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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* tmp421.c
3 *
4 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
5 * Preliminary support by:
6 * Melvin Rook, Raymond Ng
7 */
8
9/*
10 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
11 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
12 */
13
14#include <linux/module.h>
15#include <linux/init.h>
16#include <linux/slab.h>
17#include <linux/jiffies.h>
18#include <linux/i2c.h>
19#include <linux/hwmon.h>
20#include <linux/hwmon-sysfs.h>
21#include <linux/err.h>
22#include <linux/mutex.h>
23#include <linux/of.h>
24#include <linux/sysfs.h>
25
26/* Addresses to scan */
27static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
28 I2C_CLIENT_END };
29
30enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
31
32#define MAX_CHANNELS 4
33/* The TMP421 registers */
34#define TMP421_STATUS_REG 0x08
35#define TMP421_CONFIG_REG_1 0x09
36#define TMP421_CONFIG_REG_2 0x0A
37#define TMP421_CONFIG_REG_REN(x) (BIT(3 + (x)))
38#define TMP421_CONFIG_REG_REN_MASK GENMASK(6, 3)
39#define TMP421_CONVERSION_RATE_REG 0x0B
40#define TMP421_N_FACTOR_REG_1 0x21
41#define TMP421_MANUFACTURER_ID_REG 0xFE
42#define TMP421_DEVICE_ID_REG 0xFF
43
44static const u8 TMP421_TEMP_MSB[MAX_CHANNELS] = { 0x00, 0x01, 0x02, 0x03 };
45static const u8 TMP421_TEMP_LSB[MAX_CHANNELS] = { 0x10, 0x11, 0x12, 0x13 };
46
47/* Flags */
48#define TMP421_CONFIG_SHUTDOWN 0x40
49#define TMP421_CONFIG_RANGE 0x04
50
51/* Manufacturer / Device ID's */
52#define TMP421_MANUFACTURER_ID 0x55
53#define TMP421_DEVICE_ID 0x21
54#define TMP422_DEVICE_ID 0x22
55#define TMP423_DEVICE_ID 0x23
56#define TMP441_DEVICE_ID 0x41
57#define TMP442_DEVICE_ID 0x42
58
59static const struct i2c_device_id tmp421_id[] = {
60 { "tmp421", 2 },
61 { "tmp422", 3 },
62 { "tmp423", 4 },
63 { "tmp441", 2 },
64 { "tmp442", 3 },
65 { }
66};
67MODULE_DEVICE_TABLE(i2c, tmp421_id);
68
69static const struct of_device_id __maybe_unused tmp421_of_match[] = {
70 {
71 .compatible = "ti,tmp421",
72 .data = (void *)2
73 },
74 {
75 .compatible = "ti,tmp422",
76 .data = (void *)3
77 },
78 {
79 .compatible = "ti,tmp423",
80 .data = (void *)4
81 },
82 {
83 .compatible = "ti,tmp441",
84 .data = (void *)2
85 },
86 {
87 .compatible = "ti,tmp442",
88 .data = (void *)3
89 },
90 { },
91};
92MODULE_DEVICE_TABLE(of, tmp421_of_match);
93
94struct tmp421_channel {
95 const char *label;
96 bool enabled;
97 s16 temp;
98};
99
100struct tmp421_data {
101 struct i2c_client *client;
102 struct mutex update_lock;
103 u32 temp_config[MAX_CHANNELS + 1];
104 struct hwmon_channel_info temp_info;
105 const struct hwmon_channel_info *info[2];
106 struct hwmon_chip_info chip;
107 bool valid;
108 unsigned long last_updated;
109 unsigned long channels;
110 u8 config;
111 struct tmp421_channel channel[MAX_CHANNELS];
112};
113
114static int temp_from_raw(u16 reg, bool extended)
115{
116 /* Mask out status bits */
117 int temp = reg & ~0xf;
118
119 if (extended)
120 temp = temp - 64 * 256;
121 else
122 temp = (s16)temp;
123
124 return DIV_ROUND_CLOSEST(temp * 1000, 256);
125}
126
127static int tmp421_update_device(struct tmp421_data *data)
128{
129 struct i2c_client *client = data->client;
