> +	{}
>>> +};
>>> +
>>> +/* Matches for divider clocks */
>>> +static const __initconst struct of_device_id clk_div_match[] = {
>>> +	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
>>> +	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
>>> +	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
>>> +	{}
>>> +};
>>> +
>>> +static void __init of_sunxi_divider_clock_setup(void)
>>> +{
>>> +	struct device_node *np;
>>> +	const struct div_data *data;
>>> +	const struct of_device_id *match;
>>> +
>>> +	for_each_matching_node(np, clk_div_match) {
>>> +		match = of_match_node(clk_div_match, np);
>>> +		data = match->data;
>>> +		sunxi_divider_clk_setup(np, data->div, data->pow);
>>> +	}
>>> +}
>>> +
>>> +void __init sunxi_init_clocks(void)
>>> +{
>>> +	/* Register all the simple sunxi clocks on DT */
>>> +	of_clk_init(clk_match);
>>> +
>>> +	/* Register divider clocks */
>>> +	of_sunxi_divider_clock_setup();
>>> +}
>>>
>>
>> Regards,
>>
> 
> @Mike and anyone else reading: do you have any other comments before I
> send a v2 series?

I've just sent new comments about the other clocks.

Regards,

Gregory

Emilio López Feb. 8, 2013, 5:41 p.m. UTC | #5

Hello Gregory,

El 08/02/13 08:33, Gregory CLEMENT escribió:
> Hi Emilio,
> 
> This is the last part of my review, I didn't takt time to review the
> whole patch the last time. As usual, my comments are inline
> 
> On 01/22/2013 07:12 AM, Emilio López wrote:
> 
>> This commit implements the base CPU clocks for sunxi devices. It has
>> been tested using a slightly modified cpufreq driver from the
>> linux-sunxi 3.0 tree.
>>
>> Additionally, document the new bindings introduced by this patch, and drop
>> the (now unused) old sunxi clock driver.
>>
>> Idling:
>>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>>     30000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>>     60000000
>>     /sys/kernel/debug/clk/osc24M/clk_rate
>>     24000000
>>     /sys/kernel/debug/clk/osc32k/clk_rate
>>     32768
>>
>> After "yes >/dev/null &":
>>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>>     84000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>>     168000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>>     336000000
>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>>     1008000000
>>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>>     1008000000
>>     /sys/kernel/debug/clk/osc24M/clk_rate
>>     24000000
>>     /sys/kernel/debug/clk/osc32k/clk_rate
>>     32768
>>
>> Signed-off-by: Emilio López <[e-mail]>
>> ---
>>  Documentation/devicetree/bindings/clock/sunxi.txt |  47 ++++
>>  drivers/clk/Makefile                              |   2 +-
>>  drivers/clk/clk-sunxi.c                           |  30 ---
>>  drivers/clk/sunxi/Makefile                        |   5 +
>>  drivers/clk/sunxi/clk-factors.c                   | 175 ++++++++++++++
>>  drivers/clk/sunxi/clk-factors.h                   |  25 ++
>>  drivers/clk/sunxi/clk-fixed-gate.c                | 152 +++++++++++++
>>  drivers/clk/sunxi/clk-fixed-gate.h                |  13 ++
>>  drivers/clk/sunxi/clk-sunxi.c                     | 265 ++++++++++++++++++++++
>>  9 files changed, 683 insertions(+), 31 deletions(-)
>>  create mode 100644 Documentation/devicetree/bindings/clock/sunxi.txt
>>  delete mode 100644 drivers/clk/clk-sunxi.c
>>  create mode 100644 drivers/clk/sunxi/Makefile
>>  create mode 100644 drivers/clk/sunxi/clk-factors.c
>>  create mode 100644 drivers/clk/sunxi/clk-factors.h
>>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.c
>>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.h
>>  create mode 100644 drivers/clk/sunxi/clk-sunxi.c
>>
>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>> new file mode 100644
>> index 0000000..446c5ca
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>> @@ -0,0 +1,47 @@
>> +Device Tree Clock bindings for arch-sunxi
>> +
>> +This binding uses the common clock binding[1].
>> +
>> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
>> +
>> +Required properties:
>> +- compatible : shall be one of the following:
>> +	"allwinner,sunxi-osc-clk" - for a gatable oscillator
>> +	"allwinner,sunxi-pll1-clk" - for the main PLL clock
>> +	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
>> +	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
>> +	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
>> +	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
>> +
>> +Required properties for all clocks:
>> +- reg : shall be the control register address for the clock.
>> +- clocks : shall be the input parent clock(s) phandle for the clock, except for
>> +	the root gatable oscillator clock where it is not present
>> +- #clock-cells : from common clock binding; shall be set to 0.
>> +
>> +Additionally, the gatable oscillator clock requires:
>> +- clock-frequency : shall be the frequency of the oscillator.
>> +
>> +
>> +For example:
>> +
>> +osc24M: osc24M {
>> +	#clock-cells = <0>;
>> +	compatible = "allwinner,sunxi-osc-clk";
>> +	reg = <0x01c20050 0x4>;
>> +	clock-frequency = <24000000>;
>> +};
>> +
>> +pll1: pll1@01c20000 {
>> +	#clock-cells = <0>;
>> +	compatible = "allwinner,sunxi-pll1-clk";
>> +	reg = <0x01c20000 0x4>;
>> +	clocks = <&osc24M>;
>> +};
>> +
>> +cpu: cpu@01c20054 {
>> +	#clock-cells = <0>;
>> +	compatible = "allwinner,sunxi-cpu-clk";
>> +	reg = <0x01c20054 0x4>;
>> +	clocks = <&osc32k>, <&osc24M>, <&pll1>;
>> +};
>> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
>> index ee90e87..129afed 100644
>> --- a/drivers/clk/Makefile
>> +++ b/drivers/clk/Makefile
>> @@ -20,7 +20,7 @@ endif
>>  obj-$(CONFIG_MACH_LOONGSON1)	+= clk-ls1x.o
>>  obj-$(CONFIG_ARCH_U8500)	+= ux500/
>>  obj-$(CONFIG_ARCH_VT8500)	+= clk-vt8500.o
>> -obj-$(CONFIG_ARCH_SUNXI)	+= clk-sunxi.o
>> +obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
>>  obj-$(CONFIG_ARCH_ZYNQ)		+= clk-zynq.o
>>  
>>  # Chip specific
>> diff --git a/drivers/clk/clk-sunxi.c b/drivers/clk/clk-sunxi.c
>> deleted file mode 100644
>> index 0e831b5..0000000
>> --- a/drivers/clk/clk-sunxi.c
>> +++ /dev/null
>> @@ -1,30 +0,0 @@
>> -/*
>> - * Copyright 2012 Maxime Ripard
>> - *
>> - * Maxime Ripard <[e-mail]>
>> - *
>> - * This program is free software; you can redistribute it and/or modify
>> - * it under the terms of the GNU General Public License as published by
>> - * the Free Software Foundation; either version 2 of the License, or
>> - * (at your option) any later version.
>> - *
>> - * This program is distributed in the hope that it will be useful,
>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> - * GNU General Public License for more details.
>> - */
>> -
>> -#include <linux/clk-provider.h>
>> -#include <linux/clkdev.h>
>> -#include <linux/clk/sunxi.h>
>> -#include <linux/of.h>
>> -
>> -static const __initconst struct of_device_id clk_match[] = {
>> -	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
>> -	{}
>> -};
>> -
>> -void __init sunxi_init_clocks(void)
>> -{
>> -	of_clk_init(clk_match);
>> -}
>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>> new file mode 100644
>> index 0000000..8e773be
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/Makefile
>> @@ -0,0 +1,5 @@
>> +#
>> +# Makefile for sunxi specific clk
>> +#
>> +
>> +obj-y += clk-sunxi.o clk-factors.o clk-fixed-gate.o
>> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
>> new file mode 100644
>> index 0000000..428b47d
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-factors.c
>> @@ -0,0 +1,175 @@
>> +/*
>> + * Copyright (C) 2013 Emilio López <[e-mail]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * Adjustable factor-based clock implementation
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/err.h>
>> +#include <linux/string.h>
>> +
>> +#include <linux/delay.h>
>> +
>> +#include "clk-factors.h"
>> +
>> +/*
>> + * DOC: basic adjustable factor-based clock that cannot gate
>> + *
>> + * Traits of this clock:
>> + * prepare - clk_prepare only ensures that parents are prepared
>> + * enable - clk_enable only ensures that parents are enabled
>> + * rate - rate is adjustable.
>> + *        clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
>> + * parent - fixed parent.  No clk_set_parent support
>> + */
>> +
>> +struct clk_factors {
>> +	struct clk_hw hw;
>> +	void __iomem *reg;
>> +	struct clk_factors_config *config;
>> +	void (*get_factors) (u32 *rate, u8 *n, u8 *k, u8 *m, u8 *p);
>> +	spinlock_t *lock;
>> +};
>> +
>> +#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
>> +
>> +#define SETMASK(len, pos)		(((-1U) >> (31-len))  << (pos))
>> +#define CLRMASK(len, pos)		(~(SETMASK(len, pos)))
>> +#define FACTOR_GET(bit, len, reg)	(((reg) & SETMASK(len, bit)) >> (bit))
>> +
>> +#define FACTOR_SET(bit, len, reg, val) \
>> +	(((reg) & CLRMASK(len, bit)) | (val << (bit)))
>> +
>> +static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
>> +					     unsigned long parent_rate)
>> +{
>> +	u8 n, k, p, m;
>> +	u32 reg;
>> +	unsigned long rate;
>> +	struct clk_factors *factors = to_clk_factors(hw);
>> +	struct clk_factors_config *config = factors->config;
>> +
>> +	/* Fetch the register value */
>> +	reg = readl(factors->reg);
>> +
>> +	/* Get each individual factor */
>> +	n = FACTOR_GET(config->nshift, config->nwidth, reg);
>> +	k = FACTOR_GET(config->kshift, config->kwidth, reg);
>> +	m = FACTOR_GET(config->mshift, config->mwidth, reg);
>> +	p = FACTOR_GET(config->pshift, config->pwidth, reg);
>> +
>> +	/* Calculate the rate */
>> +	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>> +
>> +	return rate;
>> +}
>> +
>> +static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
>> +				   unsigned long *parent_rate)
>> +{
>> +	struct clk_factors *factors = to_clk_factors(hw);
>> +	factors->get_factors((u32 *)&rate, NULL, NULL, NULL, NULL);
>> +
>> +	return rate;
>> +}
>> +
>> +static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
>> +				unsigned long parent_rate)
>> +{
>> +	u8 n, k, m, p;
>> +	u32 reg;
>> +	struct clk_factors *factors = to_clk_factors(hw);
>> +	struct clk_factors_config *config = factors->config;
>> +	unsigned long flags = 0;
>> +
>> +	factors->get_factors((u32 *)&rate, &n, &k, &m, &p);
>> +
>> +	if (factors->lock)
>> +		spin_lock_irqsave(factors->lock, flags);
>> +
>> +	/* Fetch the register value */
>> +	reg = readl(factors->reg);
>> +
>> +	/* Set up the new factors */
>> +	reg = FACTOR_SET(config->nshift, config->nwidth, reg, n);
>> +	reg = FACTOR_SET(config->kshift, config->kwidth, reg, k);
>> +	reg = FACTOR_SET(config->mshift, config->mwidth, reg, m);
>> +	reg = FACTOR_SET(config->pshift, config->pwidth, reg, p);
>> +
>> +	/* Apply them now */
>> +	writel(reg, factors->reg);
>> +
>> +	/* delay 500us so pll stabilizes */
>> +	__delay((rate >> 20) * 500 / 2);
>> +
>> +	if (factors->lock)
>> +		spin_unlock_irqrestore(factors->lock, flags);
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct clk_ops clk_factors_ops = {
>> +	.recalc_rate = clk_factors_recalc_rate,
>> +	.round_rate = clk_factors_round_rate,
>> +	.set_rate = clk_factors_set_rate,
>> +};
>> +
>> +/**
>> + * clk_register_factors - register a factors clock with
>> + * the clock framework
>> + * @dev: device registering this clock
>> + * @name: name of this clock
>> + * @parent_name: name of clock's parent
>> + * @flags: framework-specific flags
>> + * @reg: register address to adjust factors
>> + * @config: shift and width of factors n, k, m and p
>> + * @get_factors: function to calculate the factors for a given frequency
>> + * @lock: shared register lock for this clock
>> + */
> 
> Do you have other "factors" clock than sunxi-pll1-clk?
> On your patch I only see this clock using this, and the way
> you pass a function  and a the config struct seems to me
> overcomplicated for a sinlge clock.

