hwmon: (tmp421) handle I2C errors
[linux-2.6-block.git] / drivers / hwmon / tmp421.c
CommitLineData
c942fddf 1// SPDX-License-Identifier: GPL-2.0-or-later
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2/* tmp421.c
3 *
4 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
5 * Preliminary support by:
6 * Melvin Rook, Raymond Ng
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7 */
8
9/*
10 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
05c77ab2 11 * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
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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>
a1253027 23#include <linux/of_device.h>
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24#include <linux/sysfs.h>
25
26/* Addresses to scan */
918ee91c
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27static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
28 I2C_CLIENT_END };
9410700b 29
05c77ab2 30enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
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31
32/* The TMP421 registers */
a63ee9d8 33#define TMP421_STATUS_REG 0x08
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34#define TMP421_CONFIG_REG_1 0x09
35#define TMP421_CONVERSION_RATE_REG 0x0B
36#define TMP421_MANUFACTURER_ID_REG 0xFE
37#define TMP421_DEVICE_ID_REG 0xFF
38
39static const u8 TMP421_TEMP_MSB[4] = { 0x00, 0x01, 0x02, 0x03 };
40static const u8 TMP421_TEMP_LSB[4] = { 0x10, 0x11, 0x12, 0x13 };
41
42/* Flags */
43#define TMP421_CONFIG_SHUTDOWN 0x40
44#define TMP421_CONFIG_RANGE 0x04
45
46/* Manufacturer / Device ID's */
47#define TMP421_MANUFACTURER_ID 0x55
48#define TMP421_DEVICE_ID 0x21
49#define TMP422_DEVICE_ID 0x22
50#define TMP423_DEVICE_ID 0x23
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51#define TMP441_DEVICE_ID 0x41
52#define TMP442_DEVICE_ID 0x42
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53
54static const struct i2c_device_id tmp421_id[] = {
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55 { "tmp421", 2 },
56 { "tmp422", 3 },
57 { "tmp423", 4 },
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58 { "tmp441", 2 },
59 { "tmp442", 3 },
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60 { }
61};
62MODULE_DEVICE_TABLE(i2c, tmp421_id);
63
bd7d56a7 64static const struct of_device_id __maybe_unused tmp421_of_match[] = {
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65 {
66 .compatible = "ti,tmp421",
67 .data = (void *)2
68 },
69 {
70 .compatible = "ti,tmp422",
71 .data = (void *)3
72 },
73 {
74 .compatible = "ti,tmp423",
75 .data = (void *)4
76 },
77 {
78 .compatible = "ti,tmp441",
79 .data = (void *)2
80 },
81 {
f422449b 82 .compatible = "ti,tmp442",
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83 .data = (void *)3
84 },
85 { },
86};
87MODULE_DEVICE_TABLE(of, tmp421_of_match);
88
9410700b 89struct tmp421_data {
276dac80 90 struct i2c_client *client;
9410700b 91 struct mutex update_lock;
bb43cc45
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92 u32 temp_config[5];
93 struct hwmon_channel_info temp_info;
94 const struct hwmon_channel_info *info[2];
95 struct hwmon_chip_info chip;
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96 char valid;
97 unsigned long last_updated;
a1253027 98 unsigned long channels;
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99 u8 config;
100 s16 temp[4];
101};
102
103static int temp_from_s16(s16 reg)
104{
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105 /* Mask out status bits */
106 int temp = reg & ~0xf;
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107
108 return (temp * 1000 + 128) / 256;
109}
110
111static int temp_from_u16(u16 reg)
112{
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113 /* Mask out status bits */
114 int temp = reg & ~0xf;
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115
116 /* Add offset for extended temperature range. */
117 temp -= 64 * 256;
118
119 return (temp * 1000 + 128) / 256;
120}
121
2938b297 122static int tmp421_update_device(struct tmp421_data *data)
9410700b 123{
276dac80 124 struct i2c_client *client = data->client;
2938b297 125 int ret = 0;
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126 int i;
127
128 mutex_lock(&data->update_lock);
129
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130 if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
131 !data->valid) {
2938b297
PF
132 ret = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
133 if (ret < 0)
134 goto exit;
135 data->config = ret;
9410700b 136
8d59582a 137 for (i = 0; i < data->channels; i++) {
2938b297
PF
138 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_MSB[i]);
139 if (ret < 0)
140 goto exit;
141 data->temp[i] = ret << 8;
142
143 ret = i2c_smbus_read_byte_data(client, TMP421_TEMP_LSB[i]);
144 if (ret < 0)
145 goto exit;
146 data->temp[i] |= ret;
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147 }
148 data->last_updated = jiffies;
149 data->valid = 1;
150 }
151
2938b297 152exit:
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153 mutex_unlock(&data->update_lock);
154
2938b297
PF
155 if (ret < 0) {
156 data->valid = 0;
157 return ret;
158 }
159
160 return 0;
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161}
162
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163static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
164 u32 attr, int channel, long *val)
9410700b 165{
2938b297
PF
166 struct tmp421_data *tmp421 = dev_get_drvdata(dev);
167 int ret = 0;
168
169 ret = tmp421_update_device(tmp421);
170 if (ret)
171 return ret;
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172
173 switch (attr) {
174 case hwmon_temp_input:
175 if (tmp421->config & TMP421_CONFIG_RANGE)
176 *val = temp_from_u16(tmp421->temp[channel]);
177 else
178 *val = temp_from_s16(tmp421->temp[channel]);
179 return 0;
180 case hwmon_temp_fault:
181 /*
182 * The OPEN bit signals a fault. This is bit 0 of the temperature
183 * register (low byte).