130 int ret = 0;
131 int i;
132
133 mutex_lock(&data->update_lock);
134
135 if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
136 !data->valid) {
137 ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
138 if (ret < 0)
139 goto exit;
140 data->config = ret;
141
142 for (i = 0; i < data->channels; i++) {
143 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
144 if (ret < 0)
145 goto exit;
146 data->channel[i].temp = ret << 8;
147
148 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
149 if (ret < 0)
150 goto exit;
151 data->channel[i].temp |= ret;
152 }
153 data->last_updated = jiffies;
154 data->valid = true;
155 }
156
157exit:
158 mutex_unlock(&data->update_lock);
159
160 if (ret < 0) {
161 data->valid = false;
162 return ret;
163 }
164
165 return 0;
166}
167
168static int tmp421_enable_channels(struct tmp421_data *data)
169{
170 int err;
171 struct i2c_client *client = data->client;
172 struct device *dev = &client->dev;
173 int old = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
174 int new, i;
175
176 if (old < 0) {
177 dev_err(dev, "error reading register, can't disable channels\n");
178 return old;
179 }
180
181 new = old & ~TMP421_CONFIG_REG_REN_MASK;
182 for (i = 0; i < data->channels; i++)
183 if (data->channel[i].enabled)
184 new |= TMP421_CONFIG_REG_REN(i);
185
186 if (new == old)
187 return 0;
188
189 err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, new);
190 if (err < 0)
191 dev_err(dev, "error writing register, can't disable channels\n");
192
193 return err;
194}
195
196static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
197 u32 attr, int channel, long *val)
198{
199 struct tmp421_data *tmp421 = dev_get_drvdata(dev);
200 int ret = 0;
201
202 ret = tmp421_update_device(tmp421);
203 if (ret)
204 return ret;
205
206 switch (attr) {
207 case hwmon_temp_input:
208 if (!tmp421->channel[channel].enabled)
209 return -ENODATA;
210 *val = temp_from_raw(tmp421->channel[channel].temp,
211 tmp421->config & TMP421_CONFIG_RANGE);
212 return 0;
213 case hwmon_temp_fault:
214 if (!tmp421->channel[channel].enabled)
215 return -ENODATA;
216 /*
217 * Any of OPEN or /PVLD bits indicate a hardware mulfunction
218 * and the conversion result may be incorrect
219 */
220 *val = !!(tmp421->channel[channel].temp & 0x03);
221 return 0;
222 case hwmon_temp_enable:
223 *val = tmp421->channel[channel].enabled;
224 return 0;
225 default:
226 return -EOPNOTSUPP;
227 }
228
229}
230
231static int tmp421_read_string(struct device *dev, enum hwmon_sensor_types type,
232 u32 attr, int channel, const char **str)
233{
234 struct tmp421_data *data = dev_get_drvdata(dev);
235
236 *str = data->channel[channel].label;
237
238 return 0;
239}
240
241static int tmp421_write(struct device *dev, enum hwmon_sensor_types type,
242 u32 attr, int channel, long val)
243{
244 struct tmp421_data *data = dev_get_drvdata(dev);
245 int ret;
246
247 switch (attr) {
248 case hwmon_temp_enable:
249 data->channel[channel].enabled = val;
250 ret = tmp421_enable_channels(data);
251 break;
252 default:
253 ret = -EOPNOTSUPP;
254 }
255
256 return ret;
257}
258
259static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
260 u32 attr, int channel)
261{
