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authorHans de Goede <hdegoede@redhat.com>2018-10-12 10:12:29 (GMT)
committerThierry Reding <thierry.reding@gmail.com>2018-10-12 10:33:02 (GMT)
commit280fec4c3ad6701567d7d840506b9b1463a48b71 (patch)
treea0bdc970d208ffbb84b420fcc2b1a055b336819d /drivers/pwm
parent42885551cedb45961879d2fc3dc3c4dc545cc23e (diff)
pwm: lpss: Add get_state callback
Add a get_state callback so that the initial state correctly reflects the actual hardware state. Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
Diffstat (limited to 'drivers/pwm')
-rw-r--r--drivers/pwm/pwm-lpss.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 723ca9d..ea93ef9 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -159,8 +159,42 @@ static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,
return 0;
}
+/* This function gets called once from pwmchip_add to get the initial state */
+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;
+ unsigned long long base_unit, freq, on_time_div;
+ u32 ctrl;
+
+ base_unit_range = BIT(lpwm->info->base_unit_bits);
+
+ ctrl = pwm_lpss_read(pwm);
+ on_time_div = 255 - (ctrl & PWM_ON_TIME_DIV_MASK);
+ base_unit = (ctrl >> PWM_BASE_UNIT_SHIFT) & (base_unit_range - 1);
+
+ freq = base_unit * lpwm->info->clk_rate;
+ do_div(freq, base_unit_range);
+ if (freq == 0)
+ state->period = NSEC_PER_SEC;
+ else
+ state->period = NSEC_PER_SEC / (unsigned long)freq;
+
+ on_time_div *= state->period;
+ do_div(on_time_div, 255);
+ state->duty_cycle = on_time_div;
+
+ state->polarity = PWM_POLARITY_NORMAL;
+ state->enabled = !!(ctrl & PWM_ENABLE);
+
+ if (state->enabled)
+ pm_runtime_get(chip->dev);
+}
+
static const struct pwm_ops pwm_lpss_ops = {
.apply = pwm_lpss_apply,
+ .get_state = pwm_lpss_get_state,
.owner = THIS_MODULE,
};

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