Yes, there are other "factors" clocks on sunxi hardware; I have not
added them to the driver yet, but having the factors implementation
there makes it trivial to represent them on a future patchset.

> 
>> +struct clk *clk_register_factors(struct device *dev, const char *name,
>> +				 const char *parent_name,
>> +				 unsigned long flags, void __iomem *reg,
>> +				 struct clk_factors_config *config,
>> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
>> +						      u8 *m, u8 *p),
>> +				 spinlock_t *lock)
>> +{
>> +	struct clk_factors *factors;
>> +	struct clk *clk;
>> +	struct clk_init_data init;
>> +
>> +	/* allocate the factors */
>> +	factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
>> +	if (!factors) {
>> +		pr_err("%s: could not allocate factors clk\n", __func__);
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	init.name = name;
>> +	init.ops = &clk_factors_ops;
>> +	init.flags = flags;
>> +	init.parent_names = (parent_name ? &parent_name : NULL);
>> +	init.num_parents = (parent_name ? 1 : 0);
>> +
>> +	/* struct clk_factors assignments */
>> +	factors->reg = reg;
>> +	factors->config = config;
>> +	factors->lock = lock;
>> +	factors->hw.init = &init;
>> +	factors->get_factors = get_factors;
>> +
>> +	/* register the clock */
>> +	clk = clk_register(dev, &factors->hw);
>> +
>> +	if (IS_ERR(clk))
>> +		kfree(factors);
>> +
>> +	return clk;
>> +}
>> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
>> new file mode 100644
>> index 0000000..a24c889
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-factors.h
>> @@ -0,0 +1,25 @@
>> +#ifndef __MACH_SUNXI_CLK_FACTORS_H
>> +#define __MACH_SUNXI_CLK_FACTORS_H
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/clkdev.h>
>> +
>> +struct clk_factors_config {
>> +	u8 nshift;
>> +	u8 nwidth;
>> +	u8 kshift;
>> +	u8 kwidth;
>> +	u8 mshift;
>> +	u8 mwidth;
>> +	u8 pshift;
>> +	u8 pwidth;
>> +};
>> +
>> +struct clk *clk_register_factors(struct device *dev, const char *name,
>> +				 const char *parent_name,
>> +				 unsigned long flags, void __iomem *reg,
>> +				 struct clk_factors_config *config,
>> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
>> +						      u8 *m, u8 *p),
>> +				 spinlock_t *lock);
>> +#endif
>> diff --git a/drivers/clk/sunxi/clk-fixed-gate.c b/drivers/clk/sunxi/clk-fixed-gate.c
>> new file mode 100644
>> index 0000000..b16eda5
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-fixed-gate.c
>> @@ -0,0 +1,152 @@
>> +/*
>> + * Copyright (C) 2013 Emilio López <[e-mail]>
>> + *
>> + * Based on drivers/clk/clk-gate.c,
>> + *
>> + * Copyright (C) 2010-2011 Canonical Ltd <[e-mail]>
>> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[e-mail]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + *
>> + * Fixed rate, gated clock implementation
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/module.h>
>> +#include <linux/slab.h>
>> +#include <linux/io.h>
>> +#include <linux/err.h>
>> +#include <linux/string.h>
>> +
>> +#include "clk-fixed-gate.h"
>> +
>> +/**
>> + * DOC: fixed rate clock which can gate and ungate it's ouput
>> + *
>> + * Traits of this clock:
>> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
>> + * enable - clk_enable and clk_disable are functional & control gating
>> + * rate - rate is always a fixed value.  No clk_set_rate support
>> + * parent - fixed parent.  No clk_set_parent support
>> + */
>> +
>> +struct clk_fixed_gate {
>> +	struct clk_hw hw;
>> +	u8            bit_idx;
>> +	u8            flags;
>> +	unsigned long fixed_rate;
>> +	void __iomem  *reg;
>> +	spinlock_t    *lock;
>> +};
>> +
>> +#define to_clk_fixed_gate(_hw) container_of(_hw, struct clk_fixed_gate, hw)
>> +
>> +static void clk_fixed_gate_endisable(struct clk_hw *hw, int enable)
>> +{
>> +	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
>> +	unsigned long flags = 0;
>> +	u32 reg;
>> +
>> +	if (gate->lock)
>> +		spin_lock_irqsave(gate->lock, flags);
>> +
>> +	reg = readl(gate->reg);
>> +
>> +	if (enable)
>> +		reg |= BIT(gate->bit_idx);
>> +	else
>> +		reg &= ~BIT(gate->bit_idx);
>> +
>> +	writel(reg, gate->reg);
>> +
>> +	if (gate->lock)
>> +		spin_unlock_irqrestore(gate->lock, flags);
>> +}
>> +
>> +static int clk_fixed_gate_enable(struct clk_hw *hw)
>> +{
>> +	clk_fixed_gate_endisable(hw, 1);
>> +
>> +	return 0;
>> +}
>> +
>> +static void clk_fixed_gate_disable(struct clk_hw *hw)
>> +{
>> +	clk_fixed_gate_endisable(hw, 0);
>> +}
>> +
>> +static int clk_fixed_gate_is_enabled(struct clk_hw *hw)
>> +{
>> +	u32 reg;
>> +	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
>> +
>> +	reg = readl(gate->reg);
>> +
>> +	reg &= BIT(gate->bit_idx);
>> +
>> +	return reg ? 1 : 0;
>> +}
>> +
>> +static unsigned long clk_fixed_gate_recalc_rate(struct clk_hw *hw,
>> +						unsigned long parent_rate)
>> +{
>> +	return to_clk_fixed_gate(hw)->fixed_rate;
>> +}
>> +
>> +static const struct clk_ops clk_fixed_gate_ops = {
>> +	.enable = clk_fixed_gate_enable,
>> +	.disable = clk_fixed_gate_disable,
>> +	.is_enabled = clk_fixed_gate_is_enabled,
>> +	.recalc_rate = clk_fixed_gate_recalc_rate,
>> +};
>> +
>> +/**
>> + * clk_register_fixed_gate - register a fixed rate,
>> + * gate clock with the clock framework
>> + * @dev: device that is registering this clock
>> + * @name: name of this clock
>> + * @parent_name: name of this clock's parent
>> + * @flags: framework-specific flags for this clock
>> + * @reg: register address to control gating of this clock
>> + * @bit_idx: which bit in the register controls gating of this clock
>> + * @lock: shared register lock for this clock
>> + */
>> +struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
>> +				    const char *parent_name,
>> +				    unsigned long flags, void __iomem *reg,
>> +				    u8 bit_idx, unsigned long fixed_rate,
>> +				    spinlock_t *lock)
>> +{
>> +	struct clk_fixed_gate *gate;
>> +	struct clk *clk;
>> +	struct clk_init_data init;
>> +
>> +	/* allocate the gate */
>> +	gate = kzalloc(sizeof(struct clk_fixed_gate), GFP_KERNEL);
>> +	if (!gate) {
>> +		pr_err("%s: could not allocate fixed gated clk\n", __func__);
>> +		return ERR_PTR(-ENOMEM);
>> +	}
>> +
>> +	init.name = name;
>> +	init.ops = &clk_fixed_gate_ops;
>> +	init.flags = flags | CLK_IS_BASIC;
>> +	init.parent_names = (parent_name ? &parent_name : NULL);
>> +	init.num_parents = (parent_name ? 1 : 0);
>> +
>> +	/* struct clk_fixed_gate assignments */
>> +	gate->fixed_rate = fixed_rate;
>> +	gate->reg = reg;
>> +	gate->bit_idx = bit_idx;
>> +	gate->lock = lock;
>> +	gate->hw.init = &init;
>> +
>> +	clk = clk_register(dev, &gate->hw);
>> +
>> +	if (IS_ERR(clk))
>> +		kfree(gate);
>> +
>> +	return clk;
>> +}
>> diff --git a/drivers/clk/sunxi/clk-fixed-gate.h b/drivers/clk/sunxi/clk-fixed-gate.h
>> new file mode 100644
>> index 0000000..29d9ed3
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-fixed-gate.h
>> @@ -0,0 +1,13 @@
>> +#ifndef __MACH_SUNXI_CLK_FIXED_GATE_H
>> +#define __MACH_SUNXI_CLK_FIXED_GATE_H
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/clkdev.h>
>> +
>> +struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
>> +				    const char *parent_name,
>> +				    unsigned long flags, void __iomem *reg,
>> +				    u8 bit_idx, unsigned long fixed_rate,
>> +				    spinlock_t *lock);
>> +
>> +#endif
>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>> new file mode 100644
>> index 0000000..cb587a0
>> --- /dev/null
>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>> @@ -0,0 +1,265 @@
>> +/*
>> + * Copyright 2013 Emilio López
>> + *
>> + * Emilio López <[e-mail]>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + *
>> + * This program is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>> + * GNU General Public License for more details.
>> + */
>> +
>> +#include <linux/clk-provider.h>
>> +#include <linux/clkdev.h>
>> +#include <linux/clk/sunxi.h>
>> +#include <linux/of.h>
>> +#include <linux/of_address.h>
>> +
>> +#include "clk-factors.h"
>> +#include "clk-fixed-gate.h"
>> +
>> +static DEFINE_SPINLOCK(clk_lock);
>> +
>> +/**
>> + * sunxi_osc_clk_setup() - Setup function for gatable oscillator
>> + */
>> +
>> +#define SUNXI_OSC24M_GATE	0
>> +
>> +static void __init sunxi_osc_clk_setup(struct device_node *node)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	void *reg;
>> +	u32 rate;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	if (of_property_read_u32(node, "clock-frequency", &rate))
>> +		return;
>> +
>> +	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
>> +				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
>> +				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
>> +
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +
>> +/**
>> + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
>> + * PLL1 rate is calculated as follows
>> + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>> + * parent_rate is always 24Mhz
>> + */
>> +
>> +static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
>> +{
>> +	u8 div;
>> +
>> +	/* Normalize value to a 6M multiple */
>> +	div = *freq / 6000000;
>> +	*freq = 6000000 * div;
>> +
>> +	/* we were called to round the frequency, we can now return */
>> +	if (n == NULL)
>> +		return;
>> +
>> +	/* m is always zero for pll1 */
>> +	*m = 0;
>> +
>> +	/* k is 1 only on these cases */
>> +	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
>> +		*k = 1;
>> +	else
>> +		*k = 0;
>> +
>> +	/* p will be 3 for divs under 10 */
>> +	if (div < 10)
>> +		*p = 3;
>> +
>> +	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
>> +	else if (div < 20 || (div < 32 && (div & 1)))
>> +		*p = 2;
>> +
>> +	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
>> +	 * of divs between 40-62 */
>> +	else if (div < 40 || (div < 64 && (div & 2)))
>> +		*p = 1;
>> +
>> +	/* any other entries have p = 0 */
>> +	else
>> +		*p = 0;
>> +
>> +	/* calculate a suitable n based on k and p */
>> +	div <<= *p;
>> +	div /= (*k + 1);
>> +	*n = div / 4;
>> +}
>> +
>> +/**
>> + * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
>> + */
>> +
>> +struct clk_factors_config pll1_config = {
>> +	.nshift = 8,
>> +	.nwidth = 5,
>> +	.kshift = 4,
>> +	.kwidth = 2,
>> +	.mshift = 0,
>> +	.mwidth = 2,
>> +	.pshift = 16,
>> +	.pwidth = 2,
>> +};
>> +
>> +static void __init sunxi_pll1_clk_setup(struct device_node *node)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	const char *parent;
>> +	void *reg;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	parent = of_clk_get_parent_name(node, 0);
>> +
>> +	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
>> +				   reg, &pll1_config, sunxi_get_pll1_factors,
>> +				   &clk_lock);
>> +
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +
>> +/**
>> + * sunxi_cpu_clk_setup() - Setup function for CPU mux
>> + */
>> +
>> +#define SUNXI_CPU_GATE		16
>> +#define SUNXI_CPU_GATE_WIDTH	2
>> +
>> +static void __init sunxi_cpu_clk_setup(struct device_node *node)
>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
>> +	void *reg;
>> +	int i = 0;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
>> +		i++;
>> +
>> +	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
>> +			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
>> +			       0, &clk_lock);
>> +
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +
>> +/**
>> + * sunxi_divider_clk_setup() - Setup function for simple divider clocks
>> + */
>> +
>> +#define SUNXI_DIVISOR_WIDTH	2
>> +
>> +struct div_data {
>> +	u8 div;
>> +	u8 pow;
>> +};
>> +
>> +static const __initconst struct div_data axi_data = {
>> +	.div = 0,
>> +	.pow = 0,
>> +};
>> +
>> +static const __initconst struct div_data ahb_data = {
>> +	.div = 4,
>> +	.pow = 1,
>> +};
>> +
>> +static const __initconst struct div_data apb0_data = {
>> +	.div = 8,
>> +	.pow = 1,
>> +};
> 
> Can't you read this from a register?

