diff mbox series

[v3,03/42] clk: ep93xx: add DT support for Cirrus EP93xx

Message ID 20230605-ep93xx-v3-3-3d63a5f1103e@maquefel.me (mailing list archive)
State New, archived
Headers show
Series ep93xx device tree conversion | expand

Commit Message

Nikita Shubin via B4 Relay July 20, 2023, 11:29 a.m. UTC
From: Nikita Shubin <nikita.shubin@maquefel.me>

This is a rewrite of EP93xx clock driver in arch/arm/mach-ep93xx/clock.c
trying to do everything the device tree way:

- provide clock acces via of
- drop clk_hw_register_clkdev
- drop init code and use builtin_platform_driver_probe

Also moved all clocks not accessed via device tree to syscon.

Co-developed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
---
 drivers/clk/Kconfig      |   8 +
 drivers/clk/Makefile     |   1 +
 drivers/clk/clk-ep93xx.c | 764 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 773 insertions(+)

Comments

Stephen Boyd July 20, 2023, 11:27 p.m. UTC | #1
Quoting Nikita Shubin via B4 Relay (2023-07-20 04:29:03)
> diff --git a/drivers/clk/clk-ep93xx.c b/drivers/clk/clk-ep93xx.c
> new file mode 100644
> index 000000000000..7b9b3a0894ab
> --- /dev/null
> +++ b/drivers/clk/clk-ep93xx.c
> @@ -0,0 +1,764 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Clock control for Cirrus EP93xx chips.
> + * Copyright (C) 2021 Nikita Shubin <nikita.shubin@maquefel.me>
> + *
> + * Based on a rewrite of arch/arm/mach-ep93xx/clock.c:
> + * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
> + */
> +#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
> +
> +#include <linux/bits.h>
> +#include <linux/clk-provider.h>
> +#include <linux/clk.h>
> +#include <linux/clkdev.h>

Drop the unused includes.

> +#include <linux/err.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/spinlock.h>
> +#include <linux/string.h>
> +#include <linux/sys_soc.h>
> +
> +#include <linux/soc/cirrus/ep93xx.h>
> +#include <dt-bindings/clock/cirrus,ep93xx-clock.h>
> +
> +#include <asm/div64.h>
> +
> +#define EP93XX_EXT_RTC_RATE            32768
> +
> +#define EP93XX_SYSCON_POWER_STATE      0x00
> +#define EP93XX_SYSCON_PWRCNT           0x04
> +#define EP93XX_SYSCON_PWRCNT_UARTBAUD  BIT(29)
> +#define EP93XX_SYSCON_PWRCNT_USH_EN    28
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2M1  27
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2M0  26
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P8  25
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P9  24
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P6  23
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P7  22
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P4  21
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P5  20
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P2  19
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P3  18
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P0  17
> +#define EP93XX_SYSCON_PWRCNT_DMA_M2P1  16
> +#define EP93XX_SYSCON_DEVCFG           0x80
> +#define EP93XX_SYSCON_DEVCFG_U3EN      24
> +#define EP93XX_SYSCON_DEVCFG_U2EN      20
> +#define EP93XX_SYSCON_DEVCFG_U1EN      18
> +#define EP93XX_SYSCON_VIDCLKDIV                0x84
> +#define EP93XX_SYSCON_CLKDIV_ENABLE    15
> +#define EP93XX_SYSCON_CLKDIV_ESEL      BIT(14)
> +#define EP93XX_SYSCON_CLKDIV_PSEL      BIT(13)
> +#define EP93XX_SYSCON_CLKDIV_MASK      GENMASK(14, 13)
> +#define EP93XX_SYSCON_CLKDIV_PDIV_SHIFT        8
> +#define EP93XX_SYSCON_I2SCLKDIV                0x8c
> +#define EP93XX_SYSCON_I2SCLKDIV_SENA   31
> +#define EP93XX_SYSCON_I2SCLKDIV_ORIDE  BIT(29)
> +#define EP93XX_SYSCON_I2SCLKDIV_SPOL   BIT(19)
> +#define EP93XX_I2SCLKDIV_SDIV          (1 << 16)
> +#define EP93XX_I2SCLKDIV_LRDIV32       (0 << 17)
> +#define EP93XX_I2SCLKDIV_LRDIV64       (1 << 17)
> +#define EP93XX_I2SCLKDIV_LRDIV128      (2 << 17)
> +#define EP93XX_I2SCLKDIV_LRDIV_MASK    (3 << 17)
> +#define EP93XX_SYSCON_KEYTCHCLKDIV     0x90
> +#define EP93XX_SYSCON_KEYTCHCLKDIV_TSEN        31
> +#define EP93XX_SYSCON_KEYTCHCLKDIV_ADIV        16
> +#define EP93XX_SYSCON_KEYTCHCLKDIV_KEN 15
> +#define EP93XX_SYSCON_KEYTCHCLKDIV_KDIV        0
> +#define EP93XX_SYSCON_CHIPID           0x94
> +#define EP93XX_SYSCON_CHIPID_ID                0x9213
> +
> +/* Keeps track of all clocks */
> +static const char adc_divisors[] = { 16, 4 };
> +static const char sclk_divisors[] = { 2, 4 };
> +static const char lrclk_divisors[] = { 32, 64, 128 };
> +
> +#define EP_PARENT(NAME) { .name = NAME, .fw_name = NAME }
> +
> +static const struct clk_parent_data ep93xx_clk_parents[] = {
> +       EP_PARENT("xtali"),
> +       EP_PARENT("pll1"),
> +       EP_PARENT("pll2"),

pll2 and pll1 aren't in the DT binding, so they shouldn't be set for
.fw_name here.

