X-Git-Url: https://repo.jachan.dev/linux.git/blobdiff_plain/76d7961ff4ee02cc70365600a52fb59ca544dc7c..6fa9201a89898:/drivers/pwm/pwm-stm32-lp.c

diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c
index 2211a642066d..134c14621ee0 100644
--- a/drivers/pwm/pwm-stm32-lp.c
+++ b/drivers/pwm/pwm-stm32-lp.c
@@ -32,7 +32,7 @@ static inline struct stm32_pwm_lp *to_stm32_pwm_lp(struct pwm_chip *chip)
 #define STM32_LPTIM_MAX_PRESCALER	128
 
 static int stm32_pwm_lp_apply(struct pwm_chip *chip, struct pwm_device *pwm,
-			      struct pwm_state *state)
+			      const struct pwm_state *state)
 {
 	struct stm32_pwm_lp *priv = to_stm32_pwm_lp(chip);
 	unsigned long long prd, div, dty;
@@ -59,6 +59,12 @@ static int stm32_pwm_lp_apply(struct pwm_chip *chip, struct pwm_device *pwm,
 	/* Calculate the period and prescaler value */
 	div = (unsigned long long)clk_get_rate(priv->clk) * state->period;
 	do_div(div, NSEC_PER_SEC);
+	if (!div) {
+		/* Clock is too slow to achieve requested period. */
+		dev_dbg(priv->chip.dev, "Can't reach %llu ns\n", state->period);
+		return -EINVAL;
+	}
+
 	prd = div;
 	while (div > STM32_LPTIM_MAX_ARR) {
 		presc++;