262 switch (attr) {
263 case hwmon_temp_fault:
264 case hwmon_temp_input:
265 return 0444;
266 case hwmon_temp_label:
267 return 0444;
268 case hwmon_temp_enable:
269 return 0644;
270 default:
271 return 0;
272 }
273}
274
275static int tmp421_init_client(struct tmp421_data *data)
276{
277 int config, config_orig;
278 struct i2c_client *client = data->client;
279
280 /* Set the conversion rate to 2 Hz */
281 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
282
283 /* Start conversions (disable shutdown if necessary) */
284 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
285 if (config < 0) {
286 dev_err(&client->dev,
287 "Could not read configuration register (%d)\n", config);
288 return config;
289 }
290
291 config_orig = config;
292 config &= ~TMP421_CONFIG_SHUTDOWN;
293
294 if (config != config_orig) {
295 dev_info(&client->dev, "Enable monitoring chip\n");
296 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
297 }
298
299 return tmp421_enable_channels(data);
300}
301
302static int tmp421_detect(struct i2c_client *client,
303 struct i2c_board_info *info)
304{
305 enum chips kind;
306 struct i2c_adapter *adapter = client->adapter;
307 static const char * const names[] = {
308 "TMP421", "TMP422", "TMP423",
309 "TMP441", "TMP442"
310 };
311 int addr = client->addr;
312 u8 reg;
313
314 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
315 return -ENODEV;
316
317 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
318 if (reg != TMP421_MANUFACTURER_ID)
319 return -ENODEV;
320
321 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
322 if (reg & 0xf8)
323 return -ENODEV;
324
325 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
326 if (reg & 0x7f)
327 return -ENODEV;
328
329 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
330 switch (reg) {
331 case TMP421_DEVICE_ID:
332 kind = tmp421;
333 break;
334 case TMP422_DEVICE_ID:
335 if (addr == 0x2a)
336 return -ENODEV;
337 kind = tmp422;
338 break;
339 case TMP423_DEVICE_ID:
340 if (addr != 0x4c && addr != 0x4d)
341 return -ENODEV;
342 kind = tmp423;
343 break;
344 case TMP441_DEVICE_ID:
345 kind = tmp441;
346 break;
347 case TMP442_DEVICE_ID:
348 if (addr != 0x4c && addr != 0x4d)
349 return -ENODEV;
350 kind = tmp442;
351 break;
352 default:
353 return -ENODEV;
354 }
355
356 strscpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
357 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
358 names[kind], client->addr);
359
360 return 0;
361}
362
363static int tmp421_probe_child_from_dt(struct i2c_client *client,
364 struct device_node *child,
365 struct tmp421_data *data)
366
367{
368 struct device *dev = &client->dev;
369 u32 i;
370 s32 val;
371 int err;
372
373 err = of_property_read_u32(child, "reg", &i);
374 if (err) {
375 dev_err(dev, "missing reg property of %pOFn\n", child);
376 return err;
377 }
378
379 if (i >= data->channels) {
380 dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
381 return -EINVAL;
382 }
383
384 of_property_read_string(child, "label", &data->channel[i].label);
385 if (data->channel[i].label)
386 data->temp_config[i] |= HWMON_T_LABEL;
387
388 data->channel[i].enabled = of_device_is_available(child);
389
390 err = of_property_read_s32(child, "ti,n-factor", &val);