> +};
> +
> +struct ep93xx_clk {
> +       struct clk_hw hw;
> +       u16 idx;
> +       u16 reg;
> +       u32 mask;
> +       u8 bit_idx;
> +       u8 shift;
> +       u8 width;
> +       u8 num_div;
> +       const char *div;
> +};
> +
> +struct ep93xx_clk_priv {
> +       spinlock_t lock;
> +       struct device *dev;
> +       void __iomem *base;
> +       struct regmap *map;
> +       struct clk_hw *fixed[16];
> +       struct ep93xx_clk reg[];
> +};
> +
> +static struct ep93xx_clk *ep93xx_clk_from(struct clk_hw *hw)
> +{
> +       return container_of(hw, struct ep93xx_clk, hw);
> +}
> +
> +static struct ep93xx_clk_priv *ep93xx_priv_from(struct ep93xx_clk *clk)
> +{
> +       return container_of(clk, struct ep93xx_clk_priv, reg[clk->idx]);
> +}
> +
> +static int ep93xx_clk_is_enabled(struct clk_hw *hw)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       u32 val;
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +
> +       return !!(val & BIT(clk->bit_idx));
> +}
> +
> +static int ep93xx_clk_enable(struct clk_hw *hw)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       unsigned long flags;
> +       u32 val;
> +
> +       spin_lock_irqsave(&priv->lock, flags);
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       val |= BIT(clk->bit_idx);
> +
> +       ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
> +
> +       spin_unlock_irqrestore(&priv->lock, flags);
> +
> +       return 0;
> +}
> +
> +static void ep93xx_clk_disable(struct clk_hw *hw)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       unsigned long flags;
> +       u32 val;
> +
> +       spin_lock_irqsave(&priv->lock, flags);
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       val &= ~BIT(clk->bit_idx);
> +
> +       ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
> +
> +       spin_unlock_irqrestore(&priv->lock, flags);
> +}
> +
> +static const struct clk_ops clk_ep93xx_gate_ops = {
> +       .enable = ep93xx_clk_enable,
> +       .disable = ep93xx_clk_disable,
> +       .is_enabled = ep93xx_clk_is_enabled,
> +};
> +
> +static int ep93xx_clk_register_gate(struct ep93xx_clk *clk,
> +                                       const char *name,
> +                                       const char *parent_name,
> +                                       unsigned long flags,
> +                                       unsigned int reg,
> +                                       u8 bit_idx)
> +{
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       struct clk_parent_data parent_data = { };
> +       struct clk_init_data init = { };
> +
> +       init.name = name;
> +       init.ops = &clk_ep93xx_gate_ops;
> +       init.flags = flags;
> +
> +       parent_data.fw_name = parent_name;
> +       parent_data.name = parent_name;
> +       init.parent_data = &parent_data;
> +       init.num_parents = 1;
> +
> +       clk->reg = reg;
> +       clk->bit_idx = bit_idx;
> +       clk->hw.init = &init;
> +
> +       return devm_clk_hw_register(priv->dev, &clk->hw);
> +}
> +
> +static u8 ep93xx_mux_get_parent(struct clk_hw *hw)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       u32 val;
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +
> +       val &= EP93XX_SYSCON_CLKDIV_MASK;
> +
> +       switch (val) {
> +       case EP93XX_SYSCON_CLKDIV_ESEL:
> +               return 1; // PLL1
> +       case EP93XX_SYSCON_CLKDIV_MASK:
> +               return 2; // PLL2
> +       default:
> +               break;
> +       };
> +
> +       return 0; // XTALI

Please use /* comments like this */

> +}
> +
> +static int ep93xx_mux_set_parent_lock(struct clk_hw *hw, u8 index)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       unsigned long flags;
> +       u32 val;
> +
> +       if (index >= ARRAY_SIZE(ep93xx_clk_parents))
> +               return -EINVAL;
> +
> +       spin_lock_irqsave(&priv->lock, flags);
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       val &= ~(EP93XX_SYSCON_CLKDIV_MASK);
> +       if (index) {
> +               val |= EP93XX_SYSCON_CLKDIV_ESEL;
> +               val |= (index - 1) ? EP93XX_SYSCON_CLKDIV_PSEL : 0;
> +       }
> +
> +       ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
> +
> +       spin_unlock_irqrestore(&priv->lock, flags);
> +
> +       return 0;
> +}
> +
> +static bool is_best(unsigned long rate, unsigned long now,
> +                    unsigned long best)
> +{
> +       return abs(rate - now) < abs(rate - best);

Another case where we need abs_diff() so that it doesn't get confused
when trying to do signed comparison.

