[PATCH 5/9] pwm: stm32: add support for stm32mp25

Fabrice Gasnier
2024-12-18T09:04:54Z

Add support for STM32MP25 SoC. Use newly introduced compatible to handle
new features along with registers and bits diversity.
The MFD part of the driver fills in ipidr, so it is used to check the
hardware configuration register, when available to gather the number
of PWM channels and complementary outputs.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
---
drivers/pwm/pwm-stm32.c | 39 +++++++++++++++++++++++++++++++++++----
1 file changed, 35 insertions(+), 4 deletions(-)

diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index 17e591f61efb..99383e09920e 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -19,6 +19,7 @@
#define CCMR_CHANNEL_SHIFT 8
#define CCMR_CHANNEL_MASK 0xFF
#define MAX_BREAKINPUT 2
+#define MAX_PWM_OUTPUT 4

struct stm32_breakinput {
u32 index;
@@ -775,10 +776,19 @@ static int stm32_pwm_probe_breakinputs(struct stm32_pwm *priv,
return stm32_pwm_apply_breakinputs(priv);
}

-static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
+static void stm32_pwm_detect_complementary(struct stm32_pwm *priv, struct stm32_timers *ddata)
{
u32 ccer;

+ if (ddata->ipidr) {
+ u32 val;
+
+ /* Simply read from HWCFGR the number of complementary outputs (MP25). */
+ regmap_read(priv->regmap, TIM_HWCFGR1, &val);
+ priv->have_complementary_output = !!FIELD_GET(TIM_HWCFGR1_NB_OF_DT, val);
+ return;
+ }
+
/*
* If complementary bit doesn't exist writing 1 will have no
* effect so we can detect it.
@@ -790,11 +800,31 @@ static void stm32_pwm_detect_complementary(struct stm32_pwm *priv)
priv->have_complementary_output = (ccer != 0);
}

-static unsigned int stm32_pwm_detect_channels(struct regmap *regmap,
+static unsigned int stm32_pwm_detect_channels(struct stm32_timers *ddata,
unsigned int *num_enabled)
{
+ struct regmap *regmap = ddata->regmap;
u32 ccer, ccer_backup;

+ if (ddata->ipidr) {
+ unsigned int npwm = 0;
+ u32 val;
+
+ /* Simply deduce from HWCFGR the number of outputs (MP25). */
+ regmap_read(regmap, TIM_HWCFGR1, &val);
+
+ /*
+ * Timers may have more capture/compare channels than the
+ * actual number of PWM channel outputs (e.g. TIM_CH[1..4]).
+ */
+ npwm = FIELD_GET(TIM_HWCFGR1_NB_OF_CC, val);
+
+ regmap_read(regmap, TIM_CCER, &ccer);
+ *num_enabled = hweight32(ccer & TIM_CCER_CCXE);
+
+ return npwm < MAX_PWM_OUTPUT ? npwm : MAX_PWM_OUTPUT;
+ }
+
/*
* If channels enable bits don't exist writing 1 will have no
* effect so we can detect and count them.
@@ -820,7 +850,7 @@ static int stm32_pwm_probe(struct platform_device *pdev)
unsigned int i;
int ret;

- npwm = stm32_pwm_detect_channels(ddata->regmap, &num_enabled);
+ npwm = stm32_pwm_detect_channels(ddata, &num_enabled);

chip = devm_pwmchip_alloc(dev, npwm, sizeof(*priv));
if (IS_ERR(chip))
@@ -841,7 +871,7 @@ static int stm32_pwm_probe(struct platform_device *pdev)
return dev_err_probe(dev, ret,
"Failed to configure breakinputs\n");

- stm32_pwm_detect_complementary(priv);
+ stm32_pwm_detect_complementary(priv, ddata);

ret = devm_clk_rate_exclusive_get(dev, priv->clk);
if (ret)
@@ -911,6 +941,7 @@ static DEFINE_SIMPLE_DEV_PM_OPS(stm32_pwm_pm_ops, stm32_pwm_suspend, stm32_pwm_r

static const struct of_device_id stm32_pwm_of_match[] = {
{ .compatible = "st,stm32-pwm", },
+ { .compatible = "st,stm32mp25-pwm", },
{ /* end node */ },
};
MODULE_DEVICE_TABLE(of, stm32_pwm_of_match);
--
2.25.1