[1/2,v6] clk/axs10x: Add I2S PLL clock driver

Commit Message

Jose Abreu April 21, 2016, 5:19 p.m. UTC

The ARC SDP I2S clock can be programmed using a
specific PLL.

This patch has the goal of adding a clock driver
that programs this PLL.

At this moment the rate values are hardcoded in
a table but in the future it would be ideal to
use a function which determines the PLL values
given the desired rate.

Signed-off-by: Jose Abreu <[e-mail]>
---

Changes v5 -> v6:
* Use parent clock to determine PLL input rate instead of using hardcoded values
* Documentation update (added 'clocks' field)

Changes v4 -> v5:
* Documentation update (as suggested by Alexey Brodkin)
* Changed compatible string to "snps,axs10x-i2s-pll-clock" (as suggested by Alexey Brodkin)

Changes v3 -> v4:
* Added binding document (as suggested by Stephen Boyd)
* Minor code style fixes (as suggested by Stephen Boyd)
* Use ioremap (as suggested by Stephen Boyd)
* Implement round_rate (as suggested by Stephen Boyd)
* Change to platform driver (as suggested by Stephen Boyd)
* Use {readl/writel}_relaxed (as suggested by Vineet Gupta)

Changes v2 -> v3:
* Implemented recalc_rate

Changes v1 -> v2:
* Renamed folder to axs10x (as suggested by Alexey Brodkin)
* Added more supported rates

 .../bindings/clock/axs10x-i2s-pll-clock.txt        |  25 +++
 drivers/clk/Makefile                               |   1 +
 drivers/clk/axs10x/Makefile                        |   1 +
 drivers/clk/axs10x/i2s_pll_clock.c                 | 228 +++++++++++++++++++++
 4 files changed, 255 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
 create mode 100644 drivers/clk/axs10x/Makefile
 create mode 100644 drivers/clk/axs10x/i2s_pll_clock.c

Comments

Jose Abreu April 21, 2016, 5:55 p.m. UTC | #1

Adding device tree mailing list and Rob Herring.