> +}
> +
> +static int ep93xx_mux_determine_rate(struct clk_hw *hw,
> +                               struct clk_rate_request *req)
> +{
> +       unsigned long best_rate = 0, actual_rate, mclk_rate;
> +       unsigned long rate = req->rate;
> +       struct clk_hw *parent_best = NULL;
> +       unsigned long parent_rate_best;
> +       unsigned long parent_rate;
> +       int div, pdiv;
> +       unsigned int i;
> +
> +       /*
> +        * Try the two pll's and the external clock
> +        * Because the valid predividers are 2, 2.5 and 3, we multiply
> +        * all the clocks by 2 to avoid floating point math.
> +        *
> +        * This is based on the algorithm in the ep93xx raster guide:
> +        * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
> +        *
> +        */
> +       for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
> +               struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
> +
> +               parent_rate = clk_hw_get_rate(parent);
> +               mclk_rate = parent_rate * 2;
> +
> +               /* Try each predivider value */
> +               for (pdiv = 4; pdiv <= 6; pdiv++) {
> +                       div = DIV_ROUND_CLOSEST(mclk_rate, rate * pdiv);
> +                       if (div < 1 || div > 127)
> +                               continue;
> +
> +                       actual_rate = DIV_ROUND_CLOSEST(mclk_rate, pdiv * div);
> +                       if (is_best(rate, actual_rate, best_rate)) {
> +                               best_rate = actual_rate;
> +                               parent_rate_best = parent_rate;
> +                               parent_best = parent;
> +                       }
> +               }
> +       }
> +
> +       if (!parent_best)
> +               return -EINVAL;
> +
> +       req->best_parent_rate = parent_rate_best;
> +       req->best_parent_hw = parent_best;
> +       req->rate = best_rate;
> +
> +       return 0;
> +}
> +
> +static unsigned long ep93xx_ddiv_recalc_rate(struct clk_hw *hw,
> +                                               unsigned long parent_rate)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       unsigned int pdiv, div;
> +       u32 val;
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       pdiv = ((val >> EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) & 0x03);
> +       div = val & GENMASK(6, 0);
> +       if (!div)
> +               return 0;
> +
> +       return DIV_ROUND_CLOSEST(parent_rate * 2, (pdiv + 3) * div);
> +}
> +
> +static int ep93xx_ddiv_set_rate(struct clk_hw *hw, unsigned long rate,
> +                               unsigned long parent_rate)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       int pdiv, div, npdiv, ndiv;
> +       unsigned long actual_rate, mclk_rate, rate_err = ULONG_MAX;
> +       u32 val;
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       mclk_rate = parent_rate * 2;
> +
> +       for (pdiv = 4; pdiv <= 6; pdiv++) {
> +               div = DIV_ROUND_CLOSEST(mclk_rate, rate * pdiv);
> +               if (div < 1 || div > 127)
> +                       continue;
> +
> +               actual_rate = DIV_ROUND_CLOSEST(mclk_rate, pdiv * div);
> +               if (abs(actual_rate - rate) < rate_err) {
> +                       npdiv = pdiv - 3;
> +                       ndiv = div;
> +                       rate_err = abs(actual_rate - rate);
> +               }
> +       }
> +
> +       if (rate_err == ULONG_MAX)
> +               return -EINVAL;
> +
> +       /* Clear old dividers */
> +       val &= ~(GENMASK(9, 0) & ~BIT(7));
> +
> +       /* Set the new pdiv and div bits for the new clock rate */
> +       val |= (npdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | ndiv;
> +
> +       ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
> +
> +       return 0;
> +}
> +
> +static const struct clk_ops clk_ddiv_ops = {
> +       .enable = ep93xx_clk_enable,
> +       .disable = ep93xx_clk_disable,
> +       .is_enabled = ep93xx_clk_is_enabled,
> +       .get_parent = ep93xx_mux_get_parent,
> +       .set_parent = ep93xx_mux_set_parent_lock,
> +       .determine_rate = ep93xx_mux_determine_rate,
> +       .recalc_rate = ep93xx_ddiv_recalc_rate,
> +       .set_rate = ep93xx_ddiv_set_rate,
> +};
> +
> +static int clk_hw_register_ddiv(struct ep93xx_clk *clk,
> +                                               const char *name,
> +                                               unsigned int reg,
> +                                               u8 bit_idx)
> +{
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       struct clk_init_data init = { };
> +
> +       init.name = name;
> +       init.ops = &clk_ddiv_ops;
> +       init.flags = 0;
> +       init.parent_data = ep93xx_clk_parents;
> +       init.num_parents = ARRAY_SIZE(ep93xx_clk_parents);
> +
> +       clk->reg = reg;
> +       clk->bit_idx = bit_idx;
> +       clk->hw.init = &init;
> +
> +       return devm_clk_hw_register(priv->dev, &clk->hw);
> +}
> +
> +static unsigned long ep93xx_div_recalc_rate(struct clk_hw *hw,
> +                                           unsigned long parent_rate)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       u32 val;
> +       u8 index;
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       index = (val & clk->mask) >> clk->shift;
> +       if (index > clk->num_div)
> +               return 0;
> +
> +       return DIV_ROUND_CLOSEST(parent_rate, clk->div[index]);
> +}
> +
> +static long ep93xx_div_round_rate(struct clk_hw *hw, unsigned long rate,
> +                                  unsigned long *parent_rate)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       unsigned long best = 0, now;
> +       unsigned int i;
> +
> +       for (i = 0; i < clk->num_div; i++) {
> +               if ((rate * clk->div[i]) == *parent_rate)
> +                       return rate;
> +
> +               now = DIV_ROUND_CLOSEST(*parent_rate, clk->div[i]);
> +               if (!best || is_best(rate, now, best))
> +                       best = now;
> +       }
> +
> +       return best;
> +}
> +
> +static int ep93xx_div_set_rate(struct clk_hw *hw, unsigned long rate,
> +                              unsigned long parent_rate)
> +{
> +       struct ep93xx_clk *clk = ep93xx_clk_from(hw);
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       unsigned int i;
> +       u32 val;
> +
> +       regmap_read(priv->map, clk->reg, &val);
> +       val &= ~clk->mask;
> +       for (i = 0; i < clk->num_div; i++)
> +               if (rate == DIV_ROUND_CLOSEST(parent_rate, clk->div[i])) {
> +                       val |= i << clk->shift;
> +                       break;
> +               }
> +
> +       if (i == clk->num_div)
> +               return -EINVAL;
> +
> +       ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
> +
> +       return 0;
> +}
> +
> +static const struct clk_ops ep93xx_div_ops = {
> +       .enable = ep93xx_clk_enable,
> +       .disable = ep93xx_clk_disable,
> +       .is_enabled = ep93xx_clk_is_enabled,
> +       .recalc_rate = ep93xx_div_recalc_rate,
> +       .round_rate = ep93xx_div_round_rate,
> +       .set_rate = ep93xx_div_set_rate,
> +};
> +
> +static int clk_hw_register_div(struct ep93xx_clk *clk,
> +                                         const char *name,
> +                                         const char *parent_name,

Please try to pass a direct pointer to the parent clk_hw instead or if
the clk exists outside the controller pass a DT index.

> +                                         unsigned int reg,
> +                                         u8 enable_bit,
> +                                         u8 shift,
> +                                         u8 width,
> +                                         const char *clk_divisors,
> +                                         u8 num_div)
> +{
> +       struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
> +       struct clk_parent_data parent_data = { };
> +       struct clk_init_data init = { };
> +
> +       init.name = name;
> +       init.ops = &ep93xx_div_ops;
> +       init.flags = 0;
> +       parent_data.fw_name = parent_name;
> +       parent_data.name = parent_name;
> +       init.parent_data = &parent_data;
> +       init.num_parents = 1;
> +
> +       clk->reg = reg;
> +       clk->bit_idx = enable_bit;
> +       clk->mask = GENMASK(shift + width - 1, shift);
> +       clk->shift = shift;
> +       clk->div = clk_divisors;
[...]
> +
> +static int ep93xx_clk_probe(struct platform_device *pdev)
> +{
> +       struct device *dev = &pdev->dev;
> +       struct device_node *np = dev->of_node;
> +       const struct soc_device_attribute *match;
> +       struct ep93xx_clk_priv *priv;
> +       struct ep93xx_clk *clk;
> +       struct device_node *parent;
> +       unsigned long clk_spi_div;
> +       int ret;
> +       u32 value;
> +
> +       priv = devm_kzalloc(dev, struct_size(priv, reg, EP93XX_CLK_UART), GFP_KERNEL);
> +       if (!priv)
> +               return -ENOMEM;
> +
> +       spin_lock_init(&priv->lock);
> +       priv->dev = dev;
> +       parent = of_get_parent(np);
> +       if (!parent)
> +               return dev_err_probe(dev, -EINVAL, "no syscon parent for clk node\n");
> +
> +       priv->map = syscon_node_to_regmap(parent);
> +       if (IS_ERR(priv->map)) {
> +               of_node_put(parent);
> +               return dev_err_probe(dev, -EINVAL, "no syscon regmap\n");
> +       }
> +
> +       priv->base = devm_of_iomap(dev, parent, 0, NULL);
> +       of_node_put(parent);
> +       if (IS_ERR(priv->base))
> +               return PTR_ERR(priv->base);
> +
> +       ret = ep93xx_uart_clock_init(priv);
> +       if (ret)
> +               return ret;
> +
> +       ret = ep93xx_dma_clock_init(priv);
> +       if (ret)
> +               return ret;
> +
> +       /*
> +        * EP93xx SSP clock rate was doubled in version E2. For more information
> +        * see:
> +        *     http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
> +        */
> +       clk_spi_div = 2;
> +       match = soc_device_match(ep93xx_soc_table);

Why isn't this part of the compatible string for the device? We're able
to introduce new bindings, correct?

