1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
4 *
5 * The LM95241 is a sensor chip made by National Semiconductors.
6 * It reports up to three temperatures (its own plus up to two external ones).
7 * Complete datasheet can be obtained from National's website at:
8 * http://www.national.com/ds.cgi/LM/LM95241.pdf
9 */
10
11 #include <linux/bitops.h>
12 #include <linux/err.h>
13 #include <linux/i2c.h>
14 #include <linux/init.h>
15 #include <linux/jiffies.h>
16 #include <linux/hwmon.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/slab.h>
20
21 #define DEVNAME "lm95241"
22
23 static const unsigned short normal_i2c[] = {
24 0x19, 0x2a, 0x2b, I2C_CLIENT_END };
25
26 /* LM95241 registers */
27 #define LM95241_REG_R_MAN_ID 0xFE
28 #define LM95241_REG_R_CHIP_ID 0xFF
29 #define LM95241_REG_R_STATUS 0x02
30 #define LM95241_REG_RW_CONFIG 0x03
31 #define LM95241_REG_RW_REM_FILTER 0x06
32 #define LM95241_REG_RW_TRUTHERM 0x07
33 #define LM95241_REG_W_ONE_SHOT 0x0F
34 #define LM95241_REG_R_LOCAL_TEMPH 0x10
35 #define LM95241_REG_R_REMOTE1_TEMPH 0x11
36 #define LM95241_REG_R_REMOTE2_TEMPH 0x12
37 #define LM95241_REG_R_LOCAL_TEMPL 0x20
38 #define LM95241_REG_R_REMOTE1_TEMPL 0x21
39 #define LM95241_REG_R_REMOTE2_TEMPL 0x22
40 #define LM95241_REG_RW_REMOTE_MODEL 0x30
41
42 /* LM95241 specific bitfields */
43 #define CFG_STOP BIT(6)
44 #define CFG_CR0076 0x00
45 #define CFG_CR0182 BIT(4)
46 #define CFG_CR1000 BIT(5)
47 #define CFG_CR2700 (BIT(4) | BIT(5))
48 #define CFG_CRMASK (BIT(4) | BIT(5))
49 #define R1MS_MASK BIT(0)
50 #define R2MS_MASK BIT(2)
51 #define R1DF_MASK BIT(1)
52 #define R2DF_MASK BIT(2)
53 #define R1FE_MASK BIT(0)
54 #define R2FE_MASK BIT(2)
55 #define R1DM BIT(0)
56 #define R2DM BIT(1)
57 #define TT1_SHIFT 0
58 #define TT2_SHIFT 4
59 #define TT_OFF 0
60 #define TT_ON 1
61 #define TT_MASK 7
62 #define NATSEMI_MAN_ID 0x01
63 #define LM95231_CHIP_ID 0xA1
64 #define LM95241_CHIP_ID 0xA4
65
66 static const u8 lm95241_reg_address[] = {
67 LM95241_REG_R_LOCAL_TEMPH,
68 LM95241_REG_R_LOCAL_TEMPL,
69 LM95241_REG_R_REMOTE1_TEMPH,
70 LM95241_REG_R_REMOTE1_TEMPL,
71 LM95241_REG_R_REMOTE2_TEMPH,
72 LM95241_REG_R_REMOTE2_TEMPL
73 };
74
75 /* Client data (each client gets its own) */
76 struct lm95241_data {
77 struct i2c_client *client;
78 struct mutex update_lock;
79 unsigned long last_updated; /* in jiffies */
80 unsigned long interval; /* in milli-seconds */
81 char valid; /* zero until following fields are valid */
82 /* registers values */
83 u8 temp[ARRAY_SIZE(lm95241_reg_address)];
84 u8 status, config, model, trutherm;
85 };
86
87 /* Conversions */
temp_from_reg_signed(u8 val_h,u8 val_l)88 static int temp_from_reg_signed(u8 val_h, u8 val_l)
89 {
90 s16 val_hl = (val_h << 8) | val_l;
91 return val_hl * 1000 / 256;
92 }
93
temp_from_reg_unsigned(u8 val_h,u8 val_l)94 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
95 {
96 u16 val_hl = (val_h << 8) | val_l;
97 return val_hl * 1000 / 256;
98 }
99
lm95241_update_device(struct device * dev)100 static struct lm95241_data *lm95241_update_device(struct device *dev)
101 {
102 struct lm95241_data *data = dev_get_drvdata(dev);
103 struct i2c_client *client = data->client;
104
105 mutex_lock(&data->update_lock);
106
107 if (time_after(jiffies, data->last_updated
