drm/exynos: Remove dummy encoder get_crtc operation implementation
[deliverable/linux.git] / drivers / hwmon / pcf8591.c
CommitLineData
1da177e4 1/*
57256088
GR
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>
5 *
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.
10 *
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.
15 *
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.
19 */
1da177e4 20
2caec134
JP
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
1da177e4
LT
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/i2c.h>
5c085d36 27#include <linux/mutex.h>
4275fcd6
JD
28#include <linux/err.h>
29#include <linux/hwmon.h>
1da177e4 30
1da177e4 31/* Insmod parameters */
1da177e4
LT
32
33static int input_mode;
34module_param(input_mode, int, 0);
35MODULE_PARM_DESC(input_mode,
36 "Analog input mode:\n"
37 " 0 = four single ended inputs\n"
38 " 1 = three differential inputs\n"
39 " 2 = single ended and differential mixed\n"
40 " 3 = two differential inputs\n");
41
57256088
GR
42/*
43 * The PCF8591 control byte
44 * 7 6 5 4 3 2 1 0
45 * | 0 |AOEF| AIP | 0 |AINC| AICH |
46 */
1da177e4
LT
47
48/* Analog Output Enable Flag (analog output active if 1) */
49#define PCF8591_CONTROL_AOEF 0x40
fb4504fe 50
57256088
GR
51/*
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 */
1da177e4
LT
58#define PCF8591_CONTROL_AIP_MASK 0x30
59
60/* Autoincrement Flag (switch on if 1) */
61#define PCF8591_CONTROL_AINC 0x04
62
57256088
GR
63/*
64 * Channel selection
65 * 0x00 = channel 0
66 * 0x01 = channel 1
67 * 0x02 = channel 2
68 * 0x03 = channel 3
69 */
1da177e4
LT
70#define PCF8591_CONTROL_AICH_MASK 0x03
71
72/* Initial values */
73#define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF)
74#define PCF8591_INIT_AOUT 0 /* DAC out = 0 */
75
76/* Conversions */
57256088 77#define REG_TO_SIGNED(reg) (((reg) & 0x80) ? ((reg) - 256) : (reg))
1da177e4
LT
78
79struct pcf8591_data {
4275fcd6 80 struct device *hwmon_dev;
5c085d36 81 struct mutex update_lock;
1da177e4
LT
82
83 u8 control;
84 u8 aout;
85};
86
1da177e4
LT
87static void pcf8591_init_client(struct i2c_client *client);
88static int pcf8591_read_channel(struct device *dev, int channel);
89
1da177e4
LT
90/* following are the sysfs callback functions */
91#define show_in_channel(channel) \
57256088
GR
92static ssize_t show_in##channel##_input(struct device *dev, \
93 struct device_attribute *attr, \
94 char *buf) \
1da177e4
LT
95{ \
96 return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\
97} \
98static DEVICE_ATTR(in##channel##_input, S_IRUGO, \
99 show_in##channel##_input, NULL);
100
101show_in_channel(0);
102show_in_channel(1);
103show_in_channel(2);
104show_in_channel(3);
105
57256088
GR
106static ssize_t show_out0_ouput(struct device *dev,
107 struct device_attribute *attr, char *buf)
1da177e4
LT
108{
109 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
110 return sprintf(buf, "%d\n", data->aout * 10);
111}
112
57256088
GR
113static ssize_t set_out0_output(struct device *dev,
114 struct device_attribute *attr,
115 const char *buf, size_t count)
1da177e4 116{
57256088 117 unsigned long val;
1da177e4
LT
118 struct i2c_client *client = to_i2c_client(dev);
119 struct pcf8591_data *data = i2c_get_clientdata(client);
57256088
GR
120 int err;
121
122 err = kstrtoul(buf, 10, &val);
123 if (err)
124 return err;
125
126 val /= 10;
127 if (val > 255)
128 return -EINVAL;
129
130 data->aout = val;
131 i2c_smbus_write_byte_data(client, data->control, data->aout);
132 return count;
1da177e4
LT
133}
134
fb4504fe 135static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO,
1da177e4
LT
136 show_out0_ouput, set_out0_output);
137
57256088
GR
138static ssize_t show_out0_enable(struct device *dev,
139 struct device_attribute *attr, char *buf)
1da177e4
LT
140{
141 struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev));
142 return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF)));
143}
144
57256088
GR
145static ssize_t set_out0_enable(struct device *dev,
146 struct device_attribute *attr,
147 const char *buf, size_t count)
1da177e4
LT
148{
149 struct i2c_client *client = to_i2c_client(dev);
150 struct pcf8591_data *data = i2c_get_clientdata(client);
57256088
GR
151 unsigned long val;
152 int err;
153
154 err = kstrtoul(buf, 10, &val);
155 if (err)
156 return err;
1da177e4 157
5c085d36 158 mutex_lock(&data->update_lock);
1da177e4
LT
159 if (val)
160 data->control |= PCF8591_CONTROL_AOEF;
161 else
162 data->control &= ~PCF8591_CONTROL_AOEF;
163 i2c_smbus_write_byte(client, data->control);
5c085d36 164 mutex_unlock(&data->update_lock);
1da177e4
LT
165 return count;
166}
167
fb4504fe 168static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO,
1da177e4
LT
169 show_out0_enable, set_out0_enable);
170
7d9db67f
JD
171static struct attribute *pcf8591_attributes[] = {
172 &dev_attr_out0_enable.attr,
173 &dev_attr_out0_output.attr,
174 &dev_attr_in0_input.attr,
175 &dev_attr_in1_input.attr,