> +       if (match)
> +               clk_spi_div = (unsigned long)match->data;
Andy Shevchenko July 21, 2023, 1:46 p.m. UTC | #2
On Thu, Jul 20, 2023 at 04:27:45PM -0700, Stephen Boyd wrote:
> Quoting Nikita Shubin via B4 Relay (2023-07-20 04:29:03)

...

> > +static bool is_best(unsigned long rate, unsigned long now,
> > +                    unsigned long best)
> > +{
> > +       return abs(rate - now) < abs(rate - best);
> 
> Another case where we need abs_diff() so that it doesn't get confused
> when trying to do signed comparison.

Here you are: Message-Id: <20230721134235.15517-1-andriy.shevchenko@linux.intel.com>
diff mbox series

Patch

diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index 93f38a8178ba..0c13ea504820 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -218,6 +218,14 @@  config COMMON_CLK_EN7523
 	  This driver provides the fixed clocks and gates present on Airoha
 	  ARM silicon.
 
+config COMMON_CLK_EP93XX
+	bool "Clock driver for Cirrus Logic ep93xx SoC"
+	depends on ARCH_EP93XX || COMPILE_TEST
+	select MFD_SYSCON
+	select REGMAP
+	help
+	  This driver supports the SoC clocks on the Cirrus Logic ep93xx.
+
 config COMMON_CLK_FSL_FLEXSPI
 	tristate "Clock driver for FlexSPI on Layerscape SoCs"
 	depends on ARCH_LAYERSCAPE || COMPILE_TEST
diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index 7cb000549b61..6049a2073a25 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -29,6 +29,7 @@  obj-$(CONFIG_COMMON_CLK_CDCE706)	+= clk-cdce706.o
 obj-$(CONFIG_COMMON_CLK_CDCE925)	+= clk-cdce925.o
 obj-$(CONFIG_ARCH_CLPS711X)		+= clk-clps711x.o
 obj-$(CONFIG_COMMON_CLK_CS2000_CP)	+= clk-cs2000-cp.o
+obj-$(CONFIG_COMMON_CLK_EP93XX)		+= clk-ep93xx.o
 obj-$(CONFIG_ARCH_SPARX5)		+= clk-sparx5.o
 obj-$(CONFIG_COMMON_CLK_EN7523)		+= clk-en7523.o
 obj-$(CONFIG_COMMON_CLK_FIXED_MMIO)	+= clk-fixed-mmio.o
diff --git a/drivers/clk/clk-ep93xx.c b/drivers/clk/clk-ep93xx.c
new file mode 100644
index 000000000000..7b9b3a0894ab
--- /dev/null
+++ b/drivers/clk/clk-ep93xx.c
@@ -0,0 +1,764 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Clock control for Cirrus EP93xx chips.
+ * Copyright (C) 2021 Nikita Shubin <nikita.shubin@maquefel.me>
+ *
+ * Based on a rewrite of arch/arm/mach-ep93xx/clock.c:
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ */
+#define pr_fmt(fmt) "ep93xx " KBUILD_MODNAME ": " fmt
+
+#include <linux/bits.h>
+#include <linux/clk-provider.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/sys_soc.h>
+
+#include <linux/soc/cirrus/ep93xx.h>
+#include <dt-bindings/clock/cirrus,ep93xx-clock.h>
+
+#include <asm/div64.h>
+
+#define EP93XX_EXT_RTC_RATE		32768
+
+#define EP93XX_SYSCON_POWER_STATE	0x00
+#define EP93XX_SYSCON_PWRCNT		0x04
+#define EP93XX_SYSCON_PWRCNT_UARTBAUD	BIT(29)
+#define EP93XX_SYSCON_PWRCNT_USH_EN	28
+#define EP93XX_SYSCON_PWRCNT_DMA_M2M1	27
+#define EP93XX_SYSCON_PWRCNT_DMA_M2M0	26
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P8	25
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P9	24
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P6	23
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P7	22
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P4	21
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P5	20
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P2	19
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P3	18
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P0	17
+#define EP93XX_SYSCON_PWRCNT_DMA_M2P1	16
+#define EP93XX_SYSCON_DEVCFG		0x80
+#define EP93XX_SYSCON_DEVCFG_U3EN	24
+#define EP93XX_SYSCON_DEVCFG_U2EN	20
+#define EP93XX_SYSCON_DEVCFG_U1EN	18
+#define EP93XX_SYSCON_VIDCLKDIV		0x84
+#define EP93XX_SYSCON_CLKDIV_ENABLE	15
+#define EP93XX_SYSCON_CLKDIV_ESEL	BIT(14)
+#define EP93XX_SYSCON_CLKDIV_PSEL	BIT(13)
+#define EP93XX_SYSCON_CLKDIV_MASK	GENMASK(14, 13)
+#define EP93XX_SYSCON_CLKDIV_PDIV_SHIFT	8
+#define EP93XX_SYSCON_I2SCLKDIV		0x8c
+#define EP93XX_SYSCON_I2SCLKDIV_SENA	31
+#define EP93XX_SYSCON_I2SCLKDIV_ORIDE	BIT(29)
+#define EP93XX_SYSCON_I2SCLKDIV_SPOL	BIT(19)
+#define EP93XX_I2SCLKDIV_SDIV		(1 << 16)
+#define EP93XX_I2SCLKDIV_LRDIV32	(0 << 17)
+#define EP93XX_I2SCLKDIV_LRDIV64	(1 << 17)
+#define EP93XX_I2SCLKDIV_LRDIV128	(2 << 17)
+#define EP93XX_I2SCLKDIV_LRDIV_MASK	(3 << 17)
+#define EP93XX_SYSCON_KEYTCHCLKDIV	0x90
+#define EP93XX_SYSCON_KEYTCHCLKDIV_TSEN	31
+#define EP93XX_SYSCON_KEYTCHCLKDIV_ADIV	16
+#define EP93XX_SYSCON_KEYTCHCLKDIV_KEN	15
+#define EP93XX_SYSCON_KEYTCHCLKDIV_KDIV	0
