static int max6650_init_client()

in max6650.c [358:468]

• 99 lines of code
• 20 McCabe index (conditional complexity)

static int max6650_init_client(struct max6650_data *data,
			       struct i2c_client *client)
{
	struct device *dev = &client->dev;
	int reg;
	int err;
	u32 voltage;
	u32 prescale;
	u32 target_rpm;

	if (of_property_read_u32(dev->of_node, "maxim,fan-microvolt",
				 &voltage))
		voltage = fan_voltage;
	else
		voltage /= 1000000; /* Microvolts to volts */
	if (of_property_read_u32(dev->of_node, "maxim,fan-prescale",
				 &prescale))
		prescale = prescaler;

	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_CONFIG);
	if (reg < 0) {
		dev_err(dev, "Error reading config register, aborting.\n");
		return reg;
	}

	switch (voltage) {
	case 0:
		break;
	case 5:
		reg &= ~MAX6650_CFG_V12;
		break;
	case 12:
		reg |= MAX6650_CFG_V12;
		break;
	default:
		dev_err(dev, "illegal value for fan_voltage (%d)\n", voltage);
	}

	switch (prescale) {
	case 0:
		break;
	case 1:
		reg &= ~MAX6650_CFG_PRESCALER_MASK;
		break;
	case 2:
		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
			 | MAX6650_CFG_PRESCALER_2;
		break;
	case  4:
		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
			 | MAX6650_CFG_PRESCALER_4;
		break;
	case  8:
		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
			 | MAX6650_CFG_PRESCALER_8;
		break;
	case 16:
		reg = (reg & ~MAX6650_CFG_PRESCALER_MASK)
			 | MAX6650_CFG_PRESCALER_16;
		break;
	default:
		dev_err(dev, "illegal value for prescaler (%d)\n", prescale);
	}

	dev_info(dev, "Fan voltage: %dV, prescaler: %d.\n",
		 (reg & MAX6650_CFG_V12) ? 12 : 5,
		 1 << (reg & MAX6650_CFG_PRESCALER_MASK));

	err = i2c_smbus_write_byte_data(client, MAX6650_REG_CONFIG, reg);
	if (err) {
		dev_err(dev, "Config write error, aborting.\n");
		return err;
	}
	data->config = reg;

	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_SPEED);
	if (reg < 0) {
		dev_err(dev, "Failed to read speed register, aborting.\n");
		return reg;
	}
	data->speed = reg;

	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_DAC);
	if (reg < 0) {
		dev_err(dev, "Failed to read DAC register, aborting.\n");
		return reg;
	}
	data->dac = reg;

	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_COUNT);
	if (reg < 0) {
		dev_err(dev, "Failed to read count register, aborting.\n");
		return reg;
	}
	data->count = reg;

	reg = i2c_smbus_read_byte_data(client, MAX6650_REG_ALARM_EN);
	if (reg < 0) {
		dev_err(dev, "Failed to read alarm configuration, aborting.\n");
		return reg;
	}
	data->alarm_en = reg;

	if (!of_property_read_u32(client->dev.of_node, "maxim,fan-target-rpm",
				  &target_rpm)) {
		max6650_set_target(data, target_rpm);
		max6650_set_operating_mode(data, MAX6650_CFG_MODE_CLOSED_LOOP);
	}

	return 0;
}