int pwm_config(int pwm_id, int duty_ns, int period_ns)
{
const struct s5p_timer *pwm =
(struct s5p_timer *)samsung_get_base_timer();
unsigned int offset;
unsigned long tin_rate;
unsigned long tin_ns;
unsigned long frequency;
unsigned long tcon;
unsigned long tcnt;
unsigned long tcmp;
/*
* We currently avoid using 64bit arithmetic by using the
* fact that anything faster than 1GHz is easily representable
* by 32bits.
*/
if (period_ns > NS_IN_SEC || duty_ns > NS_IN_SEC || period_ns == 0)
return -ERANGE;
if (duty_ns > period_ns)
return -EINVAL;
frequency = NS_IN_SEC / period_ns;
/* Check to see if we are changing the clock rate of the PWM */
tin_rate = pwm_calc_tin(pwm_id, frequency);
tin_ns = NS_IN_SEC / tin_rate;
tcnt = period_ns / tin_ns;
/* Note, counters count down */
tcmp = duty_ns / tin_ns;
tcmp = tcnt - tcmp;
/* Update the PWM register block. */
offset = pwm_id * 3;
if (pwm_id < 4) {
writel(tcnt, &pwm->tcntb0 + offset);
writel(tcmp, &pwm->tcmpb0 + offset);
}
tcon = readl(&pwm->tcon);
tcon |= TCON_UPDATE(pwm_id);
if (pwm_id < 4)
tcon |= TCON_AUTO_RELOAD(pwm_id);
else
tcon |= TCON4_AUTO_RELOAD;
writel(tcon, &pwm->tcon);
tcon &= ~TCON_UPDATE(pwm_id);
writel(tcon, &pwm->tcon);
return 0;
}
int pwm_config(int pwm_id, int duty_ns, int period_ns)
{
const struct s5p_timer *pwm =
(struct s5p_timer *)samsung_get_base_timer();
unsigned int offset;
unsigned long tin_rate;
unsigned long tin_ns;
unsigned long period;
unsigned long tcon;
unsigned long tcnt;
unsigned long timer_rate_hz;
unsigned long tcmp;
/*
* We currently avoid using 64bit arithmetic by using the
* fact that anything faster than 1GHz is easily representable
* by 32bits.
*/
if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ)
return -ERANGE;
if (duty_ns > period_ns)
return -EINVAL;
period = NS_IN_HZ / period_ns;
/* Check to see if we are changing the clock rate of the PWM */
tin_rate = pwm_calc_tin(pwm_id, period);
timer_rate_hz = tin_rate;
tin_ns = NS_IN_HZ / tin_rate;
tcnt = period_ns / tin_ns;
/* Note, counters count down */
tcmp = duty_ns / tin_ns;
tcmp = tcnt - tcmp;
/*
* the pwm hw only checks the compare register after a decrement,
* so the pin never toggles if tcmp = tcnt
*/
if (tcmp == tcnt)
tcmp--;
if (tcmp < 0)
tcmp = 0;
/* Update the PWM register block. */
offset = pwm_id * 3;
if (pwm_id < 4) {
writel(tcnt, &pwm->tcntb0 + offset);
writel(tcmp, &pwm->tcmpb0 + offset);
}
tcon = readl(&pwm->tcon);
tcon |= TCON_UPDATE(pwm_id);
if (pwm_id < 4)
tcon |= TCON_AUTO_RELOAD(pwm_id);
else
tcon |= TCON4_AUTO_RELOAD;
writel(tcon, &pwm->tcon);
tcon &= ~TCON_UPDATE(pwm_id);
writel(tcon, &pwm->tcon);
return 0;
}