+#define EP93XX_SYSCON_CHIPID		0x94
+#define EP93XX_SYSCON_CHIPID_ID		0x9213
+
+/* Keeps track of all clocks */
+static const char adc_divisors[] = { 16, 4 };
+static const char sclk_divisors[] = { 2, 4 };
+static const char lrclk_divisors[] = { 32, 64, 128 };
+
+#define EP_PARENT(NAME) { .name = NAME, .fw_name = NAME }
+
+static const struct clk_parent_data ep93xx_clk_parents[] = {
+	EP_PARENT("xtali"),
+	EP_PARENT("pll1"),
+	EP_PARENT("pll2"),
+};
+
+struct ep93xx_clk {
+	struct clk_hw hw;
+	u16 idx;
+	u16 reg;
+	u32 mask;
+	u8 bit_idx;
+	u8 shift;
+	u8 width;
+	u8 num_div;
+	const char *div;
+};
+
+struct ep93xx_clk_priv {
+	spinlock_t lock;
+	struct device *dev;
+	void __iomem *base;
+	struct regmap *map;
+	struct clk_hw *fixed[16];
+	struct ep93xx_clk reg[];
+};
+
+static struct ep93xx_clk *ep93xx_clk_from(struct clk_hw *hw)
+{
+	return container_of(hw, struct ep93xx_clk, hw);
+}
+
+static struct ep93xx_clk_priv *ep93xx_priv_from(struct ep93xx_clk *clk)
+{
+	return container_of(clk, struct ep93xx_clk_priv, reg[clk->idx]);
+}
+
+static int ep93xx_clk_is_enabled(struct clk_hw *hw)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	u32 val;
+
+	regmap_read(priv->map, clk->reg, &val);
+
+	return !!(val & BIT(clk->bit_idx));
+}
+
+static int ep93xx_clk_enable(struct clk_hw *hw)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	regmap_read(priv->map, clk->reg, &val);
+	val |= BIT(clk->bit_idx);
+
+	ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static void ep93xx_clk_disable(struct clk_hw *hw)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	unsigned long flags;
+	u32 val;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	regmap_read(priv->map, clk->reg, &val);
+	val &= ~BIT(clk->bit_idx);
+
+	ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+static const struct clk_ops clk_ep93xx_gate_ops = {
+	.enable = ep93xx_clk_enable,
+	.disable = ep93xx_clk_disable,
+	.is_enabled = ep93xx_clk_is_enabled,
+};
+
+static int ep93xx_clk_register_gate(struct ep93xx_clk *clk,
+					const char *name,
+					const char *parent_name,
+					unsigned long flags,
+					unsigned int reg,
+					u8 bit_idx)
+{
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	struct clk_parent_data parent_data = { };
+	struct clk_init_data init = { };
+
+	init.name = name;
+	init.ops = &clk_ep93xx_gate_ops;
+	init.flags = flags;
+
+	parent_data.fw_name = parent_name;
+	parent_data.name = parent_name;
+	init.parent_data = &parent_data;
+	init.num_parents = 1;
+
+	clk->reg = reg;
+	clk->bit_idx = bit_idx;
+	clk->hw.init = &init;
+
+	return devm_clk_hw_register(priv->dev, &clk->hw);
+}
+
+static u8 ep93xx_mux_get_parent(struct clk_hw *hw)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	u32 val;
+
+	regmap_read(priv->map, clk->reg, &val);
+
+	val &= EP93XX_SYSCON_CLKDIV_MASK;
+
+	switch (val) {
+	case EP93XX_SYSCON_CLKDIV_ESEL:
+		return 1; // PLL1
+	case EP93XX_SYSCON_CLKDIV_MASK:
+		return 2; // PLL2
+	default:
+		break;
+	};
+
+	return 0; // XTALI
+}
+
+static int ep93xx_mux_set_parent_lock(struct clk_hw *hw, u8 index)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	unsigned long flags;
+	u32 val;
+
+	if (index >= ARRAY_SIZE(ep93xx_clk_parents))
+		return -EINVAL;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	regmap_read(priv->map, clk->reg, &val);
+	val &= ~(EP93XX_SYSCON_CLKDIV_MASK);
+	if (index) {
+		val |= EP93XX_SYSCON_CLKDIV_ESEL;
+		val |= (index - 1) ? EP93XX_SYSCON_CLKDIV_PSEL : 0;
+	}
+
+	ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static bool is_best(unsigned long rate, unsigned long now,
+		     unsigned long best)
+{
+	return abs(rate - now) < abs(rate - best);
+}
+
+static int ep93xx_mux_determine_rate(struct clk_hw *hw,
+				struct clk_rate_request *req)
+{
+	unsigned long best_rate = 0, actual_rate, mclk_rate;
+	unsigned long rate = req->rate;
+	struct clk_hw *parent_best = NULL;
+	unsigned long parent_rate_best;
+	unsigned long parent_rate;
+	int div, pdiv;
+	unsigned int i;
+
+	/*
+	 * Try the two pll's and the external clock
+	 * Because the valid predividers are 2, 2.5 and 3, we multiply
+	 * all the clocks by 2 to avoid floating point math.
+	 *
+	 * This is based on the algorithm in the ep93xx raster guide:
+	 * http://be-a-maverick.com/en/pubs/appNote/AN269REV1.pdf
+	 *
+	 */
+	for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
+		struct clk_hw *parent = clk_hw_get_parent_by_index(hw, i);
+
+		parent_rate = clk_hw_get_rate(parent);
+		mclk_rate = parent_rate * 2;
+
