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authorPhilip, Avinash <avinashphilip@ti.com>2012-09-06 10:40:02 +0530
committerThierry Reding <thierry.reding@avionic-design.de>2012-09-10 17:05:52 +0200
commit454870a44b0687675180506b7774fb559d610675 (patch)
tree4ce95213a641f5911350a1a085e5fc1cee9c477b /drivers/pwm
parent6354316dbe5a13b25bea15d7ffc891be025eb267 (diff)
downloadblackbird-op-linux-454870a44b0687675180506b7774fb559d610675.tar.gz
blackbird-op-linux-454870a44b0687675180506b7774fb559d610675.zip
pwm: pwm-tiecap: Add support for configuring polarity of PWM
ECAP APWM hardware supports polarity configuration of PWM output. This commit adds support for polarity configuration of ECAP APWM. Signed-off-by: Philip, Avinash <avinashphilip@ti.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-tiecap.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 4b6688909fee..081471fbb097 100644
--- a/drivers/pwm/pwm-tiecap.c
+++ b/drivers/pwm/pwm-tiecap.c
@@ -32,6 +32,7 @@
#define CAP3 0x10
#define CAP4 0x14
#define ECCTL2 0x2A
+#define ECCTL2_APWM_POL_LOW BIT(10)
#define ECCTL2_APWM_MODE BIT(9)
#define ECCTL2_SYNC_SEL_DISA (BIT(7) | BIT(6))
#define ECCTL2_TSCTR_FREERUN BIT(4)
@@ -111,6 +112,26 @@ static int ecap_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}
+static int ecap_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
+ enum pwm_polarity polarity)
+{
+ struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
+ unsigned short reg_val;
+
+ pm_runtime_get_sync(pc->chip.dev);
+ reg_val = readw(pc->mmio_base + ECCTL2);
+ if (polarity == PWM_POLARITY_INVERSED)
+ /* Duty cycle defines LOW period of PWM */
+ reg_val |= ECCTL2_APWM_POL_LOW;
+ else
+ /* Duty cycle defines HIGH period of PWM */
+ reg_val &= ~ECCTL2_APWM_POL_LOW;
+
+ writew(reg_val, pc->mmio_base + ECCTL2);
+ pm_runtime_put_sync(pc->chip.dev);
+ return 0;
+}
+
static int ecap_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
struct ecap_pwm_chip *pc = to_ecap_pwm_chip(chip);
@@ -157,6 +178,7 @@ static void ecap_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
static const struct pwm_ops ecap_pwm_ops = {
.free = ecap_pwm_free,
.config = ecap_pwm_config,
+ .set_polarity = ecap_pwm_set_polarity,
.enable = ecap_pwm_enable,
.disable = ecap_pwm_disable,
.owner = THIS_MODULE,
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