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1 | /* | |
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 <jdelvare@suse.de> | |
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 | */ | |
20 | ||
21 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
22 | ||
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> | |
28 | #include <linux/err.h> | |
29 | #include <linux/hwmon.h> | |
30 | ||
31 | /* Insmod parameters */ | |
32 | ||
33 | static int input_mode; | |
34 | module_param(input_mode, int, 0); | |
35 | MODULE_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 | ||
42 | /* | |
43 | * The PCF8591 control byte | |
44 | * 7 6 5 4 3 2 1 0 | |
45 | * | 0 |AOEF| AIP | 0 |AINC| AICH | | |
46 | */ | |
47 | ||
48 | /* Analog Output Enable Flag (analog output active if 1) */ | |
49 | #define PCF8591_CONTROL_AOEF 0x40 | |
50 | ||
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 | */ | |
58 | #define PCF8591_CONTROL_AIP_MASK 0x30 | |
59 | ||
60 | /* Autoincrement Flag (switch on if 1) */ | |
61 | #define PCF8591_CONTROL_AINC 0x04 | |
62 | ||
63 | /* | |
64 | * Channel selection | |
65 | * 0x00 = channel 0 | |
66 | * 0x01 = channel 1 | |
67 | * 0x02 = channel 2 | |
68 | * 0x03 = channel 3 | |
69 | */ | |
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 */ | |
77 | #define REG_TO_SIGNED(reg) (((reg) & 0x80) ? ((reg) - 256) : (reg)) | |
78 | ||
79 | struct pcf8591_data { | |
80 | struct device *hwmon_dev; | |
81 | struct mutex update_lock; | |
82 | ||
83 | u8 control; | |
84 | u8 aout; | |
85 | }; | |
86 | ||
87 | static void pcf8591_init_client(struct i2c_client *client); | |
88 | static int pcf8591_read_channel(struct device *dev, int channel); | |
89 | ||
90 | /* following are the sysfs callback functions */ | |
91 | #define show_in_channel(channel) \ | |
92 | static ssize_t show_in##channel##_input(struct device *dev, \ | |
93 | struct device_attribute *attr, \ | |
94 | char *buf) \ | |
95 | { \ | |
96 | return sprintf(buf, "%d\n", pcf8591_read_channel(dev, channel));\ | |
97 | } \ | |
98 | static DEVICE_ATTR(in##channel##_input, S_IRUGO, \ | |
99 | show_in##channel##_input, NULL); | |
100 | ||
101 | show_in_channel(0); | |
102 | show_in_channel(1); | |
103 | show_in_channel(2); | |
104 | show_in_channel(3); | |
105 | ||
106 | static ssize_t out0_output_show(struct device *dev, | |
107 | struct device_attribute *attr, char *buf) | |
108 | { | |
109 | struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
110 | return sprintf(buf, "%d\n", data->aout * 10); | |
111 | } | |
112 | ||
113 | static ssize_t out0_output_store(struct device *dev, | |
114 | struct device_attribute *attr, | |
115 | const char *buf, size_t count) | |
116 | { | |
117 | unsigned long val; | |
118 | struct i2c_client *client = to_i2c_client(dev); | |
119 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
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; | |
133 | } | |
134 | ||
135 | static DEVICE_ATTR_RW(out0_output); | |
136 | ||
137 | static ssize_t out0_enable_show(struct device *dev, | |
138 | struct device_attribute *attr, char *buf) | |
139 | { | |
140 | struct pcf8591_data *data = i2c_get_clientdata(to_i2c_client(dev)); | |
141 | return sprintf(buf, "%u\n", !(!(data->control & PCF8591_CONTROL_AOEF))); | |
142 | } | |
143 | ||
144 | static ssize_t out0_enable_store(struct device *dev, | |
145 | struct device_attribute *attr, | |
146 | const char *buf, size_t count) | |
147 | { | |
148 | struct i2c_client *client = to_i2c_client(dev); | |
149 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
150 | unsigned long val; | |
151 | int err; | |
152 | ||
153 | err = kstrtoul(buf, 10, &val); | |
154 | if (err) | |
155 | return err; | |
156 | ||
157 | mutex_lock(&data->update_lock); | |
158 | if (val) | |
159 | data->control |= PCF8591_CONTROL_AOEF; | |
160 | else | |
161 | data->control &= ~PCF8591_CONTROL_AOEF; | |
162 | i2c_smbus_write_byte(client, data->control); | |
163 | mutex_unlock(&data->update_lock); | |
164 | return count; | |
165 | } | |
166 | ||
167 | static DEVICE_ATTR_RW(out0_enable); | |
168 | ||
169 | static struct attribute *pcf8591_attributes[] = { | |
170 | &dev_attr_out0_enable.attr, | |
171 | &dev_attr_out0_output.attr, | |
172 | &dev_attr_in0_input.attr, | |
173 | &dev_attr_in1_input.attr, | |
174 | NULL | |
175 | }; | |
176 | ||
177 | static const struct attribute_group pcf8591_attr_group = { | |
178 | .attrs = pcf8591_attributes, | |
179 | }; | |
180 | ||
181 | static struct attribute *pcf8591_attributes_opt[] = { | |
182 | &dev_attr_in2_input.attr, | |
183 | &dev_attr_in3_input.attr, | |
184 | NULL | |
185 | }; | |
186 | ||
187 | static const struct attribute_group pcf8591_attr_group_opt = { | |
188 | .attrs = pcf8591_attributes_opt, | |
