[PATCH] hwmon: (lm75) Drop legacy i2c driver

[PATCH] hwmon: (lm75) Drop legacy i2c driver

[Jean Delvare]

Drop the legacy lm75 driver, and add a detect callback to the
new-style driver to achieve the same functionality.

Signed-off-by: Jean Delvare <khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org>
Cc: David Brownell <david-b-yBeKhBN/0LDR7s880joybQ@public.gmane.org>
---
This patch will go to Linus by the end of the week.

David, if you haven't already, can you please test this patch and
confirm it doesn't cause any regression for you? Thanks.

 drivers/hwmon/lm75.c |  114 +++++++++-----------------------------------------
 1 file changed, 22 insertions(+), 92 deletions(-)

--- linux-2.6.26-rc9.orig/drivers/hwmon/lm75.c	2008-07-07 16:31:30.000000000 +0200
+++ linux-2.6.26-rc9/drivers/hwmon/lm75.c	2008-07-07 16:31:33.000000000 +0200
@@ -54,11 +54,11 @@ enum lm75_type {		/* keep sorted in alph
 	tmp75,
 };
 
-/* Addresses scanned by legacy style driver binding */
+/* Addresses scanned */
 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
 					0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
 
-/* Insmod parameters (only for legacy style driver binding) */
+/* Insmod parameters */
 I2C_CLIENT_INSMOD_1(lm75);
 
 
@@ -72,7 +72,6 @@ static const u8 LM75_REG_TEMP[3] = {
 
 /* Each client has this additional data */
 struct lm75_data {
-	struct i2c_client	*client;
 	struct device		*hwmon_dev;
 	struct mutex		update_lock;
 	u8			orig_conf;
@@ -138,7 +137,7 @@ static const struct attribute_group lm75
 
 /*-----------------------------------------------------------------------*/
 
-/* "New style" I2C driver binding -- following the driver model */
+/* device probe and removal */
 
 static int
 lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
@@ -157,8 +156,6 @@ lm75_probe(struct i2c_client *client, co
 		return -ENOMEM;
 
 	i2c_set_clientdata(client, data);
-
-	data->client = client;
 	mutex_init(&data->update_lock);
 
 	/* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
@@ -236,45 +233,16 @@ static const struct i2c_device_id lm75_i
 };
 MODULE_DEVICE_TABLE(i2c, lm75_ids);
 
-static struct i2c_driver lm75_driver = {
-	.driver = {
-		.name	= "lm75",
-	},
-	.probe		= lm75_probe,
-	.remove		= lm75_remove,
-	.id_table	= lm75_ids,
-};
-
-/*-----------------------------------------------------------------------*/
-
-/* "Legacy" I2C driver binding */
-
-static struct i2c_driver lm75_legacy_driver;
-
-/* This function is called by i2c_probe */
-static int lm75_detect(struct i2c_adapter *adapter, int address, int kind)
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int lm75_detect(struct i2c_client *new_client, int kind,
+		       struct i2c_board_info *info)
 {
+	struct i2c_adapter *adapter = new_client->adapter;
 	int i;
-	struct i2c_client *new_client;
-	int err = 0;
 
 	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 address. We create the
-	   client structure, even though there may be no sensor present.
-	   But it allows us to use i2c_smbus_read_*_data() calls. */
-	new_client = kzalloc(sizeof *new_client, GFP_KERNEL);
-	if (!new_client) {
-		err = -ENOMEM;
-		goto exit;
-	}
-
-	new_client->addr = address;
-	new_client->adapter = adapter;
-	new_client->driver = &lm75_legacy_driver;
-	new_client->flags = 0;
+		return -ENODEV;
 
