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83bffbce PD |
1 | /* |
2 | * Driver for +/-1 degree C, SMBus-Compatible Remote/Local Temperature Sensor | |
3 | * with Overtemperature Alarm | |
4 | * | |
5 | * Copyright (C) 2011 AppearTV AS | |
6 | * | |
7 | * Derived from: | |
8 | * | |
9 | * Based on the max1619 driver. | |
10 | * Copyright (C) 2003-2004 Alexey Fisher <fishor@mail.ru> | |
11 | * Jean Delvare <khali@linux-fr.org> | |
12 | * | |
13 | * The MAX6642 is a sensor chip made by Maxim. | |
14 | * It reports up to two temperatures (its own plus up to | |
15 | * one external one). Complete datasheet can be | |
16 | * obtained from Maxim's website at: | |
17 | * http://datasheets.maxim-ic.com/en/ds/MAX6642.pdf | |
18 | * | |
19 | * This program is free software; you can redistribute it and/or modify | |
20 | * it under the terms of the GNU General Public License as published by | |
21 | * the Free Software Foundation; either version 2 of the License, or | |
22 | * (at your option) any later version. | |
23 | * | |
24 | * This program is distributed in the hope that it will be useful, | |
25 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
26 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
27 | * GNU General Public License for more details. | |
28 | * | |
29 | * You should have received a copy of the GNU General Public License | |
30 | * along with this program; if not, write to the Free Software | |
31 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
32 | */ | |
33 | ||
34 | ||
35 | #include <linux/module.h> | |
36 | #include <linux/init.h> | |
37 | #include <linux/slab.h> | |
38 | #include <linux/jiffies.h> | |
39 | #include <linux/i2c.h> | |
40 | #include <linux/hwmon.h> | |
41 | #include <linux/hwmon-sysfs.h> | |
42 | #include <linux/err.h> | |
43 | #include <linux/mutex.h> | |
44 | #include <linux/sysfs.h> | |
45 | ||
46 | static const unsigned short normal_i2c[] = { | |
47 | 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; | |
48 | ||
49 | /* | |
50 | * The MAX6642 registers | |
51 | */ | |
52 | ||
53 | #define MAX6642_REG_R_MAN_ID 0xFE | |
54 | #define MAX6642_REG_R_CONFIG 0x03 | |
55 | #define MAX6642_REG_W_CONFIG 0x09 | |
56 | #define MAX6642_REG_R_STATUS 0x02 | |
57 | #define MAX6642_REG_R_LOCAL_TEMP 0x00 | |
58 | #define MAX6642_REG_R_LOCAL_TEMPL 0x11 | |
59 | #define MAX6642_REG_R_LOCAL_HIGH 0x05 | |
60 | #define MAX6642_REG_W_LOCAL_HIGH 0x0B | |
61 | #define MAX6642_REG_R_REMOTE_TEMP 0x01 | |
62 | #define MAX6642_REG_R_REMOTE_TEMPL 0x10 | |
63 | #define MAX6642_REG_R_REMOTE_HIGH 0x07 | |
64 | #define MAX6642_REG_W_REMOTE_HIGH 0x0D | |
65 | ||
66 | /* | |
67 | * Conversions | |
68 | */ | |
69 | ||
70 | static int temp_from_reg10(int val) | |
71 | { | |
72 | return val * 250; | |
73 | } | |
74 | ||
75 | static int temp_from_reg(int val) | |
76 | { | |
77 | return val * 1000; | |
78 | } | |
79 | ||
80 | static int temp_to_reg(int val) | |
81 | { | |
82 | return val / 1000; | |
83 | } | |
84 | ||
85 | /* | |
86 | * Client data (each client gets its own) | |
87 | */ | |
88 | ||
89 | struct max6642_data { | |
90 | struct device *hwmon_dev; | |
91 | struct mutex update_lock; | |
92 | bool valid; /* zero until following fields are valid */ | |
93 | unsigned long last_updated; /* in jiffies */ | |
94 | ||
95 | /* registers values */ | |
96 | u16 temp_input[2]; /* local/remote */ | |
97 | u16 temp_high[2]; /* local/remote */ | |
98 | u8 alarms; | |
99 | }; | |
100 | ||
101 | /* | |
102 | * Real code | |
103 | */ | |
104 | ||
105 | static void max6642_init_client(struct i2c_client *client) | |
106 | { | |
107 | u8 config; | |
108 | struct max6642_data *data = i2c_get_clientdata(client); | |
109 | ||
110 | /* | |
111 | * Start the conversions. | |
112 | */ | |
113 | config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG); | |
114 | if (config & 0x40) | |
115 | i2c_smbus_write_byte_data(client, MAX6642_REG_W_CONFIG, | |
116 | config & 0xBF); /* run */ | |
117 | ||
118 | data->temp_high[0] = i2c_smbus_read_byte_data(client, | |
119 | MAX6642_REG_R_LOCAL_HIGH); | |
120 | data->temp_high[1] = i2c_smbus_read_byte_data(client, | |
