GNU Linux-libre 4.9.328-gnu1
[releases.git] / drivers / hwmon / lm95241.c
1 /*
2  * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
3  *
4  * The LM95241 is a sensor chip made by National Semiconductors.
5  * It reports up to three temperatures (its own plus up to two external ones).
6  * Complete datasheet can be obtained from National's website at:
7  *   http://www.national.com/ds.cgi/LM/LM95241.pdf
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  */
19
20 #include <linux/bitops.h>
21 #include <linux/err.h>
22 #include <linux/i2c.h>
23 #include <linux/init.h>
24 #include <linux/jiffies.h>
25 #include <linux/hwmon.h>
26 #include <linux/module.h>
27 #include <linux/mutex.h>
28 #include <linux/slab.h>
29
30 #define DEVNAME "lm95241"
31
32 static const unsigned short normal_i2c[] = {
33         0x19, 0x2a, 0x2b, I2C_CLIENT_END };
34
35 /* LM95241 registers */
36 #define LM95241_REG_R_MAN_ID            0xFE
37 #define LM95241_REG_R_CHIP_ID           0xFF
38 #define LM95241_REG_R_STATUS            0x02
39 #define LM95241_REG_RW_CONFIG           0x03
40 #define LM95241_REG_RW_REM_FILTER       0x06
41 #define LM95241_REG_RW_TRUTHERM         0x07
42 #define LM95241_REG_W_ONE_SHOT          0x0F
43 #define LM95241_REG_R_LOCAL_TEMPH       0x10
44 #define LM95241_REG_R_REMOTE1_TEMPH     0x11
45 #define LM95241_REG_R_REMOTE2_TEMPH     0x12
46 #define LM95241_REG_R_LOCAL_TEMPL       0x20
47 #define LM95241_REG_R_REMOTE1_TEMPL     0x21
48 #define LM95241_REG_R_REMOTE2_TEMPL     0x22
49 #define LM95241_REG_RW_REMOTE_MODEL     0x30
50
51 /* LM95241 specific bitfields */
52 #define CFG_STOP        BIT(6)
53 #define CFG_CR0076      0x00
54 #define CFG_CR0182      BIT(4)
55 #define CFG_CR1000      BIT(5)
56 #define CFG_CR2700      (BIT(4) | BIT(5))
57 #define CFG_CRMASK      (BIT(4) | BIT(5))
58 #define R1MS_MASK       BIT(0)
59 #define R2MS_MASK       BIT(2)
60 #define R1DF_MASK       BIT(1)
61 #define R2DF_MASK       BIT(2)
62 #define R1FE_MASK       BIT(0)
63 #define R2FE_MASK       BIT(2)
64 #define R1DM            BIT(0)
65 #define R2DM            BIT(1)
66 #define TT1_SHIFT       0
67 #define TT2_SHIFT       4
68 #define TT_OFF          0
69 #define TT_ON           1
70 #define TT_MASK         7
71 #define NATSEMI_MAN_ID  0x01
72 #define LM95231_CHIP_ID 0xA1
73 #define LM95241_CHIP_ID 0xA4
74
75 static const u8 lm95241_reg_address[] = {
76         LM95241_REG_R_LOCAL_TEMPH,
77         LM95241_REG_R_LOCAL_TEMPL,
78         LM95241_REG_R_REMOTE1_TEMPH,
79         LM95241_REG_R_REMOTE1_TEMPL,
80         LM95241_REG_R_REMOTE2_TEMPH,
81         LM95241_REG_R_REMOTE2_TEMPL
82 };
83
84 /* Client data (each client gets its own) */
85 struct lm95241_data {
86         struct i2c_client *client;
87         struct mutex update_lock;
88         unsigned long last_updated;     /* in jiffies */
89         unsigned long interval;         /* in milli-seconds */
90         char valid;             /* zero until following fields are valid */
91         /* registers values */
92         u8 temp[ARRAY_SIZE(lm95241_reg_address)];
93         u8 status, config, model, trutherm;
94 };
95
96 /* Conversions */
97 static int temp_from_reg_signed(u8 val_h, u8 val_l)
98 {
99         s16 val_hl = (val_h << 8) | val_l;
100         return val_hl * 1000 / 256;
101 }
102
103 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
104 {
105         u16 val_hl = (val_h << 8) | val_l;
106         return val_hl * 1000 / 256;
107 }
108
109 static struct lm95241_data *lm95241_update_device(struct device *dev)
110 {
111         struct lm95241_data *data = dev_get_drvdata(dev);
112         struct i2c_client *client = data->client;
113
114         mutex_lock(&data->update_lock);
115
116         if (time_after(jiffies, data->last_updated
117                        + msecs_to_jiffies(data->interval)) ||
118             !data->valid) {
119                 int i;
120
121                 dev_dbg(dev, "Updating lm95241 data.\n");
122                 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
123                         data->temp[i]
124                           = i2c_smbus_read_byte_data(client,
125                                                      lm95241_reg_address[i]);
126
127                 data->status = i2c_smbus_read_byte_data(client,
128                                                         LM95241_REG_R_STATUS);
129                 data->last_updated = jiffies;
130                 data->valid = 1;
131         }
132
133         mutex_unlock(&data->update_lock);
134
135         return data;
136 }
137
138 static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
