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pwm: lpss: Add get_state callback

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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>
This commit is contained in:
Hans de Goede 2018-10-12 12:12:29 +02:00 committed by Thierry Reding
parent 42885551ce
commit 280fec4c3a
1 changed files with 34 additions and 0 deletions
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34
drivers/pwm/pwm-lpss.c
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@ -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,
};