I don't understand your question. "div" is the shift in the register
where the divisor gets configured. width is always 2 as indicated by the
compiler macro above.

> 
> If not then this 3 clocks are good candidates for my patch:
> "clk: add DT fixed-factor-clock binding support"
> http://www.spinics.net/lists/arm-kernel/msg191522.html

These are configurable dividers; fixed-factor appears to be for clocks
where div and mult are fixed values.

> 
> It was not merged by lack of user, but it will be pretty simple to me
> to rebase it on top of 3.8-rc6
> 
> So if it is really an informatilon you can only get from the datasheet,
> you will be able to just declare it in the DTS.
> 
>> +
>> +static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
>> +					   u8 power_of_two)

See here, .div is shift and .pow is power_of_two

>> +{
>> +	struct clk *clk;
>> +	const char *clk_name = node->name;
>> +	const char *clk_parent;
>> +	void *reg;
>> +
>> +	reg = of_iomap(node, 0);
>> +
>> +	clk_parent = of_clk_get_parent_name(node, 0);
>> +
>> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
>> +				   reg, shift, SUNXI_DIVISOR_WIDTH,
>> +				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
>> +				   &clk_lock);
>> +	if (clk) {
>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +		clk_register_clkdev(clk, clk_name, NULL);
>> +	}
>> +}
>> +
>> +
>> +/* Matches for of_clk_init */
>> +static const __initconst struct of_device_id clk_match[] = {
>> +	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
>> +	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
>> +	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
>> +	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
>> +	{}
>> +};
>> +
>> +/* Matches for divider clocks */
>> +static const __initconst struct of_device_id clk_div_match[] = {
>> +	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
>> +	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
>> +	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
>> +	{}
>> +};
>> +
>> +static void __init of_sunxi_divider_clock_setup(void)
>> +{
>> +	struct device_node *np;
>> +	const struct div_data *data;
>> +	const struct of_device_id *match;
>> +
>> +	for_each_matching_node(np, clk_div_match) {
>> +		match = of_match_node(clk_div_match, np);
>> +		data = match->data;
>> +		sunxi_divider_clk_setup(np, data->div, data->pow);
>> +	}
>> +}
>> +
>> +void __init sunxi_init_clocks(void)
>> +{
>> +	/* Register all the simple sunxi clocks on DT */
>> +	of_clk_init(clk_match);
>> +
>> +	/* Register divider clocks */
>> +	of_sunxi_divider_clock_setup();
>> +}
>>

Thanks for the review :)

