[linux-block.git] / drivers / i2c / chips / pcf8591.c

/*
    Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net>
    Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with 
    the help of Jean Delvare <khali@linux-fr.org>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/mutex.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
					0x4d, 0x4e, 0x4f, I2C_CLIENT_END };

/* Insmod parameters */
I2C_CLIENT_INSMOD_1(pcf8591);

static int input_mode;
module_param(input_mode, int, 0);
MODULE_PARM_DESC(input_mode,
	"Analog input mode:\n"
	" 0 = four single ended inputs\n"
	" 1 = three differential inputs\n"
	" 2 = single ended and differential mixed\n"
	" 3 = two differential inputs\n");

/* The PCF8591 control byte
      7    6    5    4    3    2    1    0  
   |  0 |AOEF|   AIP   |  0 |AINC|  AICH   | */

/* Analog Output Enable Flag (analog output active if 1) */
#define PCF8591_CONTROL_AOEF		0x40
					
/* Analog Input Programming 
   0x00 = four single ended inputs
   0x10 = three differential inputs
   0x20 = single ended and differential mixed
   0x30 = two differential inputs */
#define PCF8591_CONTROL_AIP_MASK	0x30

/* Autoincrement Flag (switch on if 1) */
#define PCF8591_CONTROL_AINC		0x04

/* Channel selection
   0x00 = channel 0 
   0x01 = channel 1
   0x02 = channel 2
   0x03 = channel 3 */
#define PCF8591_CONTROL_AICH_MASK	0x03

/* Initial values */
#define PCF8591_INIT_CONTROL	((input_mode << 4) | PCF8591_CONTROL_AOEF)
#define PCF8591_INIT_AOUT	0	/* DAC out = 0 */

/* Conversions */
#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)	\
{									\
	return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
}									\
static DEVICE_ATTR(in##channel##_input, S_IRUGO,			\
		   show_in##channel##_input, NULL);

show_in_channel(0);
show_in_channel(1);
show_in_channel(2);
show_in_channel(3);

static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
	return sprintf(buf, "%d\n", data->aout * 10);
}

static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	unsigned int value;
	struct i2c_client *client = to_i2c_client(dev);
	struct pcf8591_data *data = i2c_get_clientdata(client);
	if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) {
		data->aout = value;
		i2c_smbus_write_byte_data(client, data->control, data->aout);
		return count;
	}
	return -EINVAL;
}

static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO, 
		   show_out0_ouput, set_out0_output);

static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
	return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
}

static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct pcf8591_data *data = i2c_get_clientdata(client);
	unsigned long val = simple_strtoul(buf, NULL, 10);

	mutex_lock(&data->update_lock);
	if (val)
		data->control |= PCF8591_CONTROL_AOEF;
	else
		data->control &= ~PCF8591_CONTROL_AOEF;
	i2c_smbus_write_byte(client, data->control);
	mutex_unlock(&data->update_lock);
	return count;
}

static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO, 
		   show_out0_enable, set_out0_enable);

static struct attribute *pcf8591_attributes[] = {
	&dev_attr_out0_enable.attr,
	&dev_attr_out0_output.attr,
	&dev_attr_in0_input.attr,
	&dev_attr_in1_input.attr,
	NULL
};

static const struct attribute_group pcf8591_attr_group = {
	.attrs = pcf8591_attributes,
};

static struct attribute *pcf8591_attributes_opt[] = {
	&dev_attr_in2_input.attr,
	&dev_attr_in3_input.attr,
	NULL
};

static const struct attribute_group pcf8591_attr_group_opt = {
	.attrs = pcf8591_attributes_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)
{
	struct i2c_client *client;
	struct pcf8591_data *data;
	int err = 0;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
				     | I2C_FUNC_SMBUS_WRITE_BYTE_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. */
	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;

	/* Register input2 if not in "two differential inputs" mode */
	if (input_mode != 3) {
		if ((err = device_create_file(&client->dev,
					      &dev_attr_in2_input)))
			goto exit_sysfs_remove;
	}

	/* Register input3 only in "four single ended inputs" mode */
	if (input_mode == 0) {
		if ((err = device_create_file(&client->dev,
					      &dev_attr_in3_input)))
			goto exit_sysfs_remove;
	}

	return 0;

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)
{
	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;
}

/* Called when we have found a new PCF8591. */
static void pcf8591_init_client(struct i2c_client *client)
{
	struct pcf8591_data *data = i2c_get_clientdata(client);
	data->control = PCF8591_INIT_CONTROL;
	data->aout = PCF8591_INIT_AOUT;

	i2c_smbus_write_byte_data(client, data->control, data->aout);
	
