hwmon: (lm63) Add sensor type attribute for external sensor on LM96163

On LM96163, the external temperature sensor type is configurable to
either a thermal diode or a 3904 transistor. The chip reports a wrong
temperature if misconfigured. Add writable attribute to support it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/drivers/hwmon/lm63.c b/drivers/hwmon/lm63.c
index 5f6da52a721..75e3a15c2f6 100644
--- a/drivers/hwmon/lm63.c
+++ b/drivers/hwmon/lm63.c
@@ -93,6 +93,7 @@ static const unsigned short normal_i2c[] = { 0x18, 0x4c, 0x4e, I2C_CLIENT_END };
 #define LM63_REG_MAN_ID                 0xFE
 #define LM63_REG_CHIP_ID                0xFF
 
+#define LM96163_REG_TRUTHERM            0x30
 #define LM96163_REG_REMOTE_TEMP_U_MSB   0x31
 #define LM96163_REG_REMOTE_TEMP_U_LSB   0x32
 #define LM96163_REG_CONFIG_ENHANCED     0x45
@@ -213,6 +214,7 @@ struct lm63_data {
         u8 alarms;
         bool pwm_highres;
         bool remote_unsigned; /* true if unsigned remote upper limits */
+        bool trutherm;
 };
 
 static inline int temp8_from_reg(struct lm63_data *data, int nr)
@@ -513,6 +515,41 @@ static ssize_t set_update_interval(struct device *dev,
         return count;
 }
 
+static ssize_t show_type(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct lm63_data *data = i2c_get_clientdata(client);
+
+        return sprintf(buf, data->trutherm ? "1\n" : "2\n");
+}
+
+static ssize_t set_type(struct device *dev, struct device_attribute *attr,
+                        const char *buf, size_t count)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct lm63_data *data = i2c_get_clientdata(client);
+        unsigned long val;
+        int ret;
+        u8 reg;
+
+        ret = kstrtoul(buf, 10, &val);
+        if (ret < 0)
+                return ret;
+        if (val != 1 && val != 2)
+                return -EINVAL;
+
+        mutex_lock(&data->update_lock);
+        data->trutherm = val == 1;
+        reg = i2c_smbus_read_byte_data(client, LM96163_REG_TRUTHERM) & ~0x02;
+        i2c_smbus_write_byte_data(client, LM96163_REG_TRUTHERM,
+                                  reg | (data->trutherm ? 0x02 : 0x00));
+        data->valid = 0;
+        mutex_unlock(&data->update_lock);
+
+        return count;
+}
+
 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
                            char *buf)
 {
@@ -553,6 +590,8 @@ static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_remote_temp8,
 static DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_temp2_crit_hyst,
         set_temp2_crit_hyst);
 
+static DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type);
+
 /* Individual alarm files */
 static SENSOR_DEVICE_ATTR(fan1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
@@ -712,6 +751,12 @@ static int lm63_probe(struct i2c_client *new_client,
                 if (err)
                         goto exit_remove_files;
         }
+        if (data->kind == lm96163) {
+                err = device_create_file(&new_client->dev,
+                                         &dev_attr_temp2_type);
+                if (err)
+                        goto exit_remove_files;
+        }
 
         data->hwmon_dev = hwmon_device_register(&new_client->dev);
         if (IS_ERR(data->hwmon_dev)) {
@@ -722,6 +767,7 @@ static int lm63_probe(struct i2c_client *new_client,
         return 0;
 
 exit_remove_files:
+        device_remove_file(&new_client->dev, &dev_attr_temp2_type);
         sysfs_remove_group(&new_client->dev.kobj, &lm63_group);
         sysfs_remove_group(&new_client->dev.kobj, &lm63_group_fan1);
 exit_free:
@@ -763,6 +809,9 @@ static void lm63_init_client(struct i2c_client *client)
                 break;
         case lm96163:
                 data->max_convrate_hz = LM96163_MAX_CONVRATE_HZ;
+                data->trutherm
+                  = i2c_smbus_read_byte_data(client,
+                                             LM96163_REG_TRUTHERM) & 0x02;
                 break;
         }
         convrate = i2c_smbus_read_byte_data(client, LM63_REG_CONVRATE);
@@ -803,6 +852,7 @@ static int lm63_remove(struct i2c_client *client)
         struct lm63_data *data = i2c_get_clientdata(client);
 
         hwmon_device_unregister(data->hwmon_dev);
+        device_remove_file(&client->dev, &dev_attr_temp2_type);
         sysfs_remove_group(&client->dev.kobj, &lm63_group);
         sysfs_remove_group(&client->dev.kobj, &lm63_group_fan1);