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Diffstat (limited to 'drivers/i2c/chips/pcf8591.c')
-rw-r--r--drivers/i2c/chips/pcf8591.c316
1 files changed, 316 insertions, 0 deletions
diff --git a/drivers/i2c/chips/pcf8591.c b/drivers/i2c/chips/pcf8591.c
new file mode 100644
index 000000000000..b6b927d8b372
--- /dev/null
+++ b/drivers/i2c/chips/pcf8591.c
@@ -0,0 +1,316 @@
1/*
2 pcf8591.c - Part of lm_sensors, Linux kernel modules for hardware
3 monitoring
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>
7
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.
12
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.
17
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.
21*/
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/i2c.h>
27#include <linux/i2c-sensor.h>
28
29/* Addresses to scan */
30static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
31 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
32static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
33
34/* Insmod parameters */
35SENSORS_INSMOD_1(pcf8591);
36
37static int input_mode;
38module_param(input_mode, int, 0);
39MODULE_PARM_DESC(input_mode,
40 "Analog input mode:\n"
41 " 0 = four single ended inputs\n"
42 " 1 = three differential inputs\n"
43 " 2 = single ended and differential mixed\n"
44 " 3 = two differential inputs\n");
45
46/* The PCF8591 control byte
47 7 6 5 4 3 2 1 0
48 | 0 |AOEF| AIP | 0 |AINC| AICH | */
49
50/* Analog Output Enable Flag (analog output active if 1) */
51#define PCF8591_CONTROL_AOEF 0x40
52
53/* Analog Input Programming
54 0x00 = four single ended inputs
55 0x10 = three differential inputs
56 0x20 = single ended and differential mixed
57 0x30 = two differential inputs */
58#define PCF8591_CONTROL_AIP_MASK 0x30
59
60/* Autoincrement Flag (switch on if 1) */
61#define PCF8591_CONTROL_AINC 0x04
62
63/* Channel selection
64 0x00 = channel 0
65 0x01 = channel 1
66 0x02 = channel 2
67 0x03 = channel 3 */
68#define PCF8591_CONTROL_AICH_MASK 0x03
69
70/* Initial values */
71#define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)
72#define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
73
74/* Conversions */
75#define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg))
76
77struct pcf8591_data {
78 struct i2c_client client;
79 struct semaphore update_lock;
80
81 u8 control;
82 u8 aout;
83};
84
85static int pcf8591_attach_adapter(struct i2c_adapter *adapter);
86static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind);
87static int pcf8591_detach_client(struct i2c_client *client);
88static void pcf8591_init_client(struct i2c_client *client);
89static int pcf8591_read_channel(struct device *dev, int channel);
90
91/* This is the driver that will be inserted */
92static struct i2c_driver pcf8591_driver = {
93 .owner = THIS_MODULE,
94 .name = "pcf8591",
95 .id = I2C_DRIVERID_PCF8591,
96 .flags = I2C_DF_NOTIFY,
97 .attach_adapter = pcf8591_attach_adapter,
98 .detach_client = pcf8591_detach_client,
99};
100
101/* following are the sysfs callback functions */
102#define show_in_channel(channel) \
103static ssize_t show_in##channel##_input(struct device *dev, char *buf) \
104{ \
105 return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
106} \
107static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
108 show_in##channel##_input, NULL);
109
110show_in_channel(0);
111show_in_channel(1);
112show_in_channel(2);
113show_in_channel(3);
114
115static ssize_t show_out0_ouput(struct device *dev, char *buf)
116{
117 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
118 return sprintf(buf, "%d\n", data->aout * 10);
119}
120
121static ssize_t set_out0_output(struct device *dev, const char *buf, size_t count)
122{
123 unsigned int value;
124 struct i2c_client *client = to_i2c_client(dev);
125 struct pcf8591_data *data = i2c_get_clientdata(client);
126 if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) {
127 data->aout = value;
128 i2c_smbus_write_byte_data(client, data->control, data->aout);
129 return count;
130 }
131 return -EINVAL;
132}
133
134static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO,
135 show_out0_ouput, set_out0_output);
136
137static ssize_t show_out0_enable(struct device *dev, char *buf)
138{
139 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
140 return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
141}
142
143static ssize_t set_out0_enable(struct device *dev, const char *buf, size_t count)
144{
145 struct i2c_client *client = to_i2c_client(dev);
146 struct pcf8591_data *data = i2c_get_clientdata(client);
147 unsigned long val = simple_strtoul(buf, NULL, 10);
148
149 down(&data->update_lock);
150 if (val)
151 data->control |= PCF8591_CONTROL_AOEF;
152 else
153 data->control &= ~PCF8591_CONTROL_AOEF;
154 i2c_smbus_write_byte(client, data->control);
