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>
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.
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.
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.
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/i2c.h>
25 #include <linux/mutex.h>
26 #include <linux/err.h>
27 #include <linux/hwmon.h>
29 /* Addresses to scan */
30 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
31 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
33 /* Insmod parameters */
35 static int input_mode;
36 module_param(input_mode, int, 0);
37 MODULE_PARM_DESC(input_mode,
38 "Analog input mode:\n"
39 " 0 = four single ended inputs\n"
40 " 1 = three differential inputs\n"
41 " 2 = single ended and differential mixed\n"
42 " 3 = two differential inputs\n");
44 /* The PCF8591 control byte
46 | 0 |AOEF| AIP | 0 |AINC| AICH | */
48 /* Analog Output Enable Flag (analog output active if 1) */
49 #define PCF8591_CONTROL_AOEF 0x40
51 /* Analog Input Programming
52 0x00 = four single ended inputs
53 0x10 = three differential inputs
54 0x20 = single ended and differential mixed
55 0x30 = two differential inputs */
56 #define PCF8591_CONTROL_AIP_MASK 0x30
58 /* Autoincrement Flag (switch on if 1) */
59 #define PCF8591_CONTROL_AINC 0x04
66 #define PCF8591_CONTROL_AICH_MASK 0x03
69 #define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)
70 #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
73 #define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg))
76 struct device *hwmon_dev;
77 struct mutex update_lock;
83 static void pcf8591_init_client(struct i2c_client *client);
84 static int pcf8591_read_channel(struct device *dev, int channel);
86 /* following are the sysfs callback functions */
87 #define show_in_channel(channel) \
88 static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf) \
90 return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
92 static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
93 show_in##channel##_input, NULL);
100 static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf)
102 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
103 return sprintf(buf, "%d\n", data->aout * 10);
106 static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
109 struct i2c_client *client = to_i2c_client(dev);
110 struct pcf8591_data *data = i2c_get_clientdata(client);
111 if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) {
113 i2c_smbus_write_byte_data(client, data->control, data->aout);
119 static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO,
120 show_out0_ouput, set_out0_output);
122 static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf)
124 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
125 return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
128 static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
130 struct i2c_client *client = to_i2c_client(dev);
131 struct pcf8591_data *data = i2c_get_clientdata(client);
132 unsigned long val = simple_strtoul(buf, NULL, 10);
134 mutex_lock(&data->update_lock);
136 data->control |= PCF8591_CONTROL_AOEF;
138 data->control &= ~PCF8591_CONTROL_AOEF;
139 i2c_smbus_write_byte(client, data->control);
140 mutex_unlock(&data->update_lock);
144 static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO,
145 show_out0_enable, set_out0_enable);
147 static struct attribute *pcf8591_attributes[] = {
148 &dev_attr_out0_enable.attr,
149 &dev_attr_out0_output.attr,
150 &dev_attr_in0_input.attr,
151 &dev_attr_in1_input.attr,
155 static const struct attribute_group pcf8591_attr_group = {
156 .attrs = pcf8591_attributes,
159 static struct attribute *pcf8591_attributes_opt[] = {
160 &dev_attr_in2_input.attr,
161 &dev_attr_in3_input.attr,
165 static const struct attribute_group pcf8591_attr_group_opt = {
166 .attrs = pcf8591_attributes_opt,
173 /* Return 0 if detection is successful, -ENODEV otherwise */
174 static int pcf8591_detect(struct i2c_client *client,
175 struct i2c_board_info *info)
177 struct i2c_adapter *adapter = client->adapter;
179 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
180 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
183 /* Now, we would do the remaining detection. But the PCF8591 is plainly
184 impossible to detect! Stupid chip. */
186 strlcpy(info->type, "pcf8591", I2C_NAME_SIZE);
191 static int pcf8591_probe(struct i2c_client *client,
192 const struct i2c_device_id *id)
194 struct pcf8591_data *data;
197 if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
202 i2c_set_clientdata(client, data);
203 mutex_init(&data->update_lock);
205 /* Initialize the PCF8591 chip */
206 pcf8591_init_client(client);
208 /* Register sysfs hooks */
209 err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);
213 /* Register input2 if not in "two differential inputs" mode */
214 if (input_mode != 3) {
215 if ((err = device_create_file(&client->dev,
216 &dev_attr_in2_input)))
217 goto exit_sysfs_remove;
220 /* Register input3 only in "four single ended inputs" mode */
221 if (input_mode == 0) {
222 if ((err = device_create_file(&client->dev,
223 &dev_attr_in3_input)))
224 goto exit_sysfs_remove;
227 data->hwmon_dev = hwmon_device_register(&client->dev);
228 if (IS_ERR(data->hwmon_dev)) {
229 err = PTR_ERR(data->hwmon_dev);
230 goto exit_sysfs_remove;
236 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
237 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
244 static int pcf8591_remove(struct i2c_client *client)
246 struct pcf8591_data *data = i2c_get_clientdata(client);
248 hwmon_device_unregister(data->hwmon_dev);
249 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
250 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
251 kfree(i2c_get_clientdata(client));
255 /* Called when we have found a new PCF8591. */
256 static void pcf8591_init_client(struct i2c_client *client)
258 struct pcf8591_data *data = i2c_get_clientdata(client);
259 data->control = PCF8591_INIT_CONTROL;
260 data->aout = PCF8591_INIT_AOUT;
262 i2c_smbus_write_byte_data(client, data->control, data->aout);
264 /* The first byte transmitted contains the conversion code of the
265 previous read cycle. FLUSH IT! */
266 i2c_smbus_read_byte(client);
269 static int pcf8591_read_channel(struct device *dev, int channel)
272 struct i2c_client *client = to_i2c_client(dev);
273 struct pcf8591_data *data = i2c_get_clientdata(client);
275 mutex_lock(&data->update_lock);
277 if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
278 data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
280 i2c_smbus_write_byte(client, data->control);
282 /* The first byte transmitted contains the conversion code of
283 the previous read cycle. FLUSH IT! */
284 i2c_smbus_read_byte(client);
286 value = i2c_smbus_read_byte(client);
288 mutex_unlock(&data->update_lock);
290 if ((channel == 2 && input_mode == 2) ||
291 (channel != 3 && (input_mode == 1 || input_mode == 3)))
292 return (10 * REG_TO_SIGNED(value));
297 static const struct i2c_device_id pcf8591_id[] = {
301 MODULE_DEVICE_TABLE(i2c, pcf8591_id);
303 static struct i2c_driver pcf8591_driver = {
307 .probe = pcf8591_probe,
308 .remove = pcf8591_remove,
309 .id_table = pcf8591_id,
311 .class = I2C_CLASS_HWMON, /* Nearest choice */
312 .detect = pcf8591_detect,
313 .address_list = normal_i2c,
316 static int __init pcf8591_init(void)
318 if (input_mode < 0 || input_mode > 3) {
319 printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n",
323 return i2c_add_driver(&pcf8591_driver);
326 static void __exit pcf8591_exit(void)
328 i2c_del_driver(&pcf8591_driver);
331 MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
332 MODULE_DESCRIPTION("PCF8591 driver");
333 MODULE_LICENSE("GPL");
335 module_init(pcf8591_init);
336 module_exit(pcf8591_exit);