139                              long *val)
140 {
141         struct lm95241_data *data = dev_get_drvdata(dev);
142
143         switch (attr) {
144         case hwmon_chip_update_interval:
145                 *val = data->interval;
146                 return 0;
147         default:
148                 return -EOPNOTSUPP;
149         }
150 }
151
152 static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
153                              long *val)
154 {
155         struct lm95241_data *data = lm95241_update_device(dev);
156
157         switch (attr) {
158         case hwmon_temp_input:
159                 if (!channel || (data->config & BIT(channel - 1)))
160                         *val = temp_from_reg_signed(data->temp[channel * 2],
161                                                 data->temp[channel * 2 + 1]);
162                 else
163                         *val = temp_from_reg_unsigned(data->temp[channel * 2],
164                                                 data->temp[channel * 2 + 1]);
165                 return 0;
166         case hwmon_temp_min:
167                 if (channel == 1)
168                         *val = (data->config & R1DF_MASK) ? -128000 : 0;
169                 else
170                         *val = (data->config & R2DF_MASK) ? -128000 : 0;
171                 return 0;
172         case hwmon_temp_max:
173                 if (channel == 1)
174                         *val = (data->config & R1DF_MASK) ? 127875 : 255875;
175                 else
176                         *val = (data->config & R2DF_MASK) ? 127875 : 255875;
177                 return 0;
178         case hwmon_temp_type:
179                 if (channel == 1)
180                         *val = (data->model & R1MS_MASK) ? 1 : 2;
181                 else
182                         *val = (data->model & R2MS_MASK) ? 1 : 2;
183                 return 0;
184         case hwmon_temp_fault:
185                 if (channel == 1)
186                         *val = !!(data->status & R1DM);
187                 else
188                         *val = !!(data->status & R2DM);
189                 return 0;
190         default:
191                 return -EOPNOTSUPP;
192         }
193 }
194
195 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
196                         u32 attr, int channel, long *val)
197 {
198         switch (type) {
199         case hwmon_chip:
200                 return lm95241_read_chip(dev, attr, channel, val);
201         case hwmon_temp:
202                 return lm95241_read_temp(dev, attr, channel, val);
203         default:
204                 return -EOPNOTSUPP;
205         }
206 }
207
208 static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
209                               long val)
210 {
211         struct lm95241_data *data = dev_get_drvdata(dev);
212         int convrate;
213         u8 config;
214         int ret;
215
216         mutex_lock(&data->update_lock);
217
218         switch (attr) {
219         case hwmon_chip_update_interval:
220                 config = data->config & ~CFG_CRMASK;
221                 if (val < 130) {
222                         convrate = 76;
223                         config |= CFG_CR0076;
224                 } else if (val < 590) {
225                         convrate = 182;
226                         config |= CFG_CR0182;
227                 } else if (val < 1850) {
228                         convrate = 1000;
229                         config |= CFG_CR1000;
230                 } else {
231                         convrate = 2700;
232                         config |= CFG_CR2700;
233                 }
234                 data->interval = convrate;
235                 data->config = config;
236                 ret = i2c_smbus_write_byte_data(data->client,
237                                                 LM95241_REG_RW_CONFIG, config);
238                 break;
239         default:
240                 ret = -EOPNOTSUPP;
241                 break;
242         }
243         mutex_unlock(&data->update_lock);
244         return ret;
245 }
246
247 static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
248                               long val)
249 {
250         struct lm95241_data *data = dev_get_drvdata(dev);
251         struct i2c_client *client = data->client;
252         int ret;
253
254         mutex_lock(&data->update_lock);
255
256         switch (attr) {
257         case hwmon_temp_min:
258                 if (channel == 1) {
259                         if (val < 0)
260                                 data->config |= R1DF_MASK;
261                         else