184 */
185 *val = tmp421->temp[channel] & 0x01;
186 return 0;
187 default:
188 return -EOPNOTSUPP;
189 }
9410700b 190
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191}
192
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193static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
194 u32 attr, int channel)
9410700b 195{
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196 switch (attr) {
197 case hwmon_temp_fault:
198 if (channel == 0)
199 return 0;
b626eb22 200 return 0444;
bb43cc45 201 case hwmon_temp_input:
b626eb22 202 return 0444;
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203 default:
204 return 0;
205 }
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206}
207
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208static int tmp421_init_client(struct i2c_client *client)
209{
210 int config, config_orig;
211
212 /* Set the conversion rate to 2 Hz */
213 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
214
215 /* Start conversions (disable shutdown if necessary) */
216 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
217 if (config < 0) {
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218 dev_err(&client->dev,
219 "Could not read configuration register (%d)\n", config);
010a166a 220 return config;
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221 }
222
223 config_orig = config;
224 config &= ~TMP421_CONFIG_SHUTDOWN;
225
226 if (config != config_orig) {
227 dev_info(&client->dev, "Enable monitoring chip\n");
228 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
229 }
230
231 return 0;
232}
233
310ec792 234static int tmp421_detect(struct i2c_client *client,
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235 struct i2c_board_info *info)
236{
dbe73c8f 237 enum chips kind;
9410700b 238 struct i2c_adapter *adapter = client->adapter;
8b9bf554
CIK
239 static const char * const names[] = {
240 "TMP421", "TMP422", "TMP423",
241 "TMP441", "TMP442"
242 };
a63ee9d8 243 int addr = client->addr;
dbe73c8f 244 u8 reg;
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245
246 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
247 return -ENODEV;
248
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249 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
250 if (reg != TMP421_MANUFACTURER_ID)
251 return -ENODEV;
252
a63ee9d8
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253 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
254 if (reg & 0xf8)
255 return -ENODEV;
256
257 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
258 if (reg & 0x7f)
259 return -ENODEV;
260
dbe73c8f
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261 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
262 switch (reg) {
263 case TMP421_DEVICE_ID:
264 kind = tmp421;
265 break;
266 case TMP422_DEVICE_ID:
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267 if (addr == 0x2a)
268 return -ENODEV;
dbe73c8f
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269 kind = tmp422;
270 break;
271 case TMP423_DEVICE_ID:
a63ee9d8
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272 if (addr != 0x4c && addr != 0x4d)
273 return -ENODEV;
dbe73c8f
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274 kind = tmp423;
275 break;
05c77ab2
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276 case TMP441_DEVICE_ID:
277 kind = tmp441;
278 break;
279 case TMP442_DEVICE_ID:
280 if (addr != 0x4c && addr != 0x4d)
281 return -ENODEV;
282 kind = tmp442;
283 break;
dbe73c8f
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284 default:
285 return -ENODEV;
9410700b 286 }
dbe73c8f 287
dc71afe5 288 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
9410700b 289 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
dc71afe5 290 names[kind], client->addr);
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291
292 return 0;
293}
294
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295static const struct hwmon_ops tmp421_ops = {
296 .is_visible = tmp421_is_visible,
297 .read = tmp421_read,
298};
299
67487038 300static int tmp421_probe(struct i2c_client *client)
9410700b 301{
276dac80
GR
302 struct device *dev = &client->dev;
303 struct device *hwmon_dev;
9410700b 304 struct tmp421_data *data;
bb43cc45 305 int i, err;
9410700b 306
276dac80 307 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
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308 if (!data)
309 return -ENOMEM;
310
9410700b 311 mutex_init(&data->update_lock);
a1253027
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312 if (client->dev.of_node)
313 data->channels = (unsigned long)
314 of_device_get_match_data(&client->dev);
315 else
67487038 316 data->channels = i2c_match_id(tmp421_id, client)->driver_data;
276dac80 317 data->client = client;
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318
319 err = tmp421_init_client(client);
320 if (err)
f625e0fd 321 return err;
9410700b 322
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323 for (i = 0; i < data->channels; i++)
324 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
325
326 data->chip.ops = &tmp421_ops;
327 data->chip.info = data->info;
328
329 data->info[0] = &data->temp_info;
330
331 data->temp_info.type = hwmon_temp;
332 data->temp_info.config = data->temp_config;
333
334 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
335 data,
336 &data->chip,
337 NULL);
276dac80 338 return PTR_ERR_OR_ZERO(hwmon_dev);
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339}
340
341static struct i2c_driver tmp421_driver = {
342 .class = I2C_CLASS_HWMON,
343 .driver = {
344 .name = "tmp421",
a1253027 345 .of_match_table = of_match_ptr(tmp421_of_match),
9410700b 346 },
67487038 347 .probe_new = tmp421_probe,
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348 .id_table = tmp421_id,
349 .detect = tmp421_detect,
c3813d6a 350 .address_list = normal_i2c,
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351};
352
f0967eea 353module_i2c_driver(tmp421_driver);
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354
355MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
05c77ab2 356MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
9410700b 357MODULE_LICENSE("GPL");