On 21-04-2016 18:19, Jose Abreu wrote:
> The ARC SDP I2S clock can be programmed using a
> specific PLL.
>
> This patch has the goal of adding a clock driver
> that programs this PLL.
>
> At this moment the rate values are hardcoded in
> a table but in the future it would be ideal to
> use a function which determines the PLL values
> given the desired rate.
>
> Signed-off-by: Jose Abreu <[e-mail]>
> ---
>
> Changes v5 -> v6:
> * Use parent clock to determine PLL input rate instead of using hardcoded values
> * Documentation update (added 'clocks' field)
>
> Changes v4 -> v5:
> * Documentation update (as suggested by Alexey Brodkin)
> * Changed compatible string to "snps,axs10x-i2s-pll-clock" (as suggested by Alexey Brodkin)
>
> Changes v3 -> v4:
> * Added binding document (as suggested by Stephen Boyd)
> * Minor code style fixes (as suggested by Stephen Boyd)
> * Use ioremap (as suggested by Stephen Boyd)
> * Implement round_rate (as suggested by Stephen Boyd)
> * Change to platform driver (as suggested by Stephen Boyd)
> * Use {readl/writel}_relaxed (as suggested by Vineet Gupta)
>
> Changes v2 -> v3:
> * Implemented recalc_rate
>
> Changes v1 -> v2:
> * Renamed folder to axs10x (as suggested by Alexey Brodkin)
> * Added more supported rates
>
>  .../bindings/clock/axs10x-i2s-pll-clock.txt        |  25 +++
>  drivers/clk/Makefile                               |   1 +
>  drivers/clk/axs10x/Makefile                        |   1 +
>  drivers/clk/axs10x/i2s_pll_clock.c                 | 228 +++++++++++++++++++++
>  4 files changed, 255 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
>  create mode 100644 drivers/clk/axs10x/Makefile
>  create mode 100644 drivers/clk/axs10x/i2s_pll_clock.c
>
> diff --git a/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
> new file mode 100644
> index 0000000..5ffc8df
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
> @@ -0,0 +1,25 @@
> +Binding for the AXS10X I2S PLL clock
> +
> +This binding uses the common clock binding[1].
> +
> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
> +
> +Required properties:
> +- compatible: shall be "snps,axs10x-i2s-pll-clock"
> +- reg : address and length of the I2S PLL register set.
> +- clocks: shall be the input parent clock phandle for the PLL.
> +- #clock-cells: from common clock binding; Should always be set to 0.
> +
> +Example:
> +	pll_clock: pll_clock {
> +		compatible = "fixed-clock";
> +		clock-frequency = <27000000>;
> +		#clock-cells = <0>;
> +	};
> +
> +	i2s_clock@100a0 {
> +		compatible = "snps,axs10x-i2s-pll-clock";
> +		reg = <0x100a0 0x10>;
> +		clocks = <&pll_clock>;
> +		#clock-cells = <0>;
> +	};
> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
> index 46869d6..2ca62dc6 100644
> --- a/drivers/clk/Makefile
> +++ b/drivers/clk/Makefile
> @@ -84,3 +84,4 @@ obj-$(CONFIG_X86)			+= x86/
>  obj-$(CONFIG_ARCH_ZX)			+= zte/
>  obj-$(CONFIG_ARCH_ZYNQ)			+= zynq/
>  obj-$(CONFIG_H8300)		+= h8300/
> +obj-$(CONFIG_ARC_PLAT_AXS10X)		+= axs10x/
> diff --git a/drivers/clk/axs10x/Makefile b/drivers/clk/axs10x/Makefile
> new file mode 100644
> index 0000000..01996b8
> --- /dev/null
> +++ b/drivers/clk/axs10x/Makefile
> @@ -0,0 +1 @@
> +obj-y += i2s_pll_clock.o
> diff --git a/drivers/clk/axs10x/i2s_pll_clock.c b/drivers/clk/axs10x/i2s_pll_clock.c
> new file mode 100644
> index 0000000..411310d
> --- /dev/null
> +++ b/drivers/clk/axs10x/i2s_pll_clock.c
> @@ -0,0 +1,228 @@
> +/*
> + * Synopsys AXS10X SDP I2S PLL clock driver
> + *
> + * Copyright (C) 2016 Synopsys
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/platform_device.h>
> +#include <linux/module.h>
> +#include <linux/clk-provider.h>
> +#include <linux/err.h>
> +#include <linux/device.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <linux/of.h>
> +
> +/* PLL registers addresses */
> +#define PLL_IDIV_REG	0x0
> +#define PLL_FBDIV_REG	0x4
> +#define PLL_ODIV0_REG	0x8
> +#define PLL_ODIV1_REG	0xC
> +
> +struct i2s_pll_cfg {
> +	unsigned int rate;
> +	unsigned int idiv;
> +	unsigned int fbdiv;
> +	unsigned int odiv0;
> +	unsigned int odiv1;
> +};
> +
> +static const struct i2s_pll_cfg i2s_pll_cfg_27m[] = {
> +	/* 27 Mhz */
> +	{ 1024000, 0x104, 0x451, 0x10E38, 0x2000 },
> +	{ 1411200, 0x104, 0x596, 0x10D35, 0x2000 },
> +	{ 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 },
> +	{ 2048000, 0x82, 0x451, 0x10E38, 0x2000 },
> +	{ 2822400, 0x82, 0x596, 0x10D35, 0x2000 },
> +	{ 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 },
> +	{ 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 },
> +	{ 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 },
> +	{ 0, 0, 0, 0, 0 },
> +};
> +
> +static const struct i2s_pll_cfg i2s_pll_cfg_28m[] = {
> +	/* 28.224 Mhz */
> +	{ 1024000, 0x82, 0x105, 0x107DF, 0x2000 },
> +	{ 1411200, 0x28A, 0x1, 0x10001, 0x2000 },
> +	{ 1536000, 0xA28, 0x187, 0x10042, 0x2000 },
