[PATCH 2/2] hwmon: tmp102: Add support for label

[Flaviu Nistor <flaviu.nistor@gmail.com>]

Add support for label sysfs attribute similar to other hwmon devices.
This is particularly useful for systems with multiple sensors on the
same board, where identifying individual sensors is much easier since
labels can be defined via device tree.

Signed-off-by: Flaviu Nistor <flaviu.nistor@gmail.com>
---
 drivers/hwmon/tmp102.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/tmp102.c b/drivers/hwmon/tmp102.c
index a02daa496c9c..8dd295b0d87a 100644
--- a/drivers/hwmon/tmp102.c
+++ b/drivers/hwmon/tmp102.c
@@ -53,6 +53,7 @@
 #define CONVERSION_TIME_MS		35	/* in milli-seconds */
 
 struct tmp102 {
+	const char *label;
 	struct regmap *regmap;
 	u16 config_orig;
 	unsigned long ready_time;
@@ -70,6 +71,16 @@ static inline u16 tmp102_mC_to_reg(int val)
 	return (val * 128) / 1000;
 }
 
+static int tmp102_read_string(struct device *dev, enum hwmon_sensor_types type,
+				u32 attr, int channel, const char **str)
+{
+	struct tmp102 *tmp102 = dev_get_drvdata(dev);
+
+	*str = tmp102->label;
+
+	return 0;
+}
+
 static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
 		       u32 attr, int channel, long *temp)
 {
@@ -128,12 +139,18 @@ static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
 static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
 				 u32 attr, int channel)
 {
+	const struct tmp102 *tmp102 = data;
+
 	if (type != hwmon_temp)
 		return 0;
 
 	switch (attr) {
 	case hwmon_temp_input:
 		return 0444;
+	case hwmon_temp_label:
+		if (tmp102->label)
+			return 0444;
+		return 0;
 	case hwmon_temp_max_hyst:
 	case hwmon_temp_max:
 		return 0644;
@@ -146,12 +163,13 @@ static const struct hwmon_channel_info * const tmp102_info[] = {
 	HWMON_CHANNEL_INFO(chip,
 			   HWMON_C_REGISTER_TZ),
 	HWMON_CHANNEL_INFO(temp,
-			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
+			   HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_MAX | HWMON_T_MAX_HYST),
 	NULL
 };
 
 static const struct hwmon_ops tmp102_hwmon_ops = {
 	.is_visible = tmp102_is_visible,
+	.read_string = tmp102_read_string,
 	.read = tmp102_read,
 	.write = tmp102_write,
 };
@@ -213,6 +231,8 @@ static int tmp102_probe(struct i2c_client *client)
 	if (!tmp102)
 		return -ENOMEM;
 
+	of_property_read_string(dev->of_node, "label", &tmp102->label);
+
 	i2c_set_clientdata(client, tmp102);
 
 	tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
-- 
2.43.0