121 | MAX6642_REG_R_REMOTE_HIGH); | |
122 | } | |
123 | ||
124 | /* Return 0 if detection is successful, -ENODEV otherwise */ | |
125 | static int max6642_detect(struct i2c_client *client, | |
126 | struct i2c_board_info *info) | |
127 | { | |
128 | struct i2c_adapter *adapter = client->adapter; | |
129 | u8 reg_config, reg_status, man_id; | |
130 | ||
131 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
132 | return -ENODEV; | |
133 | ||
134 | /* identification */ | |
135 | man_id = i2c_smbus_read_byte_data(client, MAX6642_REG_R_MAN_ID); | |
136 | if (man_id != 0x4D) | |
137 | return -ENODEV; | |
138 | ||
139 | /* | |
140 | * We read the config and status register, the 4 lower bits in the | |
141 | * config register should be zero and bit 5, 3, 1 and 0 should be | |
142 | * zero in the status register. | |
143 | */ | |
144 | reg_config = i2c_smbus_read_byte_data(client, MAX6642_REG_R_CONFIG); | |
145 | reg_status = i2c_smbus_read_byte_data(client, MAX6642_REG_R_STATUS); | |
146 | if (((reg_config & 0x0f) != 0x00) || | |
147 | ((reg_status & 0x2b) != 0x00)) | |
148 | return -ENODEV; | |
149 | ||
150 | strlcpy(info->type, "max6642", I2C_NAME_SIZE); | |
151 | ||
152 | return 0; | |
153 | } | |
154 | ||
155 | static struct max6642_data *max6642_update_device(struct device *dev) | |
156 | { | |
157 | struct i2c_client *client = to_i2c_client(dev); | |
158 | struct max6642_data *data = i2c_get_clientdata(client); | |
159 | u16 val, tmp; | |
160 | ||
161 | mutex_lock(&data->update_lock); | |
162 | ||
163 | if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { | |
164 | dev_dbg(&client->dev, "Updating max6642 data.\n"); | |
165 | val = i2c_smbus_read_byte_data(client, | |
166 | MAX6642_REG_R_LOCAL_TEMPL); | |
167 | tmp = (val >> 6) & 3; | |
168 | val = i2c_smbus_read_byte_data(client, | |
169 | MAX6642_REG_R_LOCAL_TEMP); | |
170 | val = (val << 2) | tmp; | |
171 | data->temp_input[0] = val; | |
172 | val = i2c_smbus_read_byte_data(client, | |
173 | MAX6642_REG_R_REMOTE_TEMPL); | |
174 | tmp = (val >> 6) & 3; | |
175 | val = i2c_smbus_read_byte_data(client, | |
176 | MAX6642_REG_R_REMOTE_TEMP); | |
177 | val = (val << 2) | tmp; | |
178 | data->temp_input[1] = val; | |
179 | data->alarms = i2c_smbus_read_byte_data(client, | |
180 | MAX6642_REG_R_STATUS); | |
181 | ||
182 | data->last_updated = jiffies; | |
183 | data->valid = 1; | |
184 | } | |
185 | ||
186 | mutex_unlock(&data->update_lock); | |
187 | ||
188 | return data; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Sysfs stuff | |
193 | */ | |
194 | ||
195 | static ssize_t show_temp_max10(struct device *dev, | |
196 | struct device_attribute *dev_attr, char *buf) | |
197 | { | |
198 | struct max6642_data *data = max6642_update_device(dev); | |
199 | struct sensor_device_attribute *attr = to_sensor_dev_attr(dev_attr); | |
200 | ||
201 | return sprintf(buf, "%d\n", | |
202 | temp_from_reg10(data->temp_input[attr->index])); | |
203 | } | |
204 | ||
205 | static ssize_t show_temp_max(struct device *dev, struct device_attribute *attr, | |
206 | char *buf) | |
207 | { | |
208 | struct max6642_data *data = max6642_update_device(dev); | |
209 | struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); | |
210 | ||
211 | return sprintf(buf, "%d\n", temp_from_reg(data->temp_high[attr2->nr])); | |
212 | } | |
213 | ||
214 | static ssize_t set_temp_max(struct device *dev, struct device_attribute *attr, | |
215 | const char *buf, size_t count) | |
216 | { | |
217 | unsigned long val; | |
218 | int err; | |
219 | struct i2c_client *client = to_i2c_client(dev); | |
220 | struct max6642_data *data = i2c_get_clientdata(client); | |
221 | struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr); | |
222 | ||
223 | err = strict_strtoul(buf, 10, &val); | |
224 | if (err < 0) | |
225 | return err; | |
226 | ||
227 | mutex_lock(&data->update_lock); | |
228 | data->temp_high[attr2->nr] = SENSORS_LIMIT(temp_to_reg(val), 0, 255); | |
229 | i2c_smbus_write_byte_data(client, attr2->index, | |
230 | data->temp_high[attr2->nr]); | |
231 | mutex_unlock(&data->update_lock); | |
232 | return count; | |
233 | } | |
234 | ||
