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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> | |
1da177e4 LT |
27 | |
28 | /* Addresses to scan */ | |
29 | static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, | |
30 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; | |
1da177e4 LT |
31 | |
32 | /* Insmod parameters */ | |
f4b50261 | 33 | I2C_CLIENT_INSMOD_1(pcf8591); |
1da177e4 LT |
34 | |
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"); | |
43 | ||
44 | /* The PCF8591 control byte | |
45 | 7 6 5 4 3 2 1 0 | |
46 | | 0 |AOEF| AIP | 0 |AINC| AICH | */ | |
47 | ||
48 | /* Analog Output Enable Flag (analog output active if 1) */ | |
49 | #define PCF8591_CONTROL_AOEF 0x40 | |
50 | ||
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 | |
57 | ||
58 | /* Autoincrement Flag (switch on if 1) */ | |
59 | #define PCF8591_CONTROL_AINC 0x04 | |
60 | ||
61 | /* Channel selection | |
62 | 0x00 = channel 0 | |
63 | 0x01 = channel 1 | |
64 | 0x02 = channel 2 | |
65 | 0x03 = channel 3 */ | |
66 | #define PCF8591_CONTROL_AICH_MASK 0x03 | |
67 | ||
68 | /* Initial values */ | |
69 | #define PCF8591_INIT_CONTROL ((input_mode << 4) | PCF8591_CONTROL_AOEF) | |
70 | #define PCF8591_INIT_AOUT 0 /* DAC out = 0 */ | |
71 | ||
72 | /* Conversions */ | |
73 | #define REG_TO_SIGNED(reg) (((reg) & 0x80)?((reg) - 256):(reg)) | |
74 | ||
75 | struct pcf8591_data { | |
76 | struct i2c_client client; | |
77 | struct semaphore update_lock; | |
78 | ||
79 | u8 control; | |
80 | u8 aout; | |
81 | }; | |
82 | ||
83 | static int pcf8591_attach_adapter(struct i2c_adapter *adapter); | |
84 | static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind); | |
85 | static int pcf8591_detach_client(struct i2c_client *client); | |
86 | static void pcf8591_init_client(struct i2c_client *client); | |
87 | static int pcf8591_read_channel(struct device *dev, int channel); | |
88 | ||
89 | /* This is the driver that will be inserted */ | |
90 | static struct i2c_driver pcf8591_driver = { | |
a9718b0c | 91 | .driver = { |
a9718b0c LR |
92 | .name = "pcf8591", |
93 | }, | |
1da177e4 | 94 | .id = I2C_DRIVERID_PCF8591, |
1da177e4 LT |
95 | .attach_adapter = pcf8591_attach_adapter, |
96 | .detach_client = pcf8591_detach_client, | |
97 | }; | |
98 | ||
99 | /* following are the sysfs callback functions */ | |
100 | #define show_in_channel(channel) \ | |
a5099cfc | 101 | static ssize_t show_in##channel##_input(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
102 | { \ |
103 | return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\ | |
104 | } \ | |
105 | static DEVICE_ATTR(in##channel##_input, S_IRUGO, \ | |
106 | show_in##channel##_input, NULL); | |
107 | ||
108 | show_in_channel(0); | |
109 | show_in_channel(1); | |
110 | show_in_channel(2); | |
111 | show_in_channel(3); | |
112 | ||
a5099cfc | 113 | static ssize_t show_out0_ouput(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
114 | { |
115 | struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
116 | return sprintf(buf, "%d\n", data->aout * 10); | |
117 | } | |
118 | ||
a5099cfc | 119 | static ssize_t set_out0_output(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
120 | { |
121 | unsigned int value; | |
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) { | |
125 | data->aout = value; | |
126 | i2c_smbus_write_byte_data(client, data->control, data->aout); | |
127 | return count; | |
128 | } | |
129 | return -EINVAL; | |
130 | } | |
131 | ||
132 | static DEVICE_ATTR(out0_output, S_IWUSR | S_IRUGO, | |
133 | show_out0_ouput, set_out0_output); | |
134 | ||
a5099cfc | 135 | static ssize_t show_out0_enable(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
136 | { |
137 | struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
138 | return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF))); | |
139 | } | |
140 | ||
a5099cfc | 141 | static ssize_t set_out0_enable(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
142 | { |
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); | |
146 | ||
147 | down(&data->update_lock); | |
148 | if (val) | |
149 | data->control |= PCF8591_CONTROL_AOEF; | |
150 | else | |
151 | data->control &= ~PCF8591_CONTROL_AOEF; | |
152 | i2c_smbus_write_byte(client, data->control); | |
153 | up(&data->update_lock); | |
154 | return count; | |
155 | } | |
156 | ||
157 | static DEVICE_ATTR(out0_enable, S_IWUSR | S_IRUGO, | |
158 | show_out0_enable, set_out0_enable); | |
159 | ||
160 | /* | |
161 | * Real code | |
162 | */ | |
163 | static int pcf8591_attach_adapter(struct i2c_adapter *adapter) | |
164 | { | |
2ed2dc3c | 165 | return i2c_probe(adapter, &addr_data, pcf8591_detect); |
1da177e4 LT |
166 | } |
167 | ||
2ed2dc3c | 168 | /* This function is called by i2c_probe */ |
6344a8ec | 169 | static int pcf8591_detect(struct i2c_adapter *adapter, int address, int kind) |
1da177e4 LT |
170 | { |
171 | struct i2c_client *new_client; | |
172 | struct pcf8591_data *data; | |
173 | int err = 0; | |