> +	{ 2048000, 0x41, 0x105, 0x107DF, 0x2000 },
> +	{ 2822400, 0x145, 0x1, 0x10001, 0x2000 },
> +	{ 3072000, 0x514, 0x187, 0x10042, 0x2000 },
> +	{ 2116800, 0x514, 0x42, 0x10001, 0x2000 },
> +	{ 2304000, 0x619, 0x82, 0x10001, 0x2000 },
> +	{ 0, 0, 0, 0, 0 },
> +};
> +
> +struct i2s_pll_clk {
> +	void __iomem *base;
> +	struct clk_hw hw;
> +	struct device *dev;
> +};
> +
> +static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg,
> +		unsigned int val)
> +{
> +	writel_relaxed(val, clk->base + reg);
> +}
> +
> +static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk,
> +		unsigned int reg)
> +{
> +	return readl_relaxed(clk->base + reg);
> +}
> +
> +static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
> +{
> +	return container_of(hw, struct i2s_pll_clk, hw);
> +}
> +
> +static inline unsigned int i2s_pll_get_value(unsigned int val)
> +{
> +	return (val & 0x3F) + ((val >> 6) & 0x3F);
> +}
> +
> +static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate)
> +{
> +	switch (prate) {
> +	case 27000000:
> +		return i2s_pll_cfg_27m;
> +	case 28224000:
> +		return i2s_pll_cfg_28m;
> +	default:
> +		return NULL;
> +	}
> +}
> +
> +static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw,
> +			unsigned long parent_rate)
> +{
> +	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
> +	unsigned int idiv, fbdiv, odiv;
> +
> +	idiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_IDIV_REG));
> +	fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG));
> +	odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG));
> +
> +	return ((parent_rate / idiv) * fbdiv) / odiv;
> +}
> +
> +static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
> +			unsigned long *prate)
> +{
> +	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
> +	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate);
> +	int i;
> +
> +	if (!pll_cfg) {
> +		dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; pll_cfg[i].rate != 0; i++)
> +		if (pll_cfg[i].rate == rate)
> +			return rate;
> +
> +	return -EINVAL;
> +}
> +
> +static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
> +			unsigned long parent_rate)
> +{
> +	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
> +	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate);
> +	int i;
> +
> +	if (!pll_cfg) {
> +		dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; pll_cfg[i].rate != 0; i++) {
> +		if (pll_cfg[i].rate == rate) {
> +			i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv);
> +			i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv);
> +			i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0);
> +			i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1);
> +			return 0;
> +		}
> +	}
> +
> +	dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
> +			parent_rate);
> +	return -EINVAL;
> +}
> +
> +static const struct clk_ops i2s_pll_ops = {
> +	.recalc_rate = i2s_pll_recalc_rate,
> +	.round_rate = i2s_pll_round_rate,
> +	.set_rate = i2s_pll_set_rate,
> +};
> +
> +static int i2s_pll_clk_probe(struct platform_device *pdev)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct device_node *node = dev->of_node;
> +	const char *clk_name;
> +	const char *parent_name;
> +	struct clk *clk;
> +	struct i2s_pll_clk *pll_clk;
> +	struct clk_init_data init;
> +	struct resource *mem;
> +
> +	pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
> +	if (!pll_clk)
> +		return -ENOMEM;
> +
> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	pll_clk->base = devm_ioremap_resource(dev, mem);
> +	if (IS_ERR(pll_clk->base))
> +		return PTR_ERR(pll_clk->base);
> +
> +	clk_name = node->name;
> +	init.name = clk_name;
> +	init.ops = &i2s_pll_ops;
> +	parent_name = of_clk_get_parent_name(node, 0);
> +	init.parent_names = &parent_name;
> +	init.num_parents = 1;
> +	pll_clk->hw.init = &init;
> +	pll_clk->dev = dev;
> +
> +	clk = devm_clk_register(dev, &pll_clk->hw);
> +	if (IS_ERR(clk)) {
> +		dev_err(dev, "failed to register %s clock (%ld)\n",
> +				clk_name, PTR_ERR(clk));
> +		return PTR_ERR(clk);
> +	}
> +
> +	return of_clk_add_provider(node, of_clk_src_simple_get, clk);
> +}
> +
> +static int i2s_pll_clk_remove(struct platform_device *pdev)
> +{
> +	of_clk_del_provider(pdev->dev.of_node);
> +	return 0;
> +}
> +
> +static const struct of_device_id i2s_pll_clk_id[] = {
> +	{ .compatible = "snps,axs10x-i2s-pll-clock", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, i2s_pll_clk_id);
> +
> +static struct platform_driver i2s_pll_clk_driver = {
> +	.driver = {
> +		.name = "axs10x-i2s-pll-clock",
> +		.of_match_table = i2s_pll_clk_id,
> +	},
> +	.probe = i2s_pll_clk_probe,
> +	.remove = i2s_pll_clk_remove,
> +};
> +module_platform_driver(i2s_pll_clk_driver);
> +
> +MODULE_AUTHOR("Jose Abreu <[e-mail]>");
> +MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver");
> +MODULE_LICENSE("GPL v2");