391 if (!err) {
392 if (i == 0) {
393 dev_err(dev, "n-factor can't be set for internal channel\n");
394 return -EINVAL;
395 }
396
397 if (val > 127 || val < -128) {
398 dev_err(dev, "n-factor for channel %d invalid (%d)\n",
399 i, val);
400 return -EINVAL;
401 }
402 i2c_smbus_write_byte_data(client, TMP421_N_FACTOR_REG_1 + i - 1,
403 val);
404 }
405
406 return 0;
407}
408
409static int tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)
410{
411 struct device *dev = &client->dev;
412 const struct device_node *np = dev->of_node;
413 struct device_node *child;
414 int err;
415
416 for_each_child_of_node(np, child) {
417 if (strcmp(child->name, "channel"))
418 continue;
419
420 err = tmp421_probe_child_from_dt(client, child, data);
421 if (err) {
422 of_node_put(child);
423 return err;
424 }
425 }
426
427 return 0;
428}
429
430static const struct hwmon_ops tmp421_ops = {
431 .is_visible = tmp421_is_visible,
432 .read = tmp421_read,
433 .read_string = tmp421_read_string,
434 .write = tmp421_write,
435};
436
437static int tmp421_probe(struct i2c_client *client)
438{
439 struct device *dev = &client->dev;
440 struct device *hwmon_dev;
441 struct tmp421_data *data;
442 int i, err;
443
444 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
445 if (!data)
446 return -ENOMEM;
447
448 mutex_init(&data->update_lock);
449 if (client->dev.of_node)
450 data->channels = (unsigned long)
451 of_device_get_match_data(&client->dev);
452 else
453 data->channels = i2c_match_id(tmp421_id, client)->driver_data;
454 data->client = client;
455
456 for (i = 0; i < data->channels; i++) {
457 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT | HWMON_T_ENABLE;
458 data->channel[i].enabled = true;
459 }
460
461 err = tmp421_probe_from_dt(client, data);
462 if (err)
463 return err;
464
465 err = tmp421_init_client(data);
466 if (err)
467 return err;
468
469 data->chip.ops = &tmp421_ops;
470 data->chip.info = data->info;
471
472 data->info[0] = &data->temp_info;
473
474 data->temp_info.type = hwmon_temp;
475 data->temp_info.config = data->temp_config;
476
477 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
478 data,
479 &data->chip,
480 NULL);
481 return PTR_ERR_OR_ZERO(hwmon_dev);
482}
483
484static struct i2c_driver tmp421_driver = {
485 .class = I2C_CLASS_HWMON,
486 .driver = {
487 .name = "tmp421",
488 .of_match_table = of_match_ptr(tmp421_of_match),
489 },
490 .probe = tmp421_probe,
491 .id_table = tmp421_id,
492 .detect = tmp421_detect,
493 .address_list = normal_i2c,
494};
495
496module_i2c_driver(tmp421_driver);
497
498MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
499MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
500MODULE_LICENSE("GPL");
1/* tmp421.c
2 *
3 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
4 * Preliminary support by:
5 * Melvin Rook, Raymond Ng
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18/*
19 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
20 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
21 */
22
23#include <linux/module.h>
24#include <linux/init.h>
25#include <linux/slab.h>
26#include <linux/jiffies.h>
27#include <linux/i2c.h>
28#include <linux/hwmon.h>
29#include <linux/hwmon-sysfs.h>
