linux-imx

    return (pwm_lpss_read(pwm) & PWM_SW_UPDATE) ? -EBUSY : 0;

}

​

static void pwm_lpss_prepare(struct pwm_lpss_chip *lpwm, struct pwm_device *pwm,

                 int duty_ns, int period_ns)

{

    unsigned long long on_time_div;

    unsigned long c = lpwm->info->clk_rate, base_unit_range;

    unsigned long long base_unit, freq = NSEC_PER_SEC;

​

    do_div(freq, period_ns);

​

    /*

     * The equation is:

     * base_unit = round(base_unit_range * freq / c)

     */

    base_unit_range = BIT(lpwm->info->base_unit_bits) - 1;

    freq *= base_unit_range;

​

    base_unit = DIV_ROUND_CLOSEST_ULL(freq, c);

​

    on_time_div = 255ULL * duty_ns;

    do_div(on_time_div, period_ns);

    on_time_div = 255ULL - on_time_div;

​

    ctrl &= ~PWM_ON_TIME_DIV_MASK;

    ctrl &= ~(base_unit_range << PWM_BASE_UNIT_SHIFT);

    base_unit &= base_unit_range;

    ctrl |= (u32) base_unit << PWM_BASE_UNIT_SHIFT;

    ctrl |= on_time_div;

}

​

static inline void pwm_lpss_cond_enable(struct pwm_device *pwm, bool cond)

{

    if (cond)

        pwm_lpss_write(pwm, pwm_lpss_read(pwm) | PWM_ENABLE);

}

​

static int pwm_lpss_apply(struct pwm_chip *chip, struct pwm_device *pwm,

              struct pwm_state *state)

    if (state->enabled) {

        if (!pwm_is_enabled(pwm)) {

            pm_runtime_get_sync(chip->dev);

            ret = pwm_lpss_is_updating(pwm);

            if (ret) {

                pm_runtime_put(chip->dev);

                return ret;

            }

            pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);

            pwm_lpss_cond_enable(pwm, lpwm->info->bypass == false);

            ret = pwm_lpss_wait_for_update(pwm);

            if (ret) {

                pm_runtime_put(chip->dev);

                return ret;

            }

            pwm_lpss_cond_enable(pwm, lpwm->info->bypass == true);

        } else {

            ret = pwm_lpss_is_updating(pwm);

            if (ret)

                return ret;

            pwm_lpss_prepare(lpwm, pwm, state->duty_cycle, state->period);

            return pwm_lpss_wait_for_update(pwm);

        }

    } else if (pwm_is_enabled(pwm)) {

        pwm_lpss_write(pwm, pwm_lpss_read(pwm) & ~PWM_ENABLE);

        pm_runtime_put(chip->dev);

    }

​

    return 0;

}

​