2 pcf8591.c - Part of lm_sensors, Linux kernel modules for hardware
4 Copyright (C) 2001-2004 Aurelien Jarno <aurelien@aurel32.net>
5 Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
6 the help of Jean Delvare <khali@linux-fr.org>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 #include <linux/module.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/i2c.h>
27 #include <linux/mutex.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 */
34 I2C_CLIENT_INSMOD_1(pcf8591);
36 static int input_mode;
37 module_param(input_mode, int, 0);
38 MODULE_PARM_DESC(input_mode,
39 "Analog input mode:\n"
40 " 0 = four single ended inputs\n"
41 " 1 = three differential inputs\n"
42 " 2 = single ended and differential mixed\n"
43 " 3 = two differential inputs\n");
45 /* The PCF8591 control byte
47 | 0 |AOEF| AIP | 0 |AINC| AICH | */
49 /* Analog Output Enable Flag (analog output active if 1) */
50 #define PCF8591_CONTROL_AOEF 0x40
52 /* Analog Input Programming
53 0x00 = four single ended inputs
54 0x10 = three differential inputs
55 0x20 = single ended and differential mixed
56 0x30 = two differential inputs */
57 #define PCF8591_CONTROL_AIP_MASK 0x30
59 /* Autoincrement Flag (switch on if 1) */
60 #define PCF8591_CONTROL_AINC 0x04
67 #define PCF8591_CONTROL_AICH_MASK 0x03
70 #define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)
71 #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
74 #define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg))
77 struct i2c_client client;
78 struct mutex update_lock;
84 static int pcf8591_attach_adapter(struct i2c_adapter *adapter);
85 static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind);
86 static int pcf8591_detach_client(struct i2c_client *client);
87 static void pcf8591_init_client(struct i2c_client *client);
88 static int pcf8591_read_channel(struct device *dev, int channel);
90 /* This is the driver that will be inserted */
91 static struct i2c_driver pcf8591_driver = {
95 .attach_adapter = pcf8591_attach_adapter,
96 .detach_client = pcf8591_detach_client,
99 /* following are the sysfs callback functions */
100 #define show_in_channel(channel) \
101 static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf) \
103 return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
105 static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
106 show_in##channel##_input, NULL);
113 static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf)
115 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
116 return sprintf(buf, "%d\n", data->aout * 10);
119 static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
122 struct i2c_client *client = to_i2c_client(dev);
123 struct pcf8591_data *data = i2c_get_clientdata(client);
124 if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) {
126 i2c_smbus_write_byte_data(client, data->control, data->aout);
132 static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO,
133 show_out0_ouput, set_out0_output);
135 static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf)
137 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
138 return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
141 static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
143 struct i2c_client *client = to_i2c_client(dev);
144 struct pcf8591_data *data = i2c_get_clientdata(client);
145 unsigned long val = simple_strtoul(buf, NULL, 10);
147 mutex_lock(&data->update_lock);
149 data->control |= PCF8591_CONTROL_AOEF;
151 data->control &= ~PCF8591_CONTROL_AOEF;
152 i2c_smbus_write_byte(client, data->control);
153 mutex_unlock(&data->update_lock);
157 static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO,
158 show_out0_enable, set_out0_enable);
160 static struct attribute *pcf8591_attributes[] = {
161 &dev_attr_out0_enable.attr,
162 &dev_attr_out0_output.attr,
163 &dev_attr_in0_input.attr,
164 &dev_attr_in1_input.attr,
168 static const struct attribute_group pcf8591_attr_group = {
169 .attrs = pcf8591_attributes,
172 static struct attribute *pcf8591_attributes_opt[] = {
173 &dev_attr_in2_input.attr,
174 &dev_attr_in3_input.attr,
