[Intel-gfx] [PATCH 2/2] pwm: lpss: Add get_state callback
Hans de Goede
hdegoede at redhat.com
Fri Dec 2 10:17:36 UTC 2016
Add a get_state callback so that the initial state correctly reflects
the actual hardware state.
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
drivers/pwm/pwm-lpss.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index b4d8835..f5603c0 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -135,6 +135,33 @@ static int pwm_lpss_config(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}
+static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct pwm_lpss_chip *lpwm = to_lpwm(chip);
+ unsigned long base_unit_range, freq;
+ unsigned long long base_unit, on_time_div;
+ u32 ctrl;
+
+ base_unit_range = BIT(lpwm->info->base_unit_bits);
+
+ ctrl = pwm_lpss_read(pwm);
+ on_time_div = ctrl & PWM_ON_TIME_DIV_MASK;
+ base_unit = (ctrl >> PWM_BASE_UNIT_SHIFT) & (base_unit_range - 1);
+
+ freq = base_unit * lpwm->info->clk_rate / base_unit_range;
+ if (freq == 0)
+ freq = 1;
+
+ state->period = NSEC_PER_SEC / freq;
+ state->duty_cycle = state->period * on_time_div / 255ULL;
+ state->polarity = PWM_POLARITY_NORMAL;
+ state->enabled = (ctrl & PWM_ENABLE) ? true : false;
+
+ if (state->enabled)
+ pm_runtime_get_sync(chip->dev);
+}
+
static int pwm_lpss_enable(struct pwm_chip *chip, struct pwm_device *pwm)
{
pm_runtime_get_sync(chip->dev);
@@ -156,6 +183,7 @@ static void pwm_lpss_disable(struct pwm_chip *chip, struct pwm_device *pwm)
static const struct pwm_ops pwm_lpss_ops = {
.config = pwm_lpss_config,
+ .get_state = pwm_lpss_get_state,
.enable = pwm_lpss_enable,
.disable = pwm_lpss_disable,
.owner = THIS_MODULE,
--
2.9.3
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