Re: [PATCH v3 2/3] hwmon: add ChromeOS EC driver

[Tzung-Bi Shih]

On Mon, May 27, 2024 at 10:58:32PM +0200, Thomas Weißschuh wrote:
> diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
[...]
> + *  ChromesOS EC driver for hwmon

s/ChromesOS/ChromeOS/.

> +struct cros_ec_hwmon_priv {
> +	struct cros_ec_device *cros_ec;
> +	const char *temp_sensor_names[EC_TEMP_SENSOR_ENTRIES + EC_TEMP_SENSOR_B_ENTRIES];
> +	u8 usable_fans;
> +};
> +
> +static int cros_ec_hwmon_read_fan_speed(struct cros_ec_device *cros_ec, u8 index, u16 *speed)
> +{
> +	u16 data;
> +	int ret;
> +
> +	ret = cros_ec_cmd_readmem(cros_ec, EC_MEMMAP_FAN + index * 2, 2, &data);
> +	if (ret < 0)
> +		return ret;
> +
> +	data = le16_to_cpu(data);
> +	*speed = data;
> +
> +	if (data == EC_FAN_SPEED_NOT_PRESENT || data == EC_FAN_SPEED_STALLED)
> +		return -EIO;

`data` could be eliminated; use `*speed` instead.

> +static int cros_ec_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
> +			      u32 attr, int channel, long *val)
> +{
[...]
> +	u16 speed = 0;
> +	u8 temp = 0;

They don't need to initialize.

> +	if (type == hwmon_fan && attr == hwmon_fan_input) {
> +		ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);
> +		if (ret == 0)
> +			*val = speed;
> +	} else if (type == hwmon_fan && attr == hwmon_fan_fault) {
> +		ret = cros_ec_hwmon_read_fan_speed(priv->cros_ec, channel, &speed);
> +		if (ret == -EIO && speed == EC_FAN_SPEED_STALLED)
> +			ret = 0;
> +		if (ret == 0)
> +			*val = speed == EC_FAN_SPEED_STALLED;
> +	} else if (type == hwmon_temp && attr == hwmon_temp_input) {
> +		ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);
> +		if (ret == 0)
> +			*val = kelvin_to_millicelsius((((long)temp) + EC_TEMP_SENSOR_OFFSET));
> +	} else if (type == hwmon_temp && attr == hwmon_temp_fault) {
> +		ret = cros_ec_hwmon_read_temp(priv->cros_ec, channel, &temp);
> +		if (ret == -EIO && speed == EC_TEMP_SENSOR_ERROR)
> +			ret = 0;
> +		if (ret == 0)
> +			*val = temp == EC_TEMP_SENSOR_ERROR;
> +	}

Refactoring them by switch .. case .. may improve the readability.