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authorPaul Moore <pmoore@redhat.com>2014-06-17 17:30:23 -0400
committerPaul Moore <pmoore@redhat.com>2014-06-17 17:30:23 -0400
commit170b5910d9fbea79de1bb40df22eda5f98250c0c (patch)
treeca9560e878d2842d45c6f99077d0d8b8f8b0f9ba /drivers/pwm/pwm-atmel.c
parent47dd0b76ace953bd2c0479076db0d3e3b9594003 (diff)
parent1860e379875dfe7271c649058aeddffe5afd9d0d (diff)
Merge tag 'v3.15' into next
Linux 3.15
Diffstat (limited to 'drivers/pwm/pwm-atmel.c')
-rw-r--r--drivers/pwm/pwm-atmel.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index bf4144a1466..0adc952cc4e 100644
--- a/drivers/pwm/pwm-atmel.c
+++ b/drivers/pwm/pwm-atmel.c
@@ -32,6 +32,7 @@
/* Bit field in CMR */
#define PWM_CMR_CPOL (1 << 9)
#define PWM_CMR_UPD_CDTY (1 << 10)
+#define PWM_CMR_CPRE_MSK 0xF
/* The following registers for PWM v1 */
#define PWMV1_CDTY 0x04
@@ -104,6 +105,7 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
unsigned long clk_rate, prd, dty;
unsigned long long div;
unsigned int pres = 0;
+ u32 val;
int ret;
if (test_bit(PWMF_ENABLED, &pwm->flags) && (period_ns != pwm->period)) {
@@ -131,7 +133,7 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
prd = div;
div *= duty_ns;
do_div(div, period_ns);
- dty = div;
+ dty = prd - div;
ret = clk_enable(atmel_pwm->clk);
if (ret) {
@@ -139,7 +141,10 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return ret;
}
- atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, pres);
+ /* It is necessary to preserve CPOL, inside CMR */
+ val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR);
+ val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK);
+ atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val);
atmel_pwm->config(chip, pwm, dty, prd);
clk_disable(atmel_pwm->clk);