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1da177e4 LT |
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> | |
5c085d36 | 27 | #include <linux/mutex.h> |
1da177e4 LT |
28 | |
29 | /* Addresses to scan */ | |
30 | static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, | |
31 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; | |
1da177e4 LT |
32 | |
33 | /* Insmod parameters */ | |
f4b50261 | 34 | I2C_CLIENT_INSMOD_1(pcf8591); |
1da177e4 LT |
35 | |
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"); | |
44 | ||
45 | /* The PCF8591 control byte | |
46 | 7 6 5 4 3 2 1 0 | |
47 | | 0 |AOEF| AIP | 0 |AINC| AICH | */ | |
48 | ||
49 | /* Analog Output Enable Flag (analog output active if 1) */ | |
50 | #define PCF8591_CONTROL_AOEF 0x40 | |
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 | #define PCF8591_CONTROL_AIP_MASK 0x30 | |
58 | ||
59 | /* Autoincrement Flag (switch on if 1) */ | |
60 | #define PCF8591_CONTROL_AINC 0x04 | |
61 | ||
62 | /* Channel selection | |
63 | 0x00 = channel 0 | |
64 | 0x01 = channel 1 | |
65 | 0x02 = channel 2 | |
66 | 0x03 = channel 3 */ | |
67 | #define PCF8591_CONTROL_AICH_MASK 0x03 | |
68 | ||
69 | /* Initial values */ | |
70 | #define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF) | |
71 | #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */ | |
72 | ||
73 | /* Conversions */ | |
74 | #define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg)) | |
75 | ||
76 | struct pcf8591_data { | |
77 | struct i2c_client client; | |
5c085d36 | 78 | struct mutex update_lock; |
1da177e4 LT |
79 | |
80 | u8 control; | |
81 | u8 aout; | |
82 | }; | |
83 | ||
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); | |
89 | ||
90 | /* This is the driver that will be inserted */ | |
91 | static struct i2c_driver pcf8591_driver = { | |
a9718b0c | 92 | .driver = { |
a9718b0c LR |
93 | .name = "pcf8591", |
94 | }, | |
1da177e4 | 95 | .id = I2C_DRIVERID_PCF8591, |
1da177e4 LT |
96 | .attach_adapter = pcf8591_attach_adapter, |
97 | .detach_client = pcf8591_detach_client, | |
98 | }; | |
99 | ||
100 | /* following are the sysfs callback functions */ | |
101 | #define show_in_channel(channel) \ | |
a5099cfc | 102 | static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
103 | { \ |
104 | return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\ | |
105 | } \ | |
106 | static DEVICE_ATTR(in##channel##_input, S_IRUGO, \ | |
107 | show_in##channel##_input, NULL); | |
108 | ||
109 | show_in_channel(0); | |
110 | show_in_channel(1); | |
111 | show_in_channel(2); | |
112 | show_in_channel(3); | |
113 | ||
a5099cfc | 114 | static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
115 | { |
116 | struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
117 | return sprintf(buf, "%d\n", data->aout * 10); | |
118 | } | |
119 | ||
a5099cfc | 120 | static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
121 | { |
122 | unsigned int value; | |
123 | struct i2c_client *client = to_i2c_client(dev); | |
124 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
125 | if ((value = (simple_strtoul(buf, NULL, 10) + 5) / 10) <= 255) { | |
126 | data->aout = value; | |
127 | i2c_smbus_write_byte_data(client, data->control, data->aout); | |
128 | return count; | |
129 | } | |
130 | return -EINVAL; | |
131 | } | |
132 | ||
133 | static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO, | |
134 | show_out0_ouput, set_out0_output); | |
135 | ||
a5099cfc | 136 | static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
137 | { |
138 | struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
139 | return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF))); | |
140 | } | |
141 | ||
a5099cfc | 142 | static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
143 | { |
144 | struct i2c_client *client = to_i2c_client(dev); | |
145 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
146 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
147 | ||
5c085d36 | 148 | mutex_lock(&data->update_lock); |
1da177e4 LT |
149 | if (val) |
150 | data->control |= PCF8591_CONTROL_AOEF; | |
151 | else | |
152 | data->control &= ~PCF8591_CONTROL_AOEF; | |
153 | i2c_smbus_write_byte(client, data->control); | |
5c085d36 | 154 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
155 | return count; |
156 | } | |
157 | ||
158 | static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO, | |
159 | show_out0_enable, set_out0_enable); | |
160 | ||
161 | /* | |
162 | * Real code | |
163 | */ | |
164 | static int pcf8591_attach_adapter(struct i2c_adapter *adapter) | |
165 | { | |
2ed2dc3c | 166 | return i2c_probe(adapter, &addr_data, pcf8591_detect); |
1da177e4 LT |
167 | } |
168 | ||
2ed2dc3c | 169 | /* This function is called by i2c_probe */ |
6344a8ec | 170 | static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind) |
1da177e4 LT |
171 | { |
172 | struct i2c_client *new_client; | |
173 | struct pcf8591_data *data; | |
174 | int err = 0; | |
175 | ||