235 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, | |
236 | char *buf) | |
237 | { | |
238 | int bitnr = to_sensor_dev_attr(attr)->index; | |
239 | struct max6642_data *data = max6642_update_device(dev); | |
240 | return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1); | |
241 | } | |
242 | ||
243 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_max10, NULL, 0); | |
244 | static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_max10, NULL, 1); | |
245 | static SENSOR_DEVICE_ATTR_2(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, | |
246 | set_temp_max, 0, MAX6642_REG_W_LOCAL_HIGH); | |
247 | static SENSOR_DEVICE_ATTR_2(temp2_max, S_IWUSR | S_IRUGO, show_temp_max, | |
248 | set_temp_max, 1, MAX6642_REG_W_REMOTE_HIGH); | |
249 | static SENSOR_DEVICE_ATTR(temp_fault, S_IRUGO, show_alarm, NULL, 2); | |
250 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6); | |
251 | static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 4); | |
252 | ||
253 | static struct attribute *max6642_attributes[] = { | |
254 | &sensor_dev_attr_temp1_input.dev_attr.attr, | |
255 | &sensor_dev_attr_temp2_input.dev_attr.attr, | |
256 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
257 | &sensor_dev_attr_temp2_max.dev_attr.attr, | |
258 | ||
259 | &sensor_dev_attr_temp_fault.dev_attr.attr, | |
260 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
261 | &sensor_dev_attr_temp2_max_alarm.dev_attr.attr, | |
262 | NULL | |
263 | }; | |
264 | ||
265 | static const struct attribute_group max6642_group = { | |
266 | .attrs = max6642_attributes, | |
267 | }; | |
268 | ||
269 | static int max6642_probe(struct i2c_client *new_client, | |
270 | const struct i2c_device_id *id) | |
271 | { | |
272 | struct max6642_data *data; | |
273 | int err; | |
274 | ||
275 | data = kzalloc(sizeof(struct max6642_data), GFP_KERNEL); | |
276 | if (!data) { | |
277 | err = -ENOMEM; | |
278 | goto exit; | |
279 | } | |
280 | ||
281 | i2c_set_clientdata(new_client, data); | |
282 | mutex_init(&data->update_lock); | |
283 | ||
284 | /* Initialize the MAX6642 chip */ | |
285 | max6642_init_client(new_client); | |
286 | ||
287 | /* Register sysfs hooks */ | |
288 | err = sysfs_create_group(&new_client->dev.kobj, &max6642_group); | |
289 | if (err) | |
290 | goto exit_free; | |
291 | ||
292 | data->hwmon_dev = hwmon_device_register(&new_client->dev); | |
293 | if (IS_ERR(data->hwmon_dev)) { | |
294 | err = PTR_ERR(data->hwmon_dev); | |
295 | goto exit_remove_files; | |
296 | } | |
297 | ||
298 | return 0; | |
299 | ||
300 | exit_remove_files: | |
301 | sysfs_remove_group(&new_client->dev.kobj, &max6642_group); | |
302 | exit_free: | |
303 | kfree(data); | |
304 | exit: | |
305 | return err; | |
306 | } | |
307 | ||
308 | static int max6642_remove(struct i2c_client *client) | |
309 | { | |
310 | struct max6642_data *data = i2c_get_clientdata(client); | |
311 | ||
312 | hwmon_device_unregister(data->hwmon_dev); | |
313 | sysfs_remove_group(&client->dev.kobj, &max6642_group); | |
314 | ||
315 | kfree(data); | |
316 | return 0; | |
317 | } | |
318 | ||
319 | /* | |
320 | * Driver data (common to all clients) | |
321 | */ | |
322 | ||
323 | static const struct i2c_device_id max6642_id[] = { | |
324 | { "max6642", 0 }, | |
325 | { } | |
326 | }; | |
327 | MODULE_DEVICE_TABLE(i2c, max6642_id); | |
328 | ||
329 | static struct i2c_driver max6642_driver = { | |
330 | .class = I2C_CLASS_HWMON, | |
331 | .driver = { | |
332 | .name = "max6642", | |
333 | }, | |
334 | .probe = max6642_probe, | |
335 | .remove = max6642_remove, | |
336 | .id_table = max6642_id, | |
337 | .detect = max6642_detect, | |
338 | .address_list = normal_i2c, | |
339 | }; | |
340 | ||
341 | static int __init max6642_init(void) | |
342 | { | |
343 | return i2c_add_driver(&max6642_driver); | |
344 | } | |
345 | ||
346 | static void __exit max6642_exit(void) | |
347 | { | |
348 | i2c_del_driver(&max6642_driver); | |
349 | } | |
350 | ||
351 | MODULE_AUTHOR("Per Dalen <per.dalen@appeartv.com>"); | |
352 | MODULE_DESCRIPTION("MAX6642 sensor driver"); | |
353 | MODULE_LICENSE("GPL"); | |
354 | ||
355 | module_init(max6642_init); | |
356 | module_exit(max6642_exit); |