+		/* Try each predivider value */
+		for (pdiv = 4; pdiv <= 6; pdiv++) {
+			div = DIV_ROUND_CLOSEST(mclk_rate, rate * pdiv);
+			if (div < 1 || div > 127)
+				continue;
+
+			actual_rate = DIV_ROUND_CLOSEST(mclk_rate, pdiv * div);
+			if (is_best(rate, actual_rate, best_rate)) {
+				best_rate = actual_rate;
+				parent_rate_best = parent_rate;
+				parent_best = parent;
+			}
+		}
+	}
+
+	if (!parent_best)
+		return -EINVAL;
+
+	req->best_parent_rate = parent_rate_best;
+	req->best_parent_hw = parent_best;
+	req->rate = best_rate;
+
+	return 0;
+}
+
+static unsigned long ep93xx_ddiv_recalc_rate(struct clk_hw *hw,
+						unsigned long parent_rate)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	unsigned int pdiv, div;
+	u32 val;
+
+	regmap_read(priv->map, clk->reg, &val);
+	pdiv = ((val >> EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) & 0x03);
+	div = val & GENMASK(6, 0);
+	if (!div)
+		return 0;
+
+	return DIV_ROUND_CLOSEST(parent_rate * 2, (pdiv + 3) * div);
+}
+
+static int ep93xx_ddiv_set_rate(struct clk_hw *hw, unsigned long rate,
+				unsigned long parent_rate)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	int pdiv, div, npdiv, ndiv;
+	unsigned long actual_rate, mclk_rate, rate_err = ULONG_MAX;
+	u32 val;
+
+	regmap_read(priv->map, clk->reg, &val);
+	mclk_rate = parent_rate * 2;
+
+	for (pdiv = 4; pdiv <= 6; pdiv++) {
+		div = DIV_ROUND_CLOSEST(mclk_rate, rate * pdiv);
+		if (div < 1 || div > 127)
+			continue;
+
+		actual_rate = DIV_ROUND_CLOSEST(mclk_rate, pdiv * div);
+		if (abs(actual_rate - rate) < rate_err) {
+			npdiv = pdiv - 3;
+			ndiv = div;
+			rate_err = abs(actual_rate - rate);
+		}
+	}
+
+	if (rate_err == ULONG_MAX)
+		return -EINVAL;
+
+	/* Clear old dividers */
+	val &= ~(GENMASK(9, 0) & ~BIT(7));
+
+	/* Set the new pdiv and div bits for the new clock rate */
+	val |= (npdiv << EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | ndiv;
+
+	ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
+
+	return 0;
+}
+
+static const struct clk_ops clk_ddiv_ops = {
+	.enable = ep93xx_clk_enable,
+	.disable = ep93xx_clk_disable,
+	.is_enabled = ep93xx_clk_is_enabled,
+	.get_parent = ep93xx_mux_get_parent,
+	.set_parent = ep93xx_mux_set_parent_lock,
+	.determine_rate = ep93xx_mux_determine_rate,
+	.recalc_rate = ep93xx_ddiv_recalc_rate,
+	.set_rate = ep93xx_ddiv_set_rate,
+};
+
+static int clk_hw_register_ddiv(struct ep93xx_clk *clk,
+						const char *name,
+						unsigned int reg,
+						u8 bit_idx)
+{
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	struct clk_init_data init = { };
+
+	init.name = name;
+	init.ops = &clk_ddiv_ops;
+	init.flags = 0;
+	init.parent_data = ep93xx_clk_parents;
+	init.num_parents = ARRAY_SIZE(ep93xx_clk_parents);
+
+	clk->reg = reg;
+	clk->bit_idx = bit_idx;
+	clk->hw.init = &init;
+
+	return devm_clk_hw_register(priv->dev, &clk->hw);
+}
+
+static unsigned long ep93xx_div_recalc_rate(struct clk_hw *hw,
+					    unsigned long parent_rate)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	u32 val;
+	u8 index;
+
+	regmap_read(priv->map, clk->reg, &val);
+	index = (val & clk->mask) >> clk->shift;
+	if (index > clk->num_div)
+		return 0;
+
+	return DIV_ROUND_CLOSEST(parent_rate, clk->div[index]);
+}
+
+static long ep93xx_div_round_rate(struct clk_hw *hw, unsigned long rate,
+				   unsigned long *parent_rate)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	unsigned long best = 0, now;
+	unsigned int i;
+
+	for (i = 0; i < clk->num_div; i++) {
+		if ((rate * clk->div[i]) == *parent_rate)
+			return rate;
+
+		now = DIV_ROUND_CLOSEST(*parent_rate, clk->div[i]);
+		if (!best || is_best(rate, now, best))
+			best = now;
+	}
+
+	return best;
+}
+
+static int ep93xx_div_set_rate(struct clk_hw *hw, unsigned long rate,
+			       unsigned long parent_rate)
+{
+	struct ep93xx_clk *clk = ep93xx_clk_from(hw);
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	unsigned int i;
+	u32 val;
+
+	regmap_read(priv->map, clk->reg, &val);
+	val &= ~clk->mask;
+	for (i = 0; i < clk->num_div; i++)
+		if (rate == DIV_ROUND_CLOSEST(parent_rate, clk->div[i])) {
+			val |= i << clk->shift;
+			break;
+		}
+
+	if (i == clk->num_div)
+		return -EINVAL;
+
+	ep93xx_syscon_swlocked_write(priv->map, clk->reg, val);
+
+	return 0;
+}
+
+static const struct clk_ops ep93xx_div_ops = {
+	.enable = ep93xx_clk_enable,
+	.disable = ep93xx_clk_disable,
+	.is_enabled = ep93xx_clk_is_enabled,
+	.recalc_rate = ep93xx_div_recalc_rate,
+	.round_rate = ep93xx_div_round_rate,