176 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE | |
177 | | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) | |
178 | goto exit; | |
179 | ||
180 | /* OK. For now, we presume we have a valid client. We now create the | |
181 | client structure, even though we cannot fill it completely yet. */ | |
5263ebb5 | 182 | if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) { |
1da177e4 LT |
183 | err = -ENOMEM; |
184 | goto exit; | |
185 | } | |
1da177e4 LT |
186 | |
187 | new_client = &data->client; | |
188 | i2c_set_clientdata(new_client, data); | |
189 | new_client->addr = address; | |
190 | new_client->adapter = adapter; | |
191 | new_client->driver = &pcf8591_driver; | |
192 | new_client->flags = 0; | |
193 | ||
194 | /* Now, we would do the remaining detection. But the PCF8591 is plainly | |
195 | impossible to detect! Stupid chip. */ | |
196 | ||
197 | /* Determine the chip type - only one kind supported! */ | |
198 | if (kind <= 0) | |
199 | kind = pcf8591; | |
200 | ||
201 | /* Fill in the remaining client fields and put it into the global | |
202 | list */ | |
203 | strlcpy(new_client->name, "pcf8591", I2C_NAME_SIZE); | |
5c085d36 | 204 | mutex_init(&data->update_lock); |
1da177e4 LT |
205 | |
206 | /* Tell the I2C layer a new client has arrived */ | |
207 | if ((err = i2c_attach_client(new_client))) | |
208 | goto exit_kfree; | |
209 | ||
210 | /* Initialize the PCF8591 chip */ | |
211 | pcf8591_init_client(new_client); | |
212 | ||
213 | /* Register sysfs hooks */ | |
214 | device_create_file(&new_client->dev, &dev_attr_out0_enable); | |
215 | device_create_file(&new_client->dev, &dev_attr_out0_output); | |
216 | device_create_file(&new_client->dev, &dev_attr_in0_input); | |
217 | device_create_file(&new_client->dev, &dev_attr_in1_input); | |
218 | ||
219 | /* Register input2 if not in "two differential inputs" mode */ | |
220 | if (input_mode != 3 ) | |
221 | device_create_file(&new_client->dev, &dev_attr_in2_input); | |
222 | ||
223 | /* Register input3 only in "four single ended inputs" mode */ | |
224 | if (input_mode == 0) | |
225 | device_create_file(&new_client->dev, &dev_attr_in3_input); | |
226 | ||
227 | return 0; | |
228 | ||
229 | /* OK, this is not exactly good programming practice, usually. But it is | |
230 | very code-efficient in this case. */ | |
231 | ||
232 | exit_kfree: | |
233 | kfree(data); | |
234 | exit: | |
235 | return err; | |
236 | } | |
237 | ||
238 | static int pcf8591_detach_client(struct i2c_client *client) | |
239 | { | |
240 | int err; | |
241 | ||
7bef5594 | 242 | if ((err = i2c_detach_client(client))) |
1da177e4 | 243 | return err; |
1da177e4 LT |
244 | |
245 | kfree(i2c_get_clientdata(client)); | |
246 | return 0; | |
247 | } | |
248 | ||
249 | /* Called when we have found a new PCF8591. */ | |
250 | static void pcf8591_init_client(struct i2c_client *client) | |
251 | { | |
252 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
253 | data->control = PCF8591_INIT_CONTROL; | |
254 | data->aout = PCF8591_INIT_AOUT; | |
255 | ||
256 | i2c_smbus_write_byte_data(client, data->control, data->aout); | |
257 | ||
258 | /* The first byte transmitted contains the conversion code of the | |
259 | previous read cycle. FLUSH IT! */ | |
260 | i2c_smbus_read_byte(client); | |
261 | } | |
262 | ||
263 | static int pcf8591_read_channel(struct device *dev, int channel) | |
264 | { | |
265 | u8 value; | |
266 | struct i2c_client *client = to_i2c_client(dev); | |
267 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
268 | ||
5c085d36 | 269 | mutex_lock(&data->update_lock); |
1da177e4 LT |
270 | |
271 | if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) { | |
272 | data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK) | |
273 | | channel; | |
274 | i2c_smbus_write_byte(client, data->control); | |
275 | ||
276 | /* The first byte transmitted contains the conversion code of | |
277 | the previous read cycle. FLUSH IT! */ | |
278 | i2c_smbus_read_byte(client); | |
279 | } | |
280 | value = i2c_smbus_read_byte(client); | |
281 | ||
5c085d36 | 282 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
283 | |
284 | if ((channel == 2 && input_mode == 2) || | |
285 | (channel != 3 && (input_mode == 1 || input_mode == 3))) | |
286 | return (10 * REG_TO_SIGNED(value)); | |
287 | else | |
288 | return (10 * value); | |
289 | } | |
290 | ||
291 | static int __init pcf8591_init(void) | |
292 | { | |
293 | if (input_mode < 0 || input_mode > 3) { | |
294 | printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n", | |
295 | input_mode); | |
296 | input_mode = 0; | |
297 | } | |
298 | return i2c_add_driver(&pcf8591_driver); | |
299 | } | |
300 | ||
301 | static void __exit pcf8591_exit(void) | |
302 | { | |
303 | i2c_del_driver(&pcf8591_driver); | |
304 | } | |
305 | ||
306 | MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); | |
307 | MODULE_DESCRIPTION("PCF8591 driver"); | |
308 | MODULE_LICENSE("GPL"); | |
309 | ||
310 | module_init(pcf8591_init); | |
311 | module_exit(pcf8591_exit); |