drivers/hwmon/pcf8591.c - fp2-dev/kernel/msm - Gitiles

 /*
     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.
 */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

 /* Insmod parameters */

 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 device *hwmon_dev;
 	struct mutex update_lock;

 	u8 control;
 	u8 aout;
 };

 static void pcf8591_init_client(struct i2c_client *client);
 static int pcf8591_read_channel(struct device *dev, int channel);

 /* 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_probe(struct i2c_client *client,
 			 const struct i2c_device_id *id)
 {
 	struct pcf8591_data *data;
 	int err;

 	if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
 		err = -ENOMEM;
 		goto exit;
 	}

 	i2c_set_clientdata(client, data);
 	mutex_init(&data->update_lock);

 	/* 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_kfree;

 	/* 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;
 	}

 	data->hwmon_dev = hwmon_device_register(&client->dev);
 	if (IS_ERR(data->hwmon_dev)) {
 		err = PTR_ERR(data->hwmon_dev);
 		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_kfree:
 	kfree(data);
 exit:
 	return err;
 }

 static int pcf8591_remove(struct i2c_client *client)
 {
 	struct pcf8591_data *data = i2c_get_clientdata(client);

 	hwmon_device_unregister(data->hwmon_dev);
 	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
 	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
 	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 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,
 };

 static int __init pcf8591_init(void)
 {
 	if (input_mode < 0 || input_mode > 3) {
 		pr_warn("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);
	/*
	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.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

	/* Insmod parameters */

	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 device *hwmon_dev;
	struct mutex update_lock;

	u8 control;
	u8 aout;
	};

	static void pcf8591_init_client(struct i2c_client *client);
	static int pcf8591_read_channel(struct device *dev, int channel);

	/* 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_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct pcf8591_data *data;
	int err;

	if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
	err = -ENOMEM;
	goto exit;
	}

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* 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_kfree;

	/* 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;
	}

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
	err = PTR_ERR(data->hwmon_dev);
	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_kfree:
	kfree(data);
	exit:
	return err;
	}

	static int pcf8591_remove(struct i2c_client *client)
	{
	struct pcf8591_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
	sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
	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 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,
	};

	static int __init pcf8591_init(void)
	{
	if (input_mode < 0 \|\| input_mode > 3) {
	pr_warn("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);