+	.set_rate = ep93xx_div_set_rate,
+};
+
+static int clk_hw_register_div(struct ep93xx_clk *clk,
+					  const char *name,
+					  const char *parent_name,
+					  unsigned int reg,
+					  u8 enable_bit,
+					  u8 shift,
+					  u8 width,
+					  const char *clk_divisors,
+					  u8 num_div)
+{
+	struct ep93xx_clk_priv *priv = ep93xx_priv_from(clk);
+	struct clk_parent_data parent_data = { };
+	struct clk_init_data init = { };
+
+	init.name = name;
+	init.ops = &ep93xx_div_ops;
+	init.flags = 0;
+	parent_data.fw_name = parent_name;
+	parent_data.name = parent_name;
+	init.parent_data = &parent_data;
+	init.num_parents = 1;
+
+	clk->reg = reg;
+	clk->bit_idx = enable_bit;
+	clk->mask = GENMASK(shift + width - 1, shift);
+	clk->shift = shift;
+	clk->div = clk_divisors;
+	clk->num_div = num_div;
+	clk->hw.init = &init;
+
+	return devm_clk_hw_register(priv->dev, &clk->hw);
+}
+
+struct ep93xx_gate {
+	unsigned int idx;
+	unsigned int bit;
+	const char *name;
+};
+
+static const struct ep93xx_gate ep93xx_uarts[] = {
+	{ EP93XX_CLK_UART1, EP93XX_SYSCON_DEVCFG_U1EN, "uart1" },
+	{ EP93XX_CLK_UART2, EP93XX_SYSCON_DEVCFG_U2EN, "uart2" },
+	{ EP93XX_CLK_UART3, EP93XX_SYSCON_DEVCFG_U3EN, "uart3" },
+};
+
+static int ep93xx_uart_clock_init(struct ep93xx_clk_priv *priv)
+{
+	struct ep93xx_clk *clk;
+	unsigned int i, ret, clk_uart_div;
+	u32 val;
+
+	regmap_read(priv->map, EP93XX_SYSCON_PWRCNT, &val);
+	if (val & EP93XX_SYSCON_PWRCNT_UARTBAUD)
+		clk_uart_div = 1;
+	else
+		clk_uart_div = 2;
+
+	priv->fixed[0] = clk_hw_register_fixed_factor(NULL, "uart", "xtali", 0, 1, clk_uart_div);
+
+	/* parenting uart gate clocks to uart clock */
+	for (i = 0; i < ARRAY_SIZE(ep93xx_uarts); i++) {
+		clk = &priv->reg[ep93xx_uarts[i].idx];
+		clk->idx = ep93xx_uarts[i].idx;
+		ret = ep93xx_clk_register_gate(clk,
+					ep93xx_uarts[i].name,
+					"uart", CLK_SET_RATE_PARENT,
+					EP93XX_SYSCON_DEVCFG,
+					ep93xx_uarts[i].bit);
+		if (ret)
+			return dev_err_probe(priv->dev, ret, "failed to register dma clock\n");
+	}
+
+	return 0;
+}
+
+static const struct ep93xx_gate ep93xx_dmas[] = {
+	{ EP93XX_CLK_M2M0, EP93XX_SYSCON_PWRCNT_DMA_M2M0, "m2m0" },
+	{ EP93XX_CLK_M2M1, EP93XX_SYSCON_PWRCNT_DMA_M2M1, "m2m1" },
+	{ EP93XX_CLK_M2P0, EP93XX_SYSCON_PWRCNT_DMA_M2P0, "m2p0" },
+	{ EP93XX_CLK_M2P1, EP93XX_SYSCON_PWRCNT_DMA_M2P1, "m2p1" },
+	{ EP93XX_CLK_M2P2, EP93XX_SYSCON_PWRCNT_DMA_M2P2, "m2p2" },
+	{ EP93XX_CLK_M2P3, EP93XX_SYSCON_PWRCNT_DMA_M2P3, "m2p3" },
+	{ EP93XX_CLK_M2P4, EP93XX_SYSCON_PWRCNT_DMA_M2P4, "m2p4" },
+	{ EP93XX_CLK_M2P5, EP93XX_SYSCON_PWRCNT_DMA_M2P5, "m2p5" },
+	{ EP93XX_CLK_M2P6, EP93XX_SYSCON_PWRCNT_DMA_M2P6, "m2p6" },
+	{ EP93XX_CLK_M2P7, EP93XX_SYSCON_PWRCNT_DMA_M2P7, "m2p7" },
+	{ EP93XX_CLK_M2P8, EP93XX_SYSCON_PWRCNT_DMA_M2P8, "m2p8" },
+	{ EP93XX_CLK_M2P9, EP93XX_SYSCON_PWRCNT_DMA_M2P9, "m2p9" },
+};
+
+static int ep93xx_dma_clock_init(struct ep93xx_clk_priv *priv)
+{
+	unsigned int i, idx;
+
+	for (i = 0; i < ARRAY_SIZE(ep93xx_dmas); i++) {
+		idx = ep93xx_dmas[i].idx - EP93XX_CLK_UART;
+		priv->fixed[idx] = devm_clk_hw_register_gate(priv->dev,
+					ep93xx_dmas[i].name,
+					"hclk", 0,
+					priv->base + EP93XX_SYSCON_PWRCNT,
+					ep93xx_dmas[i].bit,
+					0,
+					&priv->lock);
+		if (IS_ERR(priv->fixed[idx]))
+			return PTR_ERR(priv->fixed[idx]);
+	}
+
+	return 0;
+}
+
+static struct clk_hw *ep93xx_clk_get(struct of_phandle_args *clkspec, void *data)
+{
+	struct ep93xx_clk_priv *priv = data;
+	unsigned int idx = clkspec->args[0];
+
+	if (idx < EP93XX_CLK_UART)
+		return &priv->reg[idx].hw;
+
+	if (idx < EP93XX_CLK_END)
+		return priv->fixed[idx - EP93XX_CLK_UART];
+
+	return ERR_PTR(-EINVAL);
+}
+
+static const struct soc_device_attribute ep93xx_soc_table[] = {
+	{ .revision = "E2", .data = (void *)1 },
+	{ /* sentinel */ }
+};
+
+static int ep93xx_clk_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	const struct soc_device_attribute *match;
+	struct ep93xx_clk_priv *priv;
+	struct ep93xx_clk *clk;
+	struct device_node *parent;
+	unsigned long clk_spi_div;
+	int ret;
+	u32 value;
+
+	priv = devm_kzalloc(dev, struct_size(priv, reg, EP93XX_CLK_UART), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spin_lock_init(&priv->lock);
+	priv->dev = dev;
+	parent = of_get_parent(np);
+	if (!parent)
+		return dev_err_probe(dev, -EINVAL, "no syscon parent for clk node\n");
+
+	priv->map = syscon_node_to_regmap(parent);
+	if (IS_ERR(priv->map)) {
+		of_node_put(parent);
+		return dev_err_probe(dev, -EINVAL, "no syscon regmap\n");
