diff options
| author | Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> | 2019-01-09 17:19:05 +0900 |
|---|---|---|
| committer | Thierry Reding <thierry.reding@gmail.com> | 2019-03-04 12:14:05 +0100 |
| commit | 7f68ce8287d3b25a70455aec18ff678a908d49ee (patch) | |
| tree | 0cb52f72f3a27a736137a0b8578f0bd05b793d01 /drivers/pwm | |
| parent | 74d0c3b2050927f364e3320091f234c108bd845d (diff) | |
| download | linux-7f68ce8287d3b25a70455aec18ff678a908d49ee.tar.bz2 | |
pwm: rcar: Add support "atomic" API
This patch adds support for "atomic" API. This behavior differs with
legacy APIs a little.
Legacy APIs:
The PWMCNT register will be updated in rcar_pwm_config() even if
the PWM state is disabled.
Atomic API:
The PWMCNT register will be updated in rcar_pwm_apply() only if
the PWM state is enabled. Otherwize, if a PWM runs with 30% duty
cycles and the pwm_apply_state() is called with state->enabled = 0,
->duty_cycle = 60 and ->period = 100, this is possible to output
a 60% duty cycle.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
| -rw-r--r-- | drivers/pwm/pwm-rcar.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-rcar.c b/drivers/pwm/pwm-rcar.c index a41812fc6f95..e3ab663ff3a7 100644 --- a/drivers/pwm/pwm-rcar.c +++ b/drivers/pwm/pwm-rcar.c @@ -192,12 +192,49 @@ static void rcar_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) rcar_pwm_update(rp, RCAR_PWMCR_EN0, 0, RCAR_PWMCR); } +static int rcar_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct rcar_pwm_chip *rp = to_rcar_pwm_chip(chip); + struct pwm_state cur_state; + int div, ret; + + /* This HW/driver only supports normal polarity */ + pwm_get_state(pwm, &cur_state); + if (state->polarity != PWM_POLARITY_NORMAL) + return -ENOTSUPP; + + if (!state->enabled) { + rcar_pwm_disable(chip, pwm); + return 0; + } + + div = rcar_pwm_get_clock_division(rp, state->period); + if (div < 0) + return div; + + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, RCAR_PWMCR_SYNC, RCAR_PWMCR); + + ret = rcar_pwm_set_counter(rp, div, state->duty_cycle, state->period); + if (!ret) + rcar_pwm_set_clock_control(rp, div); + + /* The SYNC should be set to 0 even if rcar_pwm_set_counter failed */ + rcar_pwm_update(rp, RCAR_PWMCR_SYNC, 0, RCAR_PWMCR); + + if (!ret && state->enabled) + ret = rcar_pwm_enable(chip, pwm); + + return ret; +} + static const struct pwm_ops rcar_pwm_ops = { .request = rcar_pwm_request, .free = rcar_pwm_free, .config = rcar_pwm_config, .enable = rcar_pwm_enable, .disable = rcar_pwm_disable, + .apply = rcar_pwm_apply, .owner = THIS_MODULE, }; |