diff options
Diffstat (limited to 'drivers/pwm/pwm-atmel.c')
-rw-r--r-- | drivers/pwm/pwm-atmel.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c index bf4144a14661..0adc952cc4ef 100644 --- a/drivers/pwm/pwm-atmel.c +++ b/drivers/pwm/pwm-atmel.c | |||
@@ -32,6 +32,7 @@ | |||
32 | /* Bit field in CMR */ | 32 | /* Bit field in CMR */ |
33 | #define PWM_CMR_CPOL (1 << 9) | 33 | #define PWM_CMR_CPOL (1 << 9) |
34 | #define PWM_CMR_UPD_CDTY (1 << 10) | 34 | #define PWM_CMR_UPD_CDTY (1 << 10) |
35 | #define PWM_CMR_CPRE_MSK 0xF | ||
35 | 36 | ||
36 | /* The following registers for PWM v1 */ | 37 | /* The following registers for PWM v1 */ |
37 | #define PWMV1_CDTY 0x04 | 38 | #define PWMV1_CDTY 0x04 |
@@ -104,6 +105,7 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |||
104 | unsigned long clk_rate, prd, dty; | 105 | unsigned long clk_rate, prd, dty; |
105 | unsigned long long div; | 106 | unsigned long long div; |
106 | unsigned int pres = 0; | 107 | unsigned int pres = 0; |
108 | u32 val; | ||
107 | int ret; | 109 | int ret; |
108 | 110 | ||
109 | if (test_bit(PWMF_ENABLED, &pwm->flags) && (period_ns != pwm->period)) { | 111 | 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, | |||
131 | prd = div; | 133 | prd = div; |
132 | div *= duty_ns; | 134 | div *= duty_ns; |
133 | do_div(div, period_ns); | 135 | do_div(div, period_ns); |
134 | dty = div; | 136 | dty = prd - div; |
135 | 137 | ||
136 | ret = clk_enable(atmel_pwm->clk); | 138 | ret = clk_enable(atmel_pwm->clk); |
137 | if (ret) { | 139 | if (ret) { |
@@ -139,7 +141,10 @@ static int atmel_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, | |||
139 | return ret; | 141 | return ret; |
140 | } | 142 | } |
141 | 143 | ||
142 | atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, pres); | 144 | /* It is necessary to preserve CPOL, inside CMR */ |
145 | val = atmel_pwm_ch_readl(atmel_pwm, pwm->hwpwm, PWM_CMR); | ||
146 | val = (val & ~PWM_CMR_CPRE_MSK) | (pres & PWM_CMR_CPRE_MSK); | ||
147 | atmel_pwm_ch_writel(atmel_pwm, pwm->hwpwm, PWM_CMR, val); | ||
143 | atmel_pwm->config(chip, pwm, dty, prd); | 148 | atmel_pwm->config(chip, pwm, dty, prd); |
144 | 149 | ||
145 | clk_disable(atmel_pwm->clk); | 150 | clk_disable(atmel_pwm->clk); |