30#include <linux/err.h>
31#include <linux/mutex.h>
32#include <linux/sysfs.h>
33
34/* Addresses to scan */
35static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
36 I2C_CLIENT_END };
37
38enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
39
40/* The TMP421 registers */
41#define TMP421_STATUS_REG 0x08
42#define TMP421_CONFIG_REG_1 0x09
43#define TMP421_CONVERSION_RATE_REG 0x0B
44#define TMP421_MANUFACTURER_ID_REG 0xFE
45#define TMP421_DEVICE_ID_REG 0xFF
46
47static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
48static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
49
50/* Flags */
51#define TMP421_CONFIG_SHUTDOWN 0x40
52#define TMP421_CONFIG_RANGE 0x04
53
54/* Manufacturer / Device ID's */
55#define TMP421_MANUFACTURER_ID 0x55
56#define TMP421_DEVICE_ID 0x21
57#define TMP422_DEVICE_ID 0x22
58#define TMP423_DEVICE_ID 0x23
59#define TMP441_DEVICE_ID 0x41
60#define TMP442_DEVICE_ID 0x42
61
62static const struct i2c_device_id tmp421_id[] = {
63 { "tmp421", 2 },
64 { "tmp422", 3 },
65 { "tmp423", 4 },
66 { "tmp441", 2 },
67 { "tmp442", 3 },
68 { }
69};
70MODULE_DEVICE_TABLE(i2c, tmp421_id);
71
72struct tmp421_data {
73 struct i2c_client *client;
74 struct mutex update_lock;
75 char valid;
76 unsigned long last_updated;
77 int channels;
78 u8 config;
79 s16 temp[4];
80};
81
82static int temp_from_s16(s16 reg)
83{
84 /* Mask out status bits */
85 int temp = reg & ~0xf;
86
87 return (temp * 1000 + 128) / 256;
88}
89
90static int temp_from_u16(u16 reg)
91{
92 /* Mask out status bits */
93 int temp = reg & ~0xf;
94
95 /* Add offset for extended temperature range. */
96 temp -= 64 * 256;
97
98 return (temp * 1000 + 128) / 256;
99}
100
101static struct tmp421_data *tmp421_update_device(struct device *dev)
102{
103 struct tmp421_data *data = dev_get_drvdata(dev);
104 struct i2c_client *client = data->client;
105 int i;
106
107 mutex_lock(&data->update_lock);
108
109 if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
110 data->config = i2c_smbus_read_byte_data(client,
111 TMP421_CONFIG_REG_1);
112
113 for (i = 0; i < data->channels; i++) {
114 data->temp[i] = i2c_smbus_read_byte_data(client,
115 TMP421_TEMP_MSB[i]) << 8;
116 data->temp[i] |= i2c_smbus_read_byte_data(client,
117 TMP421_TEMP_LSB[i]);
118 }
119 data->last_updated = jiffies;
120 data->valid = 1;
121 }
122
123 mutex_unlock(&data->update_lock);
124
125 return data;
126}
127
128static ssize_t show_temp_value(struct device *dev,
129 struct device_attribute *devattr, char *buf)
130{
131 int index = to_sensor_dev_attr(devattr)->index;
132 struct tmp421_data *data = tmp421_update_device(dev);
133 int temp;
134
135 mutex_lock(&data->update_lock);
136 if (data->config & TMP421_CONFIG_RANGE)
137 temp = temp_from_u16(data->temp[index]);
138 else
139 temp = temp_from_s16(data->temp[index]);
140 mutex_unlock(&data->update_lock);
141
142 return sprintf(buf, "%d\n", temp);
143}
144
145static ssize_t show_fault(struct device *dev,
146 struct device_attribute *devattr, char *buf)
147{
148 int index = to_sensor_dev_attr(devattr)->index;
149 struct tmp421_data *data = tmp421_update_device(dev);
150
151 /*
152 * The OPEN bit signals a fault. This is bit 0 of the temperature
153 * register (low byte).