+	}
+
+	priv->base = devm_of_iomap(dev, parent, 0, NULL);
+	of_node_put(parent);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	ret = ep93xx_uart_clock_init(priv);
+	if (ret)
+		return ret;
+
+	ret = ep93xx_dma_clock_init(priv);
+	if (ret)
+		return ret;
+
+	/*
+	 * EP93xx SSP clock rate was doubled in version E2. For more information
+	 * see:
+	 *     http://www.cirrus.com/en/pubs/appNote/AN273REV4.pdf
+	 */
+	clk_spi_div = 2;
+	match = soc_device_match(ep93xx_soc_table);
+	if (match)
+		clk_spi_div = (unsigned long)match->data;
+
+	priv->fixed[1] = devm_clk_hw_register_fixed_factor(dev, "ep93xx-spi.0", "xtali",
+							0, 1, clk_spi_div);
+	if (IS_ERR(priv->fixed[1]))
+		return PTR_ERR(priv->fixed[1]);
+
+	/* PWM clock */
+	priv->fixed[2] = devm_clk_hw_register_fixed_factor(dev, "pwm_clk", "xtali", 0, 1, 1);
+	if (IS_ERR(priv->fixed[2]))
+		return PTR_ERR(priv->fixed[2]);
+
+	/* USB clock */
+	priv->fixed[3] = devm_clk_hw_register_gate(priv->dev,
+					"ohci-platform",
+					"usb_clk", 0,
+					priv->base + EP93XX_SYSCON_PWRCNT,
+					EP93XX_SYSCON_PWRCNT_USH_EN,
+					0,
+					&priv->lock);
+	if (IS_ERR(priv->fixed[3]))
+		return PTR_ERR(priv->fixed[3]);
+
+	/* touchscreen/adc clock */
+	clk = &priv->reg[EP93XX_CLK_ADC];
+	clk->idx = EP93XX_CLK_ADC;
+	ret = clk_hw_register_div(clk, "ep93xx-adc", "xtali",
+				EP93XX_SYSCON_KEYTCHCLKDIV,
+				EP93XX_SYSCON_KEYTCHCLKDIV_TSEN,
+				EP93XX_SYSCON_KEYTCHCLKDIV_ADIV,
+				1,
+				adc_divisors,
+				ARRAY_SIZE(adc_divisors));
+
+
+	/* keypad clock */
+	clk = &priv->reg[EP93XX_CLK_KEYPAD];
+	clk->idx = EP93XX_CLK_KEYPAD;
+	ret = clk_hw_register_div(clk, "ep93xx-keypad", "xtali",
+				EP93XX_SYSCON_KEYTCHCLKDIV,
+				EP93XX_SYSCON_KEYTCHCLKDIV_KEN,
+				EP93XX_SYSCON_KEYTCHCLKDIV_KDIV,
+				1,
+				adc_divisors,
+				ARRAY_SIZE(adc_divisors));
+
+	/*
+	 * On reset PDIV and VDIV is set to zero, while PDIV zero
+	 * means clock disable, VDIV shouldn't be zero.
+	 * So i set both dividers to minimum.
+	 */
+	/* ENA - Enable CLK divider. */
+	/* PDIV - 00 - Disable clock */
+	/* VDIV - at least 2 */
+	/* Check and enable video clk registers */
+	regmap_read(priv->map, EP93XX_SYSCON_VIDCLKDIV, &value);
+	value |= BIT(EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | 2;
+	ep93xx_syscon_swlocked_write(priv->map, EP93XX_SYSCON_VIDCLKDIV, value);
+
+	/* check and enable i2s clk registers */
+	regmap_read(priv->map, EP93XX_SYSCON_I2SCLKDIV, &value);
+	value |= BIT(EP93XX_SYSCON_CLKDIV_PDIV_SHIFT) | 2;
+	/*
+	 * Override the SAI_MSTR_CLK_CFG from the I2S block and use the
+	 * I2SClkDiv Register settings. LRCLK transitions on the falling SCLK
+	 * edge.
+	 */
+	value |= EP93XX_SYSCON_I2SCLKDIV_ORIDE | EP93XX_SYSCON_I2SCLKDIV_SPOL;
+	ep93xx_syscon_swlocked_write(priv->map, EP93XX_SYSCON_I2SCLKDIV, value);
+
+	/* video clk */
+	clk = &priv->reg[EP93XX_CLK_VIDEO];
+	clk->idx = EP93XX_CLK_VIDEO;
+	ret = clk_hw_register_ddiv(clk, "ep93xx-fb",
+				EP93XX_SYSCON_VIDCLKDIV,
+				EP93XX_SYSCON_CLKDIV_ENABLE);
+
+	/* i2s clk */
+	clk = &priv->reg[EP93XX_CLK_I2S_MCLK];
+	clk->idx = EP93XX_CLK_I2S_MCLK;
+	ret = clk_hw_register_ddiv(clk, "mclk",
+				EP93XX_SYSCON_I2SCLKDIV,
+				EP93XX_SYSCON_CLKDIV_ENABLE);
+
+	/* i2s sclk */
+	clk = &priv->reg[EP93XX_CLK_I2S_SCLK];
+	clk->idx = EP93XX_CLK_I2S_SCLK;
+	ret = clk_hw_register_div(clk, "sclk", "mclk",
+				EP93XX_SYSCON_I2SCLKDIV,
+				EP93XX_SYSCON_I2SCLKDIV_SENA,
+				16, /* EP93XX_I2SCLKDIV_SDIV_SHIFT */
+				1,  /* EP93XX_I2SCLKDIV_SDIV_WIDTH */
+				sclk_divisors,
+				ARRAY_SIZE(sclk_divisors));
+
+	/* i2s lrclk */
+	clk = &priv->reg[EP93XX_CLK_I2S_LRCLK];
+	clk->idx = EP93XX_CLK_I2S_LRCLK;
+	ret = clk_hw_register_div(clk, "lrclk", "sclk",
+				EP93XX_SYSCON_I2SCLKDIV,
+				EP93XX_SYSCON_I2SCLKDIV_SENA,
+				17, /* EP93XX_I2SCLKDIV_LRDIV32_SHIFT */
+				2,  /* EP93XX_I2SCLKDIV_LRDIV32_WIDTH */
+				lrclk_divisors,
+				ARRAY_SIZE(lrclk_divisors));
+
+	/* IrDa clk uses same pattern but no init code presents in original clock driver */
+	return devm_of_clk_add_hw_provider(priv->dev, ep93xx_clk_get, priv);
+}
+
+static const struct of_device_id ep93xx_clk_dt_ids[] = {
+	{ .compatible = "cirrus,ep9301-clk" },
+	{ /* sentinel */ }
+};
+
+static struct platform_driver ep93xx_clk_driver = {
+	.driver = {
+		.name = "ep93xx-clk",
+		.of_match_table = ep93xx_clk_dt_ids,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver_probe(ep93xx_clk_driver, ep93xx_clk_probe);
+MODULE_IMPORT_NS(EP93XX_SOC);