 	/* Now, we do the remaining detection. There is no identification-
 	   dedicated register so we have to rely on several tricks:
@@ -294,71 +262,44 @@ static int lm75_detect(struct i2c_adapte
 		 || i2c_smbus_read_word_data(new_client, 5) != hyst
 		 || i2c_smbus_read_word_data(new_client, 6) != hyst
 		 || i2c_smbus_read_word_data(new_client, 7) != hyst)
-			goto exit_free;
+			return -ENODEV;
 		os = i2c_smbus_read_word_data(new_client, 3);
 		if (i2c_smbus_read_word_data(new_client, 4) != os
 		 || i2c_smbus_read_word_data(new_client, 5) != os
 		 || i2c_smbus_read_word_data(new_client, 6) != os
 		 || i2c_smbus_read_word_data(new_client, 7) != os)
-			goto exit_free;
+			return -ENODEV;
 
 		/* Unused bits */
 		if (conf & 0xe0)
-			goto exit_free;
+			return -ENODEV;
 
 		/* Addresses cycling */
 		for (i = 8; i < 0xff; i += 8)
 			if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
 			 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
 			 || i2c_smbus_read_word_data(new_client, i + 3) != os)
-				goto exit_free;
+				return -ENODEV;
 	}
 
 	/* NOTE: we treat "force=..." and "force_lm75=..." the same.
 	 * Only new-style driver binding distinguishes chip types.
 	 */
-	strlcpy(new_client->name, "lm75", I2C_NAME_SIZE);
-
-	/* Tell the I2C layer a new client has arrived */
-	err = i2c_attach_client(new_client);
-	if (err)
-		goto exit_free;
+	strlcpy(info->type, "lm75", I2C_NAME_SIZE);
 
-	err = lm75_probe(new_client, NULL);
-	if (err < 0)
-		goto exit_detach;
-
-	return 0;
-
-exit_detach:
-	i2c_detach_client(new_client);
-exit_free:
-	kfree(new_client);
-exit:
-	return err;
-}
-
-static int lm75_attach_adapter(struct i2c_adapter *adapter)
-{
-	if (!(adapter->class & I2C_CLASS_HWMON))
-		return 0;
-	return i2c_probe(adapter, &addr_data, lm75_detect);
-}
-
-static int lm75_detach_client(struct i2c_client *client)
-{
-	lm75_remove(client);
-	i2c_detach_client(client);
-	kfree(client);
 	return 0;
 }
 
-static struct i2c_driver lm75_legacy_driver = {
+static struct i2c_driver lm75_driver = {
+	.class		= I2C_CLASS_HWMON,
 	.driver = {
-		.name	= "lm75_legacy",
+		.name	= "lm75",
 	},
-	.attach_adapter	= lm75_attach_adapter,
-	.detach_client	= lm75_detach_client,
+	.probe		= lm75_probe,
+	.remove		= lm75_remove,
+	.id_table	= lm75_ids,
+	.detect		= lm75_detect,
+	.address_data	= &addr_data,
 };
 
 /*-----------------------------------------------------------------------*/
@@ -424,22 +365,11 @@ static struct lm75_data *lm75_update_dev
 
 static int __init sensors_lm75_init(void)
 {
-	int status;
-
-	status = i2c_add_driver(&lm75_driver);
-	if (status < 0)
-		return status;
-
-	status = i2c_add_driver(&lm75_legacy_driver);
-	if (status < 0)
-		i2c_del_driver(&lm75_driver);
-
-	return status;
+	return i2c_add_driver(&lm75_driver);
 }
 
 static void __exit sensors_lm75_exit(void)
 {
-	i2c_del_driver(&lm75_legacy_driver);
 	i2c_del_driver(&lm75_driver);
 }
 


-- 
Jean Delvare

_______________________________________________
i2c mailing list
i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
http://lists.lm-sensors.org/mailman/listinfo/i2c

Re: [PATCH] hwmon: (lm75) Drop legacy i2c driver

[David Brownell]

On Thursday 07 August 2008, Jean Delvare wrote:
> David, if you haven't already, can you please test this patch and
> confirm it doesn't cause any regression for you? Thanks.

Worked for me.  But I found a bizarre non-I2C problem.

It seems the second element of my i2c_boardinfo array
is getting its "type" field clobbered very early ...
it's correct in the object file, but not when the table
gets handed off to the I2C code.  New behavior.  :(

- Dave




_______________________________________________
i2c mailing list
i2c-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org
http://lists.lm-sensors.org/mailman/listinfo/i2c