Re: [PATCH v3] hwmon: Driver for TI TMP103 temperature sensor

[Guenter Roeck <linux@roeck-us.net>]

On 06/15/2014 11:47 PM, Heiko Schocher wrote:
> Driver for the TI TMP103.
>
> The TI TMP103 is similar to the TMP102.  It differs from the TMP102
> by having only 8 bit registers.
>
> Signed-off-by: Heiko Schocher <hs@denx.de>
>
Hello Heiko,

Almost there.

> ---
>
> +static int tmp103_probe(struct i2c_client *client,
> +			const struct i2c_device_id *id)
> +{
> +	struct device *dev = &client->dev;
> +	struct device *hwmon_dev;
> +	struct regmap *regmap;
> +	int ret;
> +
> +	if (!i2c_check_functionality(client->adapter,
> +				     I2C_FUNC_SMBUS_BYTE_DATA)) {
> +		dev_err(&client->dev,
> +			"adapter doesn't support SMBus byte transactions\n");
> +		return -ENODEV;
> +	}
> +
> +	regmap = devm_regmap_init_i2c(client, &tmp103_regmap_config);
> +	if (IS_ERR(regmap)) {
> +		dev_err(dev, "failed to allocate register map\n");
> +		return PTR_ERR(regmap);
> +	}
> +
> +	ret = regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONFIG,
> +				 TMP103_CONFIG);

You actually want to mask out CR0, CR1, M0, and M1 here.

> +	if (ret < 0) {
> +		dev_err(&client->dev, "error writing config register\n");
> +		return ret;
> +	}
> +
> +	hwmon_dev = hwmon_device_register_with_groups(dev, client->name,
> +						      regmap, tmp103_groups);
> +	return PTR_ERR_OR_ZERO(hwmon_dev);
> +}
> +
> +#ifdef CONFIG_PM
> +static int tmp103_suspend(struct device *dev)
> +{
> +	struct regmap *regmap = dev_get_drvdata(dev);
> +
> +	return regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONF_SD, 0);
> +}
> +
> +static int tmp103_resume(struct device *dev)
> +{
> +	struct regmap *regmap = dev_get_drvdata(dev);
> +
> +	return regmap_update_bits(regmap, TMP103_CONF_REG, TMP103_CONF_SD,
> +				  TMP103_CONF_SD);

That changes {M0, M1} to {1, 1}, but you really want {0, 1} to restore the
pre-suspend configuration.

One solution for both would be to define TMP103_CONFIG_MASK and TMP103_CONF_SD_MASK
separately to ensure you catch all the to-be-cleared bits.

Guenter