On Tue, Sep 25, 2018 at 09:25:36AM +0200, Hans de Goede wrote:
> Add a get_state callback so that the initial state correctly reflects
> the actual hardware state.
>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Acked-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> Changes in v2:
> -Stop using the dropped pwm_lpss_get_put_runtime_pm() helper
> ---
> drivers/pwm/pwm-lpss.c | 34 ++++++++++++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
> index 723ca9de8325..ea93ef9f3672 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,
> };
>
> --
> 2.19.0.rc1
>
--
With Best Regards,
Andy Shevchenko
