Merge branch 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm

[firefly-linux-kernel-4.4.55.git] / drivers / pwm / pwm-atmel.c

diff --git a/drivers/pwm/pwm-atmel.c b/drivers/pwm/pwm-atmel.c
index bf4144a14661bdeb00baedc628131a5a1c81e39e..0adc952cc4ef5e95d8a5bd0fa0a680663150b7e8 100644 (file)
--- 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);