	/* The first byte transmitted contains the conversion code of the 
	   previous read cycle. FLUSH IT! */
	i2c_smbus_read_byte(client);
}

static int pcf8591_read_channel(struct device *dev, int channel)
{
	u8 value;
	struct i2c_client *client = to_i2c_client(dev);
	struct pcf8591_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
		data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
			      | channel;
		i2c_smbus_write_byte(client, data->control);
	
		/* The first byte transmitted contains the conversion code of 
		   the previous read cycle. FLUSH IT! */
		i2c_smbus_read_byte(client);
	}
	value = i2c_smbus_read_byte(client);

	mutex_unlock(&data->update_lock);

	if ((channel == 2 && input_mode == 2) ||
	    (channel != 3 && (input_mode == 1 || input_mode == 3)))
		return (10 * REG_TO_SIGNED(value));
	else
		return (10 * value);
}

static int __init pcf8591_init(void)
{
	if (input_mode < 0 || input_mode > 3) {
		printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n",
		       input_mode);
		input_mode = 0;
	}
	return i2c_add_driver(&pcf8591_driver);
}

static void __exit pcf8591_exit(void)
{
	i2c_del_driver(&pcf8591_driver);
}

MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
MODULE_DESCRIPTION("PCF8591 driver");
MODULE_LICENSE("GPL");

