The ingenic-timer "TCU" driver provides us with clocks, that can be
(un)gated, reparented or reclocked from devicetree, instead of having
these settings hardcoded in this driver.

While this driver is devicetree-compatible, it is never (as of now)
probed from devicetree, so this change does not introduce a ABI problem
with current devicetree files.

Signed-off-by: Paul Cercueil <p...@crapouillou.net>
---

Notes:
     v9: New patch

 drivers/pwm/Kconfig      |  3 ++-
 drivers/pwm/pwm-jz4740.c | 39 ++++++++++++++++++++++++++-------------
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig
index 4ed003bc3d8d..0343f0c1238e 100644
--- a/drivers/pwm/Kconfig
+++ b/drivers/pwm/Kconfig
@@ -202,7 +202,8 @@ config PWM_IMX
 config PWM_JZ4740
        tristate "Ingenic JZ47xx PWM support"
        depends on MACH_INGENIC
-       select REGMAP
+       depends on COMMON_CLK
+       select INGENIC_TIMER
        help
          Generic PWM framework driver for Ingenic JZ47xx based
          machines.
diff --git a/drivers/pwm/pwm-jz4740.c b/drivers/pwm/pwm-jz4740.c
index 8dfac5ffd71c..c6136bd4434b 100644
--- a/drivers/pwm/pwm-jz4740.c
+++ b/drivers/pwm/pwm-jz4740.c
@@ -28,7 +28,7 @@
 
 struct jz4740_pwm_chip {
        struct pwm_chip chip;
-       struct clk *clk;
+       struct clk *clks[NUM_PWM];
        struct regmap *map;
 };
 
@@ -40,6 +40,9 @@ static inline struct jz4740_pwm_chip *to_jz4740(struct 
pwm_chip *chip)
 static int jz4740_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 {
        struct jz4740_pwm_chip *jz = to_jz4740(chip);
+       struct clk *clk;
+       char clk_name[16];
+       int ret;
 
        /*
         * Timers 0 and 1 are used for system tasks, so they are unavailable
@@ -48,16 +51,29 @@ static int jz4740_pwm_request(struct pwm_chip *chip, struct 
pwm_device *pwm)
        if (pwm->hwpwm < 2)
                return -EBUSY;
 
-       regmap_write(jz->map, TCU_REG_TSCR, BIT(pwm->hwpwm));
+       snprintf(clk_name, sizeof(clk_name), "timer%u", pwm->hwpwm);
 
+       clk = clk_get(chip->dev, clk_name);
+       if (IS_ERR(clk))
+               return PTR_ERR(clk);
+
+       ret = clk_prepare_enable(clk);
+       if (ret) {
+               clk_put(clk);
+               return ret;
+       }
+
+       jz->clks[pwm->hwpwm] = clk;
        return 0;
 }
 
 static void jz4740_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 {
        struct jz4740_pwm_chip *jz = to_jz4740(chip);
+       struct clk *clk = jz->clks[pwm->hwpwm];
 
-       regmap_write(jz->map, TCU_REG_TSCR, BIT(pwm->hwpwm));
+       clk_disable_unprepare(clk);
+       clk_put(clk);
 }
 
 static int jz4740_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
@@ -92,16 +108,20 @@ static int jz4740_pwm_apply(struct pwm_chip *chip, struct 
pwm_device *pwm,
                            struct pwm_state *state)
 {
        struct jz4740_pwm_chip *jz4740 = to_jz4740(pwm->chip);
+       struct clk *clk = jz4740->clks[pwm->hwpwm],
+                  *parent_clk = clk_get_parent(clk);
+       unsigned long rate, period, duty;
        unsigned long long tmp;
-       unsigned long period, duty;
        unsigned int prescaler = 0;
 
-       tmp = (unsigned long long)clk_get_rate(jz4740->clk) * state->period;
+       rate = clk_get_rate(parent_clk);
+       tmp = (unsigned long long)rate * state->period;
        do_div(tmp, 1000000000);
        period = tmp;
 
        while (period > 0xffff && prescaler < 6) {
                period >>= 2;
+               rate >>= 2;
                ++prescaler;
        }
 
@@ -121,10 +141,7 @@ static int jz4740_pwm_apply(struct pwm_chip *chip, struct 
pwm_device *pwm,
        regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
                           TCU_TCSR_PWM_SD, TCU_TCSR_PWM_SD);
 
-       /* Set clock prescale */
-       regmap_update_bits(jz4740->map, TCU_REG_TCSRc(pwm->hwpwm),
-                          TCU_TCSR_PRESCALE_MASK,
-                          prescaler << TCU_TCSR_PRESCALE_LSB);
+       clk_set_rate(clk, rate);
 
        /* Reset counter to 0 */
        regmap_write(jz4740->map, TCU_REG_TCNTc(pwm->hwpwm), 0);
@@ -170,10 +187,6 @@ static int jz4740_pwm_probe(struct platform_device *pdev)
        if (!jz4740)
                return -ENOMEM;
 
-       jz4740->clk = devm_clk_get(&pdev->dev, "ext");
-       if (IS_ERR(jz4740->clk))
-               return PTR_ERR(jz4740->clk);
-
        jz4740->map = dev_get_regmap(dev->parent, NULL);
        if (!jz4740->map) {
                dev_err(dev, "regmap not found\n");
-- 
2.11.0

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