155 up(&data->update_lock);
156 return count;
157}
158
159static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO,
160 show_out0_enable, set_out0_enable);
161
162/*
163 * Real code
164 */
165static int pcf8591_attach_adapter(struct i2c_adapter *adapter)
166{
167 return i2c_detect(adapter, &addr_data, pcf8591_detect);
168}
169
170/* This function is called by i2c_detect */
171int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind)
172{
173 struct i2c_client *new_client;
174 struct pcf8591_data *data;
175 int err = 0;
176
177 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
178 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
179 goto exit;
180
181 /* OK. For now, we presume we have a valid client. We now create the
182 client structure, even though we cannot fill it completely yet. */
183 if (!(data = kmalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) {
184 err = -ENOMEM;
185 goto exit;
186 }
187 memset(data, 0, sizeof(struct pcf8591_data));
188
189 new_client = &data->client;
190 i2c_set_clientdata(new_client, data);
191 new_client->addr = address;
192 new_client->adapter = adapter;
193 new_client->driver = &pcf8591_driver;
194 new_client->flags = 0;
195
196 /* Now, we would do the remaining detection. But the PCF8591 is plainly
197 impossible to detect! Stupid chip. */
198
199 /* Determine the chip type - only one kind supported! */
200 if (kind <= 0)
201 kind = pcf8591;
202
203 /* Fill in the remaining client fields and put it into the global
204 list */
205 strlcpy(new_client->name, "pcf8591", I2C_NAME_SIZE);
206 init_MUTEX(&data->update_lock);
207
208 /* Tell the I2C layer a new client has arrived */
209 if ((err = i2c_attach_client(new_client)))
210 goto exit_kfree;
211
212 /* Initialize the PCF8591 chip */
213 pcf8591_init_client(new_client);
214
215 /* Register sysfs hooks */
216 device_create_file(&new_client->dev, &dev_attr_out0_enable);
217 device_create_file(&new_client->dev, &dev_attr_out0_output);
218 device_create_file(&new_client->dev, &dev_attr_in0_input);
219 device_create_file(&new_client->dev, &dev_attr_in1_input);
220
221 /* Register input2 if not in "two differential inputs" mode */
222 if (input_mode != 3 )
223 device_create_file(&new_client->dev, &dev_attr_in2_input);
224
225 /* Register input3 only in "four single ended inputs" mode */
226 if (input_mode == 0)
227 device_create_file(&new_client->dev, &dev_attr_in3_input);
228
229 return 0;
230
231 /* OK, this is not exactly good programming practice, usually. But it is
232 very code-efficient in this case. */
233
234exit_kfree:
235 kfree(data);
236exit:
237 return err;
238}
239
240static int pcf8591_detach_client(struct i2c_client *client)
241{
242 int err;
243
244 if ((err = i2c_detach_client(client))) {
245 dev_err(&client->dev,
246 "Client deregistration failed, client not detached.\n");
247 return err;
248 }
249
250 kfree(i2c_get_clientdata(client));
251 return 0;
252}
253
254/* Called when we have found a new PCF8591. */
255static void pcf8591_init_client(struct i2c_client *client)
256{
257 struct pcf8591_data *data = i2c_get_clientdata(client);
258 data->control = PCF8591_INIT_CONTROL;
259 data->aout = PCF8591_INIT_AOUT;
260
261 i2c_smbus_write_byte_data(client, data->control, data->aout);
262
263 /* The first byte transmitted contains the conversion code of the
264 previous read cycle. FLUSH IT! */
265 i2c_smbus_read_byte(client);
266}
267
268static int pcf8591_read_channel(struct device *dev, int channel)
269{
270 u8 value;
271 struct i2c_client *client = to_i2c_client(dev);
272 struct pcf8591_data *data = i2c_get_clientdata(client);
273
274 down(&data->update_lock);
275
276 if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
277 data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
278 | channel;
279 i2c_smbus_write_byte(client, data->control);
280
281 /* The first byte transmitted contains the conversion code of
282 the previous read cycle. FLUSH IT! */
283 i2c_smbus_read_byte(client);
284 }
285 value = i2c_smbus_read_byte(client);
286
287 up(&data->update_lock);
288
289 if ((channel == 2 && input_mode == 2) ||
290 (channel != 3 && (input_mode == 1 || input_mode == 3)))
291 return (10 * REG_TO_SIGNED(value));
292 else
293 return (10 * value);
294}
295
296static int __init pcf8591_init(void)
297{
298 if (input_mode < 0 || input_mode > 3) {
299 printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n",
300 input_mode);
301 input_mode = 0;
302 }
303 return i2c_add_driver(&pcf8591_driver);
304}
305
306static void __exit pcf8591_exit(void)
307{
308 i2c_del_driver(&pcf8591_driver);
309}
310
311MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
312MODULE_DESCRIPTION("PCF8591 driver");
313MODULE_LICENSE("GPL");
314
315module_init(pcf8591_init);
316module_exit(pcf8591_exit);