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hwmon: (tmp421) really disable channels 

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@nokia.com>
Link: https://lore.kernel.org/r/d451cacdf21bf8eff38a47c055aad8c0c6e8755a.1634206677.git.krzysztof.adamski@nokia.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Krzysztof Adamski 2021-10-14 15:09:08 +02:00 committed by Guenter Roeck
parent 3fba10dc03
commit f3fbf4b81d
1 changed files with 38 additions and 6 deletions
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44
drivers/hwmon/tmp421.c
View File

@ -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 GENMASK(6, 3)
#define TMP421_CONVERSION_RATE_REG 0x0B
#define TMP421_N_FACTOR_REG_1 0x21
#define TMP421_MANUFACTURER_ID_REG 0xFE
@ -162,6 +165,34 @@ exit:
return 0;
}
static int tmp421_enable_channels(struct tmp421_data *data)
{
int err;
struct i2c_client *client = data->client;
struct device *dev = &client->dev;
int old = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
int new, i;
if (old < 0) {
dev_err(dev, "error reading register, can't disable channels\n");
return old;
}
new = old & ~TMP421_CONFIG_REG_REN_MASK;
for (i = 0; i < data->channels; i++)
if (data->channel[i].enabled)
new |= TMP421_CONFIG_REG_REN(i);
if (new == old)
return 0;
err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, new);
if (err < 0)
dev_err(dev, "error writing register, can't disable channels\n");
return err;
}
static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
@ -217,9 +248,10 @@ static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
}
}
static int tmp421_init_client(struct i2c_client *client)
static int tmp421_init_client(struct tmp421_data *data)
{
int config, config_orig;
struct i2c_client *client = data->client;
/* Set the conversion rate to 2 Hz */
i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
@ -240,7 +272,7 @@ static int tmp421_init_client(struct i2c_client *client)
i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
}
return 0;
return tmp421_enable_channels(data);
}
static int tmp421_detect(struct i2c_client *client,
@ -391,10 +423,6 @@ static int tmp421_probe(struct i2c_client *client)
data->channels = i2c_match_id(tmp421_id, client)->driver_data;
data->client = client;
err = tmp421_init_client(client);
if (err)
return err;
for (i = 0; i < data->channels; i++) {
data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
data->channel[i].enabled = true;
@ -404,6 +432,10 @@ static int tmp421_probe(struct i2c_client *client)
if (err)
return err;
err = tmp421_init_client(data);
if (err)
return err;
data->chip.ops = &tmp421_ops;
data->chip.info = data->info;