262                                 data->config &= ~R1DF_MASK;
263                 } else {
264                         if (val < 0)
265                                 data->config |= R2DF_MASK;
266                         else
267                                 data->config &= ~R2DF_MASK;
268                 }
269                 data->valid = 0;
270                 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
271                                                 data->config);
272                 break;
273         case hwmon_temp_max:
274                 if (channel == 1) {
275                         if (val <= 127875)
276                                 data->config |= R1DF_MASK;
277                         else
278                                 data->config &= ~R1DF_MASK;
279                 } else {
280                         if (val <= 127875)
281                                 data->config |= R2DF_MASK;
282                         else
283                                 data->config &= ~R2DF_MASK;
284                 }
285                 data->valid = 0;
286                 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
287                                                 data->config);
288                 break;
289         case hwmon_temp_type:
290                 if (val != 1 && val != 2) {
291                         ret = -EINVAL;
292                         break;
293                 }
294                 if (channel == 1) {
295                         data->trutherm &= ~(TT_MASK << TT1_SHIFT);
296                         if (val == 1) {
297                                 data->model |= R1MS_MASK;
298                                 data->trutherm |= (TT_ON << TT1_SHIFT);
299                         } else {
300                                 data->model &= ~R1MS_MASK;
301                                 data->trutherm |= (TT_OFF << TT1_SHIFT);
302                         }
303                 } else {
304                         data->trutherm &= ~(TT_MASK << TT2_SHIFT);
305                         if (val == 1) {
306                                 data->model |= R2MS_MASK;
307                                 data->trutherm |= (TT_ON << TT2_SHIFT);
308                         } else {
309                                 data->model &= ~R2MS_MASK;
310                                 data->trutherm |= (TT_OFF << TT2_SHIFT);
311                         }
312                 }
313                 ret = i2c_smbus_write_byte_data(client,
314                                                 LM95241_REG_RW_REMOTE_MODEL,
315                                                 data->model);
316                 if (ret < 0)
317                         break;
318                 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
319                                                 data->trutherm);
320                 break;
321         default:
322                 ret = -EOPNOTSUPP;
323                 break;
324         }
325
326         mutex_unlock(&data->update_lock);
327
328         return ret;
329 }
330
331 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
332                          u32 attr, int channel, long val)
333 {
334         switch (type) {
335         case hwmon_chip:
336                 return lm95241_write_chip(dev, attr, channel, val);
337         case hwmon_temp:
338                 return lm95241_write_temp(dev, attr, channel, val);
339         default:
340                 return -EOPNOTSUPP;
341         }
342 }
343
344 static umode_t lm95241_is_visible(const void *data,
345                                   enum hwmon_sensor_types type,
346                                   u32 attr, int channel)
347 {
348         switch (type) {
349         case hwmon_chip:
350                 switch (attr) {
351                 case hwmon_chip_update_interval:
352                         return S_IRUGO | S_IWUSR;
353                 }
354                 break;
355         case hwmon_temp:
356                 switch (attr) {
357                 case hwmon_temp_input:
358                         return S_IRUGO;
359                 case hwmon_temp_fault:
360                         return S_IRUGO;
361                 case hwmon_temp_min:
362                 case hwmon_temp_max:
363                 case hwmon_temp_type:
364                         return S_IRUGO | S_IWUSR;
365                 }
366                 break;
367         default:
368                 break;
369         }
370         return 0;
371 }
372
373 /* Return 0 if detection is successful, -ENODEV otherwise */
