/**
* Preset PWM operation clock.
*
* @param none
* @return none
* @notes changed when initial or HOOK_FREQ_CHANGE command
*/
void pwm_freq_changed(void)
{
uint32_t prescaler_divider = 0;
if (pwm_init_ch == PWM_CH_FAN) {
/*
* Using PWM Frequency and Resolution we calculate
* prescaler for input clock
*/
/* (Benson_TBD_9) pwm_clock/freq/resolution not confirm */
#ifdef CONFIG_PWM_INPUT_LFCLK
prescaler_divider = (uint32_t)(32768 /
pwm_channels[pwm_init_ch].freq);
#else
prescaler_divider = (uint32_t)(clock_get_apb2_freq()
/ pwm_channels[pwm_init_ch].freq);
#endif
} else {
prescaler_divider = (uint32_t)(clock_get_apb2_freq()
/ pwm_channels[pwm_init_ch].freq);
}
/* Set clock prescalre divider to ADC module*/
if (prescaler_divider >= 1)
prescaler_divider = prescaler_divider - 1;
if (prescaler_divider > 0xFFFF)
prescaler_divider = 0xFFFF;
/* Configure computed prescaler and resolution */
NPCX_PRSC(pwm_channels[pwm_init_ch].channel) =
(uint16_t)prescaler_divider;
}
/**
* Set PWM operation clock.
*
* @param ch operation channel
* @param freq desired PWM frequency
* @param res resolution for duty cycle
* @notes changed when initialization
*/
void pwm_set_freq(enum pwm_channel ch, uint32_t freq, uint32_t res)
{
int mdl = pwm_channels[ch].channel;
uint32_t prescaler_divider = 0;
uint32_t clock;
/* Disable PWM for module configuration */
pwm_enable(ch, 0);
/* Get PWM clock frequency */
if (pwm_channels[ch].flags & PWM_CONFIG_DSLEEP_CLK)
clock = INT_32K_CLOCK;
else
clock = clock_get_apb2_freq();
/*
* Using PWM Frequency and Resolution we calculate
* prescaler for input clock
*/
prescaler_divider = ((clock / freq)/res);
/* Set clock prescaler divider to PWM module*/
if (prescaler_divider >= 1)
prescaler_divider = prescaler_divider - 1;
if (prescaler_divider > 0xFFFF)
prescaler_divider = 0xFFFF;
/* Configure computed prescaler and resolution */
NPCX_PRSC(mdl) = (uint16_t)prescaler_divider - 1;
/* Set PWM cycle time */
NPCX_CTR(mdl) = res - 1;
/* Set the duty cycle to 0% since DCR > CTR */
NPCX_DCR(mdl) = res;
}
