hwmon: (tmp421) support HWMON_T_ENABLE

Since the recent patches added possibility of disabling sensor channels
via DT, it only make sense to allow controlling that from userspace via
HWMON_T_ENABLE mechanism. This patches adds support for that.

Signed-off-by: Krzysztof Adamski <krzysztof.adamski@nokia.com>
Link: https://lore.kernel.org/r/a64c22e7323bd5a083f37aaaca91a745ac1beef3.1634206677.git.krzysztof.adamski@nokia.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/tmp421.c b/drivers/hwmon/tmp421.c
index 776464820a3da76e04ec69a321dd28b317543ce4..277628e2a5103aecbd5572d19d1e918aeabe1861 100644 (file)
--- a/drivers/hwmon/tmp421.c
+++ b/drivers/hwmon/tmp421.c
@@ -203,21 +203,25 @@ static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
        if (ret)
                return ret;
 
-       if (!tmp421->channel[channel].enabled)
-               return -ENODATA;
-
        switch (attr) {
        case hwmon_temp_input:
+               if (!tmp421->channel[channel].enabled)
+                       return -ENODATA;
                *val = temp_from_raw(tmp421->channel[channel].temp,
                                     tmp421->config & TMP421_CONFIG_RANGE);
                return 0;
        case hwmon_temp_fault:
+               if (!tmp421->channel[channel].enabled)
+                       return -ENODATA;
                /*
                 * Any of OPEN or /PVLD bits indicate a hardware mulfunction
                 * and the conversion result may be incorrect
                 */
                *val = !!(tmp421->channel[channel].temp & 0x03);
                return 0;
+       case hwmon_temp_enable:
+               *val = tmp421->channel[channel].enabled;
+               return 0;
        default:
                return -EOPNOTSUPP;
        }
@@ -234,6 +238,24 @@ static int tmp421_read_string(struct device *dev, enum hwmon_sensor_types type,
        return 0;
 }
 
+static int tmp421_write(struct device *dev, enum hwmon_sensor_types type,
+                       u32 attr, int channel, long val)
+{
+       struct tmp421_data *data = dev_get_drvdata(dev);
+       int ret;
+
+       switch (attr) {
+       case hwmon_temp_enable:
+               data->channel[channel].enabled = val;
+               ret = tmp421_enable_channels(data);
+               break;
+       default:
+           ret = -EOPNOTSUPP;
+       }
+
+       return ret;
+}
+
 static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
                                 u32 attr, int channel)
 {
@@ -243,6 +265,8 @@ static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
                return 0444;
        case hwmon_temp_label:
                return 0444;
+       case hwmon_temp_enable:
+               return 0644;
        default:
                return 0;
        }
@@ -402,6 +426,7 @@ static const struct hwmon_ops tmp421_ops = {
        .is_visible = tmp421_is_visible,
        .read = tmp421_read,
        .read_string = tmp421_read_string,
+       .write = tmp421_write,
 };
 
 static int tmp421_probe(struct i2c_client *client)
@@ -424,7 +449,7 @@ static int tmp421_probe(struct i2c_client *client)
        data->client = client;
 
        for (i = 0; i < data->channels; i++) {
-               data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
+               data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_ENABLE;
                data->channel[i].enabled = true;
        }