Emilio

Gregory CLEMENT Feb. 8, 2013, 5:51 p.m. UTC | #6

On 02/08/2013 06:41 PM, Emilio López wrote:
> Hello Gregory,
> 
> El 08/02/13 08:33, Gregory CLEMENT escribió:
>> Hi Emilio,
>>
>> This is the last part of my review, I didn't takt time to review the
>> whole patch the last time. As usual, my comments are inline
>>
>> On 01/22/2013 07:12 AM, Emilio López wrote:
>>
>>> This commit implements the base CPU clocks for sunxi devices. It has
>>> been tested using a slightly modified cpufreq driver from the
>>> linux-sunxi 3.0 tree.
>>>
>>> Additionally, document the new bindings introduced by this patch, and drop
>>> the (now unused) old sunxi clock driver.
>>>
>>> Idling:
>>>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>>>     30000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>>>     60000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>>>     60000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>>>     60000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>>>     60000000
>>>     /sys/kernel/debug/clk/osc24M/clk_rate
>>>     24000000
>>>     /sys/kernel/debug/clk/osc32k/clk_rate
>>>     32768
>>>
>>> After "yes >/dev/null &":
>>>     / # find /sys/kernel/debug/clk -name clk_rate -print -exec cat {} \;
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/apb0/clk_rate
>>>     84000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/ahb/clk_rate
>>>     168000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/axi/clk_rate
>>>     336000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/cpu/clk_rate
>>>     1008000000
>>>     /sys/kernel/debug/clk/osc24M/pll1/clk_rate
>>>     1008000000
>>>     /sys/kernel/debug/clk/osc24M/clk_rate
>>>     24000000
>>>     /sys/kernel/debug/clk/osc32k/clk_rate
>>>     32768
>>>
>>> Signed-off-by: Emilio López <[e-mail]>
>>> ---
>>>  Documentation/devicetree/bindings/clock/sunxi.txt |  47 ++++
>>>  drivers/clk/Makefile                              |   2 +-
>>>  drivers/clk/clk-sunxi.c                           |  30 ---
>>>  drivers/clk/sunxi/Makefile                        |   5 +
>>>  drivers/clk/sunxi/clk-factors.c                   | 175 ++++++++++++++
>>>  drivers/clk/sunxi/clk-factors.h                   |  25 ++
>>>  drivers/clk/sunxi/clk-fixed-gate.c                | 152 +++++++++++++
>>>  drivers/clk/sunxi/clk-fixed-gate.h                |  13 ++
>>>  drivers/clk/sunxi/clk-sunxi.c                     | 265 ++++++++++++++++++++++
>>>  9 files changed, 683 insertions(+), 31 deletions(-)
>>>  create mode 100644 Documentation/devicetree/bindings/clock/sunxi.txt
>>>  delete mode 100644 drivers/clk/clk-sunxi.c
>>>  create mode 100644 drivers/clk/sunxi/Makefile
>>>  create mode 100644 drivers/clk/sunxi/clk-factors.c
>>>  create mode 100644 drivers/clk/sunxi/clk-factors.h
>>>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.c
>>>  create mode 100644 drivers/clk/sunxi/clk-fixed-gate.h
>>>  create mode 100644 drivers/clk/sunxi/clk-sunxi.c
>>>
>>> diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
>>> new file mode 100644
>>> index 0000000..446c5ca
>>> --- /dev/null
>>> +++ b/Documentation/devicetree/bindings/clock/sunxi.txt
>>> @@ -0,0 +1,47 @@
>>> +Device Tree Clock bindings for arch-sunxi
>>> +
>>> +This binding uses the common clock binding[1].
>>> +
>>> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
>>> +
>>> +Required properties:
>>> +- compatible : shall be one of the following:
>>> +	"allwinner,sunxi-osc-clk" - for a gatable oscillator
>>> +	"allwinner,sunxi-pll1-clk" - for the main PLL clock
>>> +	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
>>> +	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
>>> +	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
>>> +	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
>>> +
>>> +Required properties for all clocks:
>>> +- reg : shall be the control register address for the clock.
>>> +- clocks : shall be the input parent clock(s) phandle for the clock, except for
>>> +	the root gatable oscillator clock where it is not present
>>> +- #clock-cells : from common clock binding; shall be set to 0.
>>> +
>>> +Additionally, the gatable oscillator clock requires:
>>> +- clock-frequency : shall be the frequency of the oscillator.
>>> +
>>> +
>>> +For example:
>>> +
>>> +osc24M: osc24M {
>>> +	#clock-cells = <0>;
>>> +	compatible = "allwinner,sunxi-osc-clk";
>>> +	reg = <0x01c20050 0x4>;
>>> +	clock-frequency = <24000000>;
>>> +};
>>> +
>>> +pll1: pll1@01c20000 {
>>> +	#clock-cells = <0>;
>>> +	compatible = "allwinner,sunxi-pll1-clk";
>>> +	reg = <0x01c20000 0x4>;
>>> +	clocks = <&osc24M>;
>>> +};
>>> +
>>> +cpu: cpu@01c20054 {
>>> +	#clock-cells = <0>;
>>> +	compatible = "allwinner,sunxi-cpu-clk";
>>> +	reg = <0x01c20054 0x4>;
>>> +	clocks = <&osc32k>, <&osc24M>, <&pll1>;
>>> +};
>>> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
>>> index ee90e87..129afed 100644
>>> --- a/drivers/clk/Makefile
>>> +++ b/drivers/clk/Makefile
>>> @@ -20,7 +20,7 @@ endif
>>>  obj-$(CONFIG_MACH_LOONGSON1)	+= clk-ls1x.o
>>>  obj-$(CONFIG_ARCH_U8500)	+= ux500/
>>>  obj-$(CONFIG_ARCH_VT8500)	+= clk-vt8500.o
>>> -obj-$(CONFIG_ARCH_SUNXI)	+= clk-sunxi.o
>>> +obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
>>>  obj-$(CONFIG_ARCH_ZYNQ)		+= clk-zynq.o
>>>  
>>>  # Chip specific
>>> diff --git a/drivers/clk/clk-sunxi.c b/drivers/clk/clk-sunxi.c
>>> deleted file mode 100644
>>> index 0e831b5..0000000
>>> --- a/drivers/clk/clk-sunxi.c
>>> +++ /dev/null
>>> @@ -1,30 +0,0 @@
>>> -/*
>>> - * Copyright 2012 Maxime Ripard
>>> - *
>>> - * Maxime Ripard <[e-mail]>
>>> - *
>>> - * This program is free software; you can redistribute it and/or modify
>>> - * it under the terms of the GNU General Public License as published by
>>> - * the Free Software Foundation; either version 2 of the License, or
>>> - * (at your option) any later version.
>>> - *
>>> - * This program is distributed in the hope that it will be useful,
>>> - * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> - * GNU General Public License for more details.
>>> - */
>>> -
>>> -#include <linux/clk-provider.h>
>>> -#include <linux/clkdev.h>
>>> -#include <linux/clk/sunxi.h>
>>> -#include <linux/of.h>
>>> -
>>> -static const __initconst struct of_device_id clk_match[] = {
>>> -	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
>>> -	{}
>>> -};
>>> -
>>> -void __init sunxi_init_clocks(void)
>>> -{
>>> -	of_clk_init(clk_match);
>>> -}
>>> diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
>>> new file mode 100644
>>> index 0000000..8e773be
>>> --- /dev/null
>>> +++ b/drivers/clk/sunxi/Makefile
>>> @@ -0,0 +1,5 @@
>>> +#
>>> +# Makefile for sunxi specific clk
>>> +#
>>> +
>>> +obj-y += clk-sunxi.o clk-factors.o clk-fixed-gate.o
>>> diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
>>> new file mode 100644
>>> index 0000000..428b47d
>>> --- /dev/null
>>> +++ b/drivers/clk/sunxi/clk-factors.c
>>> @@ -0,0 +1,175 @@
>>> +/*
>>> + * Copyright (C) 2013 Emilio López <[e-mail]>
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 as
>>> + * published by the Free Software Foundation.
>>> + *
>>> + * Adjustable factor-based clock implementation
>>> + */
>>> +
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/module.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/io.h>
>>> +#include <linux/err.h>
>>> +#include <linux/string.h>
>>> +
>>> +#include <linux/delay.h>
>>> +
>>> +#include "clk-factors.h"
>>> +
>>> +/*
>>> + * DOC: basic adjustable factor-based clock that cannot gate
>>> + *
>>> + * Traits of this clock:
>>> + * prepare - clk_prepare only ensures that parents are prepared
>>> + * enable - clk_enable only ensures that parents are enabled
>>> + * rate - rate is adjustable.
>>> + *        clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
>>> + * parent - fixed parent.  No clk_set_parent support
>>> + */
>>> +
>>> +struct clk_factors {
>>> +	struct clk_hw hw;
>>> +	void __iomem *reg;
>>> +	struct clk_factors_config *config;
>>> +	void (*get_factors) (u32 *rate, u8 *n, u8 *k, u8 *m, u8 *p);
>>> +	spinlock_t *lock;
>>> +};
>>> +
>>> +#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
>>> +
>>> +#define SETMASK(len, pos)		(((-1U) >> (31-len))  << (pos))
>>> +#define CLRMASK(len, pos)		(~(SETMASK(len, pos)))
>>> +#define FACTOR_GET(bit, len, reg)	(((reg) & SETMASK(len, bit)) >> (bit))
>>> +
>>> +#define FACTOR_SET(bit, len, reg, val) \
>>> +	(((reg) & CLRMASK(len, bit)) | (val << (bit)))
>>> +
>>> +static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
>>> +					     unsigned long parent_rate)
>>> +{
>>> +	u8 n, k, p, m;
>>> +	u32 reg;
>>> +	unsigned long rate;
>>> +	struct clk_factors *factors = to_clk_factors(hw);
>>> +	struct clk_factors_config *config = factors->config;
>>> +
>>> +	/* Fetch the register value */
>>> +	reg = readl(factors->reg);
>>> +
>>> +	/* Get each individual factor */
>>> +	n = FACTOR_GET(config->nshift, config->nwidth, reg);
>>> +	k = FACTOR_GET(config->kshift, config->kwidth, reg);
>>> +	m = FACTOR_GET(config->mshift, config->mwidth, reg);
>>> +	p = FACTOR_GET(config->pshift, config->pwidth, reg);
>>> +
>>> +	/* Calculate the rate */
>>> +	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>>> +
>>> +	return rate;
>>> +}
>>> +
>>> +static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
>>> +				   unsigned long *parent_rate)
>>> +{
>>> +	struct clk_factors *factors = to_clk_factors(hw);
>>> +	factors->get_factors((u32 *)&rate, NULL, NULL, NULL, NULL);
>>> +
>>> +	return rate;
>>> +}
>>> +
>>> +static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
>>> +				unsigned long parent_rate)
>>> +{
>>> +	u8 n, k, m, p;
>>> +	u32 reg;
>>> +	struct clk_factors *factors = to_clk_factors(hw);
>>> +	struct clk_factors_config *config = factors->config;
>>> +	unsigned long flags = 0;
>>> +
>>> +	factors->get_factors((u32 *)&rate, &n, &k, &m, &p);
>>> +
>>> +	if (factors->lock)
>>> +		spin_lock_irqsave(factors->lock, flags);
>>> +
>>> +	/* Fetch the register value */
>>> +	reg = readl(factors->reg);
>>> +
>>> +	/* Set up the new factors */
>>> +	reg = FACTOR_SET(config->nshift, config->nwidth, reg, n);
>>> +	reg = FACTOR_SET(config->kshift, config->kwidth, reg, k);
>>> +	reg = FACTOR_SET(config->mshift, config->mwidth, reg, m);
>>> +	reg = FACTOR_SET(config->pshift, config->pwidth, reg, p);
>>> +
>>> +	/* Apply them now */
>>> +	writel(reg, factors->reg);
>>> +
>>> +	/* delay 500us so pll stabilizes */
>>> +	__delay((rate >> 20) * 500 / 2);
>>> +
>>> +	if (factors->lock)
>>> +		spin_unlock_irqrestore(factors->lock, flags);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static const struct clk_ops clk_factors_ops = {
>>> +	.recalc_rate = clk_factors_recalc_rate,
>>> +	.round_rate = clk_factors_round_rate,
>>> +	.set_rate = clk_factors_set_rate,
>>> +};
>>> +
>>> +/**
>>> + * clk_register_factors - register a factors clock with
>>> + * the clock framework
>>> + * @dev: device registering this clock
>>> + * @name: name of this clock
>>> + * @parent_name: name of clock's parent
>>> + * @flags: framework-specific flags
>>> + * @reg: register address to adjust factors
>>> + * @config: shift and width of factors n, k, m and p
>>> + * @get_factors: function to calculate the factors for a given frequency
>>> + * @lock: shared register lock for this clock
>>> + */
>>
>> Do you have other "factors" clock than sunxi-pll1-clk?
>> On your patch I only see this clock using this, and the way
>> you pass a function  and a the config struct seems to me
>> overcomplicated for a sinlge clock.
> 
> Yes, there are other "factors" clocks on sunxi hardware; I have not
> added them to the driver yet, but having the factors implementation
> there makes it trivial to represent them on a future patchset.

