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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>
This commit is contained in:
Philip, Avinash 2012-09-06 10:40:02 +05:30 committed by Thierry Reding
parent 6354316dbe
commit 454870a44b
1 changed files with 22 additions and 0 deletions
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22
drivers/pwm/pwm-tiecap.c
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@ -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,