On 20/05/2022 11:32, Slawomir Stepien wrote: > From: Slawomir Stepien <slawomir.stepien@xxxxxxxxx> > > Try to read the channel's label from device-tree. Having label in > device-tree node is not mandatory. > > Signed-off-by: Slawomir Stepien <slawomir.stepien@xxxxxxxxx> > --- > drivers/hwmon/lm90.c | 70 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 70 insertions(+) > > diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c > index 67d48707a8d6..e81cc21e525f 100644 > --- a/drivers/hwmon/lm90.c > +++ b/drivers/hwmon/lm90.c > @@ -525,6 +525,7 @@ struct lm90_data { > struct i2c_client *client; > struct device *hwmon_dev; > u32 channel_config[MAX_CHANNELS + 1]; > + const char *channel_label[MAX_CHANNELS]; > struct hwmon_channel_info temp_info; > const struct hwmon_channel_info *info[MAX_CHANNELS]; > struct hwmon_chip_info chip; > @@ -1393,6 +1394,7 @@ static umode_t lm90_temp_is_visible(const void *data, u32 attr, int channel) > case hwmon_temp_emergency_alarm: > case hwmon_temp_emergency_hyst: > case hwmon_temp_fault: > + case hwmon_temp_label: > return 0444; > case hwmon_temp_min: > case hwmon_temp_max: > @@ -1486,6 +1488,16 @@ static int lm90_read(struct device *dev, enum hwmon_sensor_types type, > } > } > > +static int lm90_read_string(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, const char **str) > +{ > + struct lm90_data *data = dev_get_drvdata(dev); > + > + *str = data->channel_label[channel]; > + > + return 0; > +} > + > static int lm90_write(struct device *dev, enum hwmon_sensor_types type, > u32 attr, int channel, long val) > { > @@ -1904,10 +1916,64 @@ static void lm90_regulator_disable(void *regulator) > regulator_disable(regulator); > } > > +static int lm90_probe_channel_from_dt(struct i2c_client *client, > + struct device_node *child, > + struct lm90_data *data) > +{ > + u32 id; > + int err; > + struct device *dev = &client->dev; > + > + err = of_property_read_u32(child, "reg", &id); > + if (err) { > + dev_err(dev, "missing reg property of %pOFn\n", child); > + return err; > + } > + > + if (id >= MAX_CHANNELS) { > + dev_err(dev, "invalid reg %d in %pOFn\n", id, child); > + return -EINVAL; > + } > + > + err = of_property_read_string(child, "label", &data->channel_label[id]); > + if (err == -ENODATA || err == -EILSEQ) { > + dev_err(dev, "invalid label in %pOFn\n", child); You did not make it a required property, so why failing? > + return err; > + } > + > + if (data->channel_label[id]) > + data->channel_config[id] |= HWMON_T_LABEL; > + > + return 0; > +} > + > +static int lm90_parse_dt_channel_info(struct i2c_client *client, > + struct lm90_data *data) > +{ > + int err; > + struct device_node *child; > + struct device *dev = &client->dev; > + const struct device_node *np = dev->of_node; > + > + for_each_child_of_node(np, child) { > + if (strcmp(child->name, "channel")) > + continue; > + > + err = lm90_probe_channel_from_dt(client, child, data); > + if (err) { > + of_node_put(child); > + return err; > + } > + } > + > + return 0; > +} > + > No need for double blank lines. > static const struct hwmon_ops lm90_ops = { > .is_visible = lm90_is_visible, > .read = lm90_read, > + .read_string = lm90_read_string, > .write = lm90_write, > }; > > @@ -2027,6 +2093,10 @@ static int lm90_probe(struct i2c_client *client) > return err; > } > } > + > + err = lm90_parse_dt_channel_info(client, data); > + if (err) > + return err; > } > > /* Initialize the LM90 chip */ Best regards, Krzysztof