OK, in this case it make sens to have this.

> 
>>
>>> +struct clk *clk_register_factors(struct device *dev, const char *name,
>>> +				 const char *parent_name,
>>> +				 unsigned long flags, void __iomem *reg,
>>> +				 struct clk_factors_config *config,
>>> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
>>> +						      u8 *m, u8 *p),
>>> +				 spinlock_t *lock)
>>> +{
>>> +	struct clk_factors *factors;
>>> +	struct clk *clk;
>>> +	struct clk_init_data init;
>>> +
>>> +	/* allocate the factors */
>>> +	factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
>>> +	if (!factors) {
>>> +		pr_err("%s: could not allocate factors clk\n", __func__);
>>> +		return ERR_PTR(-ENOMEM);
>>> +	}
>>> +
>>> +	init.name = name;
>>> +	init.ops = &clk_factors_ops;
>>> +	init.flags = flags;
>>> +	init.parent_names = (parent_name ? &parent_name : NULL);
>>> +	init.num_parents = (parent_name ? 1 : 0);
>>> +
>>> +	/* struct clk_factors assignments */
>>> +	factors->reg = reg;
>>> +	factors->config = config;
>>> +	factors->lock = lock;
>>> +	factors->hw.init = &init;
>>> +	factors->get_factors = get_factors;
>>> +
>>> +	/* register the clock */
>>> +	clk = clk_register(dev, &factors->hw);
>>> +
>>> +	if (IS_ERR(clk))
>>> +		kfree(factors);
>>> +
>>> +	return clk;
>>> +}
>>> diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
>>> new file mode 100644
>>> index 0000000..a24c889
>>> --- /dev/null
>>> +++ b/drivers/clk/sunxi/clk-factors.h
>>> @@ -0,0 +1,25 @@
>>> +#ifndef __MACH_SUNXI_CLK_FACTORS_H
>>> +#define __MACH_SUNXI_CLK_FACTORS_H
>>> +
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/clkdev.h>
>>> +
>>> +struct clk_factors_config {
>>> +	u8 nshift;
>>> +	u8 nwidth;
>>> +	u8 kshift;
>>> +	u8 kwidth;
>>> +	u8 mshift;
>>> +	u8 mwidth;
>>> +	u8 pshift;
>>> +	u8 pwidth;
>>> +};
>>> +
>>> +struct clk *clk_register_factors(struct device *dev, const char *name,
>>> +				 const char *parent_name,
>>> +				 unsigned long flags, void __iomem *reg,
>>> +				 struct clk_factors_config *config,
>>> +				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
>>> +						      u8 *m, u8 *p),
>>> +				 spinlock_t *lock);
>>> +#endif
>>> diff --git a/drivers/clk/sunxi/clk-fixed-gate.c b/drivers/clk/sunxi/clk-fixed-gate.c
>>> new file mode 100644
>>> index 0000000..b16eda5
>>> --- /dev/null
>>> +++ b/drivers/clk/sunxi/clk-fixed-gate.c
>>> @@ -0,0 +1,152 @@
>>> +/*
>>> + * Copyright (C) 2013 Emilio López <[e-mail]>
>>> + *
>>> + * Based on drivers/clk/clk-gate.c,
>>> + *
>>> + * Copyright (C) 2010-2011 Canonical Ltd <[e-mail]>
>>> + * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[e-mail]>
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License version 2 as
>>> + * published by the Free Software Foundation.
>>> + *
>>> + * Fixed rate, gated clock implementation
>>> + */
>>> +
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/module.h>
>>> +#include <linux/slab.h>
>>> +#include <linux/io.h>
>>> +#include <linux/err.h>
>>> +#include <linux/string.h>
>>> +
>>> +#include "clk-fixed-gate.h"
>>> +
>>> +/**
>>> + * DOC: fixed rate clock which can gate and ungate it's ouput
>>> + *
>>> + * Traits of this clock:
>>> + * prepare - clk_(un)prepare only ensures parent is (un)prepared
>>> + * enable - clk_enable and clk_disable are functional & control gating
>>> + * rate - rate is always a fixed value.  No clk_set_rate support
>>> + * parent - fixed parent.  No clk_set_parent support
>>> + */
>>> +
>>> +struct clk_fixed_gate {
>>> +	struct clk_hw hw;
>>> +	u8            bit_idx;
>>> +	u8            flags;
>>> +	unsigned long fixed_rate;
>>> +	void __iomem  *reg;
>>> +	spinlock_t    *lock;
>>> +};
>>> +
>>> +#define to_clk_fixed_gate(_hw) container_of(_hw, struct clk_fixed_gate, hw)
>>> +
>>> +static void clk_fixed_gate_endisable(struct clk_hw *hw, int enable)
>>> +{
>>> +	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
>>> +	unsigned long flags = 0;
>>> +	u32 reg;
>>> +
>>> +	if (gate->lock)
>>> +		spin_lock_irqsave(gate->lock, flags);
>>> +
>>> +	reg = readl(gate->reg);
>>> +
>>> +	if (enable)
>>> +		reg |= BIT(gate->bit_idx);
>>> +	else
>>> +		reg &= ~BIT(gate->bit_idx);
>>> +
>>> +	writel(reg, gate->reg);
>>> +
>>> +	if (gate->lock)
>>> +		spin_unlock_irqrestore(gate->lock, flags);
>>> +}
>>> +
>>> +static int clk_fixed_gate_enable(struct clk_hw *hw)
>>> +{
>>> +	clk_fixed_gate_endisable(hw, 1);
>>> +
>>> +	return 0;
>>> +}
>>> +
>>> +static void clk_fixed_gate_disable(struct clk_hw *hw)
>>> +{
>>> +	clk_fixed_gate_endisable(hw, 0);
>>> +}
>>> +
>>> +static int clk_fixed_gate_is_enabled(struct clk_hw *hw)
>>> +{
>>> +	u32 reg;
>>> +	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
>>> +
>>> +	reg = readl(gate->reg);
>>> +
>>> +	reg &= BIT(gate->bit_idx);
>>> +
>>> +	return reg ? 1 : 0;
>>> +}
>>> +
>>> +static unsigned long clk_fixed_gate_recalc_rate(struct clk_hw *hw,
>>> +						unsigned long parent_rate)
>>> +{
>>> +	return to_clk_fixed_gate(hw)->fixed_rate;
>>> +}
>>> +
>>> +static const struct clk_ops clk_fixed_gate_ops = {
>>> +	.enable = clk_fixed_gate_enable,
>>> +	.disable = clk_fixed_gate_disable,
>>> +	.is_enabled = clk_fixed_gate_is_enabled,
>>> +	.recalc_rate = clk_fixed_gate_recalc_rate,
>>> +};
>>> +
>>> +/**
>>> + * clk_register_fixed_gate - register a fixed rate,
>>> + * gate clock with the clock framework
>>> + * @dev: device that is registering this clock
>>> + * @name: name of this clock
>>> + * @parent_name: name of this clock's parent
>>> + * @flags: framework-specific flags for this clock
>>> + * @reg: register address to control gating of this clock
>>> + * @bit_idx: which bit in the register controls gating of this clock
>>> + * @lock: shared register lock for this clock
>>> + */
>>> +struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
>>> +				    const char *parent_name,
>>> +				    unsigned long flags, void __iomem *reg,
>>> +				    u8 bit_idx, unsigned long fixed_rate,
>>> +				    spinlock_t *lock)
>>> +{
>>> +	struct clk_fixed_gate *gate;
>>> +	struct clk *clk;
>>> +	struct clk_init_data init;
>>> +
>>> +	/* allocate the gate */
>>> +	gate = kzalloc(sizeof(struct clk_fixed_gate), GFP_KERNEL);
>>> +	if (!gate) {
>>> +		pr_err("%s: could not allocate fixed gated clk\n", __func__);
>>> +		return ERR_PTR(-ENOMEM);
>>> +	}
>>> +
>>> +	init.name = name;
>>> +	init.ops = &clk_fixed_gate_ops;
>>> +	init.flags = flags | CLK_IS_BASIC;
>>> +	init.parent_names = (parent_name ? &parent_name : NULL);
>>> +	init.num_parents = (parent_name ? 1 : 0);
>>> +
>>> +	/* struct clk_fixed_gate assignments */
>>> +	gate->fixed_rate = fixed_rate;
>>> +	gate->reg = reg;
>>> +	gate->bit_idx = bit_idx;
>>> +	gate->lock = lock;
>>> +	gate->hw.init = &init;
>>> +
>>> +	clk = clk_register(dev, &gate->hw);
>>> +
>>> +	if (IS_ERR(clk))
>>> +		kfree(gate);
>>> +
>>> +	return clk;
>>> +}
>>> diff --git a/drivers/clk/sunxi/clk-fixed-gate.h b/drivers/clk/sunxi/clk-fixed-gate.h
>>> new file mode 100644
>>> index 0000000..29d9ed3
>>> --- /dev/null
>>> +++ b/drivers/clk/sunxi/clk-fixed-gate.h
>>> @@ -0,0 +1,13 @@
>>> +#ifndef __MACH_SUNXI_CLK_FIXED_GATE_H
>>> +#define __MACH_SUNXI_CLK_FIXED_GATE_H
>>> +
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/clkdev.h>
>>> +
>>> +struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
>>> +				    const char *parent_name,
>>> +				    unsigned long flags, void __iomem *reg,
>>> +				    u8 bit_idx, unsigned long fixed_rate,
>>> +				    spinlock_t *lock);
>>> +
>>> +#endif
>>> diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
>>> new file mode 100644
>>> index 0000000..cb587a0
>>> --- /dev/null
>>> +++ b/drivers/clk/sunxi/clk-sunxi.c
>>> @@ -0,0 +1,265 @@
>>> +/*
>>> + * Copyright 2013 Emilio López
>>> + *
>>> + * Emilio López <[e-mail]>
>>> + *
>>> + * This program is free software; you can redistribute it and/or modify
>>> + * it under the terms of the GNU General Public License as published by
>>> + * the Free Software Foundation; either version 2 of the License, or
>>> + * (at your option) any later version.
>>> + *
>>> + * This program is distributed in the hope that it will be useful,
>>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
>>> + * GNU General Public License for more details.
>>> + */
>>> +
>>> +#include <linux/clk-provider.h>
>>> +#include <linux/clkdev.h>
>>> +#include <linux/clk/sunxi.h>
>>> +#include <linux/of.h>
>>> +#include <linux/of_address.h>
>>> +
>>> +#include "clk-factors.h"
>>> +#include "clk-fixed-gate.h"
>>> +
>>> +static DEFINE_SPINLOCK(clk_lock);
>>> +
>>> +/**
>>> + * sunxi_osc_clk_setup() - Setup function for gatable oscillator
>>> + */
>>> +
>>> +#define SUNXI_OSC24M_GATE	0
>>> +
>>> +static void __init sunxi_osc_clk_setup(struct device_node *node)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	void *reg;
>>> +	u32 rate;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	if (of_property_read_u32(node, "clock-frequency", &rate))
>>> +		return;
>>> +
>>> +	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
>>> +				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
>>> +				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
>>> +
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +
>>> +/**
>>> + * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
>>> + * PLL1 rate is calculated as follows
>>> + * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
>>> + * parent_rate is always 24Mhz
>>> + */
>>> +
>>> +static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
>>> +{
>>> +	u8 div;
>>> +
>>> +	/* Normalize value to a 6M multiple */
>>> +	div = *freq / 6000000;
>>> +	*freq = 6000000 * div;
>>> +
>>> +	/* we were called to round the frequency, we can now return */
>>> +	if (n == NULL)
>>> +		return;
>>> +
>>> +	/* m is always zero for pll1 */
>>> +	*m = 0;
>>> +
>>> +	/* k is 1 only on these cases */
>>> +	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
>>> +		*k = 1;
>>> +	else
>>> +		*k = 0;
>>> +
>>> +	/* p will be 3 for divs under 10 */
>>> +	if (div < 10)
>>> +		*p = 3;
>>> +
>>> +	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
>>> +	else if (div < 20 || (div < 32 && (div & 1)))
>>> +		*p = 2;
>>> +
>>> +	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
>>> +	 * of divs between 40-62 */
>>> +	else if (div < 40 || (div < 64 && (div & 2)))
>>> +		*p = 1;
>>> +
>>> +	/* any other entries have p = 0 */
>>> +	else
>>> +		*p = 0;
>>> +
>>> +	/* calculate a suitable n based on k and p */
>>> +	div <<= *p;
>>> +	div /= (*k + 1);
>>> +	*n = div / 4;
>>> +}
>>> +
>>> +/**
>>> + * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
>>> + */
>>> +
>>> +struct clk_factors_config pll1_config = {
>>> +	.nshift = 8,
>>> +	.nwidth = 5,
>>> +	.kshift = 4,
>>> +	.kwidth = 2,
>>> +	.mshift = 0,
>>> +	.mwidth = 2,
>>> +	.pshift = 16,
>>> +	.pwidth = 2,
>>> +};
>>> +
>>> +static void __init sunxi_pll1_clk_setup(struct device_node *node)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	const char *parent;
>>> +	void *reg;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	parent = of_clk_get_parent_name(node, 0);
>>> +
>>> +	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
>>> +				   reg, &pll1_config, sunxi_get_pll1_factors,
>>> +				   &clk_lock);
>>> +
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +
>>> +/**
>>> + * sunxi_cpu_clk_setup() - Setup function for CPU mux
>>> + */
>>> +
>>> +#define SUNXI_CPU_GATE		16
>>> +#define SUNXI_CPU_GATE_WIDTH	2
>>> +
>>> +static void __init sunxi_cpu_clk_setup(struct device_node *node)
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
>>> +	void *reg;
>>> +	int i = 0;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
>>> +		i++;
>>> +
>>> +	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
>>> +			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
>>> +			       0, &clk_lock);
>>> +
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +
>>> +/**
>>> + * sunxi_divider_clk_setup() - Setup function for simple divider clocks
>>> + */
>>> +
>>> +#define SUNXI_DIVISOR_WIDTH	2
>>> +
>>> +struct div_data {
>>> +	u8 div;
>>> +	u8 pow;
>>> +};
>>> +
>>> +static const __initconst struct div_data axi_data = {
>>> +	.div = 0,
>>> +	.pow = 0,
>>> +};
>>> +
>>> +static const __initconst struct div_data ahb_data = {
>>> +	.div = 4,
>>> +	.pow = 1,
>>> +};
>>> +
>>> +static const __initconst struct div_data apb0_data = {
>>> +	.div = 8,
>>> +	.pow = 1,
>>> +};
>>
>> Can't you read this from a register?
> 
> I don't understand your question. "div" is the shift in the register
> where the divisor gets configured. width is always 2 as indicated by the
> compiler macro above.