108 + msecs_to_jiffies(data->interval)) ||
109 !data->valid) {
110 int i;
111
112 dev_dbg(dev, "Updating lm95241 data.\n");
113 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
114 data->temp[i]
115 = i2c_smbus_read_byte_data(client,
116 lm95241_reg_address[i]);
117
118 data->status = i2c_smbus_read_byte_data(client,
119 LM95241_REG_R_STATUS);
120 data->last_updated = jiffies;
121 data->valid = 1;
122 }
123
124 mutex_unlock(&data->update_lock);
125
126 return data;
127 }
128
lm95241_read_chip(struct device * dev,u32 attr,int channel,long * val)129 static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
130 long *val)
131 {
132 struct lm95241_data *data = dev_get_drvdata(dev);
133
134 switch (attr) {
135 case hwmon_chip_update_interval:
136 *val = data->interval;
137 return 0;
138 default:
139 return -EOPNOTSUPP;
140 }
141 }
142
lm95241_read_temp(struct device * dev,u32 attr,int channel,long * val)143 static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
144 long *val)
145 {
146 struct lm95241_data *data = lm95241_update_device(dev);
147
148 switch (attr) {
149 case hwmon_temp_input:
150 if (!channel || (data->config & BIT(channel - 1)))
151 *val = temp_from_reg_signed(data->temp[channel * 2],
152 data->temp[channel * 2 + 1]);
153 else
154 *val = temp_from_reg_unsigned(data->temp[channel * 2],
155 data->temp[channel * 2 + 1]);
156 return 0;
157 case hwmon_temp_min:
158 if (channel == 1)
159 *val = (data->config & R1DF_MASK) ? -128000 : 0;
160 else
161 *val = (data->config & R2DF_MASK) ? -128000 : 0;
162 return 0;
163 case hwmon_temp_max:
164 if (channel == 1)
165 *val = (data->config & R1DF_MASK) ? 127875 : 255875;
166 else
167 *val = (data->config & R2DF_MASK) ? 127875 : 255875;
168 return 0;
169 case hwmon_temp_type:
170 if (channel == 1)
171 *val = (data->model & R1MS_MASK) ? 1 : 2;
172 else
173 *val = (data->model & R2MS_MASK) ? 1 : 2;
174 return 0;
175 case hwmon_temp_fault:
176 if (channel == 1)
177 *val = !!(data->status & R1DM);
178 else
179 *val = !!(data->status & R2DM);
180 return 0;
181 default:
182 return -EOPNOTSUPP;
183 }
184 }
185
lm95241_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)186 static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
187 u32 attr, int channel, long *val)
188 {
189 switch (type) {
190 case hwmon_chip:
191 return lm95241_read_chip(dev, attr, channel, val);
192 case hwmon_temp:
193 return lm95241_read_temp(dev, attr, channel, val);
194 default:
195 return -EOPNOTSUPP;
196 }
197 }
198
lm95241_write_chip(struct device * dev,u32 attr,int channel,long val)199 static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
200 long val)
201 {
202 struct lm95241_data *data = dev_get_drvdata(dev);
203 int convrate;
204 u8 config;
205 int ret;
206
207 mutex_lock(&data->update_lock);
208
209 switch (attr) {
210 case hwmon_chip_update_interval:
211 config = data->config & ~CFG_CRMASK;
212 if (val < 130) {
213 convrate = 76;
214 config |= CFG_CR0076;
215 } else if (val < 590) {
216 convrate = 182;
217 config |= CFG_CR0182;
218 } else if (val < 1850) {
219 convrate = 1000;
220 config |= CFG_CR1000;
221 } else {
222 convrate = 2700;
223 config |= CFG_CR2700;
224 }
225 data->interval = convrate;
226 data->config = config;
227 ret = i2c_smbus_write_byte_data(data->client,
228 LM95241_REG_RW_CONFIG, config);
