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>
diff --git a/drivers/pwm/pwm-tiecap.c b/drivers/pwm/pwm-tiecap.c
index 4b66889..081471f 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 @@
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 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,