374 static int lm95241_detect(struct i2c_client *new_client,
375                           struct i2c_board_info *info)
376 {
377         struct i2c_adapter *adapter = new_client->adapter;
378         const char *name;
379         int mfg_id, chip_id;
380
381         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
382                 return -ENODEV;
383
384         mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
385         if (mfg_id != NATSEMI_MAN_ID)
386                 return -ENODEV;
387
388         chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
389         switch (chip_id) {
390         case LM95231_CHIP_ID:
391                 name = "lm95231";
392                 break;
393         case LM95241_CHIP_ID:
394                 name = "lm95241";
395                 break;
396         default:
397                 return -ENODEV;
398         }
399
400         /* Fill the i2c board info */
401         strlcpy(info->type, name, I2C_NAME_SIZE);
402         return 0;
403 }
404
405 static void lm95241_init_client(struct i2c_client *client,
406                                 struct lm95241_data *data)
407 {
408         data->interval = 1000;
409         data->config = CFG_CR1000;
410         data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
411
412         i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
413         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
414                                   R1FE_MASK | R2FE_MASK);
415         i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
416                                   data->trutherm);
417         i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
418                                   data->model);
419 }
420
421 static const u32 lm95241_chip_config[] = {
422         HWMON_C_UPDATE_INTERVAL,
423         0
424 };
425
426 static const struct hwmon_channel_info lm95241_chip = {
427         .type = hwmon_chip,
428         .config = lm95241_chip_config,
429 };
430
431 static const u32 lm95241_temp_config[] = {
432         HWMON_T_INPUT,
433         HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_TYPE |
434                 HWMON_T_FAULT,
435         HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN | HWMON_T_TYPE |
436                 HWMON_T_FAULT,
437         0
438 };
439
440 static const struct hwmon_channel_info lm95241_temp = {
441         .type = hwmon_temp,
442         .config = lm95241_temp_config,
443 };
444
445 static const struct hwmon_channel_info *lm95241_info[] = {
446         &lm95241_chip,
447         &lm95241_temp,
448         NULL
449 };
450
451 static const struct hwmon_ops lm95241_hwmon_ops = {
452         .is_visible = lm95241_is_visible,
453         .read = lm95241_read,
454         .write = lm95241_write,
455 };
456
457 static const struct hwmon_chip_info lm95241_chip_info = {
458         .ops = &lm95241_hwmon_ops,
459         .info = lm95241_info,
460 };
461
462 static int lm95241_probe(struct i2c_client *client,
463                          const struct i2c_device_id *id)
464 {
465         struct device *dev = &client->dev;
466         struct lm95241_data *data;
467         struct device *hwmon_dev;
468
469         data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
470         if (!data)
471                 return -ENOMEM;
472
473         data->client = client;
474         mutex_init(&data->update_lock);
475
476         /* Initialize the LM95241 chip */
477         lm95241_init_client(client, data);
478
479         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
480                                                            data,
481                                                            &lm95241_chip_info,
482                                                            NULL);
483         return PTR_ERR_OR_ZERO(hwmon_dev);
484 }
485
486 /* Driver data (common to all clients) */
487 static const struct i2c_device_id lm95241_id[] = {
488         { "lm95231", 0 },
489         { "lm95241", 0 },
490         { }
491 };
492 MODULE_DEVICE_TABLE(i2c, lm95241_id);
493
494 static struct i2c_driver lm95241_driver = {
495         .class          = I2C_CLASS_HWMON,
496         .driver = {
497                 .name   = DEVNAME,
498         },
499         .probe          = lm95241_probe,
500         .id_table       = lm95241_id,
501         .detect         = lm95241_detect,
502         .address_list   = normal_i2c,
503 };
504
505 module_i2c_driver(lm95241_driver);
506
507 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
508 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
509 MODULE_LICENSE("GPL");