Linux 5.4-rc3
[sfrench/cifs-2.6.git] / drivers / hwmon / tmp421.c
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 */
27 static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
28                                              I2C_CLIENT_END };
29
30 enum 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
39 static const u8 TMP421_TEMP_MSB[4]              = { 0x00, 0x01, 0x02, 0x03 };
40 static 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
54 static const struct i2c_device_id tmp421_id[] = {
55         { "tmp421", 2 },
56         { "tmp422", 3 },
57         { "tmp423", 4 },
58         { "tmp441", 2 },
59         { "tmp442", 3 },
60         { }
61 };
62 MODULE_DEVICE_TABLE(i2c, tmp421_id);
63
64 static 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 };
87 MODULE_DEVICE_TABLE(of, tmp421_of_match);
88
89 struct 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
103 static 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
111 static 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
122 static 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 + 2 * HZ) || !data->valid) {
131                 data->config = i2c_smbus_read_byte_data(client,
132                         TMP421_CONFIG_REG_1);
133
134                 for (i = 0; i < data->channels; i++) {
135                         data->temp[i] = i2c_smbus_read_byte_data(client,
136                                 TMP421_TEMP_MSB[i]) << 8;
137                         data->temp[i] |= i2c_smbus_read_byte_data(client,
138                                 TMP421_TEMP_LSB[i]);
139                 }
140                 data->last_updated = jiffies;
141                 data->valid = 1;
142         }
143
144         mutex_unlock(&data->update_lock);
145
146         return data;
147 }
148
149 static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
150                        u32 attr, int channel, long *val)
151 {
152         struct tmp421_data *tmp421 = tmp421_update_device(dev);
153
154         switch (attr) {
155         case hwmon_temp_input:
156                 if (tmp421->config & TMP421_CONFIG_RANGE)
157                         *val = temp_from_u16(tmp421->temp[channel]);
158                 else
159                         *val = temp_from_s16(tmp421->temp[channel]);
160                 return 0;
161         case hwmon_temp_fault:
162                 /*
163                  * The OPEN bit signals a fault. This is bit 0 of the temperature
164                  * register (low byte).
165                  */
166                 *val = tmp421->temp[channel] & 0x01;
167                 return 0;
168         default:
169                 return -EOPNOTSUPP;
170         }
171
172 }
173
174 static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
175                                  u32 attr, int channel)
176 {
177         switch (attr) {
178         case hwmon_temp_fault:
179                 if (channel == 0)
180                         return 0;
181                 return 0444;
182         case hwmon_temp_input:
183                 return 0444;
184         default:
185                 return 0;
186         }
187 }
188
189 static int tmp421_init_client(struct i2c_client *client)
190 {
191         int config, config_orig;
192
193         /* Set the conversion rate to 2 Hz */
194         i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
195
196         /* Start conversions (disable shutdown if necessary) */
197         config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
198         if (config < 0) {
199                 dev_err(&client->dev,
200                         "Could not read configuration register (%d)\n", config);
201                 return config;
202         }
203
204         config_orig = config;
205         config &= ~TMP421_CONFIG_SHUTDOWN;
206
207         if (config != config_orig) {
208                 dev_info(&client->dev, "Enable monitoring chip\n");
209                 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
210         }
211
212         return 0;
213 }
214
215 static int tmp421_detect(struct i2c_client *client,
216                          struct i2c_board_info *info)
217 {
218         enum chips kind;
219         struct i2c_adapter *adapter = client->adapter;
220         static const char * const names[] = {
221                 "TMP421", "TMP422", "TMP423",
222                 "TMP441", "TMP442"
223         };
224         int addr = client->addr;
225         u8 reg;
226
227         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
228                 return -ENODEV;
229
230         reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
231         if (reg != TMP421_MANUFACTURER_ID)
232                 return -ENODEV;
233
234         reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
235         if (reg & 0xf8)
236                 return -ENODEV;
237
238         reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
239         if (reg & 0x7f)
240                 return -ENODEV;
241
242         reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
243         switch (reg) {
244         case TMP421_DEVICE_ID:
245                 kind = tmp421;
246                 break;
247         case TMP422_DEVICE_ID:
248                 if (addr == 0x2a)
249                         return -ENODEV;
250                 kind = tmp422;
251                 break;
252         case TMP423_DEVICE_ID:
253                 if (addr != 0x4c && addr != 0x4d)
254                         return -ENODEV;
255                 kind = tmp423;
256                 break;
257         case TMP441_DEVICE_ID:
258                 kind = tmp441;
259                 break;
260         case TMP442_DEVICE_ID:
261                 if (addr != 0x4c && addr != 0x4d)
262                         return -ENODEV;
263                 kind = tmp442;
264                 break;
265         default:
266                 return -ENODEV;
267         }
268
269         strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
270         dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
271                  names[kind], client->addr);
272
273         return 0;
274 }
275
276 static const struct hwmon_ops tmp421_ops = {
277         .is_visible = tmp421_is_visible,
278         .read = tmp421_read,
279 };
280
281 static int tmp421_probe(struct i2c_client *client,
282                         const struct i2c_device_id *id)
283 {
284         struct device *dev = &client->dev;
285         struct device *hwmon_dev;
286         struct tmp421_data *data;
287         int i, err;
288
289         data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
290         if (!data)
291                 return -ENOMEM;
292
293         mutex_init(&data->update_lock);
294         if (client->dev.of_node)
295                 data->channels = (unsigned long)
296                         of_device_get_match_data(&client->dev);
297         else
298                 data->channels = id->driver_data;
299         data->client = client;
300
301         err = tmp421_init_client(client);
302         if (err)
303                 return err;
304
305         for (i = 0; i < data->channels; i++)
306                 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
307
308         data->chip.ops = &tmp421_ops;
309         data->chip.info = data->info;
310
311         data->info[0] = &data->temp_info;
312
313         data->temp_info.type = hwmon_temp;
314         data->temp_info.config = data->temp_config;
315
316         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
317                                                          data,
318                                                          &data->chip,
319                                                          NULL);
320         return PTR_ERR_OR_ZERO(hwmon_dev);
321 }
322
323 static struct i2c_driver tmp421_driver = {
324         .class = I2C_CLASS_HWMON,
325         .driver = {
326                 .name   = "tmp421",
327                 .of_match_table = of_match_ptr(tmp421_of_match),
328         },
329         .probe = tmp421_probe,
330         .id_table = tmp421_id,
331         .detect = tmp421_detect,
332         .address_list = normal_i2c,
333 };
334
335 module_i2c_driver(tmp421_driver);
336
337 MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
338 MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
339 MODULE_LICENSE("GPL");