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Jose Abreu April 26, 2016, 9:24 a.m. UTC | #2

Hi,

@Stephen: Is this version ok? The DT bindings were already acked by Vineet and
Alexey.

@Rob: Is this version ok? You already acked the previous version[1], see the
version log for differences. Please see also if [2] is ok.

[1] https://marc.info/?l=devicetree&m=146056894500509&w=2

[2] https://marc.info/?l=devicetree&m=146126139521541&w=2

On 21-04-2016 18:55, Jose Abreu wrote:
> Adding device tree mailing list and Rob Herring.
>
> On 21-04-2016 18:19, Jose Abreu wrote:
>> The ARC SDP I2S clock can be programmed using a
>> specific PLL.
>>
>> This patch has the goal of adding a clock driver
>> that programs this PLL.
>>
>> At this moment the rate values are hardcoded in
>> a table but in the future it would be ideal to
>> use a function which determines the PLL values
>> given the desired rate.
>>
>> Signed-off-by: Jose Abreu <[e-mail]>
>> ---
>>
>> Changes v5 -> v6:
>> * Use parent clock to determine PLL input rate instead of using hardcoded values
>> * Documentation update (added 'clocks' field)
>>
>> Changes v4 -> v5:
>> * Documentation update (as suggested by Alexey Brodkin)
>> * Changed compatible string to "snps,axs10x-i2s-pll-clock" (as suggested by Alexey Brodkin)
>>
>> Changes v3 -> v4:
>> * Added binding document (as suggested by Stephen Boyd)
>> * Minor code style fixes (as suggested by Stephen Boyd)
>> * Use ioremap (as suggested by Stephen Boyd)
>> * Implement round_rate (as suggested by Stephen Boyd)
>> * Change to platform driver (as suggested by Stephen Boyd)
>> * Use {readl/writel}_relaxed (as suggested by Vineet Gupta)
>>
>> Changes v2 -> v3:
>> * Implemented recalc_rate
>>
>> Changes v1 -> v2:
>> * Renamed folder to axs10x (as suggested by Alexey Brodkin)
>> * Added more supported rates
>>
>>  .../bindings/clock/axs10x-i2s-pll-clock.txt        |  25 +++
>>  drivers/clk/Makefile                               |   1 +
>>  drivers/clk/axs10x/Makefile                        |   1 +
>>  drivers/clk/axs10x/i2s_pll_clock.c                 | 228 +++++++++++++++++++++
>>  4 files changed, 255 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
>>  create mode 100644 drivers/clk/axs10x/Makefile
>>  create mode 100644 drivers/clk/axs10x/i2s_pll_clock.c
>>
>> diff --git a/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
>> new file mode 100644
>> index 0000000..5ffc8df
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
>> @@ -0,0 +1,25 @@
>> +Binding for the AXS10X I2S PLL clock
>> +
>> +This binding uses the common clock binding[1].
>> +
>> +[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
>> +
>> +Required properties:
>> +- compatible: shall be "snps,axs10x-i2s-pll-clock"
>> +- reg : address and length of the I2S PLL register set.
>> +- clocks: shall be the input parent clock phandle for the PLL.
>> +- #clock-cells: from common clock binding; Should always be set to 0.
>> +
>> +Example:
>> +	pll_clock: pll_clock {
>> +		compatible = "fixed-clock";
>> +		clock-frequency = <27000000>;
>> +		#clock-cells = <0>;
>> +	};
>> +
>> +	i2s_clock@100a0 {
>> +		compatible = "snps,axs10x-i2s-pll-clock";
>> +		reg = <0x100a0 0x10>;
>> +		clocks = <&pll_clock>;
>> +		#clock-cells = <0>;
>> +	};
>> diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
>> index 46869d6..2ca62dc6 100644
>> --- a/drivers/clk/Makefile
>> +++ b/drivers/clk/Makefile
>> @@ -84,3 +84,4 @@ obj-$(CONFIG_X86)			+= x86/
>>  obj-$(CONFIG_ARCH_ZX)			+= zte/
>>  obj-$(CONFIG_ARCH_ZYNQ)			+= zynq/
>>  obj-$(CONFIG_H8300)		+= h8300/
>> +obj-$(CONFIG_ARC_PLAT_AXS10X)		+= axs10x/
>> diff --git a/drivers/clk/axs10x/Makefile b/drivers/clk/axs10x/Makefile
>> new file mode 100644
>> index 0000000..01996b8
>> --- /dev/null
>> +++ b/drivers/clk/axs10x/Makefile
>> @@ -0,0 +1 @@
>> +obj-y += i2s_pll_clock.o
>> diff --git a/drivers/clk/axs10x/i2s_pll_clock.c b/drivers/clk/axs10x/i2s_pll_clock.c
>> new file mode 100644
>> index 0000000..411310d
>> --- /dev/null
>> +++ b/drivers/clk/axs10x/i2s_pll_clock.c
>> @@ -0,0 +1,228 @@
>> +/*
>> + * Synopsys AXS10X SDP I2S PLL clock driver
>> + *
>> + * Copyright (C) 2016 Synopsys
>> + *
>> + * This file is licensed under the terms of the GNU General Public
>> + * License version 2. This program is licensed "as is" without any
>> + * warranty of any kind, whether express or implied.
>> + */
>> +
>> +#include <linux/platform_device.h>
>> +#include <linux/module.h>
>> +#include <linux/clk-provider.h>
>> +#include <linux/err.h>
>> +#include <linux/device.h>
>> +#include <linux/of_address.h>
>> +#include <linux/slab.h>
>> +#include <linux/of.h>
>> +
>> +/* PLL registers addresses */
>> +#define PLL_IDIV_REG	0x0
>> +#define PLL_FBDIV_REG	0x4
>> +#define PLL_ODIV0_REG	0x8
>> +#define PLL_ODIV1_REG	0xC
>> +
>> +struct i2s_pll_cfg {
>> +	unsigned int rate;
>> +	unsigned int idiv;
>> +	unsigned int fbdiv;
>> +	unsigned int odiv0;
>> +	unsigned int odiv1;
>> +};
>> +
>> +static const struct i2s_pll_cfg i2s_pll_cfg_27m[] = {
>> +	/* 27 Mhz */
>> +	{ 1024000, 0x104, 0x451, 0x10E38, 0x2000 },
>> +	{ 1411200, 0x104, 0x596, 0x10D35, 0x2000 },
>> +	{ 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 },
>> +	{ 2048000, 0x82, 0x451, 0x10E38, 0x2000 },
>> +	{ 2822400, 0x82, 0x596, 0x10D35, 0x2000 },
>> +	{ 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 },
>> +	{ 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 },
>> +	{ 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 },
