linux-imx

    unsigned long long c;

    unsigned long period_cycles;

    unsigned long duty_cycles;

    unsigned long term;

    int ret = 0;

​

    /*

     * The clock needs to be enabled to access the PWM registers.

     * Configuration can be changed at any time.

     */

        ret = clk_enable(ep93xx_pwm->clk);

        if (ret)

            return ret;

    }

​

    c = clk_get_rate(ep93xx_pwm->clk);

    c *= period_ns;

    do_div(c, 1000000000);

    period_cycles = c;

​

            writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);

            writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);

        } else {

            writew(duty_cycles, base + EP93XX_PWMx_DUTY_CYCLE);

            writew(period_cycles, base + EP93XX_PWMx_TERM_COUNT);

        }

    } else {

        ret = -EINVAL;

    }

​

        clk_disable(ep93xx_pwm->clk);

​

    return ret;

}

​

static int ep93xx_pwm_polarity(struct pwm_chip *chip, struct pwm_device *pwm,

                   enum pwm_polarity polarity)

{

    struct ep93xx_pwm *ep93xx_pwm = to_ep93xx_pwm(chip);

    int ret;