154 */
155 if (data->temp[index] & 0x01)
156 return sprintf(buf, "1\n");
157 else
158 return sprintf(buf, "0\n");
159}
160
161static umode_t tmp421_is_visible(struct kobject *kobj, struct attribute *a,
162 int n)
163{
164 struct device *dev = container_of(kobj, struct device, kobj);
165 struct tmp421_data *data = dev_get_drvdata(dev);
166 struct device_attribute *devattr;
167 unsigned int index;
168
169 devattr = container_of(a, struct device_attribute, attr);
170 index = to_sensor_dev_attr(devattr)->index;
171
172 if (index < data->channels)
173 return a->mode;
174
175 return 0;
176}
177
178static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_value, NULL, 0);
179static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp_value, NULL, 1);
180static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
181static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp_value, NULL, 2);
182static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
183static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp_value, NULL, 3);
184static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
185
186static struct attribute *tmp421_attr[] = {
187 &sensor_dev_attr_temp1_input.dev_attr.attr,
188 &sensor_dev_attr_temp2_input.dev_attr.attr,
189 &sensor_dev_attr_temp2_fault.dev_attr.attr,
190 &sensor_dev_attr_temp3_input.dev_attr.attr,
191 &sensor_dev_attr_temp3_fault.dev_attr.attr,
192 &sensor_dev_attr_temp4_input.dev_attr.attr,
193 &sensor_dev_attr_temp4_fault.dev_attr.attr,
194 NULL
195};
196
197static const struct attribute_group tmp421_group = {
198 .attrs = tmp421_attr,
199 .is_visible = tmp421_is_visible,
200};
201
202static const struct attribute_group *tmp421_groups[] = {
203 &tmp421_group,
204 NULL
205};
206
207static int tmp421_init_client(struct i2c_client *client)
208{
209 int config, config_orig;
210
211 /* Set the conversion rate to 2 Hz */
212 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
213
214 /* Start conversions (disable shutdown if necessary) */
215 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
216 if (config < 0) {
217 dev_err(&client->dev,
218 "Could not read configuration register (%d)\n", config);
219 return config;
220 }
221
222 config_orig = config;
223 config &= ~TMP421_CONFIG_SHUTDOWN;
224
225 if (config != config_orig) {
226 dev_info(&client->dev, "Enable monitoring chip\n");
227 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
228 }
229
230 return 0;
231}
232
233static int tmp421_detect(struct i2c_client *client,
234 struct i2c_board_info *info)
235{
236 enum chips kind;
237 struct i2c_adapter *adapter = client->adapter;
238 const char * const names[] = { "TMP421", "TMP422", "TMP423",
239 "TMP441", "TMP442" };
240 int addr = client->addr;
241 u8 reg;
242
243 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
244 return -ENODEV;
245
246 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
247 if (reg != TMP421_MANUFACTURER_ID)
248 return -ENODEV;
249
250 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
251 if (reg & 0xf8)
252 return -ENODEV;
253
254 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
255 if (reg & 0x7f)
256 return -ENODEV;
257
258 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
259 switch (reg) {
260 case TMP421_DEVICE_ID:
261 kind = tmp421;
262 break;
263 case TMP422_DEVICE_ID:
264 if (addr == 0x2a)
265 return -ENODEV;
266 kind = tmp422;
267 break;
268 case TMP423_DEVICE_ID:
269 if (addr != 0x4c && addr != 0x4d)
270 return -ENODEV;
271 kind = tmp423;
272 break;
273 case TMP441_DEVICE_ID:
274 kind = tmp441;
275 break;
276 case TMP442_DEVICE_ID:
277 if (addr != 0x4c && addr != 0x4d)
278 return -ENODEV;
279 kind = tmp442;
280 break;
281 default:
282 return -ENODEV;
283 }
284
285 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
286 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
287 names[kind], client->addr);
288
289 return 0;
290}
291
292static int tmp421_probe(struct i2c_client *client,
293 const struct i2c_device_id *id)
294{
295 struct device *dev = &client->dev;
296 struct device *hwmon_dev;
297 struct tmp421_data *data;
298 int err;
299
300 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
301 if (!data)
302 return -ENOMEM;
303
304 mutex_init(&data->update_lock);
305 data->channels = id->driver_data;
306 data->client = client;
307
308 err = tmp421_init_client(client);
309 if (err)
310 return err;
311
312 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
313 data, tmp421_groups);
314 return PTR_ERR_OR_ZERO(hwmon_dev);
315}
316
317static struct i2c_driver tmp421_driver = {
318 .class = I2C_CLASS_HWMON,
319 .driver = {
320 .name = "tmp421",
321 },
322 .probe = tmp421_probe,
323 .id_table = tmp421_id,
324 .detect = tmp421_detect,
325 .address_list = normal_i2c,
326};
327
328module_i2c_driver(tmp421_driver);
329
330MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
331MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
332MODULE_LICENSE("GPL");