>> +	{ 0, 0, 0, 0, 0 },
>> +};
>> +
>> +static const struct i2s_pll_cfg i2s_pll_cfg_28m[] = {
>> +	/* 28.224 Mhz */
>> +	{ 1024000, 0x82, 0x105, 0x107DF, 0x2000 },
>> +	{ 1411200, 0x28A, 0x1, 0x10001, 0x2000 },
>> +	{ 1536000, 0xA28, 0x187, 0x10042, 0x2000 },
>> +	{ 2048000, 0x41, 0x105, 0x107DF, 0x2000 },
>> +	{ 2822400, 0x145, 0x1, 0x10001, 0x2000 },
>> +	{ 3072000, 0x514, 0x187, 0x10042, 0x2000 },
>> +	{ 2116800, 0x514, 0x42, 0x10001, 0x2000 },
>> +	{ 2304000, 0x619, 0x82, 0x10001, 0x2000 },
>> +	{ 0, 0, 0, 0, 0 },
>> +};
>> +
>> +struct i2s_pll_clk {
>> +	void __iomem *base;
>> +	struct clk_hw hw;
>> +	struct device *dev;
>> +};
>> +
>> +static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg,
>> +		unsigned int val)
>> +{
>> +	writel_relaxed(val, clk->base + reg);
>> +}
>> +
>> +static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk,
>> +		unsigned int reg)
>> +{
>> +	return readl_relaxed(clk->base + reg);
>> +}
>> +
>> +static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
>> +{
>> +	return container_of(hw, struct i2s_pll_clk, hw);
>> +}
>> +
>> +static inline unsigned int i2s_pll_get_value(unsigned int val)
>> +{
>> +	return (val & 0x3F) + ((val >> 6) & 0x3F);
>> +}
>> +
>> +static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate)
>> +{
>> +	switch (prate) {
>> +	case 27000000:
>> +		return i2s_pll_cfg_27m;
>> +	case 28224000:
>> +		return i2s_pll_cfg_28m;
>> +	default:
>> +		return NULL;
>> +	}
>> +}
>> +
>> +static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw,
>> +			unsigned long parent_rate)
>> +{
>> +	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
>> +	unsigned int idiv, fbdiv, odiv;
>> +
>> +	idiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_IDIV_REG));
>> +	fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG));
>> +	odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG));
>> +
>> +	return ((parent_rate / idiv) * fbdiv) / odiv;
>> +}
>> +
>> +static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
>> +			unsigned long *prate)
>> +{
>> +	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
>> +	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate);
>> +	int i;
>> +
>> +	if (!pll_cfg) {
>> +		dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; pll_cfg[i].rate != 0; i++)
>> +		if (pll_cfg[i].rate == rate)
>> +			return rate;
>> +
>> +	return -EINVAL;
>> +}
>> +
>> +static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
>> +			unsigned long parent_rate)
>> +{
>> +	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
>> +	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate);
>> +	int i;
>> +
>> +	if (!pll_cfg) {
>> +		dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
>> +		return -EINVAL;
>> +	}
>> +
>> +	for (i = 0; pll_cfg[i].rate != 0; i++) {
>> +		if (pll_cfg[i].rate == rate) {
>> +			i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv);
>> +			i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv);
>> +			i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0);
>> +			i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1);
>> +			return 0;
>> +		}
>> +	}
>> +
>> +	dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
>> +			parent_rate);
>> +	return -EINVAL;
>> +}
>> +
>> +static const struct clk_ops i2s_pll_ops = {
>> +	.recalc_rate = i2s_pll_recalc_rate,
>> +	.round_rate = i2s_pll_round_rate,
>> +	.set_rate = i2s_pll_set_rate,
>> +};
>> +
>> +static int i2s_pll_clk_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +	struct device_node *node = dev->of_node;
>> +	const char *clk_name;
>> +	const char *parent_name;
>> +	struct clk *clk;
>> +	struct i2s_pll_clk *pll_clk;
>> +	struct clk_init_data init;
>> +	struct resource *mem;
>> +
>> +	pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
>> +	if (!pll_clk)
>> +		return -ENOMEM;
>> +
>> +	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> +	pll_clk->base = devm_ioremap_resource(dev, mem);
>> +	if (IS_ERR(pll_clk->base))
>> +		return PTR_ERR(pll_clk->base);
>> +
>> +	clk_name = node->name;
>> +	init.name = clk_name;
>> +	init.ops = &i2s_pll_ops;
>> +	parent_name = of_clk_get_parent_name(node, 0);
>> +	init.parent_names = &parent_name;
>> +	init.num_parents = 1;
>> +	pll_clk->hw.init = &init;
>> +	pll_clk->dev = dev;
>> +
>> +	clk = devm_clk_register(dev, &pll_clk->hw);
>> +	if (IS_ERR(clk)) {
>> +		dev_err(dev, "failed to register %s clock (%ld)\n",
>> +				clk_name, PTR_ERR(clk));
>> +		return PTR_ERR(clk);
>> +	}
>> +
>> +	return of_clk_add_provider(node, of_clk_src_simple_get, clk);
>> +}
>> +
>> +static int i2s_pll_clk_remove(struct platform_device *pdev)
>> +{
>> +	of_clk_del_provider(pdev->dev.of_node);
>> +	return 0;
>> +}
>> +
>> +static const struct of_device_id i2s_pll_clk_id[] = {
>> +	{ .compatible = "snps,axs10x-i2s-pll-clock", },
>> +	{ },
>> +};
>> +MODULE_DEVICE_TABLE(of, i2s_pll_clk_id);
>> +
>> +static struct platform_driver i2s_pll_clk_driver = {
>> +	.driver = {
>> +		.name = "axs10x-i2s-pll-clock",
>> +		.of_match_table = i2s_pll_clk_id,
>> +	},
>> +	.probe = i2s_pll_clk_probe,
>> +	.remove = i2s_pll_clk_remove,
>> +};
>> +module_platform_driver(i2s_pll_clk_driver);
>> +
>> +MODULE_AUTHOR("Jose Abreu <[e-mail]>");
>> +MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver");
>> +MODULE_LICENSE("GPL v2");
> --
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Best regards,
Jose Miguel Abreu
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Rob Herring (Arm) May 4, 2016, 2:34 a.m. UTC | #3