189 | }; | |
190 | ||
191 | /* | |
192 | * Real code | |
193 | */ | |
194 | ||
195 | static int pcf8591_probe(struct i2c_client *client, | |
196 | const struct i2c_device_id *id) | |
197 | { | |
198 | struct pcf8591_data *data; | |
199 | int err; | |
200 | ||
201 | data = devm_kzalloc(&client->dev, sizeof(struct pcf8591_data), | |
202 | GFP_KERNEL); | |
203 | if (!data) | |
204 | return -ENOMEM; | |
205 | ||
206 | i2c_set_clientdata(client, data); | |
207 | mutex_init(&data->update_lock); | |
208 | ||
209 | /* Initialize the PCF8591 chip */ | |
210 | pcf8591_init_client(client); | |
211 | ||
212 | /* Register sysfs hooks */ | |
213 | err = sysfs_create_group(&client->dev.kobj, &pcf8591_attr_group); | |
214 | if (err) | |
215 | return err; | |
216 | ||
217 | /* Register input2 if not in "two differential inputs" mode */ | |
218 | if (input_mode != 3) { | |
219 | err = device_create_file(&client->dev, &dev_attr_in2_input); | |
220 | if (err) | |
221 | goto exit_sysfs_remove; | |
222 | } | |
223 | ||
224 | /* Register input3 only in "four single ended inputs" mode */ | |
225 | if (input_mode == 0) { | |
226 | err = device_create_file(&client->dev, &dev_attr_in3_input); | |
227 | if (err) | |
228 | goto exit_sysfs_remove; | |
229 | } | |
230 | ||
231 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
232 | if (IS_ERR(data->hwmon_dev)) { | |
233 | err = PTR_ERR(data->hwmon_dev); | |
234 | goto exit_sysfs_remove; | |
235 | } | |
236 | ||
237 | return 0; | |
238 | ||
239 | exit_sysfs_remove: | |
240 | sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); | |
241 | sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); | |
242 | return err; | |
243 | } | |
244 | ||
245 | static int pcf8591_remove(struct i2c_client *client) | |
246 | { | |
247 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
248 | ||
249 | hwmon_device_unregister(data->hwmon_dev); | |
250 | sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group_opt); | |
251 | sysfs_remove_group(&client->dev.kobj, &pcf8591_attr_group); | |
252 | return 0; | |
253 | } | |
254 | ||
255 | /* Called when we have found a new PCF8591. */ | |
256 | static void pcf8591_init_client(struct i2c_client *client) | |
257 | { | |
258 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
259 | data->control = PCF8591_INIT_CONTROL; | |
260 | data->aout = PCF8591_INIT_AOUT; | |
261 | ||
262 | i2c_smbus_write_byte_data(client, data->control, data->aout); | |
263 | ||
264 | /* | |
265 | * The first byte transmitted contains the conversion code of the | |
266 | * previous read cycle. FLUSH IT! | |
267 | */ | |
268 | i2c_smbus_read_byte(client); | |
269 | } | |
270 | ||
271 | static int pcf8591_read_channel(struct device *dev, int channel) | |
272 | { | |
273 | u8 value; | |
274 | struct i2c_client *client = to_i2c_client(dev); | |
275 | struct pcf8591_data *data = i2c_get_clientdata(client); | |
276 | ||
277 | mutex_lock(&data->update_lock); | |
278 | ||
279 | if ((data->control & PCF8591_CONTROL_AICH_MASK) != channel) { | |
280 | data->control = (data->control & ~PCF8591_CONTROL_AICH_MASK) | |
281 | | channel; | |
282 | i2c_smbus_write_byte(client, data->control); | |
283 | ||
284 | /* | |
285 | * The first byte transmitted contains the conversion code of | |
286 | * the previous read cycle. FLUSH IT! | |
287 | */ | |
288 | i2c_smbus_read_byte(client); | |
289 | } | |
290 | value = i2c_smbus_read_byte(client); | |
291 | ||
292 | mutex_unlock(&data->update_lock); | |
293 | ||
294 | if ((channel == 2 && input_mode == 2) || | |
295 | (channel != 3 && (input_mode == 1 || input_mode == 3))) | |
296 | return 10 * REG_TO_SIGNED(value); | |
297 | else | |
298 | return 10 * value; | |
299 | } | |
300 | ||
301 | static const struct i2c_device_id pcf8591_id[] = { | |
302 | { "pcf8591", 0 }, | |
303 | { } | |
304 | }; | |
305 | MODULE_DEVICE_TABLE(i2c, pcf8591_id); | |
306 | ||
307 | static struct i2c_driver pcf8591_driver = { | |
308 | .driver = { | |
309 | .name = "pcf8591", | |
310 | }, | |
311 | .probe = pcf8591_probe, | |
312 | .remove = pcf8591_remove, | |
313 | .id_table = pcf8591_id, | |
314 | }; | |
315 | ||
316 | static int __init pcf8591_init(void) | |
317 | { | |
318 | if (input_mode < 0 || input_mode > 3) { | |
319 | pr_warn("invalid input_mode (%d)\n", input_mode); | |
320 | input_mode = 0; | |
321 | } | |
322 | return i2c_add_driver(&pcf8591_driver); | |
323 | } | |
324 | ||
325 | static void __exit pcf8591_exit(void) | |
326 | { | |
327 | i2c_del_driver(&pcf8591_driver); | |
328 | } | |
329 | ||
330 | MODULE_AUTHOR("Aurelien Jarno <aurelien@aurel32.net>"); | |
331 | MODULE_DESCRIPTION("PCF8591 driver"); | |
332 | MODULE_LICENSE("GPL"); | |
333 | ||
334 | module_init(pcf8591_init); | |
335 | module_exit(pcf8591_exit); |