static int atmel_tcb_pwm_request()

in pwm-atmel-tcb.c [82:137]

• 44 lines of code
• 5 McCabe index (conditional complexity)

static int atmel_tcb_pwm_request(struct pwm_chip *chip,
				 struct pwm_device *pwm)
{
	struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip);
	struct atmel_tcb_pwm_device *tcbpwm;
	unsigned cmr;
	int ret;

	tcbpwm = devm_kzalloc(chip->dev, sizeof(*tcbpwm), GFP_KERNEL);
	if (!tcbpwm)
		return -ENOMEM;

	ret = clk_prepare_enable(tcbpwmc->clk);
	if (ret) {
		devm_kfree(chip->dev, tcbpwm);
		return ret;
	}

	pwm_set_chip_data(pwm, tcbpwm);
	tcbpwm->polarity = PWM_POLARITY_NORMAL;
	tcbpwm->duty = 0;
	tcbpwm->period = 0;
	tcbpwm->div = 0;

	spin_lock(&tcbpwmc->lock);
	regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr);
	/*
	 * Get init config from Timer Counter registers if
	 * Timer Counter is already configured as a PWM generator.
	 */
	if (cmr & ATMEL_TC_WAVE) {
		if (pwm->hwpwm == 0)
			regmap_read(tcbpwmc->regmap,
				    ATMEL_TC_REG(tcbpwmc->channel, RA),
				    &tcbpwm->duty);
		else
			regmap_read(tcbpwmc->regmap,
				    ATMEL_TC_REG(tcbpwmc->channel, RB),
				    &tcbpwm->duty);

		tcbpwm->div = cmr & ATMEL_TC_TCCLKS;
		regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC),
			    &tcbpwm->period);
		cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK |
			ATMEL_TC_BCMR_MASK);
	} else
		cmr = 0;

	cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0;
	regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr);
	spin_unlock(&tcbpwmc->lock);

	tcbpwmc->pwms[pwm->hwpwm] = tcbpwm;

	return 0;
}