On Mon, May 02, 2016 at 10:39:05AM +0100, Jose Abreu wrote:
> The ARC SDP I2S clock can be programmed using a
> specific PLL.
> 
> This patch has the goal of adding a clock driver
> that programs this PLL.
> 
> At this moment the rate values are hardcoded in
> a table but in the future it would be ideal to
> use a function which determines the PLL values
> given the desired rate.
> 
> Signed-off-by: Jose Abreu <[e-mail]>
> ---
> 
> Changes v5 -> v6:
> * Use parent clock to determine PLL input rate instead of using hardcoded values
> * Documentation update (added 'clocks' field)
> 
> Changes v4 -> v5:
> * Documentation update (as suggested by Alexey Brodkin)
> * Changed compatible string to "snps,axs10x-i2s-pll-clock" (as suggested by Alexey Brodkin)
> 
> Changes v3 -> v4:
> * Added binding document (as suggested by Stephen Boyd)
> * Minor code style fixes (as suggested by Stephen Boyd)
> * Use ioremap (as suggested by Stephen Boyd)
> * Implement round_rate (as suggested by Stephen Boyd)
> * Change to platform driver (as suggested by Stephen Boyd)
> * Use {readl/writel}_relaxed (as suggested by Vineet Gupta)
> 
> Changes v2 -> v3:
> * Implemented recalc_rate
> 
> Changes v1 -> v2:
> * Renamed folder to axs10x (as suggested by Alexey Brodkin)
> * Added more supported rates
> 
> Cc: Carlos Palminha <[e-mail]>
> Cc: Rob Herring <[e-mail]>
> Cc: Pawel Moll <[e-mail]>
> Cc: Mark Rutland <[e-mail]>
> Cc: Ian Campbell <[e-mail]>
> Cc: Kumar Gala <[e-mail]>
> Cc: Michael Turquette <[e-mail]>
> Cc: Stephen Boyd <[e-mail]>
> Cc: Alexey Brodkin <[e-mail]>
> Cc: Vineet Gupta <[e-mail]>
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> Cc: [e-mail]
> 
>  .../bindings/clock/axs10x-i2s-pll-clock.txt        |  25 +++

Acked-by: Rob Herring <[e-mail]>

>  drivers/clk/Makefile                               |   1 +
>  drivers/clk/axs10x/Makefile                        |   1 +
>  drivers/clk/axs10x/i2s_pll_clock.c                 | 228 +++++++++++++++++++++
>  4 files changed, 255 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
>  create mode 100644 drivers/clk/axs10x/Makefile
>  create mode 100644 drivers/clk/axs10x/i2s_pll_clock.c
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Stephen Boyd May 6, 2016, 5:35 p.m. UTC | #4

On 05/02, Jose Abreu wrote:
> The ARC SDP I2S clock can be programmed using a
> specific PLL.
> 
> This patch has the goal of adding a clock driver
> that programs this PLL.
> 
> At this moment the rate values are hardcoded in
> a table but in the future it would be ideal to
> use a function which determines the PLL values
> given the desired rate.
> 
> Signed-off-by: Jose Abreu <[e-mail]>
> ---

Applied to clk-next

I'm not applying the arc dts file (patch #2 in this series).

