hwmon: (lm87) Restore original configuration register on removal

This means that if we have to start the monitor when probed, we also
stop it on removal.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 7 insertions, 5 deletions

diff --git a/drivers/hwmon/lm87.c b/drivers/hwmon/lm87.c
index 0fecbfd2ba5b..fa0e3794d9a4 100644
--- a/drivers/hwmon/lm87.c
+++ b/drivers/hwmon/lm87.c
@@ -199,6 +199,7 @@ struct lm87_data {
         unsigned long last_updated; /* In jiffies */
 
         u8 channel;             /* register value */
+        u8 config;              /* original register value */
 
         u8 in[8];               /* register value */
         u8 in_max[8];           /* register value */
@@ -832,6 +833,7 @@ exit_remove:
         sysfs_remove_group(&new_client->dev.kobj, &lm87_group);
         sysfs_remove_group(&new_client->dev.kobj, &lm87_group_opt);
 exit_free:
+        lm87_write_value(new_client, LM87_REG_CONFIG, data->config);
         kfree(data);
 exit:
         return err;
@@ -840,12 +842,11 @@ exit:
 static void lm87_init_client(struct i2c_client *client)
 {
         struct lm87_data *data = i2c_get_clientdata(client);
-        u8 config;
 
         data->channel = lm87_read_value(client, LM87_REG_CHANNEL_MODE);
+        data->config = lm87_read_value(client, LM87_REG_CONFIG) & 0x6F;
 
-        config = lm87_read_value(client, LM87_REG_CONFIG);
-        if (!(config & 0x01)) {
+        if (!(data->config & 0x01)) {
                 int i;
 
                 /* Limits are left uninitialized after power-up */
@@ -869,9 +870,9 @@ static void lm87_init_client(struct i2c_client *client)
         }
 
         /* Make sure Start is set and INT#_Clear is clear */
-        if ((config & 0x09) != 0x01)
+        if ((data->config & 0x09) != 0x01)
                 lm87_write_value(client, LM87_REG_CONFIG,
-                                 (config & 0x77) | 0x01);
+                                 (data->config & 0x77) | 0x01);
 }
 
 static int lm87_remove(struct i2c_client *client)
@@ -882,6 +883,7 @@ static int lm87_remove(struct i2c_client *client)
         sysfs_remove_group(&client->dev.kobj, &lm87_group);
         sysfs_remove_group(&client->dev.kobj, &lm87_group_opt);
 
+        lm87_write_value(client, LM87_REG_CONFIG, data->config);
         kfree(data);
         return 0;
 }