diff options
| author |   Rasmus Villemoes <linux@rasmusvillemoes.dk> | 2019-10-04 15:32:04 +0200 |
|---|---|---|
| committer |   Thierry Reding <thierry.reding@gmail.com> | 2020-01-08 13:33:37 +0100 |
| commit | 2cf0f6fece5b97e67c8d5e84fda3790fe213454a (patch) | |
| tree | 4d7669a14c7745c722b17fdf0e717d86f279da6f /drivers/pwm | |
| parent | pwm: mxs: Remove legacy methods (diff) | |
| download | linux-dev-2cf0f6fece5b97e67c8d5e84fda3790fe213454a.tar.xz linux-dev-2cf0f6fece5b97e67c8d5e84fda3790fe213454a.zip | |
pwm: mxs: Add support for inverse polarity
If I'm reading of_pwm_xlate_with_flags() right, existing device trees
that set #pwm-cells = 2 will continue to work.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/pwm-mxs.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/pwm/pwm-mxs.c b/drivers/pwm/pwm-mxs.c index 5a6835e18fc6..57562221c439 100644 --- a/drivers/pwm/pwm-mxs.c +++ b/drivers/pwm/pwm-mxs.c @@ -25,8 +25,11 @@ #define PERIOD_PERIOD(p) ((p) & 0xffff) #define PERIOD_PERIOD_MAX 0x10000 #define PERIOD_ACTIVE_HIGH (3 << 16) +#define PERIOD_ACTIVE_LOW (2 << 16) +#define PERIOD_INACTIVE_HIGH (3 << 18) #define PERIOD_INACTIVE_LOW (2 << 18) #define PERIOD_POLARITY_NORMAL (PERIOD_ACTIVE_HIGH | PERIOD_INACTIVE_LOW) +#define PERIOD_POLARITY_INVERSE (PERIOD_ACTIVE_LOW | PERIOD_INACTIVE_HIGH) #define PERIOD_CDIV(div) (((div) & 0x7) << 20) #define PERIOD_CDIV_MAX 8 @@ -50,9 +53,7 @@ static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, unsigned int period_cycles, duty_cycles; unsigned long rate; unsigned long long c; - - if (state->polarity != PWM_POLARITY_NORMAL) - return -ENOTSUPP; + unsigned int pol_bits; /* * If the PWM channel is disabled, make sure to turn on the @@ -91,9 +92,12 @@ static int mxs_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, * only take effect at the beginning of a new period, avoiding * glitches. */ + + pol_bits = state->polarity == PWM_POLARITY_NORMAL ? + PERIOD_POLARITY_NORMAL : PERIOD_POLARITY_INVERSE; writel(duty_cycles << 16, mxs->base + PWM_ACTIVE0 + pwm->hwpwm * 0x20); - writel(PERIOD_PERIOD(period_cycles) | PERIOD_POLARITY_NORMAL | PERIOD_CDIV(div), + writel(PERIOD_PERIOD(period_cycles) | pol_bits | PERIOD_CDIV(div), mxs->base + PWM_PERIOD0 + pwm->hwpwm * 0x20); if (state->enabled) { @@ -135,6 +139,8 @@ static int mxs_pwm_probe(struct platform_device *pdev) mxs->chip.dev = &pdev->dev; mxs->chip.ops = &mxs_pwm_ops; + mxs->chip.of_xlate = of_pwm_xlate_with_flags; + mxs->chip.of_pwm_n_cells = 3; mxs->chip.base = -1; ret = of_property_read_u32(np, "fsl,pwm-number", &mxs->chip.npwm); |