Commit 8b77e6ac authored by Jean Delvare's avatar Jean Delvare Committed by Jean Delvare
Browse files

i2c: Convert the pcf8591 driver to a new-style i2c driver 



The new-style pcf8591 driver implements the optional detect() callback
to cover the use cases of the legacy driver.

Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 68be3363

drivers/i2c/chips/pcf8591.c

+40 −54
Original line number Diff line number Diff line
@@ -72,28 +72,15 @@ MODULE_PARM_DESC(input_mode, 
#define REG_TO_SIGNED(reg)	(((reg) & 0x80)?((reg) - 256):(reg))



struct pcf8591_data {

	struct i2c_client client;

	struct mutex update_lock;



	u8 control;

	u8 aout;

};



static int pcf8591_attach_adapter(struct i2c_adapter *adapter);

static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind);

static int pcf8591_detach_client(struct i2c_client *client);

static void pcf8591_init_client(struct i2c_client *client);

static int pcf8591_read_channel(struct device *dev, int channel);



/* This is the driver that will be inserted */

static struct i2c_driver pcf8591_driver = {

	.driver = {

		.name	= "pcf8591",

	},

	.attach_adapter	= pcf8591_attach_adapter,

	.detach_client	= pcf8591_detach_client,

};



/* following are the sysfs callback functions */

#define show_in_channel(channel)					\

static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf)	\
@@ -180,58 +167,46 @@ static const struct attribute_group pcf8591_attr_group_opt = { 
/*

 * Real code

 */

static int pcf8591_attach_adapter(struct i2c_adapter *adapter)

{

	return i2c_probe(adapter, &addr_data, pcf8591_detect);

}



/* This function is called by i2c_probe */

static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)

/* Return 0 if detection is successful, -ENODEV otherwise */

static int pcf8591_detect(struct i2c_client *client, int kind,

			  struct i2c_board_info *info)

{

	struct i2c_client *client;

	struct pcf8591_data *data;

	int err = 0;

	struct i2c_adapter *adapter = client->adapter;



	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE

				     | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))

		goto exit;

		return -ENODEV;



	/* Now, we would do the remaining detection. But the PCF8591 is plainly

	   impossible to detect! Stupid chip. */



	strlcpy(info->type, "pcf8591", I2C_NAME_SIZE);



	return 0;

}



static int pcf8591_probe(struct i2c_client *client,

			 const struct i2c_device_id *id)

{

	struct pcf8591_data *data;

	int err;



	/* OK. For now, we presume we have a valid client. We now create the

	   client structure, even though we cannot fill it completely yet. */

	if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {

		err = -ENOMEM;

		goto exit;

	}

	

	client = &data->client;

	i2c_set_clientdata(client, data);

	client->addr = address;

	client->adapter = adapter;

	client->driver = &pcf8591_driver;



	/* Now, we would do the remaining detection. But the PCF8591 is plainly

	   impossible to detect! Stupid chip. */



	/* Determine the chip type - only one kind supported! */

	if (kind <= 0)

		kind = pcf8591;



	/* Fill in the remaining client fields and put it into the global 

	   list */

	strlcpy(client->name, "pcf8591", I2C_NAME_SIZE);

	mutex_init(&data->update_lock);



	/* Tell the I2C layer a new client has arrived */

	if ((err = i2c_attach_client(client)))

		goto exit_kfree;



	/* Initialize the PCF8591 chip */

	pcf8591_init_client(client);



	/* Register sysfs hooks */

	err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);

	if (err)

		goto exit_detach;

		goto exit_kfree;



	/* Register input2 if not in "two differential inputs" mode */

	if (input_mode != 3) {
@@ -252,24 +227,16 @@ static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind) 
exit_sysfs_remove:

	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);

	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);

exit_detach:

	i2c_detach_client(client);

exit_kfree:

	kfree(data);

exit:

	return err;

}



static int pcf8591_detach_client(struct i2c_client *client)

static int pcf8591_remove(struct i2c_client *client)

{

	int err;



	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);

	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);



	if ((err = i2c_detach_client(client)))

		return err;



	kfree(i2c_get_clientdata(client));

	return 0;

}
@@ -316,6 +283,25 @@ static int pcf8591_read_channel(struct device *dev, int channel) 
		return (10 * value);

}



static const struct i2c_device_id pcf8591_id[] = {

	{ "pcf8591", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, pcf8591_id);



static struct i2c_driver pcf8591_driver = {

	.driver = {

		.name	= "pcf8591",

	},

	.probe		= pcf8591_probe,

	.remove		= pcf8591_remove,

	.id_table	= pcf8591_id,



	.class		= I2C_CLASS_HWMON,	/* Nearest choice */

	.detect		= pcf8591_detect,

	.address_data	= &addr_data,

};



static int __init pcf8591_init(void)

{

	if (input_mode < 0 || input_mode > 3) {