176 NULL
177};
178
179static const struct attribute_group pcf8591_attr_group = {
180 .attrs = pcf8591_attributes,
181};
182
183static struct attribute *pcf8591_attributes_opt[] = {
184 &dev_attr_in2_input.attr,
185 &dev_attr_in3_input.attr,
186 NULL
187};
188
189static const struct attribute_group pcf8591_attr_group_opt = {
190 .attrs = pcf8591_attributes_opt,
191};
192
1da177e4
LT
193/*
194 * Real code
195 */
1da177e4 196
8b77e6ac
JD
197static int pcf8591_probe(struct i2c_client *client,
198 const struct i2c_device_id *id)
199{
200 struct pcf8591_data *data;
201 int err;
1da177e4 202
57256088
GR
203 data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL);
204 if (!data) {
1da177e4
LT
205 err = -ENOMEM;
206 goto exit;
207 }
fb4504fe 208
f741f673 209 i2c_set_clientdata(client, data);
5c085d36 210 mutex_init(&data->update_lock);
1da177e4 211
1da177e4 212 /* Initialize the PCF8591 chip */
f741f673 213 pcf8591_init_client(client);
1da177e4
LT
214
215 /* Register sysfs hooks */
f741f673 216 err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group);
7d9db67f 217 if (err)
8b77e6ac 218 goto exit_kfree;
1da177e4
LT
219
220 /* Register input2 if not in "two differential inputs" mode */
7d9db67f 221 if (input_mode != 3) {
57256088
GR
222 err = device_create_file(&client->dev, &dev_attr_in2_input);
223 if (err)
7d9db67f
JD
224 goto exit_sysfs_remove;
225 }
226
1da177e4 227 /* Register input3 only in "four single ended inputs" mode */
7d9db67f 228 if (input_mode == 0) {
57256088
GR
229 err = device_create_file(&client->dev, &dev_attr_in3_input);
230 if (err)
7d9db67f
JD
231 goto exit_sysfs_remove;
232 }
233
4275fcd6
JD
234 data->hwmon_dev = hwmon_device_register(&client->dev);
235 if (IS_ERR(data->hwmon_dev)) {
236 err = PTR_ERR(data->hwmon_dev);
237 goto exit_sysfs_remove;
238 }
239
1da177e4 240 return 0;
1da177e4 241
7d9db67f 242exit_sysfs_remove:
f741f673
JD
243 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
244 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
1da177e4
LT
245exit_kfree:
246 kfree(data);
247exit:
248 return err;
249}
250
8b77e6ac 251static int pcf8591_remove(struct i2c_client *client)
1da177e4 252{
4275fcd6
JD
253 struct pcf8591_data *data = i2c_get_clientdata(client);
254
255 hwmon_device_unregister(data->hwmon_dev);
7d9db67f
JD
256 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt);
257 sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group);
1da177e4
LT
258 kfree(i2c_get_clientdata(client));
259 return 0;
260}
261
262/* Called when we have found a new PCF8591. */
263static void pcf8591_init_client(struct i2c_client *client)
264{
265 struct pcf8591_data *data = i2c_get_clientdata(client);
266 data->control = PCF8591_INIT_CONTROL;
267 data->aout = PCF8591_INIT_AOUT;
268
269 i2c_smbus_write_byte_data(client, data->control, data->aout);
fb4504fe 270
57256088
GR
271 /*
272 * The first byte transmitted contains the conversion code of the
273 * previous read cycle. FLUSH IT!
274 */
1da177e4
LT
275 i2c_smbus_read_byte(client);
276}
277
278static int pcf8591_read_channel(struct device *dev, int channel)
279{
280 u8 value;
281 struct i2c_client *client = to_i2c_client(dev);
282 struct pcf8591_data *data = i2c_get_clientdata(client);
283
5c085d36 284 mutex_lock(&data->update_lock);
1da177e4
LT
285
286 if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) {
287 data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK)
288 | channel;
289 i2c_smbus_write_byte(client, data->control);
fb4504fe 290
57256088
GR
291 /*
292 * The first byte transmitted contains the conversion code of
293 * the previous read cycle. FLUSH IT!
294 */
1da177e4
LT
295 i2c_smbus_read_byte(client);
296 }
297 value = i2c_smbus_read_byte(client);
298
5c085d36 299 mutex_unlock(&data->update_lock);
1da177e4
LT
300
301 if ((channel == 2 && input_mode == 2) ||
302 (channel != 3 && (input_mode == 1 || input_mode == 3)))
7fe83ad8 303 return 10 * REG_TO_SIGNED(value);
1da177e4 304 else
7fe83ad8 305 return 10 * value;
1da177e4
LT
306}
307
8b77e6ac
JD
308static const struct i2c_device_id pcf8591_id[] = {
309 { "pcf8591", 0 },
310 { }
311};
312MODULE_DEVICE_TABLE(i2c, pcf8591_id);
313
314static struct i2c_driver pcf8591_driver = {
315 .driver = {
316 .name = "pcf8591",
317 },
318 .probe = pcf8591_probe,
319 .remove = pcf8591_remove,
320 .id_table = pcf8591_id,
8b77e6ac
JD
321};
322
1da177e4
LT
323static int __init pcf8591_init(void)
324{
325 if (input_mode < 0 || input_mode > 3) {
2caec134 326 pr_warn("invalid input_mode (%d)\n", input_mode);
1da177e4
LT
327 input_mode = 0;
328 }
329 return i2c_add_driver(&pcf8591_driver);
330}
331
332static void __exit pcf8591_exit(void)
333{
334 i2c_del_driver(&pcf8591_driver);
335}
336
337MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>");
338MODULE_DESCRIPTION("PCF8591 driver");
339MODULE_LICENSE("GPL");
340
341module_init(pcf8591_init);
342module_exit(pcf8591_exit);
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