diff options
| author | Philipp Zabel <p.zabel@pengutronix.de> | 2023-10-19 22:07:04 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-01-25 15:45:07 -0800 |
| commit | 1bf92921641f108c1b173f496edb8be80d13d8e4 (patch) | |
| tree | 3333b9b009996db6e902b32bfaffc340afcc6ec4 | |
| parent | 888a98a4ee0510ea968d2c8ffc2cab1bdba66ac6 (diff) | |
pwm: stm32: Fix enable count for clk in .probe()
[ Upstream commit 19f1016ea9600ed89bc24247c36ff5934ad94fbb ]
Make the driver take over hardware state without disabling in .probe()
and enable the clock for each enabled channel.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
[ukleinek: split off from a patch that also implemented .get_state()]
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 7edf7369205b ("pwm: Add driver for STM32 plaftorm")
Reviewed-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/pwm/pwm-stm32.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index ffdfd81c0613..58ece15ef6c3 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -578,17 +578,21 @@ static void stm32_pwm_detect_complementary(struct stm32_pwm *priv) priv->have_complementary_output = (ccer != 0); } -static unsigned int stm32_pwm_detect_channels(struct stm32_pwm *priv) +static unsigned int stm32_pwm_detect_channels(struct stm32_pwm *priv, + unsigned int *num_enabled) { - u32 ccer; + u32 ccer, ccer_backup; /* * If channels enable bits don't exist writing 1 will have no * effect so we can detect and count them. */ + regmap_read(priv->regmap, TIM_CCER, &ccer_backup); regmap_set_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE); regmap_read(priv->regmap, TIM_CCER, &ccer); - regmap_clear_bits(priv->regmap, TIM_CCER, TIM_CCER_CCXE); + regmap_write(priv->regmap, TIM_CCER, ccer_backup); + + *num_enabled = hweight32(ccer_backup & TIM_CCER_CCXE); return hweight32(ccer & TIM_CCER_CCXE); } @@ -599,6 +603,8 @@ static int stm32_pwm_probe(struct platform_device *pdev) struct device_node *np = dev->of_node; struct stm32_timers *ddata = dev_get_drvdata(pdev->dev.parent); struct stm32_pwm *priv; + unsigned int num_enabled; + unsigned int i; int ret; priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); @@ -621,7 +627,11 @@ static int stm32_pwm_probe(struct platform_device *pdev) priv->chip.dev = dev; priv->chip.ops = &stm32pwm_ops; - priv->chip.npwm = stm32_pwm_detect_channels(priv); + priv->chip.npwm = stm32_pwm_detect_channels(priv, &num_enabled); + + /* Initialize clock refcount to number of enabled PWM channels. */ + for (i = 0; i < num_enabled; i++) + clk_enable(priv->clk); ret = devm_pwmchip_add(dev, &priv->chip); if (ret < 0) |