178 static const struct attribute_group pcf8591_attr_group_opt = {
179 .attrs = pcf8591_attributes_opt,
185 static int pcf8591_attach_adapter(struct i2c_adapter *adapter)
187 return i2c_probe(adapter, &addr_data, pcf8591_detect);
190 /* This function is called by i2c_probe */
191 static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
193 struct i2c_client *new_client;
194 struct pcf8591_data *data;
197 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
198 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
201 /* OK. For now, we presume we have a valid client. We now create the
202 client structure, even though we cannot fill it completely yet. */
203 if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
208 new_client = &data->client;
209 i2c_set_clientdata(new_client, data);
210 new_client->addr = address;
211 new_client->adapter = adapter;
212 new_client->driver = &pcf8591_driver;
213 new_client->flags = 0;
215 /* Now, we would do the remaining detection. But the PCF8591 is plainly
216 impossible to detect! Stupid chip. */
218 /* Determine the chip type - only one kind supported! */
222 /* Fill in the remaining client fields and put it into the global
224 strlcpy(new_client->name, "pcf8591", I2C_NAME_SIZE);
225 mutex_init(&data->update_lock);
227 /* Tell the I2C layer a new client has arrived */
228 if ((err = i2c_attach_client(new_client)))
231 /* Initialize the PCF8591 chip */
232 pcf8591_init_client(new_client);
234 /* Register sysfs hooks */
235 err = sysfs_create_group(&new_client->dev.kobj, &pcf8591_attr_group);
239 /* Register input2 if not in "two differential inputs" mode */
240 if (input_mode != 3) {
241 if ((err = device_create_file(&new_client->dev,
242 &dev_attr_in2_input)))
243 goto exit_sysfs_remove;
246 /* Register input3 only in "four single ended inputs" mode */
247 if (input_mode == 0) {
248 if ((err = device_create_file(&new_client->dev,
249 &dev_attr_in3_input)))
250 goto exit_sysfs_remove;
256 sysfs_remove_group(&new_client->dev.kobj, &pcf8591_attr_group_opt);
257 sysfs_remove_group(&new_client->dev.kobj, &pcf8591_attr_group);
259 i2c_detach_client(new_client);
266 static int pcf8591_detach_client(struct i2c_client *client)
270 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
271 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
273 if ((err = i2c_detach_client(client)))
276 kfree(i2c_get_clientdata(client));
280 /* Called when we have found a new PCF8591. */
281 static void pcf8591_init_client(struct i2c_client *client)
283 struct pcf8591_data *data = i2c_get_clientdata(client);
284 data->control = PCF8591_INIT_CONTROL;
285 data->aout = PCF8591_INIT_AOUT;
287 i2c_smbus_write_byte_data(client, data->control, data->aout);
289 /* The first byte transmitted contains the conversion code of the
290 previous read cycle. FLUSH IT! */
291 i2c_smbus_read_byte(client);
294 static int pcf8591_read_channel(struct device *dev, int channel)
297 struct i2c_client *client = to_i2c_client(dev);
298 struct pcf8591_data *data = i2c_get_clientdata(client);
300 mutex_lock(&data->update_lock);
302 if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
303 data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
305 i2c_smbus_write_byte(client, data->control);
307 /* The first byte transmitted contains the conversion code of
308 the previous read cycle. FLUSH IT! */
309 i2c_smbus_read_byte(client);
311 value = i2c_smbus_read_byte(client);
313 mutex_unlock(&data->update_lock);
315 if ((channel == 2 && input_mode == 2) ||
316 (channel != 3 && (input_mode == 1 || input_mode == 3)))
317 return (10 * REG_TO_SIGNED(value));
322 static int __init pcf8591_init(void)
324 if (input_mode < 0 || input_mode > 3) {
325 printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n",
329 return i2c_add_driver(&pcf8591_driver);
332 static void __exit pcf8591_exit(void)
334 i2c_del_driver(&pcf8591_driver);
337 MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
338 MODULE_DESCRIPTION("PCF8591 driver");
339 MODULE_LICENSE("GPL");
341 module_init(pcf8591_init);
342 module_exit(pcf8591_exit);