module_init(pcf8591_init);
module_exit(pcf8591_exit);
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net>
	3	Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
	4	the help of Jean Delvare <khali@linux-fr.org>
	5
	6	This program is free software; you can redistribute it and/or modify
	7	it under the terms of the GNU General Public License as published by
	8	the Free Software Foundation; either version 2 of the License, or
	9	(at your option) any later version.
	10
	11	This program is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	GNU General Public License for more details.
	15
	16	You should have received a copy of the GNU General Public License
	17	along with this program; if not, write to the Free Software
	18	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	19	*/
	20
	21	#include <linux/module.h>
	22	#include <linux/init.h>
	23	#include <linux/slab.h>
	24	#include <linux/i2c.h>
5c085d36	25	#include <linux/mutex.h>
1da177e4 LT	26
1da177e4 LT	27	/* Addresses to scan */
2cdddeb8	28	static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
1da177e4	29	0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
1da177e4 LT	30
1da177e4 LT	31	/* Insmod parameters */
f4b50261	32	I2C_CLIENT_INSMOD_1(pcf8591);
1da177e4 LT	33
	34	static int input_mode;
	35	module_param(input_mode, int, 0);
	36	MODULE_PARM_DESC(input_mode,
	37	"Analog input mode:\n"
	38	" 0 = four single ended inputs\n"
	39	" 1 = three differential inputs\n"
	40	" 2 = single ended and differential mixed\n"
	41	" 3 = two differential inputs\n");
	42
	43	/* The PCF8591 control byte
	44	7 6 5 4 3 2 1 0
	45	\| 0 \|AOEF\| AIP \| 0 \|AINC\| AICH \| */
	46
	47	/* Analog Output Enable Flag (analog output active if 1) */
	48	#define PCF8591_CONTROL_AOEF 0x40
	49
	50	/* Analog Input Programming
	51	0x00 = four single ended inputs
	52	0x10 = three differential inputs
	53	0x20 = single ended and differential mixed
	54	0x30 = two differential inputs */
	55	#define PCF8591_CONTROL_AIP_MASK 0x30
	56
	57	/* Autoincrement Flag (switch on if 1) */
	58	#define PCF8591_CONTROL_AINC 0x04
	59
	60	/* Channel selection
	61	0x00 = channel 0
	62	0x01 = channel 1
	63	0x02 = channel 2
	64	0x03 = channel 3 */
	65	#define PCF8591_CONTROL_AICH_MASK 0x03
	66
	67	/* Initial values */
	68	#define PCF8591_INIT_CONTROL ((input_mode << 4) \| PCF8591_CONTROL_AOEF)
	69	#define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
	70
	71	/* Conversions */
	72	#define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg))
	73
	74	struct pcf8591_data {
	75	struct i2c_client client;
5c085d36	76	struct mutex update_lock;
1da177e4 LT	77
	78	u8 control;
	79	u8 aout;
	80	};
	81
	82	static int pcf8591_attach_adapter(struct i2c_adapter *adapter);
	83	static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind);
	84	static int pcf8591_detach_client(struct i2c_client *client);
	85	static void pcf8591_init_client(struct i2c_client *client);
	86	static int pcf8591_read_channel(struct device *dev, int channel);
	87
	88	/* This is the driver that will be inserted */
	89	static struct i2c_driver pcf8591_driver = {
a9718b0c	90	.driver = {
a9718b0c LR	91	.name = "pcf8591",
a9718b0c LR	92	},
1da177e4 LT	93	.attach_adapter = pcf8591_attach_adapter,
	94	.detach_client = pcf8591_detach_client,
	95	};
	96
	97	/* following are the sysfs callback functions */
	98	#define show_in_channel(channel) \
a5099cfc	99	static ssize_t show_in##channel##_input(struct device dev, struct device_attribute attr, char *buf) \
1da177e4 LT	100	{ \
	101	return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
	102	} \
	103	static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
	104	show_in##channel##_input, NULL);
	105
	106	show_in_channel(0);
	107	show_in_channel(1);
	108	show_in_channel(2);
	109	show_in_channel(3);
	110
a5099cfc	111	static ssize_t show_out0_ouput(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	112	{
	113	struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
	114	return sprintf(buf, "%d\n", data->aout * 10);
	115	}
	116
a5099cfc	117	static ssize_t set_out0_output(struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	118	{
	119	unsigned int value;
	120	struct i2c_client *client = to_i2c_client(dev);
	121	struct pcf8591_data *data = i2c_get_clientdata(client);
	122	if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) {
	123	data->aout = value;
	124	i2c_smbus_write_byte_data(client, data->control, data->aout);
	125	return count;
	126	}
	127	return -EINVAL;
	128	}
	129
	130	static DEVICE_ATTR(out0_output, S_IWUSR \| S_IRUGO,
	131	show_out0_ouput, set_out0_output);
	132
a5099cfc	133	static ssize_t show_out0_enable(struct device dev, struct device_attribute attr, char *buf)
1da177e4 LT	134	{
	135	struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
	136	return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
	137	}
	138
a5099cfc	139	static ssize_t set_out0_enable(struct device dev, struct device_attribute attr, const char *buf, size_t count)
1da177e4 LT	140	{
	141	struct i2c_client *client = to_i2c_client(dev);
	142	struct pcf8591_data *data = i2c_get_clientdata(client);
	143	unsigned long val = simple_strtoul(buf, NULL, 10);
	144
5c085d36	145	mutex_lock(&data->update_lock);
1da177e4 LT	146	if (val)
	147	data->control \|= PCF8591_CONTROL_AOEF;
	148	else
	149	data->control &= ~PCF8591_CONTROL_AOEF;
	150	i2c_smbus_write_byte(client, data->control);
5c085d36	151	mutex_unlock(&data->update_lock);
1da177e4 LT	152	return count;
	153	}
	154
	155	static DEVICE_ATTR(out0_enable, S_IWUSR \| S_IRUGO,
	156	show_out0_enable, set_out0_enable);
	157
7d9db67f JD	158	static struct attribute *pcf8591_attributes[] = {
	159	&dev_attr_out0_enable.attr,