My bad, I went to fast on this one.

> 
>>
>> If not then this 3 clocks are good candidates for my patch:
>> "clk: add DT fixed-factor-clock binding support"
>> http://www.spinics.net/lists/arm-kernel/msg191522.html
> 
> These are configurable dividers; fixed-factor appears to be for clocks
> where div and mult are fixed values.
> 
>>
>> It was not merged by lack of user, but it will be pretty simple to me
>> to rebase it on top of 3.8-rc6
>>
>> So if it is really an informatilon you can only get from the datasheet,
>> you will be able to just declare it in the DTS.
>>
>>> +
>>> +static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
>>> +					   u8 power_of_two)
> 
> See here, .div is shift and .pow is power_of_two
> 
>>> +{
>>> +	struct clk *clk;
>>> +	const char *clk_name = node->name;
>>> +	const char *clk_parent;
>>> +	void *reg;
>>> +
>>> +	reg = of_iomap(node, 0);
>>> +
>>> +	clk_parent = of_clk_get_parent_name(node, 0);
>>> +
>>> +	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
>>> +				   reg, shift, SUNXI_DIVISOR_WIDTH,
>>> +				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
>>> +				   &clk_lock);
>>> +	if (clk) {
>>> +		of_clk_add_provider(node, of_clk_src_simple_get, clk);
>>> +		clk_register_clkdev(clk, clk_name, NULL);
>>> +	}
>>> +}
>>> +
>>> +
>>> +/* Matches for of_clk_init */
>>> +static const __initconst struct of_device_id clk_match[] = {
>>> +	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
>>> +	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
>>> +	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
>>> +	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
>>> +	{}
>>> +};
>>> +
>>> +/* Matches for divider clocks */
>>> +static const __initconst struct of_device_id clk_div_match[] = {
>>> +	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
>>> +	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
>>> +	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
>>> +	{}
>>> +};
>>> +
>>> +static void __init of_sunxi_divider_clock_setup(void)
>>> +{
>>> +	struct device_node *np;
>>> +	const struct div_data *data;
>>> +	const struct of_device_id *match;
>>> +
>>> +	for_each_matching_node(np, clk_div_match) {
>>> +		match = of_match_node(clk_div_match, np);
>>> +		data = match->data;
>>> +		sunxi_divider_clk_setup(np, data->div, data->pow);
>>> +	}
>>> +}
>>> +
>>> +void __init sunxi_init_clocks(void)
>>> +{
>>> +	/* Register all the simple sunxi clocks on DT */
>>> +	of_clk_init(clk_match);
>>> +
>>> +	/* Register divider clocks */
>>> +	of_sunxi_divider_clock_setup();
>>> +}
>>>
> 
> Thanks for the review :)

You're welcome :)

Gregory

Patch

diff --git a/Documentation/devicetree/bindings/clock/sunxi.txt b/Documentation/devicetree/bindings/clock/sunxi.txt
new file mode 100644
index 0000000..446c5ca
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/sunxi.txt
@@ -0,0 +1,47 @@ 
+Device Tree Clock bindings for arch-sunxi
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible : shall be one of the following:
+	"allwinner,sunxi-osc-clk" - for a gatable oscillator
+	"allwinner,sunxi-pll1-clk" - for the main PLL clock
+	"allwinner,sunxi-cpu-clk" - for the CPU multiplexer clock
+	"allwinner,sunxi-axi-clk" - for the sunxi AXI clock
+	"allwinner,sunxi-ahb-clk" - for the sunxi AHB clock
+	"allwinner,sunxi-apb0-clk" - for the sunxi APB0 clock
+
+Required properties for all clocks:
+- reg : shall be the control register address for the clock.
+- clocks : shall be the input parent clock(s) phandle for the clock, except for
+	the root gatable oscillator clock where it is not present
+- #clock-cells : from common clock binding; shall be set to 0.
+
+Additionally, the gatable oscillator clock requires:
+- clock-frequency : shall be the frequency of the oscillator.
+
+
+For example:
+
+osc24M: osc24M {
+	#clock-cells = <0>;
+	compatible = "allwinner,sunxi-osc-clk";
+	reg = <0x01c20050 0x4>;
+	clock-frequency = <24000000>;
+};
+
+pll1: pll1@01c20000 {
+	#clock-cells = <0>;
+	compatible = "allwinner,sunxi-pll1-clk";
+	reg = <0x01c20000 0x4>;
+	clocks = <&osc24M>;
+};
+
+cpu: cpu@01c20054 {
+	#clock-cells = <0>;
+	compatible = "allwinner,sunxi-cpu-clk";
+	reg = <0x01c20054 0x4>;
+	clocks = <&osc32k>, <&osc24M>, <&pll1>;
+};
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index ee90e87..129afed 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -20,7 +20,7 @@  endif
 obj-$(CONFIG_MACH_LOONGSON1)	+= clk-ls1x.o
 obj-$(CONFIG_ARCH_U8500)	+= ux500/
 obj-$(CONFIG_ARCH_VT8500)	+= clk-vt8500.o
-obj-$(CONFIG_ARCH_SUNXI)	+= clk-sunxi.o
+obj-$(CONFIG_ARCH_SUNXI)	+= sunxi/
 obj-$(CONFIG_ARCH_ZYNQ)		+= clk-zynq.o
 
