On Fri, Sep 24, 2021 at 11:42:40AM +0200, Krzysztof Adamski wrote:
> Recent patch added possibility to disable selected channels. That would
> only make sure that the ENODATA is returned for those channels but would
> not configure the actual hardware.
>
> With this patch, the config register is written to make sure the
> channels are disabled also at hardware level.
>
> Signed-off-by: Krzysztof Adamski <krzysztof.adamski@xxxxxxxxx>
> ---
> drivers/hwmon/tmp421.c | 34 ++++++++++++++++++++++++++++++++++
> 1 file changed, 34 insertions(+)
>
> diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
> index 0fa4c02f5808..4934ce13afb4 100644
> --- a/drivers/hwmon/tmp421.c
> +++ b/drivers/hwmon/tmp421.c
> @@ -33,6 +33,9 @@ enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
> /* The TMP421 registers */
> #define TMP421_STATUS_REG 0x08
> #define TMP421_CONFIG_REG_1 0x09
> +#define TMP421_CONFIG_REG_2 0x0A
> +#define TMP421_CONFIG_REG_REN(x) (BIT(3 + (x)))
> +#define TMP421_CONFIG_REG_REN_MASK (BIT(3)|BIT(4)|BIT(5)|BIT(6))
GENMASK() would probably be better here.
> #define TMP421_CONVERSION_RATE_REG 0x0B
> #define TMP421_N_FACTOR_REG_1 0x21
> #define TMP421_MANUFACTURER_ID_REG 0xFE
> @@ -155,6 +158,33 @@ static struct tmp421_data *tmp421_update_device(struct device *dev)
> return data;
> }
>
> +static int tmp421_enable_channels(struct tmp421_data *data)
> +{
> + int err;
> + struct i2c_client *client = data->client;
> + struct device *dev = &client->dev;
> + int cfg = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
> + int i;
> +
> + if (cfg < 0) {
> + dev_err(dev,
> + "error reading register, can't disable channels\n");
Unnecessary line break
> + return err;
return cfg;
> + }
> +
> + cfg &= ~TMP421_CONFIG_REG_REN_MASK;
> + for (i = 0; i < data->channels; i++)
> + if (data->channel[i].enabled)
> + cfg |= TMP421_CONFIG_REG_REN(i);
> +
> + err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, cfg);
> + if (err < 0)
> + dev_err(dev,
> + "error writing register, can't disable channels\n");
Unnecessary line break
> +
> + return err;
> +}
> +
> static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
> u32 attr, int channel, long *val)
> {
> @@ -395,6 +425,10 @@ static int tmp421_probe(struct i2c_client *client)
> if (err)
> return err;
>
> + err = tmp421_enable_channels(data);
> + if (err)
> + return err;
This should really be called from tmp421_init_client(). After all, that is what
the function is for.
> +
> data->chip.ops = &tmp421_ops;
> data->chip.info = data->info;
>