	160	&dev_attr_out0_output.attr,
	161	&dev_attr_in0_input.attr,
	162	&dev_attr_in1_input.attr,
	163	NULL
	164	};
	165
	166	static const struct attribute_group pcf8591_attr_group = {
	167	.attrs = pcf8591_attributes,
	168	};
	169
	170	static struct attribute *pcf8591_attributes_opt[] = {
	171	&dev_attr_in2_input.attr,
	172	&dev_attr_in3_input.attr,
	173	NULL
	174	};
	175
	176	static const struct attribute_group pcf8591_attr_group_opt = {
	177	.attrs = pcf8591_attributes_opt,
	178	};
	179
1da177e4 LT	180	/*
	181	* Real code
	182	*/
	183	static int pcf8591_attach_adapter(struct i2c_adapter *adapter)
	184	{
2ed2dc3c	185	return i2c_probe(adapter, &addr_data, pcf8591_detect);
1da177e4 LT	186	}
1da177e4 LT	187
2ed2dc3c	188	/* This function is called by i2c_probe */
6344a8ec	189	static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
1da177e4	190	{
f741f673	191	struct i2c_client *client;
1da177e4 LT	192	struct pcf8591_data *data;
	193	int err = 0;
	194
	195	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
	196	\| I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
	197	goto exit;
	198
	199	/* OK. For now, we presume we have a valid client. We now create the
	200	client structure, even though we cannot fill it completely yet. */
5263ebb5	201	if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
1da177e4 LT	202	err = -ENOMEM;
	203	goto exit;
	204	}
1da177e4	205
f741f673 JD	206	client = &data->client;
	207	i2c_set_clientdata(client, data);
	208	client->addr = address;
	209	client->adapter = adapter;
	210	client->driver = &pcf8591_driver;
1da177e4 LT	211
	212	/* Now, we would do the remaining detection. But the PCF8591 is plainly
	213	impossible to detect! Stupid chip. */
	214
	215	/* Determine the chip type - only one kind supported! */
	216	if (kind <= 0)
	217	kind = pcf8591;
	218
	219	/* Fill in the remaining client fields and put it into the global
	220	list */
f741f673	221	strlcpy(client->name, "pcf8591", I2C_NAME_SIZE);
5c085d36	222	mutex_init(&data->update_lock);
1da177e4 LT	223
1da177e4 LT	224	/* Tell the I2C layer a new client has arrived */
f741f673	225	if ((err = i2c_attach_client(client)))
1da177e4 LT	226	goto exit_kfree;
	227
	228	/* Initialize the PCF8591 chip */
f741f673	229	pcf8591_init_client(client);
1da177e4 LT	230
1da177e4 LT	231	/* Register sysfs hooks */
f741f673	232	err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);
7d9db67f JD	233	if (err)
7d9db67f JD	234	goto exit_detach;
1da177e4 LT	235
1da177e4 LT	236	/* Register input2 if not in "two differential inputs" mode */
7d9db67f	237	if (input_mode != 3) {
f741f673	238	if ((err = device_create_file(&client->dev,
7d9db67f JD	239	&dev_attr_in2_input)))
	240	goto exit_sysfs_remove;
	241	}
	242
1da177e4	243	/* Register input3 only in "four single ended inputs" mode */
7d9db67f	244	if (input_mode == 0) {
f741f673	245	if ((err = device_create_file(&client->dev,
7d9db67f JD	246	&dev_attr_in3_input)))
	247	goto exit_sysfs_remove;
	248	}
	249
1da177e4	250	return 0;
1da177e4	251
7d9db67f	252	exit_sysfs_remove:
f741f673 JD	253	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
f741f673 JD	254	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
7d9db67f	255	exit_detach:
f741f673	256	i2c_detach_client(client);
1da177e4 LT	257	exit_kfree:
	258	kfree(data);
	259	exit:
	260	return err;
	261	}
	262
	263	static int pcf8591_detach_client(struct i2c_client *client)
	264	{
	265	int err;
	266
7d9db67f JD	267	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
	268	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
	269
7bef5594	270	if ((err = i2c_detach_client(client)))
1da177e4	271	return err;
1da177e4 LT	272
	273	kfree(i2c_get_clientdata(client));
	274	return 0;
	275	}
	276
	277	/* Called when we have found a new PCF8591. */
	278	static void pcf8591_init_client(struct i2c_client *client)
	279	{
	280	struct pcf8591_data *data = i2c_get_clientdata(client);
	281	data->control = PCF8591_INIT_CONTROL;
	282	data->aout = PCF8591_INIT_AOUT;
	283
	284	i2c_smbus_write_byte_data(client, data->control, data->aout);
	285
	286	/* The first byte transmitted contains the conversion code of the
	287	previous read cycle. FLUSH IT! */
	288	i2c_smbus_read_byte(client);
	289	}
	290
	291	static int pcf8591_read_channel(struct device *dev, int channel)
	292	{
	293	u8 value;
	294	struct i2c_client *client = to_i2c_client(dev);
	295	struct pcf8591_data *data = i2c_get_clientdata(client);
	296
5c085d36	297	mutex_lock(&data->update_lock);
1da177e4 LT	298
	299	if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
	300	data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
	301	\| channel;
	302	i2c_smbus_write_byte(client, data->control);
	303
	304	/* The first byte transmitted contains the conversion code of
	305	the previous read cycle. FLUSH IT! */
	306	i2c_smbus_read_byte(client);
	307	}
	308	value = i2c_smbus_read_byte(client);
	309
5c085d36	310	mutex_unlock(&data->update_lock);
1da177e4 LT	311
	312	if ((channel == 2 && input_mode == 2) \|\|
	313	(channel != 3 && (input_mode == 1 \|\| input_mode == 3)))
	314	return (10 * REG_TO_SIGNED(value));
	315	else
	316	return (10 * value);
	317	}
	318
	319	static int __init pcf8591_init(void)
	320	{
	321	if (input_mode < 0 \|\| input_mode > 3) {
	322	printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n",
	323	input_mode);
	324	input_mode = 0;
	325	}
	326	return i2c_add_driver(&pcf8591_driver);
	327	}
	328
	329	static void __exit pcf8591_exit(void)
	330	{
	331	i2c_del_driver(&pcf8591_driver);
	332	}
	333
	334	MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
	335	MODULE_DESCRIPTION("PCF8591 driver");
	336	MODULE_LICENSE("GPL");
	337
	338	module_init(pcf8591_init);
	339	module_exit(pcf8591_exit);