diff options
Diffstat (limited to 'drivers/pwm')
| -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 9a7d7891edde..5f10cba492ec 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -605,17 +605,21 @@ 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); } @@ -626,6 +630,8 @@ 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); @@ -648,7 +654,11 @@ 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) |