174 | ||
175 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE | |
176 | | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) | |
177 | goto exit; | |
178 | ||
179 | /* OK. For now, we presume we have a valid client. We now create the | |
180 | client structure, even though we cannot fill it completely yet. */ | |
5263ebb5 | 181 | if (!(data = kzalloc(sizeof(struct pcf8591_data), GFP_KERNEL))) { |
1da177e4 LT |
182 | err = -ENOMEM; |
183 | goto exit; | |
184 | } | |
1da177e4 LT |
185 | |
186 | new_client = &data->client; | |
187 | i2c_set_clientdata(new_client, data); | |
188 | new_client->addr = address; | |
189 | new_client->adapter = adapter; | |
190 | new_client->driver = &pcf8591_driver; | |
191 | new_client->flags = 0; | |
192 | ||
193 | /* Now, we would do the remaining detection. But the PCF8591 is plainly | |
194 | impossible to detect! Stupid chip. */ | |
195 | ||
196 | /* Determine the chip type - only one kind supported! */ | |
197 | if (kind <= 0) | |
198 | kind = pcf8591; | |
199 | ||
200 | /* Fill in the remaining client fields and put it into the global | |
201 | list */ | |
202 | strlcpy(new_client->name, "pcf8591", I2C_NAME_SIZE); | |
203 | init_MUTEX(&data->update_lock); | |
204 | ||
205 | /* Tell the I2C layer a new client has arrived */ | |
206 | if ((err = i2c_attach_client(new_client))) | |
207 | goto exit_kfree; | |
208 | ||
209 | /* Initialize the PCF8591 chip */ | |
210 | pcf8591_init_client(new_client); | |
211 | ||
212 | /* Register sysfs hooks */ | |
213 | device_create_file(&new_client->dev, &dev_attr_out0_enable); | |
214 | device_create_file(&new_client->dev, &dev_attr_out0_output); | |
215 | device_create_file(&new_client->dev, &dev_attr_in0_input); | |
216 | device_create_file(&new_client->dev, &dev_attr_in1_input); | |
217 | ||
218 | /* Register input2 if not in "two differential inputs" mode */ | |
219 | if (input_mode != 3 ) | |
220 | device_create_file(&new_client->dev, &dev_attr_in2_input); | |
221 | ||
222 | /* Register input3 only in "four single ended inputs" mode */ | |
223 | if (input_mode == 0) | |
224 | device_create_file(&new_client->dev, &dev_attr_in3_input); | |
225 | ||
226 | return 0; | |
227 | ||
228 | /* OK, this is not exactly good programming practice, usually. But it is | |
229 | very code-efficient in this case. */ | |
230 | ||
231 | exit_kfree: | |
232 | kfree(data); | |
233 | exit: | |
234 | return err; | |
235 | } | |
236 | ||
237 | static int pcf8591_detach_client(struct i2c_client *client) | |
238 | { | |
239 | int err; | |
240 | ||
7bef5594 | 241 | if ((err = i2c_detach_client(client))) |
1da177e4 | 242 | return err; |
1da177e4 LT |
243 | |
244 | kfree(i2c_get_clientdata(client)); | |
245 | return 0; | |
246 | } | |
247 | ||
248 | /* Called when we have found a new PCF8591. */ | |
249 | static void pcf8591_init_client(struct i2c_client *client) | |
250 | { | |
251 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
252 | data->control = PCF8591_INIT_CONTROL; | |
253 | data->aout = PCF8591_INIT_AOUT; | |
254 | ||
255 | i2c_smbus_write_byte_data(client, data->control, data->aout); | |
256 | ||
257 | /* The first byte transmitted contains the conversion code of the | |
258 | previous read cycle. FLUSH IT! */ | |
259 | i2c_smbus_read_byte(client); | |
260 | } | |
261 | ||
262 | static int pcf8591_read_channel(struct device *dev, int channel) | |
263 | { | |
264 | u8 value; | |
265 | struct i2c_client *client = to_i2c_client(dev); | |
266 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
267 | ||
268 | down(&data->update_lock); | |
269 | ||
270 | if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) { | |
271 | data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK) | |
272 | | channel; | |
273 | i2c_smbus_write_byte(client, data->control); | |
274 | ||
275 | /* The first byte transmitted contains the conversion code of | |
276 | the previous read cycle. FLUSH IT! */ | |
277 | i2c_smbus_read_byte(client); | |
278 | } | |
279 | value = i2c_smbus_read_byte(client); | |
280 | ||
281 | up(&data->update_lock); | |
282 | ||
283 | if ((channel == 2 && input_mode == 2) || | |
284 | (channel != 3 && (input_mode == 1 || input_mode == 3))) | |
285 | return (10 * REG_TO_SIGNED(value)); | |
286 | else | |
287 | return (10 * value); | |
288 | } | |
289 | ||
290 | static int __init pcf8591_init(void) | |
291 | { | |
292 | if (input_mode < 0 || input_mode > 3) { | |
293 | printk(KERN_WARNING "pcf8591: invalid input_mode (%d)\n", | |
294 | input_mode); | |
295 | input_mode = 0; | |
296 | } | |
297 | return i2c_add_driver(&pcf8591_driver); | |
298 | } | |
299 | ||
300 | static void __exit pcf8591_exit(void) | |
301 | { | |
302 | i2c_del_driver(&pcf8591_driver); | |
303 | } | |
304 | ||
305 | MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); | |
306 | MODULE_DESCRIPTION("PCF8591 driver"); | |
307 | MODULE_LICENSE("GPL"); | |
308 | ||
309 | module_init(pcf8591_init); | |
310 | module_exit(pcf8591_exit); |