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| author |   Krzysztof Adamski <krzysztof.adamski@nokia.com> | 2021-10-14 15:01:28 +0200 |
|---|---|---|
| committer |   Guenter Roeck <linux@roeck-us.net> | 2021-10-15 15:49:32 -0700 |
| commit | 3fba10dc0341462a907c2eb31e1dc60b83da23fa (patch) | |
| tree | d81d27b68ebafe5ff20b3394d5bb469e66a6fc46 /drivers/hwmon | |
| parent | hwmon: (tmp421) support disabling channels from DT (diff) | |
| download | linux-dev-3fba10dc0341462a907c2eb31e1dc60b83da23fa.tar.xz linux-dev-3fba10dc0341462a907c2eb31e1dc60b83da23fa.zip | |
hwmon: (tmp421) support specifying n-factor via DT
Previous patches added a way to specify some channel specific parameters
in DT and n-factor is definitely one of them. This calibration mechanism
is board specific as its value depends on the diodes/transistors being
connected to the sensor and thus the DT seems like a right fit for that
information. It is very similar to the value of shunt resistor that some
drivers allows specifying in DT.
This patch adds a possibility to set n-factor for each channel via
"n-factor" DT property in each channel subnode.
Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Link: https://lore.kernel.org/r/69d0bfcc5ba27c67f21d3eabfb100656a14c75b9.1634206677.git.krzysztof.adamski@nokia.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/tmp421.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c index af08bc985a13..4f3737d14ade 100644 --- a/drivers/hwmon/tmp421.c +++ b/drivers/hwmon/tmp421.c @@ -34,6 +34,7 @@ enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 }; #define TMP421_STATUS_REG 0x08 #define TMP421_CONFIG_REG_1 0x09 #define TMP421_CONVERSION_RATE_REG 0x0B +#define TMP421_N_FACTOR_REG_1 0x21 #define TMP421_MANUFACTURER_ID_REG 0xFE #define TMP421_DEVICE_ID_REG 0xFF @@ -310,6 +311,7 @@ static int tmp421_probe_child_from_dt(struct i2c_client *client, { struct device *dev = &client->dev; u32 i; + s32 val; int err; err = of_property_read_u32(child, "reg", &i); @@ -329,6 +331,22 @@ static int tmp421_probe_child_from_dt(struct i2c_client *client, data->channel[i].enabled = of_device_is_available(child); + err = of_property_read_s32(child, "ti,n-factor", &val); + if (!err) { + if (i == 0) { + dev_err(dev, "n-factor can't be set for internal channel\n"); + return -EINVAL; + } + + if (val > 127 || val < -128) { + dev_err(dev, "n-factor for channel %d invalid (%d)\n", + i, val); + return -EINVAL; + } + i2c_smbus_write_byte_data(client, TMP421_N_FACTOR_REG_1 + i - 1, + val); + } + return 0; } |