static int stm32_count_function_write()

in stm32-timer-cnt.c [98:136]

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

static int stm32_count_function_write(struct counter_device *counter,
				      struct counter_count *count,
				      enum counter_function function)
{
	struct stm32_timer_cnt *const priv = counter_priv(counter);
	u32 cr1, sms;

	switch (function) {
	case COUNTER_FUNCTION_INCREASE:
		sms = TIM_SMCR_SMS_SLAVE_MODE_DISABLED;
		break;
	case COUNTER_FUNCTION_QUADRATURE_X2_A:
		sms = TIM_SMCR_SMS_ENCODER_MODE_1;
		break;
	case COUNTER_FUNCTION_QUADRATURE_X2_B:
		sms = TIM_SMCR_SMS_ENCODER_MODE_2;
		break;
	case COUNTER_FUNCTION_QUADRATURE_X4:
		sms = TIM_SMCR_SMS_ENCODER_MODE_3;
		break;
	default:
		return -EINVAL;
	}

	/* Store enable status */
	regmap_read(priv->regmap, TIM_CR1, &cr1);

	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, 0);

	regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);

	/* Make sure that registers are updated */
	regmap_update_bits(priv->regmap, TIM_EGR, TIM_EGR_UG, TIM_EGR_UG);

	/* Restore the enable status */
	regmap_update_bits(priv->regmap, TIM_CR1, TIM_CR1_CEN, cr1);

	return 0;
}