 # Chip specific
diff --git a/drivers/clk/clk-sunxi.c b/drivers/clk/clk-sunxi.c
deleted file mode 100644
index 0e831b5..0000000
--- a/drivers/clk/clk-sunxi.c
+++ /dev/null
@@ -1,30 +0,0 @@ 
-/*
- * Copyright 2012 Maxime Ripard
- *
- * Maxime Ripard <[e-mail]>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-#include <linux/clk-provider.h>
-#include <linux/clkdev.h>
-#include <linux/clk/sunxi.h>
-#include <linux/of.h>
-
-static const __initconst struct of_device_id clk_match[] = {
-	{ .compatible = "fixed-clock", .data = of_fixed_clk_setup, },
-	{}
-};
-
-void __init sunxi_init_clocks(void)
-{
-	of_clk_init(clk_match);
-}
diff --git a/drivers/clk/sunxi/Makefile b/drivers/clk/sunxi/Makefile
new file mode 100644
index 0000000..8e773be
--- /dev/null
+++ b/drivers/clk/sunxi/Makefile
@@ -0,0 +1,5 @@ 
+#
+# Makefile for sunxi specific clk
+#
+
+obj-y += clk-sunxi.o clk-factors.o clk-fixed-gate.o
diff --git a/drivers/clk/sunxi/clk-factors.c b/drivers/clk/sunxi/clk-factors.c
new file mode 100644
index 0000000..428b47d
--- /dev/null
+++ b/drivers/clk/sunxi/clk-factors.c
@@ -0,0 +1,175 @@ 
+/*
+ * Copyright (C) 2013 Emilio López <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Adjustable factor-based clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+
+#include <linux/delay.h>
+
+#include "clk-factors.h"
+
+/*
+ * DOC: basic adjustable factor-based clock that cannot gate
+ *
+ * Traits of this clock:
+ * prepare - clk_prepare only ensures that parents are prepared
+ * enable - clk_enable only ensures that parents are enabled
+ * rate - rate is adjustable.
+ *        clk->rate = (parent->rate * N * (K + 1) >> P) / (M + 1)
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+struct clk_factors {
+	struct clk_hw hw;
+	void __iomem *reg;
+	struct clk_factors_config *config;
+	void (*get_factors) (u32 *rate, u8 *n, u8 *k, u8 *m, u8 *p);
+	spinlock_t *lock;
+};
+
+#define to_clk_factors(_hw) container_of(_hw, struct clk_factors, hw)
+
+#define SETMASK(len, pos)		(((-1U) >> (31-len))  << (pos))
+#define CLRMASK(len, pos)		(~(SETMASK(len, pos)))
+#define FACTOR_GET(bit, len, reg)	(((reg) & SETMASK(len, bit)) >> (bit))
+
+#define FACTOR_SET(bit, len, reg, val) \
+	(((reg) & CLRMASK(len, bit)) | (val << (bit)))
+
+static unsigned long clk_factors_recalc_rate(struct clk_hw *hw,
+					     unsigned long parent_rate)
+{
+	u8 n, k, p, m;
+	u32 reg;
+	unsigned long rate;
+	struct clk_factors *factors = to_clk_factors(hw);
+	struct clk_factors_config *config = factors->config;
+
+	/* Fetch the register value */
+	reg = readl(factors->reg);
+
+	/* Get each individual factor */
+	n = FACTOR_GET(config->nshift, config->nwidth, reg);
+	k = FACTOR_GET(config->kshift, config->kwidth, reg);
+	m = FACTOR_GET(config->mshift, config->mwidth, reg);
+	p = FACTOR_GET(config->pshift, config->pwidth, reg);
+
+	/* Calculate the rate */
+	rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
+
+	return rate;
+}
+
+static long clk_factors_round_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long *parent_rate)
+{
+	struct clk_factors *factors = to_clk_factors(hw);
+	factors->get_factors((u32 *)&rate, NULL, NULL, NULL, NULL);
+
+	return rate;
+}
+
+static int clk_factors_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	u8 n, k, m, p;
+	u32 reg;
+	struct clk_factors *factors = to_clk_factors(hw);
+	struct clk_factors_config *config = factors->config;
+	unsigned long flags = 0;
+
+	factors->get_factors((u32 *)&rate, &n, &k, &m, &p);
+
+	if (factors->lock)
+		spin_lock_irqsave(factors->lock, flags);
+
+	/* Fetch the register value */
+	reg = readl(factors->reg);
+
+	/* Set up the new factors */
+	reg = FACTOR_SET(config->nshift, config->nwidth, reg, n);
+	reg = FACTOR_SET(config->kshift, config->kwidth, reg, k);
+	reg = FACTOR_SET(config->mshift, config->mwidth, reg, m);
+	reg = FACTOR_SET(config->pshift, config->pwidth, reg, p);
+
+	/* Apply them now */
+	writel(reg, factors->reg);
+
+	/* delay 500us so pll stabilizes */
+	__delay((rate >> 20) * 500 / 2);
+
+	if (factors->lock)
+		spin_unlock_irqrestore(factors->lock, flags);
+
+	return 0;
+}
+
+static const struct clk_ops clk_factors_ops = {
+	.recalc_rate = clk_factors_recalc_rate,
+	.round_rate = clk_factors_round_rate,
+	.set_rate = clk_factors_set_rate,
+};
+
+/**
+ * clk_register_factors - register a factors clock with
+ * the clock framework
+ * @dev: device registering this clock
+ * @name: name of this clock
+ * @parent_name: name of clock's parent
+ * @flags: framework-specific flags
+ * @reg: register address to adjust factors
+ * @config: shift and width of factors n, k, m and p
+ * @get_factors: function to calculate the factors for a given frequency
+ * @lock: shared register lock for this clock
+ */
+struct clk *clk_register_factors(struct device *dev, const char *name,
+				 const char *parent_name,
+				 unsigned long flags, void __iomem *reg,
+				 struct clk_factors_config *config,
+				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
+						      u8 *m, u8 *p),
+				 spinlock_t *lock)
+{
+	struct clk_factors *factors;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	/* allocate the factors */
+	factors = kzalloc(sizeof(struct clk_factors), GFP_KERNEL);
+	if (!factors) {
+		pr_err("%s: could not allocate factors clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	init.name = name;
+	init.ops = &clk_factors_ops;
+	init.flags = flags;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+
+	/* struct clk_factors assignments */
+	factors->reg = reg;
+	factors->config = config;
+	factors->lock = lock;
+	factors->hw.init = &init;
+	factors->get_factors = get_factors;
+
+	/* register the clock */
+	clk = clk_register(dev, &factors->hw);
+
+	if (IS_ERR(clk))
+		kfree(factors);
+
+	return clk;
+}
diff --git a/drivers/clk/sunxi/clk-factors.h b/drivers/clk/sunxi/clk-factors.h
new file mode 100644
index 0000000..a24c889
--- /dev/null
+++ b/drivers/clk/sunxi/clk-factors.h
@@ -0,0 +1,25 @@ 
+#ifndef __MACH_SUNXI_CLK_FACTORS_H
+#define __MACH_SUNXI_CLK_FACTORS_H
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+
+struct clk_factors_config {
+	u8 nshift;
+	u8 nwidth;
+	u8 kshift;
+	u8 kwidth;
+	u8 mshift;
+	u8 mwidth;
+	u8 pshift;
+	u8 pwidth;
+};
+
+struct clk *clk_register_factors(struct device *dev, const char *name,
+				 const char *parent_name,
+				 unsigned long flags, void __iomem *reg,
+				 struct clk_factors_config *config,
+				 void (*get_factors) (u32 *rate, u8 *n, u8 *k,
+						      u8 *m, u8 *p),
+				 spinlock_t *lock);
+#endif
diff --git a/drivers/clk/sunxi/clk-fixed-gate.c b/drivers/clk/sunxi/clk-fixed-gate.c
new file mode 100644
index 0000000..b16eda5
--- /dev/null
+++ b/drivers/clk/sunxi/clk-fixed-gate.c
@@ -0,0 +1,152 @@ 
+/*
+ * Copyright (C) 2013 Emilio López <[e-mail]>
+ *
+ * Based on drivers/clk/clk-gate.c,
+ *
+ * Copyright (C) 2010-2011 Canonical Ltd <[e-mail]>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Fixed rate, gated clock implementation
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/string.h>
+
+#include "clk-fixed-gate.h"
+
+/**
+ * DOC: fixed rate clock which can gate and ungate it's ouput
+ *
+ * Traits of this clock:
+ * prepare - clk_(un)prepare only ensures parent is (un)prepared
+ * enable - clk_enable and clk_disable are functional & control gating
+ * rate - rate is always a fixed value.  No clk_set_rate support
+ * parent - fixed parent.  No clk_set_parent support
+ */
+
+struct clk_fixed_gate {
+	struct clk_hw hw;
+	u8            bit_idx;
+	u8            flags;
+	unsigned long fixed_rate;
+	void __iomem  *reg;
+	spinlock_t    *lock;
+};
+
+#define to_clk_fixed_gate(_hw) container_of(_hw, struct clk_fixed_gate, hw)
+
+static void clk_fixed_gate_endisable(struct clk_hw *hw, int enable)
+{
+	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
+	unsigned long flags = 0;
+	u32 reg;
+
+	if (gate->lock)
+		spin_lock_irqsave(gate->lock, flags);
+
+	reg = readl(gate->reg);
+
+	if (enable)
+		reg |= BIT(gate->bit_idx);
+	else
+		reg &= ~BIT(gate->bit_idx);
+
+	writel(reg, gate->reg);
+
+	if (gate->lock)
+		spin_unlock_irqrestore(gate->lock, flags);
+}
+
+static int clk_fixed_gate_enable(struct clk_hw *hw)
+{
+	clk_fixed_gate_endisable(hw, 1);
+
+	return 0;
+}
+
+static void clk_fixed_gate_disable(struct clk_hw *hw)
+{
+	clk_fixed_gate_endisable(hw, 0);
+}
+
+static int clk_fixed_gate_is_enabled(struct clk_hw *hw)
+{
+	u32 reg;
+	struct clk_fixed_gate *gate = to_clk_fixed_gate(hw);
