static int w1_ds2438_get_voltage()

in slaves/w1_ds2438.c [224:271]

• 39 lines of code
• 7 McCabe index (conditional complexity)

static int w1_ds2438_get_voltage(struct w1_slave *sl,
				 int adc_input, uint16_t *voltage)
{
	unsigned int retries = W1_DS2438_RETRIES;
	u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/];
	unsigned int tm = DS2438_MAX_CONVERSION_TIME;
	unsigned long sleep_rem;
	int ret;

	mutex_lock(&sl->master->bus_mutex);

	if (w1_ds2438_change_config_bit(sl, DS2438_STATUS_AD, adc_input)) {
		ret = -1;
		goto pre_unlock;
	}

	while (retries--) {
		if (w1_reset_select_slave(sl))
			continue;
		w1_write_8(sl->master, W1_DS2438_CONVERT_VOLTAGE);

		mutex_unlock(&sl->master->bus_mutex);
		sleep_rem = msleep_interruptible(tm);
		if (sleep_rem != 0) {
			ret = -1;
			goto post_unlock;
		}

		if (mutex_lock_interruptible(&sl->master->bus_mutex) != 0) {
			ret = -1;
			goto post_unlock;
		}

		break;
	}

	if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) {
		*voltage = (((uint16_t) w1_buf[DS2438_VOLTAGE_MSB]) << 8) | ((uint16_t) w1_buf[DS2438_VOLTAGE_LSB]);
		ret = 0;
	} else
		ret = -1;

pre_unlock:
	mutex_unlock(&sl->master->bus_mutex);

post_unlock:
	return ret;
}