Patch

diff --git a/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
new file mode 100644
index 0000000..5ffc8df
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/axs10x-i2s-pll-clock.txt
@@ -0,0 +1,25 @@ 
+Binding for the AXS10X I2S PLL clock
+
+This binding uses the common clock binding[1].
+
+[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
+
+Required properties:
+- compatible: shall be "snps,axs10x-i2s-pll-clock"
+- reg : address and length of the I2S PLL register set.
+- clocks: shall be the input parent clock phandle for the PLL.
+- #clock-cells: from common clock binding; Should always be set to 0.
+
+Example:
+	pll_clock: pll_clock {
+		compatible = "fixed-clock";
+		clock-frequency = <27000000>;
+		#clock-cells = <0>;
+	};
+
+	i2s_clock@100a0 {
+		compatible = "snps,axs10x-i2s-pll-clock";
+		reg = <0x100a0 0x10>;
+		clocks = <&pll_clock>;
+		#clock-cells = <0>;
+	};
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 46869d6..2ca62dc6 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -84,3 +84,4 @@  obj-$(CONFIG_X86)			+= x86/
 obj-$(CONFIG_ARCH_ZX)			+= zte/
 obj-$(CONFIG_ARCH_ZYNQ)			+= zynq/
 obj-$(CONFIG_H8300)		+= h8300/
+obj-$(CONFIG_ARC_PLAT_AXS10X)		+= axs10x/
diff --git a/drivers/clk/axs10x/Makefile b/drivers/clk/axs10x/Makefile
new file mode 100644
index 0000000..01996b8
--- /dev/null
+++ b/drivers/clk/axs10x/Makefile
@@ -0,0 +1 @@ 
+obj-y += i2s_pll_clock.o
diff --git a/drivers/clk/axs10x/i2s_pll_clock.c b/drivers/clk/axs10x/i2s_pll_clock.c
new file mode 100644
index 0000000..411310d
--- /dev/null
+++ b/drivers/clk/axs10x/i2s_pll_clock.c
@@ -0,0 +1,228 @@ 
+/*
+ * Synopsys AXS10X SDP I2S PLL clock driver
+ *
+ * Copyright (C) 2016 Synopsys
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/device.h>
+#include <linux/of_address.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+/* PLL registers addresses */
+#define PLL_IDIV_REG	0x0
+#define PLL_FBDIV_REG	0x4
+#define PLL_ODIV0_REG	0x8
+#define PLL_ODIV1_REG	0xC
+
+struct i2s_pll_cfg {
+	unsigned int rate;
+	unsigned int idiv;
+	unsigned int fbdiv;
+	unsigned int odiv0;
+	unsigned int odiv1;
+};
+
+static const struct i2s_pll_cfg i2s_pll_cfg_27m[] = {
+	/* 27 Mhz */
+	{ 1024000, 0x104, 0x451, 0x10E38, 0x2000 },
+	{ 1411200, 0x104, 0x596, 0x10D35, 0x2000 },
+	{ 1536000, 0x208, 0xA28, 0x10B2C, 0x2000 },
+	{ 2048000, 0x82, 0x451, 0x10E38, 0x2000 },
+	{ 2822400, 0x82, 0x596, 0x10D35, 0x2000 },
+	{ 3072000, 0x104, 0xA28, 0x10B2C, 0x2000 },
+	{ 2116800, 0x82, 0x3CF, 0x10C30, 0x2000 },
+	{ 2304000, 0x104, 0x79E, 0x10B2C, 0x2000 },
+	{ 0, 0, 0, 0, 0 },
+};
+
+static const struct i2s_pll_cfg i2s_pll_cfg_28m[] = {
+	/* 28.224 Mhz */
+	{ 1024000, 0x82, 0x105, 0x107DF, 0x2000 },
+	{ 1411200, 0x28A, 0x1, 0x10001, 0x2000 },
+	{ 1536000, 0xA28, 0x187, 0x10042, 0x2000 },
+	{ 2048000, 0x41, 0x105, 0x107DF, 0x2000 },
+	{ 2822400, 0x145, 0x1, 0x10001, 0x2000 },
+	{ 3072000, 0x514, 0x187, 0x10042, 0x2000 },
+	{ 2116800, 0x514, 0x42, 0x10001, 0x2000 },
+	{ 2304000, 0x619, 0x82, 0x10001, 0x2000 },
+	{ 0, 0, 0, 0, 0 },
+};
+
+struct i2s_pll_clk {
+	void __iomem *base;
+	struct clk_hw hw;
+	struct device *dev;
+};
+
+static inline void i2s_pll_write(struct i2s_pll_clk *clk, unsigned int reg,
+		unsigned int val)
+{
+	writel_relaxed(val, clk->base + reg);
+}
+
+static inline unsigned int i2s_pll_read(struct i2s_pll_clk *clk,
+		unsigned int reg)
+{
+	return readl_relaxed(clk->base + reg);
+}
+
+static inline struct i2s_pll_clk *to_i2s_pll_clk(struct clk_hw *hw)
+{
+	return container_of(hw, struct i2s_pll_clk, hw);
+}
+
+static inline unsigned int i2s_pll_get_value(unsigned int val)
+{
+	return (val & 0x3F) + ((val >> 6) & 0x3F);
+}
+
