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path: root/drivers/hwmon/lm73.c
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Diffstat (limited to 'drivers/hwmon/lm73.c')
-rw-r--r--drivers/hwmon/lm73.c30
1 files changed, 22 insertions, 8 deletions
diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c
index 29b9030d42c3..9e64d96620d3 100644
--- a/drivers/hwmon/lm73.c
+++ b/drivers/hwmon/lm73.c
@@ -34,7 +34,7 @@ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
 #define LM73_REG_CTRL		0x04
 #define LM73_REG_ID		0x07
 
-#define LM73_ID			0x9001 /* or 0x190 after a swab16() */
+#define LM73_ID			0x9001	/* 0x0190, byte-swapped */
 #define DRVNAME			"lm73"
 #define LM73_TEMP_MIN		(-40)
 #define LM73_TEMP_MAX		150
@@ -57,7 +57,7 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *da,
 	/* Write value */
 	value = (short) SENSORS_LIMIT(temp/250, (LM73_TEMP_MIN*4),
 		(LM73_TEMP_MAX*4)) << 5;
-	i2c_smbus_write_word_data(client, attr->index, swab16(value));
+	i2c_smbus_write_word_swapped(client, attr->index, value);
 	return count;
 }
 
@@ -68,8 +68,8 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *da,
 	struct i2c_client *client = to_i2c_client(dev);
 	/* use integer division instead of equivalent right shift to
 	   guarantee arithmetic shift and preserve the sign */
-	int temp = ((s16) (swab16(i2c_smbus_read_word_data(client,
-		attr->index)))*250) / 32;
+	int temp = ((s16) (i2c_smbus_read_word_swapped(client,
+		    attr->index))*250) / 32;
 	return sprintf(buf, "%d\n", temp);
 }
 
@@ -150,17 +150,31 @@ static int lm73_detect(struct i2c_client *new_client,
 			struct i2c_board_info *info)
 {
 	struct i2c_adapter *adapter = new_client->adapter;
-	u16 id;
-	u8 ctrl;
+	int id, ctrl, conf;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 					I2C_FUNC_SMBUS_WORD_DATA))
 		return -ENODEV;
 
+	/*
+	 * Do as much detection as possible with byte reads first, as word
+	 * reads can confuse other devices.
+	 */
+	ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
+	if (ctrl < 0 || (ctrl & 0x10))
+		return -ENODEV;
+
+	conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF);
+	if (conf < 0 || (conf & 0x0c))
+		return -ENODEV;
+
+	id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID);
+	if (id < 0 || id != (LM73_ID & 0xff))
+		return -ENODEV;
+
 	/* Check device ID */
 	id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
-	ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
-	if ((id != LM73_ID) || (ctrl & 0x10))
+	if (id < 0 || id != LM73_ID)
 		return -ENODEV;
 
 	strlcpy(info->type, "lm73", I2C_NAME_SIZE);