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Subject[PATCH v9 13/27] pwm: jz4740: Use clocks from TCU driver
Date
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 <paul@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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