+static const struct i2s_pll_cfg *i2s_pll_get_cfg(unsigned long prate)
+{
+	switch (prate) {
+	case 27000000:
+		return i2s_pll_cfg_27m;
+	case 28224000:
+		return i2s_pll_cfg_28m;
+	default:
+		return NULL;
+	}
+}
+
+static unsigned long i2s_pll_recalc_rate(struct clk_hw *hw,
+			unsigned long parent_rate)
+{
+	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
+	unsigned int idiv, fbdiv, odiv;
+
+	idiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_IDIV_REG));
+	fbdiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_FBDIV_REG));
+	odiv = i2s_pll_get_value(i2s_pll_read(clk, PLL_ODIV0_REG));
+
+	return ((parent_rate / idiv) * fbdiv) / odiv;
+}
+
+static long i2s_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+			unsigned long *prate)
+{
+	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
+	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(*prate);
+	int i;
+
+	if (!pll_cfg) {
+		dev_err(clk->dev, "invalid parent rate=%ld\n", *prate);
+		return -EINVAL;
+	}
+
+	for (i = 0; pll_cfg[i].rate != 0; i++)
+		if (pll_cfg[i].rate == rate)
+			return rate;
+
+	return -EINVAL;
+}
+
+static int i2s_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+			unsigned long parent_rate)
+{
+	struct i2s_pll_clk *clk = to_i2s_pll_clk(hw);
+	const struct i2s_pll_cfg *pll_cfg = i2s_pll_get_cfg(parent_rate);
+	int i;
+
+	if (!pll_cfg) {
+		dev_err(clk->dev, "invalid parent rate=%ld\n", parent_rate);
+		return -EINVAL;
+	}
+
+	for (i = 0; pll_cfg[i].rate != 0; i++) {
+		if (pll_cfg[i].rate == rate) {
+			i2s_pll_write(clk, PLL_IDIV_REG, pll_cfg[i].idiv);
+			i2s_pll_write(clk, PLL_FBDIV_REG, pll_cfg[i].fbdiv);
+			i2s_pll_write(clk, PLL_ODIV0_REG, pll_cfg[i].odiv0);
+			i2s_pll_write(clk, PLL_ODIV1_REG, pll_cfg[i].odiv1);
+			return 0;
+		}
+	}
+
+	dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
+			parent_rate);
+	return -EINVAL;
+}
+
+static const struct clk_ops i2s_pll_ops = {
+	.recalc_rate = i2s_pll_recalc_rate,
+	.round_rate = i2s_pll_round_rate,
+	.set_rate = i2s_pll_set_rate,
+};
+
+static int i2s_pll_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	const char *clk_name;
+	const char *parent_name;
+	struct clk *clk;
+	struct i2s_pll_clk *pll_clk;
+	struct clk_init_data init;
+	struct resource *mem;
+
+	pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
+	if (!pll_clk)
+		return -ENOMEM;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	pll_clk->base = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(pll_clk->base))
+		return PTR_ERR(pll_clk->base);
+
+	clk_name = node->name;
+	init.name = clk_name;
+	init.ops = &i2s_pll_ops;
+	parent_name = of_clk_get_parent_name(node, 0);
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	pll_clk->hw.init = &init;
+	pll_clk->dev = dev;
+
+	clk = devm_clk_register(dev, &pll_clk->hw);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "failed to register %s clock (%ld)\n",
+				clk_name, PTR_ERR(clk));
+		return PTR_ERR(clk);
+	}
+
+	return of_clk_add_provider(node, of_clk_src_simple_get, clk);
+}
+
+static int i2s_pll_clk_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+	return 0;
+}
+
+static const struct of_device_id i2s_pll_clk_id[] = {
+	{ .compatible = "snps,axs10x-i2s-pll-clock", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, i2s_pll_clk_id);
+
+static struct platform_driver i2s_pll_clk_driver = {
+	.driver = {
+		.name = "axs10x-i2s-pll-clock",
+		.of_match_table = i2s_pll_clk_id,
+	},
+	.probe = i2s_pll_clk_probe,
+	.remove = i2s_pll_clk_remove,
+};
+module_platform_driver(i2s_pll_clk_driver);
+
+MODULE_AUTHOR("Jose Abreu <[e-mail]>");
+MODULE_DESCRIPTION("Synopsys AXS10X SDP I2S PLL Clock Driver");
+MODULE_LICENSE("GPL v2");