diff options
Diffstat (limited to 'arch/arm/cpu/armv7/s5p-common/pwm.c')
| -rw-r--r-- | arch/arm/cpu/armv7/s5p-common/pwm.c | 42 |
1 files changed, 21 insertions, 21 deletions
diff --git a/arch/arm/cpu/armv7/s5p-common/pwm.c b/arch/arm/cpu/armv7/s5p-common/pwm.c index 44d7bc360..6f401b8d9 100644 --- a/arch/arm/cpu/armv7/s5p-common/pwm.c +++ b/arch/arm/cpu/armv7/s5p-common/pwm.c @@ -70,7 +70,7 @@ static unsigned long pwm_calc_tin(int pwm_id, unsigned long freq) return tin_parent_rate / 16; } -#define NS_IN_HZ (1000000000UL) +#define NS_IN_SEC 1000000000UL int pwm_config(int pwm_id, int duty_ns, int period_ns) { @@ -79,7 +79,7 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns) unsigned int offset; unsigned long tin_rate; unsigned long tin_ns; - unsigned long period; + unsigned long frequency; unsigned long tcon; unsigned long tcnt; unsigned long tcmp; @@ -89,34 +89,24 @@ int pwm_config(int pwm_id, int duty_ns, int period_ns) * fact that anything faster than 1GHz is easily representable * by 32bits. */ - if (period_ns > NS_IN_HZ || duty_ns > NS_IN_HZ) + if (period_ns > NS_IN_SEC || duty_ns > NS_IN_SEC || period_ns == 0) return -ERANGE; if (duty_ns > period_ns) return -EINVAL; - period = NS_IN_HZ / period_ns; + 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, period); + tin_rate = pwm_calc_tin(pwm_id, frequency); - tin_ns = NS_IN_HZ / tin_rate; + tin_ns = NS_IN_SEC / 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) { @@ -143,7 +133,7 @@ int pwm_init(int pwm_id, int div, int invert) u32 val; const struct s5p_timer *pwm = (struct s5p_timer *)samsung_get_base_timer(); - unsigned long timer_rate_hz; + unsigned long ticks_per_period; unsigned int offset, prescaler; /* @@ -167,14 +157,24 @@ int pwm_init(int pwm_id, int div, int invert) val |= (div & 0xf) << MUX_DIV_SHIFT(pwm_id); writel(val, &pwm->tcfg1); - timer_rate_hz = get_pwm_clk() / ((prescaler + 1) * - (div + 1)); + if (pwm_id == 4) { + /* + * TODO(sjg): Use this as a countdown timer for now. We count + * down from the maximum value to 0, then reset. + */ + ticks_per_period = -1UL; + } else { + const unsigned long pwm_hz = 1000; + unsigned long timer_rate_hz = get_pwm_clk() / + ((prescaler + 1) * (1 << div)); - timer_rate_hz = timer_rate_hz / CONFIG_SYS_HZ; + ticks_per_period = timer_rate_hz / pwm_hz; + } /* set count value */ offset = pwm_id * 3; - writel(timer_rate_hz, &pwm->tcntb0 + offset); + + writel(ticks_per_period, &pwm->tcntb0 + offset); val = readl(&pwm->tcon) & ~(0xf << TCON_OFFSET(pwm_id)); if (invert && (pwm_id < 4)) |