Merge tag 'perf-urgent-for-mingo-5.4-20191001' of git://git.kernel.org/pub/scm/linux...

[linux-2.6-microblaze.git] / drivers / pwm / pwm-stm32-lp.c

diff --git a/drivers/pwm/pwm-stm32-lp.c b/drivers/pwm/pwm-stm32-lp.c
index 2211a64..67fca62 100644 (file)
--- 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 %u ns\n",  state->period);
+               return -EINVAL;
+       }
+
        prd = div;
        while (div > STM32_LPTIM_MAX_ARR) {
                presc++;