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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_device.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/* The TMP421 registers */
33#define TMP421_STATUS_REG 0x08
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
51#define TMP441_DEVICE_ID 0x41
52#define TMP442_DEVICE_ID 0x42
53
54static const struct i2c_device_id tmp421_id[] = {
55 { "tmp421", 2 },
56 { "tmp422", 3 },
57 { "tmp423", 4 },
58 { "tmp441", 2 },
59 { "tmp442", 3 },
60 { }
61};
62MODULE_DEVICE_TABLE(i2c, tmp421_id);
63
64static const struct of_device_id __maybe_unused tmp421_of_match[] = {
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 {
82 .compatible = "ti,tmp442",
83 .data = (void *)3
84 },
85 { },
86};
87MODULE_DEVICE_TABLE(of, tmp421_of_match);
88
89struct tmp421_data {
90 struct i2c_client *client;
91 struct mutex update_lock;
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;
96 char valid;
97 unsigned long last_updated;
98 unsigned long channels;
99 u8 config;
100 s16 temp[4];
101};
102
103static int temp_from_s16(s16 reg)
104{
105 /* Mask out status bits */
106 int temp = reg & ~0xf;
107
108 return (temp * 1000 + 128) / 256;
109}
110
111static int temp_from_u16(u16 reg)
112{
113 /* Mask out status bits */
114 int temp = reg & ~0xf;
115
116 /* Add offset for extended temperature range. */
117 temp -= 64 * 256;
118
119 return (temp * 1000 + 128) / 256;
120}
121
122static struct tmp421_data *tmp421_update_device(struct device *dev)
123{
124 struct tmp421_data *data = dev_get_drvdata(dev);
125 struct i2c_client *client = data->client;
126 int i;
127
128 mutex_lock(&data->update_lock);
129
130 if (time_after(jiffies, data->last_updated + (HZ / 2)) ||
131 !data->valid) {
132 data->config = i2c_smbus_read_byte_data(client,
133 TMP421_CONFIG_REG_1);
134
135 for (i = 0; i < data->channels; i++) {
136 data->temp[i] = i2c_smbus_read_byte_data(client,
137 TMP421_TEMP_MSB[i]) << 8;
138 data->temp[i] |= i2c_smbus_read_byte_data(client,
139 TMP421_TEMP_LSB[i]);
140 }
141 data->last_updated = jiffies;
142 data->valid = 1;
143 }
144
145 mutex_unlock(&data->update_lock);
146
147 return data;
148}
149
150static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
151 u32 attr, int channel, long *val)
152{
153 struct tmp421_data *tmp421 = tmp421_update_device(dev);
154
155 switch (attr) {
156 case hwmon_temp_input:
157 if (tmp421->config & TMP421_CONFIG_RANGE)
158 *val = temp_from_u16(tmp421->temp[channel]);
159 else
160 *val = temp_from_s16(tmp421->temp[channel]);
161 return 0;
162 case hwmon_temp_fault:
163 /*
164 * The OPEN bit signals a fault. This is bit 0 of the temperature
165 * register (low byte).
166 */
167 *val = tmp421->temp[channel] & 0x01;
168 return 0;
169 default:
170 return -EOPNOTSUPP;
171 }
172
173}
174
175static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
176 u32 attr, int channel)
177{
178 switch (attr) {
179 case hwmon_temp_fault:
180 if (channel == 0)
181 return 0;
182 return 0444;
183 case hwmon_temp_input:
184 return 0444;
185 default:
186 return 0;
187 }
188}
189
190static int tmp421_init_client(struct i2c_client *client)
191{
192 int config, config_orig;
193
194 /* Set the conversion rate to 2 Hz */
195 i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
196
197 /* Start conversions (disable shutdown if necessary) */
198 config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
199 if (config < 0) {
200 dev_err(&client->dev,
201 "Could not read configuration register (%d)\n", config);
202 return config;
203 }
204
205 config_orig = config;
206 config &= ~TMP421_CONFIG_SHUTDOWN;
207
208 if (config != config_orig) {
209 dev_info(&client->dev, "Enable monitoring chip\n");
210 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
211 }
212
213 return 0;
214}
215
216static int tmp421_detect(struct i2c_client *client,
217 struct i2c_board_info *info)
218{
219 enum chips kind;
220 struct i2c_adapter *adapter = client->adapter;
221 static const char * const names[] = {
222 "TMP421", "TMP422", "TMP423",
223 "TMP441", "TMP442"
224 };
225 int addr = client->addr;
226 u8 reg;
227
228 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
229 return -ENODEV;
230
231 reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
232 if (reg != TMP421_MANUFACTURER_ID)
233 return -ENODEV;
234
235 reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
236 if (reg & 0xf8)
237 return -ENODEV;
238
239 reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
240 if (reg & 0x7f)
241 return -ENODEV;
242
243 reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
244 switch (reg) {
245 case TMP421_DEVICE_ID:
246 kind = tmp421;
247 break;
248 case TMP422_DEVICE_ID:
249 if (addr == 0x2a)
250 return -ENODEV;
251 kind = tmp422;
252 break;
253 case TMP423_DEVICE_ID:
254 if (addr != 0x4c && addr != 0x4d)
255 return -ENODEV;
256 kind = tmp423;
257 break;
258 case TMP441_DEVICE_ID:
259 kind = tmp441;
260 break;
261 case TMP442_DEVICE_ID:
262 if (addr != 0x4c && addr != 0x4d)
263 return -ENODEV;
264 kind = tmp442;
265 break;
266 default:
267 return -ENODEV;
268 }
269
270 strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
271 dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
272 names[kind], client->addr);
273
274 return 0;
275}
276
277static const struct hwmon_ops tmp421_ops = {
278 .is_visible = tmp421_is_visible,
279 .read = tmp421_read,
280};
281
282static int tmp421_probe(struct i2c_client *client,
283 const struct i2c_device_id *id)
284{
285 struct device *dev = &client->dev;
286 struct device *hwmon_dev;
287 struct tmp421_data *data;
288 int i, err;
289
290 data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
291 if (!data)
292 return -ENOMEM;
293
294 mutex_init(&data->update_lock);
295 if (client->dev.of_node)
296 data->channels = (unsigned long)
297 of_device_get_match_data(&client->dev);
298 else
299 data->channels = id->driver_data;
300 data->client = client;
301
302 err = tmp421_init_client(client);
303 if (err)
304 return err;
305
306 for (i = 0; i < data->channels; i++)
307 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
308
309 data->chip.ops = &tmp421_ops;
310 data->chip.info = data->info;
311
312 data->info[0] = &data->temp_info;
313
314 data->temp_info.type = hwmon_temp;
315 data->temp_info.config = data->temp_config;
316
317 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
318 data,
319 &data->chip,
320 NULL);
321 return PTR_ERR_OR_ZERO(hwmon_dev);
322}
323
324static struct i2c_driver tmp421_driver = {
325 .class = I2C_CLASS_HWMON,
326 .driver = {
327 .name = "tmp421",
328 .of_match_table = of_match_ptr(tmp421_of_match),
329 },
330 .probe = tmp421_probe,
331 .id_table = tmp421_id,
332 .detect = tmp421_detect,
333 .address_list = normal_i2c,
334};
335
336module_i2c_driver(tmp421_driver);
337
338MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
339MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
340MODULE_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");