diff options
Diffstat (limited to 'chip/npcx/pwm.c')
| -rw-r--r-- | chip/npcx/pwm.c | 24 |
1 files changed, 9 insertions, 15 deletions
diff --git a/chip/npcx/pwm.c b/chip/npcx/pwm.c index b5ff0da835..eb743b3db4 100644 --- a/chip/npcx/pwm.c +++ b/chip/npcx/pwm.c @@ -54,7 +54,7 @@ enum npcx_pwm_heartbeat_mode { * @param freq desired PWM frequency * @notes changed when initialization */ -void pwm_set_freq(enum pwm_channel ch, uint32_t freq) +static void pwm_set_freq(enum pwm_channel ch, uint32_t freq) { int mdl = pwm_channels[ch].channel; uint32_t clock; @@ -77,8 +77,11 @@ void pwm_set_freq(enum pwm_channel ch, uint32_t freq) /* Calculate prescaler */ pre = DIV_ROUND_UP(clock, (0xffff * freq)); - /* Calculate maximum resolution for the given freq. and prescaler */ - pwm_res[ch] = (clock / pre) / freq; + /* + * Calculate maximum resolution for the given freq. and prescaler. And + * prevent it exceed the resolution of CTR/DCR registers. + */ + pwm_res[ch] = MIN((clock / pre) / freq, NPCX_PWM_MAX_RAW_DUTY); /* Set PWM prescaler. */ NPCX_PRSC(mdl) = pre - 1; @@ -95,7 +98,6 @@ void pwm_set_freq(enum pwm_channel ch, uint32_t freq) * * @param ch operation channel * @param enabled enabled flag - * @return none */ void pwm_enable(enum pwm_channel ch, int enabled) { @@ -122,7 +124,6 @@ int pwm_get_enabled(enum pwm_channel ch) * * @param ch operation channel * @param percent duty cycle percent - * @return none */ void pwm_set_duty(enum pwm_channel ch, int percent) { @@ -135,7 +136,6 @@ void pwm_set_duty(enum pwm_channel ch, int percent) * * @param ch operation channel * @param duty cycle duty - * @return none */ void pwm_set_raw_duty(enum pwm_channel ch, uint16_t duty) { @@ -154,10 +154,8 @@ void pwm_set_raw_duty(enum pwm_channel ch, uint16_t duty) /* duty ranges from 0 - 0xffff, so scale down to 0 - pwm_res[ch] */ sd = DIV_ROUND_NEAREST(duty * pwm_res[ch], EC_PWM_MAX_DUTY); - /* Set the duty cycle */ - NPCX_DCR(mdl) = (uint16_t)sd; - - pwm_enable(ch, !!duty); + /* Set the duty cycle. If it is zero, set DCR > CTR */ + NPCX_DCR(mdl) = sd ? sd : NPCX_PWM_MAX_RAW_DUTY + 1; } /** @@ -183,7 +181,7 @@ uint16_t pwm_get_raw_duty(enum pwm_channel ch) int mdl = pwm_channels[ch].channel; /* Return duty */ - if (!pwm_get_enabled(ch)) + if (NPCX_DCR(mdl) > NPCX_CTR(mdl)) return 0; else /* @@ -198,7 +196,6 @@ uint16_t pwm_get_raw_duty(enum pwm_channel ch) * PWM configuration. * * @param ch operation channel - * @return none */ void pwm_config(enum pwm_channel ch) { @@ -232,9 +229,6 @@ void pwm_config(enum pwm_channel ch) /** * PWM initial. - * - * @param none - * @return none */ static void pwm_init(void) { |