static void
pwm_timer_init(unsigned timer)
{
/* enable the timer clock before we try to talk to it */
modifyreg32(pwm_timers[timer].clock_register, 0, pwm_timers[timer].clock_bit);
/* disable and configure the timer */
rCR1(timer) = 0;
rCR2(timer) = 0;
rSMCR(timer) = 0;
rDIER(timer) = 0;
rCCER(timer) = 0;
rCCMR1(timer) = 0;
rCCMR2(timer) = 0;
rCCER(timer) = 0;
rDCR(timer) = 0;
/* configure the timer to free-run at 1MHz */
rPSC(timer) = (pwm_timers[timer].clock_freq / 1000000) - 1;
/* default to updating at 50Hz */
pwm_timer_set_rate(timer, 50);
/* note that the timer is left disabled - arming is performed separately */
}
int
up_pwm_servo_set_rate(unsigned rate)
{
if ((rate < 50) || (rate > 400))
return -ERANGE;
for (unsigned i = 0; i < PWM_SERVO_MAX_TIMERS; i++) {
if (pwm_timers[i].base != 0)
pwm_timer_set_rate(i, rate);
}
return OK;
}
int
up_pwm_servo_set_rate_group_update(unsigned group, unsigned rate)
{
/* limit update rate to 1..10000Hz; somewhat arbitrary but safe */
if (rate < 1)
return -ERANGE;
if (rate > 10000)
return -ERANGE;
if ((group >= PWM_SERVO_MAX_TIMERS) || (pwm_timers[group].base == 0))
return ERROR;
pwm_timer_set_rate(group, rate);
return OK;
}
