diff options
| -rw-r--r-- | drivers/pwm/pwm-atmel.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index ebaeb50dcfde..29b5ad03f715 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -124,6 +124,7 @@ static inline void atmel_pwm_ch_writel(struct atmel_pwm_chip *chip, } static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip, + unsigned long clkrate, const struct pwm_state *state, unsigned long *cprd, u32 *pres) { @@ -132,7 +133,7 @@ static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip, int shift; /* Calculate the period cycles and prescale value */ - cycles *= clk_get_rate(atmel_pwm->clk); + cycles *= clkrate; do_div(cycles, NSEC_PER_SEC); /* @@ -158,12 +159,14 @@ static int atmel_pwm_calculate_cprd_and_pres(struct pwm_chip *chip, } static void atmel_pwm_calculate_cdty(const struct pwm_state *state, - unsigned long cprd, unsigned long *cdty) + unsigned long clkrate, unsigned long cprd, + u32 pres, unsigned long *cdty) { unsigned long long cycles = state->duty_cycle; - cycles *= cprd; - do_div(cycles, state->period); + cycles *= clkrate; + do_div(cycles, NSEC_PER_SEC); + cycles >>= pres; *cdty = cprd - cycles; } @@ -244,17 +247,23 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, pwm_get_state(pwm, &cstate); if (state->enabled) { + unsigned long clkrate = clk_get_rate(atmel_pwm->clk); + if (cstate.enabled && cstate.polarity == state->polarity && cstate.period == state->period) { + u32 cmr = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); + cprd = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, atmel_pwm->data->regs.period); - atmel_pwm_calculate_cdty(state, cprd, &cdty); + pres = cmr & PWM_CMR_CPRE_MSK; + + atmel_pwm_calculate_cdty(state, clkrate, cprd, pres, &cdty); atmel_pwm_update_cdty(chip, pwm, cdty); return 0; } - ret = atmel_pwm_calculate_cprd_and_pres(chip, state, &cprd, + ret = atmel_pwm_calculate_cprd_and_pres(chip, clkrate, state, &cprd, &pres); if (ret) { dev_err(chip->dev, @@ -262,7 +271,7 @@ static int atmel_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return ret; } - atmel_pwm_calculate_cdty(state, cprd, &cdty); + atmel_pwm_calculate_cdty(state, clkrate, cprd, pres, &cdty); if (cstate.enabled) { atmel_pwm_disable(chip, pwm, false); |