[PATCH] hwmon: (lm77) Convert to a new-style i2c driver

[Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>]

The new-style lm77 driver implements the optional detect() callback
to cover the use cases of the legacy driver.

Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: Andras Bali <drewie-Y8qEzhMunLyT9ig0jae3mg@public.gmane.org>
---
 drivers/hwmon/lm77.c |  102 ++++++++++++++++++++++----------------------------
 1 file changed, 45 insertions(+), 57 deletions(-)

--- linux-2.6.26-rc9.orig/drivers/hwmon/lm77.c	2008-07-12 09:20:29.000000000 +0200
+++ linux-2.6.26-rc9/drivers/hwmon/lm77.c	2008-07-12 10:27:19.000000000 +0200
@@ -52,7 +52,6 @@ I2C_CLIENT_INSMOD_1(lm77);
 
 /* Each client has this additional data */
 struct lm77_data {
-	struct i2c_client	client;
 	struct device 		*hwmon_dev;
 	struct mutex		update_lock;
 	char			valid;
@@ -65,23 +64,35 @@ struct lm77_data {
 	u8			alarms;
 };
 
-static int lm77_attach_adapter(struct i2c_adapter *adapter);
-static int lm77_detect(struct i2c_adapter *adapter, int address, int kind);
+static int lm77_probe(struct i2c_client *client,
+		      const struct i2c_device_id *id);
+static int lm77_detect(struct i2c_client *client, int kind,
+		       struct i2c_board_info *info);
 static void lm77_init_client(struct i2c_client *client);
-static int lm77_detach_client(struct i2c_client *client);
+static int lm77_remove(struct i2c_client *client);
 static u16 lm77_read_value(struct i2c_client *client, u8 reg);
 static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
 
 static struct lm77_data *lm77_update_device(struct device *dev);
 
 
+static const struct i2c_device_id lm77_id[] = {
+	{ "lm77", lm77 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, lm77_id);
+
 /* This is the driver that will be inserted */
 static struct i2c_driver lm77_driver = {
+	.class		= I2C_CLASS_HWMON,
 	.driver = {
 		.name	= "lm77",
 	},
-	.attach_adapter = lm77_attach_adapter,
-	.detach_client	= lm77_detach_client,
+	.probe		= lm77_probe,
+	.remove		= lm77_remove,
+	.id_table	= lm77_id,
+	.detect		= lm77_detect,
+	.address_data	= &addr_data,
 };
 
 /* straight from the datasheet */
@@ -215,13 +226,6 @@ static SENSOR_DEVICE_ATTR(temp1_crit_ala
 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
 
-static int lm77_attach_adapter(struct i2c_adapter *adapter)
-{
-	if (!(adapter->class & I2C_CLASS_HWMON))
-		return 0;
-	return i2c_probe(adapter, &addr_data, lm77_detect);
-}
-
 static struct attribute *lm77_attributes[] = {
 	&dev_attr_temp1_input.attr,
 	&dev_attr_temp1_crit.attr,
@@ -240,32 +244,15 @@ static const struct attribute_group lm77
 	.attrs = lm77_attributes,
 };
 
-/* This function is called by i2c_probe */
-static int lm77_detect(struct i2c_adapter *adapter, int address, int kind)
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm77_detect(struct i2c_client *new_client, int kind,
+		       struct i2c_board_info *info)
 {
-	struct i2c_client *new_client;
-	struct lm77_data *data;
-	int err = 0;
-	const char *name = "";
+	struct i2c_adapter *adapter = new_client->adapter;
 
 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
 				     I2C_FUNC_SMBUS_WORD_DATA))
-		goto exit;
-
-	/* OK. For now, we presume we have a valid client. We now create the
-	   client structure, even though we cannot fill it completely yet.
-	   But it allows us to access lm77_{read,write}_value. */
-	if (!(data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL))) {
-		err = -ENOMEM;
-		goto exit;
-	}
-
-	new_client = &data->client;
-	i2c_set_clientdata(new_client, data);
-	new_client->addr = address;
-	new_client->adapter = adapter;
-	new_client->driver = &lm77_driver;
-	new_client->flags = 0;
+		return -ENODEV;
 
 	/* Here comes the remaining detection.  Since the LM77 has no
 	   register dedicated to identification, we have to rely on the
@@ -294,7 +281,7 @@ static int lm77_detect(struct i2c_adapte
 			    || i2c_smbus_read_word_data(new_client, i + 3) != crit
 			    || i2c_smbus_read_word_data(new_client, i + 4) != min
 			    || i2c_smbus_read_word_data(new_client, i + 5) != max)
-				goto exit_free;
+				return -ENODEV;
 
 		/* sign bits */
 		if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
@@ -302,51 +289,55 @@ static int lm77_detect(struct i2c_adapte
 		    || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
 		    || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
 		    || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
-			goto exit_free;
+			return -ENODEV;
 
 		/* unused bits */
 		if (conf & 0xe0)
-			goto exit_free;
+			return -ENODEV;
 
 		/* 0x06 and 0x07 return the last read value */
 		cur = i2c_smbus_read_word_data(new_client, 0);
 		if (i2c_smbus_read_word_data(new_client, 6) != cur
 		    || i2c_smbus_read_word_data(new_client, 7) != cur)
-			goto exit_free;
+			return -ENODEV;
 		hyst = i2c_smbus_read_word_data(new_client, 2);
 		if (i2c_smbus_read_word_data(new_client, 6) != hyst
 		    || i2c_smbus_read_word_data(new_client, 7) != hyst)
-			goto exit_free;
+			return -ENODEV;
 		min = i2c_smbus_read_word_data(new_client, 4);
 		if (i2c_smbus_read_word_data(new_client, 6) != min
 		    || i2c_smbus_read_word_data(new_client, 7) != min)
-			goto exit_free;
+			return -ENODEV;
 
 	}
 
-	/* Determine the chip type - only one kind supported! */
-	if (kind <= 0)
-		kind = lm77;
+	strlcpy(info->type, "lm77", I2C_NAME_SIZE);
 
-	if (kind == lm77) {
-		name = "lm77";
+	return 0;
+}
+
+static int lm77_probe(struct i2c_client *new_client,
+		      const struct i2c_device_id *id)
+{
+	struct lm77_data *data;
+	int err;
+
+	data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
 	}
 
-	/* Fill in the remaining client fields and put it into the global list */
-	strlcpy(new_client->name, name, I2C_NAME_SIZE);
+	i2c_set_clientdata(new_client, data);
 	data->valid = 0;
 	mutex_init(&data->update_lock);
 
-	/* Tell the I2C layer a new client has arrived */
-	if ((err = i2c_attach_client(new_client)))
-		goto exit_free;
-
 	/* Initialize the LM77 chip */
 	lm77_init_client(new_client);
 
 	/* Register sysfs hooks */
 	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group)))
-		goto exit_detach;
+		goto exit_free;
 
 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
 	if (IS_ERR(data->hwmon_dev)) {
@@ -358,20 +349,17 @@ static int lm77_detect(struct i2c_adapte
 
 exit_remove:
 	sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
-exit_detach:
-	i2c_detach_client(new_client);
 exit_free:
 	kfree(data);
 exit:
 	return err;
 }
 
-static int lm77_detach_client(struct i2c_client *client)
+static int lm77_remove(struct i2c_client *client)
 {
 	struct lm77_data *data = i2c_get_clientdata(client);
 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &lm77_group);
-	i2c_detach_client(client);
 	kfree(data);
 	return 0;
 }


-- 
Jean Delvare

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