1 files changed, 17 insertions, 1 deletions

diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c
index 014e2a759fa6..2708212933f7 100644
--- a/drivers/pwm/pwm-stm32.c
+++ b/drivers/pwm/pwm-stm32.c
@@ -20,6 +20,7 @@
 
 struct stm32_pwm {
         struct pwm_chip chip;
+        struct mutex lock; /* protect pwm config/enable */
         struct clk *clk;
         struct regmap *regmap;
         u32 max_arr;
@@ -212,9 +213,23 @@ static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
         return ret;
 }
 
+static int stm32_pwm_apply_locked(struct pwm_chip *chip, struct pwm_device *pwm,
+                                  struct pwm_state *state)
+{
+        struct stm32_pwm *priv = to_stm32_pwm_dev(chip);
+        int ret;
+
+        /* protect common prescaler for all active channels */
+        mutex_lock(&priv->lock);
+        ret = stm32_pwm_apply(chip, pwm, state);
+        mutex_unlock(&priv->lock);
+
+        return ret;
+}
+
 static const struct pwm_ops stm32pwm_ops = {
         .owner = THIS_MODULE,
-        .apply = stm32_pwm_apply,
+        .apply = stm32_pwm_apply_locked,
 };
 
 static int stm32_pwm_set_breakinput(struct stm32_pwm *priv,
@@ -334,6 +349,7 @@ static int stm32_pwm_probe(struct platform_device *pdev)
         if (!priv)
                 return -ENOMEM;
 
+        mutex_init(&priv->lock);
         priv->regmap = ddata->regmap;
         priv->clk = ddata->clk;
         priv->max_arr = ddata->max_arr;