+
+	reg = readl(gate->reg);
+
+	reg &= BIT(gate->bit_idx);
+
+	return reg ? 1 : 0;
+}
+
+static unsigned long clk_fixed_gate_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	return to_clk_fixed_gate(hw)->fixed_rate;
+}
+
+static const struct clk_ops clk_fixed_gate_ops = {
+	.enable = clk_fixed_gate_enable,
+	.disable = clk_fixed_gate_disable,
+	.is_enabled = clk_fixed_gate_is_enabled,
+	.recalc_rate = clk_fixed_gate_recalc_rate,
+};
+
+/**
+ * clk_register_fixed_gate - register a fixed rate,
+ * gate clock with the clock framework
+ * @dev: device that is registering this clock
+ * @name: name of this clock
+ * @parent_name: name of this clock's parent
+ * @flags: framework-specific flags for this clock
+ * @reg: register address to control gating of this clock
+ * @bit_idx: which bit in the register controls gating of this clock
+ * @lock: shared register lock for this clock
+ */
+struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
+				    const char *parent_name,
+				    unsigned long flags, void __iomem *reg,
+				    u8 bit_idx, unsigned long fixed_rate,
+				    spinlock_t *lock)
+{
+	struct clk_fixed_gate *gate;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	/* allocate the gate */
+	gate = kzalloc(sizeof(struct clk_fixed_gate), GFP_KERNEL);
+	if (!gate) {
+		pr_err("%s: could not allocate fixed gated clk\n", __func__);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	init.name = name;
+	init.ops = &clk_fixed_gate_ops;
+	init.flags = flags | CLK_IS_BASIC;
+	init.parent_names = (parent_name ? &parent_name : NULL);
+	init.num_parents = (parent_name ? 1 : 0);
+
+	/* struct clk_fixed_gate assignments */
+	gate->fixed_rate = fixed_rate;
+	gate->reg = reg;
+	gate->bit_idx = bit_idx;
+	gate->lock = lock;
+	gate->hw.init = &init;
+
+	clk = clk_register(dev, &gate->hw);
+
+	if (IS_ERR(clk))
+		kfree(gate);
+
+	return clk;
+}
diff --git a/drivers/clk/sunxi/clk-fixed-gate.h b/drivers/clk/sunxi/clk-fixed-gate.h
new file mode 100644
index 0000000..29d9ed3
--- /dev/null
+++ b/drivers/clk/sunxi/clk-fixed-gate.h
@@ -0,0 +1,13 @@ 
+#ifndef __MACH_SUNXI_CLK_FIXED_GATE_H
+#define __MACH_SUNXI_CLK_FIXED_GATE_H
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+
+struct clk *clk_register_fixed_gate(struct device *dev, const char *name,
+				    const char *parent_name,
+				    unsigned long flags, void __iomem *reg,
+				    u8 bit_idx, unsigned long fixed_rate,
+				    spinlock_t *lock);
+
+#endif
diff --git a/drivers/clk/sunxi/clk-sunxi.c b/drivers/clk/sunxi/clk-sunxi.c
new file mode 100644
index 0000000..cb587a0
--- /dev/null
+++ b/drivers/clk/sunxi/clk-sunxi.c
@@ -0,0 +1,265 @@ 
+/*
+ * Copyright 2013 Emilio López
+ *
+ * Emilio López <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/clkdev.h>
+#include <linux/clk/sunxi.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "clk-factors.h"
+#include "clk-fixed-gate.h"
+
+static DEFINE_SPINLOCK(clk_lock);
+
+/**
+ * sunxi_osc_clk_setup() - Setup function for gatable oscillator
+ */
+
+#define SUNXI_OSC24M_GATE	0
+
+static void __init sunxi_osc_clk_setup(struct device_node *node)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	void *reg;
+	u32 rate;
+
+	reg = of_iomap(node, 0);
+
+	if (of_property_read_u32(node, "clock-frequency", &rate))
+		return;
+
+	clk = clk_register_fixed_gate(NULL, clk_name, NULL,
+				      CLK_IS_ROOT | CLK_IGNORE_UNUSED,
+				      reg, SUNXI_OSC24M_GATE, rate, &clk_lock);
+
+	if (clk) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		clk_register_clkdev(clk, clk_name, NULL);
+	}
+}
+
+
+
+/**
+ * sunxi_get_pll1_factors() - calculates n, k, m, p factors for PLL1
+ * PLL1 rate is calculated as follows
+ * rate = (parent_rate * n * (k + 1) >> p) / (m + 1);
+ * parent_rate is always 24Mhz
+ */
+
+static void sunxi_get_pll1_factors(u32 *freq, u8 *n, u8 *k, u8 *m, u8 *p)
+{
+	u8 div;
+
+	/* Normalize value to a 6M multiple */
+	div = *freq / 6000000;
+	*freq = 6000000 * div;
+
+	/* we were called to round the frequency, we can now return */
+	if (n == NULL)
+		return;
+
+	/* m is always zero for pll1 */
+	*m = 0;
+
+	/* k is 1 only on these cases */
+	if (*freq >= 768000000 || *freq == 42000000 || *freq == 54000000)
+		*k = 1;
+	else
+		*k = 0;
+
+	/* p will be 3 for divs under 10 */
+	if (div < 10)
+		*p = 3;
+
+	/* p will be 2 for divs between 10 - 20 and odd divs under 32 */
+	else if (div < 20 || (div < 32 && (div & 1)))
+		*p = 2;
+
+	/* p will be 1 for even divs under 32, divs under 40 and odd pairs
+	 * of divs between 40-62 */
+	else if (div < 40 || (div < 64 && (div & 2)))
+		*p = 1;
+
+	/* any other entries have p = 0 */
+	else
+		*p = 0;
+
+	/* calculate a suitable n based on k and p */
+	div <<= *p;
+	div /= (*k + 1);
+	*n = div / 4;
+}
+
+/**
+ * sunxi_pll1_clk_setup() - Setup function for PLL1 clock
+ */
+
+struct clk_factors_config pll1_config = {
+	.nshift = 8,
+	.nwidth = 5,
+	.kshift = 4,
+	.kwidth = 2,
+	.mshift = 0,
+	.mwidth = 2,
+	.pshift = 16,
+	.pwidth = 2,
+};
+
+static void __init sunxi_pll1_clk_setup(struct device_node *node)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	const char *parent;
+	void *reg;
+
+	reg = of_iomap(node, 0);
+
+	parent = of_clk_get_parent_name(node, 0);
+
+	clk = clk_register_factors(NULL, clk_name, parent, CLK_IGNORE_UNUSED,
+				   reg, &pll1_config, sunxi_get_pll1_factors,
+				   &clk_lock);
+
+	if (clk) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		clk_register_clkdev(clk, clk_name, NULL);
+	}
+}
+
+
+
+/**
+ * sunxi_cpu_clk_setup() - Setup function for CPU mux
+ */
+
+#define SUNXI_CPU_GATE		16
+#define SUNXI_CPU_GATE_WIDTH	2
+
+static void __init sunxi_cpu_clk_setup(struct device_node *node)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	const char **parents = kmalloc(sizeof(char *) * 5, GFP_KERNEL);
+	void *reg;
+	int i = 0;
+
+	reg = of_iomap(node, 0);
+
+	while (i < 5 && (parents[i] = of_clk_get_parent_name(node, i)) != NULL)
+		i++;
+
+	clk = clk_register_mux(NULL, clk_name, parents, i, 0, reg,
+			       SUNXI_CPU_GATE, SUNXI_CPU_GATE_WIDTH,
+			       0, &clk_lock);
+
+	if (clk) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		clk_register_clkdev(clk, clk_name, NULL);
+	}
+}
+
+
+
+/**
+ * sunxi_divider_clk_setup() - Setup function for simple divider clocks
+ */
+
+#define SUNXI_DIVISOR_WIDTH	2
+
+struct div_data {
+	u8 div;
+	u8 pow;
+};
+
+static const __initconst struct div_data axi_data = {
+	.div = 0,
+	.pow = 0,
+};
+
+static const __initconst struct div_data ahb_data = {
+	.div = 4,
+	.pow = 1,
+};
+
+static const __initconst struct div_data apb0_data = {
+	.div = 8,
+	.pow = 1,
+};
+
+static void __init sunxi_divider_clk_setup(struct device_node *node, u8 shift,
+					   u8 power_of_two)
+{
+	struct clk *clk;
+	const char *clk_name = node->name;
+	const char *clk_parent;
+	void *reg;
+
+	reg = of_iomap(node, 0);
+
+	clk_parent = of_clk_get_parent_name(node, 0);
+
+	clk = clk_register_divider(NULL, clk_name, clk_parent, 0,
+				   reg, shift, SUNXI_DIVISOR_WIDTH,
+				   power_of_two ? CLK_DIVIDER_POWER_OF_TWO : 0,
+				   &clk_lock);
+	if (clk) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		clk_register_clkdev(clk, clk_name, NULL);
+	}
+}
+
+
+/* Matches for of_clk_init */
+static const __initconst struct of_device_id clk_match[] = {
+	{.compatible = "fixed-clock", .data = of_fixed_clk_setup,},
+	{.compatible = "allwinner,sunxi-osc-clk", .data = sunxi_osc_clk_setup,},
+	{.compatible = "allwinner,sunxi-pll1-clk", .data = sunxi_pll1_clk_setup,},
+	{.compatible = "allwinner,sunxi-cpu-clk", .data = sunxi_cpu_clk_setup,},
+	{}
+};
+
+/* Matches for divider clocks */
+static const __initconst struct of_device_id clk_div_match[] = {
+	{.compatible = "allwinner,sunxi-axi-clk", .data = &axi_data,},
+	{.compatible = "allwinner,sunxi-ahb-clk", .data = &ahb_data,},
+	{.compatible = "allwinner,sunxi-apb0-clk", .data = &apb0_data,},
+	{}
+};
+
+static void __init of_sunxi_divider_clock_setup(void)
+{
+	struct device_node *np;
+	const struct div_data *data;
+	const struct of_device_id *match;
+
+	for_each_matching_node(np, clk_div_match) {
+		match = of_match_node(clk_div_match, np);
+		data = match->data;
+		sunxi_divider_clk_setup(np, data->div, data->pow);
+	}
+}
+
+void __init sunxi_init_clocks(void)
+{
+	/* Register all the simple sunxi clocks on DT */
+	of_clk_init(clk_match);
+
+	/* Register divider clocks */
+	of_sunxi_divider_clock_setup();
+}