229 break;
230 default:
231 ret = -EOPNOTSUPP;
232 break;
233 }
234 mutex_unlock(&data->update_lock);
235 return ret;
236 }
237
lm95241_write_temp(struct device * dev,u32 attr,int channel,long val)238 static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
239 long val)
240 {
241 struct lm95241_data *data = dev_get_drvdata(dev);
242 struct i2c_client *client = data->client;
243 int ret;
244
245 mutex_lock(&data->update_lock);
246
247 switch (attr) {
248 case hwmon_temp_min:
249 if (channel == 1) {
250 if (val < 0)
251 data->config |= R1DF_MASK;
252 else
253 data->config &= ~R1DF_MASK;
254 } else {
255 if (val < 0)
256 data->config |= R2DF_MASK;
257 else
258 data->config &= ~R2DF_MASK;
259 }
260 data->valid = 0;
261 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
262 data->config);
263 break;
264 case hwmon_temp_max:
265 if (channel == 1) {
266 if (val <= 127875)
267 data->config |= R1DF_MASK;
268 else
269 data->config &= ~R1DF_MASK;
270 } else {
271 if (val <= 127875)
272 data->config |= R2DF_MASK;
273 else
274 data->config &= ~R2DF_MASK;
275 }
276 data->valid = 0;
277 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
278 data->config);
279 break;
280 case hwmon_temp_type:
281 if (val != 1 && val != 2) {
282 ret = -EINVAL;
283 break;
284 }
285 if (channel == 1) {
286 data->trutherm &= ~(TT_MASK << TT1_SHIFT);
287 if (val == 1) {
288 data->model |= R1MS_MASK;
289 data->trutherm |= (TT_ON << TT1_SHIFT);
290 } else {
291 data->model &= ~R1MS_MASK;
292 data->trutherm |= (TT_OFF << TT1_SHIFT);
293 }
294 } else {
295 data->trutherm &= ~(TT_MASK << TT2_SHIFT);
296 if (val == 1) {
297 data->model |= R2MS_MASK;
298 data->trutherm |= (TT_ON << TT2_SHIFT);
299 } else {
300 data->model &= ~R2MS_MASK;
301 data->trutherm |= (TT_OFF << TT2_SHIFT);
302 }
303 }
304 ret = i2c_smbus_write_byte_data(client,
305 LM95241_REG_RW_REMOTE_MODEL,
306 data->model);
307 if (ret < 0)
308 break;
309 ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
310 data->trutherm);
311 break;
312 default:
313 ret = -EOPNOTSUPP;
314 break;
315 }
316
317 mutex_unlock(&data->update_lock);
318
319 return ret;
320 }
321
lm95241_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)322 static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
323 u32 attr, int channel, long val)
324 {
325 switch (type) {
326 case hwmon_chip:
327 return lm95241_write_chip(dev, attr, channel, val);
328 case hwmon_temp:
329 return lm95241_write_temp(dev, attr, channel, val);
330 default:
331 return -EOPNOTSUPP;
332 }
333 }
334
lm95241_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)335 static umode_t lm95241_is_visible(const void *data,
336 enum hwmon_sensor_types type,
337 u32 attr, int channel)
338 {
339 switch (type) {
340 case hwmon_chip:
341 switch (attr) {
342 case hwmon_chip_update_interval:
343 return 0644;
344 }
345 break;
346 case hwmon_temp:
347 switch (attr) {
348 case hwmon_temp_input:
349 return 0444;
350 case hwmon_temp_fault:
351 return 0444;
352 case hwmon_temp_min:
353 case hwmon_temp_max:
354 case hwmon_temp_type:
355 return 0644;
356 }
357 break;
358 default:
359 break;
360 }
361 return 0;
362 }
363
364 /* Return 0 if detection is successful, -ENODEV otherwise */
lm95241_detect(struct i2c_client * new_client,struct i2c_board_info * info)365 static int lm95241_detect(struct i2c_client *new_client,
