/*
* 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 long val;
struct i2c_client *client = to_i2c_client(dev);
struct pcf8591_data *data = i2c_get_clientdata(client);
int err;
err = kstrtoul(buf, 10, &val);
if (err)
return err;
val /= 10;
if (val > 255)
return -EINVAL;
data->aout = val;
i2c_smbus_write_byte_data(client, data->control, data->aout);
return count;
}
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;
int err;
err = kstrtoul(buf, 10, &val);
if (err)
return err;
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;
data = devm_kzalloc(&client->dev, sizeof(struct pcf8591_data),
GFP_KERNEL);
if (!data)
return -ENOMEM;
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)
return err;
/* Register input2 if not in "two differential inputs" mode */
if (input_mode != 3) {
err = device_create_file(&client->dev, &dev_attr_in2_input);
if (err)
goto exit_sysfs_remove;
}
/* Register input3 only in "four single ended inputs" mode */
if (input_mode == 0) {
err = device_create_file(&client->dev, &dev_attr_in3_input);
if (err)
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);
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);
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);
