hwmon: (lm90) Restore configuration on exit

Restore the chip configuration when unloading the driver. This ensures
we don't leave the chip running if it was initially stopped.

Signed-off-by: Jean Delvare <khali@linux-fr.org>

diff --git a/drivers/hwmon/lm90.c b/drivers/hwmon/lm90.c
index ddf617f..4cbbf15 100644 (file)
--- a/drivers/hwmon/lm90.c
+++ b/drivers/hwmon/lm90.c
@@ -1,7 +1,7 @@
 /*
  * lm90.c - Part of lm_sensors, Linux kernel modules for hardware
  *          monitoring
- * Copyright (C) 2003-2009  Jean Delvare <khali@linux-fr.org>
+ * Copyright (C) 2003-2010  Jean Delvare <khali@linux-fr.org>
  *
  * Based on the lm83 driver. The LM90 is a sensor chip made by National
  * Semiconductor. It reports up to two temperatures (its own plus up to
@@ -203,6 +203,8 @@ struct lm90_data {
        int kind;
        int flags;
 
+       u8 config_orig;         /* Original configuration register value */
+
        /* registers values */
        s8 temp8[4];    /* 0: local low limit
                           1: local high limit
@@ -840,7 +842,7 @@ exit:
 
 static void lm90_init_client(struct i2c_client *client)
 {
-       u8 config, config_orig;
+       u8 config;
        struct lm90_data *data = i2c_get_clientdata(client);
 
        /*
@@ -852,7 +854,7 @@ static void lm90_init_client(struct i2c_client *client)
                dev_warn(&client->dev, "Initialization failed!\n");
                return;
        }
-       config_orig = config;
+       data->config_orig = config;
 
        /* Check Temperature Range Select */
        if (data->kind == adt7461) {
@@ -870,7 +872,7 @@ static void lm90_init_client(struct i2c_client *client)
        }
 
        config &= 0xBF; /* run */
-       if (config != config_orig) /* Only write if changed */
+       if (config != data->config_orig) /* Only write if changed */
                i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1, config);
 }
 
@@ -885,6 +887,10 @@ static int lm90_remove(struct i2c_client *client)
                device_remove_file(&client->dev,
                                   &sensor_dev_attr_temp2_offset.dev_attr);
 
+       /* Restore initial configuration */
+       i2c_smbus_write_byte_data(client, LM90_REG_W_CONFIG1,
+                                 data->config_orig);
+
        kfree(data);
        return 0;
 }