366 struct i2c_board_info *info)
367 {
368 struct i2c_adapter *adapter = new_client->adapter;
369 const char *name;
370 int mfg_id, chip_id;
371
372 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
373 return -ENODEV;
374
375 mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
376 if (mfg_id != NATSEMI_MAN_ID)
377 return -ENODEV;
378
379 chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
380 switch (chip_id) {
381 case LM95231_CHIP_ID:
382 name = "lm95231";
383 break;
384 case LM95241_CHIP_ID:
385 name = "lm95241";
386 break;
387 default:
388 return -ENODEV;
389 }
390
391 /* Fill the i2c board info */
392 strlcpy(info->type, name, I2C_NAME_SIZE);
393 return 0;
394 }
395
lm95241_init_client(struct i2c_client * client,struct lm95241_data * data)396 static void lm95241_init_client(struct i2c_client *client,
397 struct lm95241_data *data)
398 {
399 data->interval = 1000;
400 data->config = CFG_CR1000;
401 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
402
403 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
404 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
405 R1FE_MASK | R2FE_MASK);
406 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
407 data->trutherm);
408 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
409 data->model);
410 }
411
412 static const struct hwmon_channel_info *lm95241_info[] = {
413 HWMON_CHANNEL_INFO(chip,
414 HWMON_C_UPDATE_INTERVAL),
415 HWMON_CHANNEL_INFO(temp,
416 HWMON_T_INPUT,
417 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
418 HWMON_T_TYPE | HWMON_T_FAULT,
419 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
420 HWMON_T_TYPE | HWMON_T_FAULT),
421 NULL
422 };
423
424 static const struct hwmon_ops lm95241_hwmon_ops = {
425 .is_visible = lm95241_is_visible,
426 .read = lm95241_read,
427 .write = lm95241_write,
428 };
429
430 static const struct hwmon_chip_info lm95241_chip_info = {
431 .ops = &lm95241_hwmon_ops,
432 .info = lm95241_info,
433 };
434
lm95241_probe(struct i2c_client * client)435 static int lm95241_probe(struct i2c_client *client)
436 {
437 struct device *dev = &client->dev;
438 struct lm95241_data *data;
439 struct device *hwmon_dev;
440
441 data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
442 if (!data)
443 return -ENOMEM;
444
445 data->client = client;
446 mutex_init(&data->update_lock);
447
448 /* Initialize the LM95241 chip */
449 lm95241_init_client(client, data);
450
451 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
452 data,
453 &lm95241_chip_info,
454 NULL);
455 return PTR_ERR_OR_ZERO(hwmon_dev);
456 }
457
458 /* Driver data (common to all clients) */
459 static const struct i2c_device_id lm95241_id[] = {
460 { "lm95231", 0 },
461 { "lm95241", 0 },
462 { }
463 };
464 MODULE_DEVICE_TABLE(i2c, lm95241_id);
465
466 static struct i2c_driver lm95241_driver = {
467 .class = I2C_CLASS_HWMON,
468 .driver = {
469 .name = DEVNAME,
470 },
471 .probe_new = lm95241_probe,
472 .id_table = lm95241_id,
473 .detect = lm95241_detect,
474 .address_list = normal_i2c,
475 };
476
477 module_i2c_driver(lm95241_driver);
478
479 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
480 MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
481 MODULE_LICENSE("GPL");
482