diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2015-05-25 15:19:55 +0200 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2015-06-12 11:12:20 +0200 |
| commit | 4c027f7ba8520df088d34ae045205a6f8e2a1d76 (patch) | |
| tree | 2858c9721a8a1419c19aa24dfd74965cbc9732ff /drivers | |
| parent | cccb94543c8299e0bc7564cc6f8b26e0f15bafde (diff) | |
| download | linux-4c027f7ba8520df088d34ae045205a6f8e2a1d76.tar.bz2 | |
pwm: atmel: Fix incorrect CDTY value after enabling
CUPD is not flushed before enabling the channel so it will update
CDTY/CPRD just after one period. So we always set CUPD, even when the
channel is not enabled.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pwm/pwm-atmel.c | 35 |
1 files changed, 18 insertions, 17 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index d3c22de9ee47..89f9ca41d9af 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c @@ -155,24 +155,25 @@ static void atmel_pwm_config_v1(struct pwm_chip *chip, struct pwm_device *pwm, struct atmel_pwm_chip *atmel_pwm = to_atmel_pwm_chip(chip); unsigned int val; - if (test_bit(PWMF_ENABLED, &pwm->flags)) { - /* - * If the PWM channel is enabled, using the update register, - * it needs to set bit 10 of CMR to 0 - */ - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CUPD, dty); - val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); - val &= ~PWM_CMR_UPD_CDTY; - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); - } else { - /* - * If the PWM channel is disabled, write value to duty and - * period registers directly. - */ - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CDTY, dty); - atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CPRD, prd); - } + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CUPD, dty); + + val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); + val &= ~PWM_CMR_UPD_CDTY; + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); + + /* + * If the PWM channel is enabled, only update CDTY by using the update + * register, it needs to set bit 10 of CMR to 0 + */ + if (test_bit(PWMF_ENABLED, &pwm->flags)) + return; + /* + * If the PWM channel is disabled, write value to duty and period + * registers directly. + */ + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CDTY, dty); + atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWMV1_CPRD, prd); } static void atmel_pwm_config_v2(struct pwm_chip *chip, struct pwm_device *pwm, |