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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Texas Instruments TMP102 SMBus temperature sensor driver
3 *
4 * Copyright (C) 2010 Steven King <[email protected]>
5 */
6
7#include <linux/delay.h>
8#include <linux/module.h>
9#include <linux/init.h>
10#include <linux/slab.h>
11#include <linux/i2c.h>
12#include <linux/hwmon.h>
13#include <linux/err.h>
14#include <linux/device.h>
15#include <linux/jiffies.h>
16#include <linux/regmap.h>
17#include <linux/regulator/consumer.h>
18#include <linux/property.h>
19
20#define DRIVER_NAME "tmp102"
21
22#define TMP102_TEMP_REG 0x00
23#define TMP102_CONF_REG 0x01
24/* note: these bit definitions are byte swapped */
25#define TMP102_CONF_SD 0x0100
26#define TMP102_CONF_TM 0x0200
27#define TMP102_CONF_POL 0x0400
28#define TMP102_CONF_F0 0x0800
29#define TMP102_CONF_F1 0x1000
30#define TMP102_CONF_R0 0x2000
31#define TMP102_CONF_R1 0x4000
32#define TMP102_CONF_OS 0x8000
33#define TMP102_CONF_EM 0x0010
34#define TMP102_CONF_AL 0x0020
35#define TMP102_CONF_CR0 0x0040
36#define TMP102_CONF_CR1 0x0080
37#define TMP102_TLOW_REG 0x02
38#define TMP102_THIGH_REG 0x03
39
40#define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \
41 TMP102_CONF_POL | TMP102_CONF_F0 | \
42 TMP102_CONF_F1 | TMP102_CONF_OS | \
43 TMP102_CONF_EM | TMP102_CONF_AL | \
44 TMP102_CONF_CR0 | TMP102_CONF_CR1)
45
46#define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \
47 TMP102_CONF_CR0)
48#define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \
49 TMP102_CONF_CR1)
50
51#define CONVERSION_TIME_MS 35 /* in milli-seconds */
52
53#define NUM_SAMPLE_TIMES 4
54#define DEFAULT_SAMPLE_TIME_MS 250
55static const unsigned int *sample_times = (const unsigned int []){ 125, 250, 1000, 4000 };
56
57struct tmp102 {
58 const char *label;
59 struct regmap *regmap;
60 u16 config_orig;
61 unsigned long ready_time;
62 u16 sample_time;
63};
64
65/* convert left adjusted 13-bit TMP102 register value to milliCelsius */
66static inline int tmp102_reg_to_mC(s16 val)
67{
68 return ((val & ~0x01) * 1000) / 128;
69}
70
71/* convert milliCelsius to left adjusted 13-bit TMP102 register value */
72static inline u16 tmp102_mC_to_reg(int val)
73{
74 return (val * 128) / 1000;
75}
76
77static int tmp102_read_string(struct device *dev, enum hwmon_sensor_types type,
78 u32 attr, int channel, const char **str)
79{
80 struct tmp102 *tmp102 = dev_get_drvdata(dev);
81
82 *str = tmp102->label;
83
84 return 0;
85}
86
87static int tmp102_read_chip(struct device *dev, u32 attr, long *val)
88{
89 struct tmp102 *tmp102 = dev_get_drvdata(dev);
90
91 switch (attr) {
92 case hwmon_chip_update_interval:
93 *val = tmp102->sample_time;
94 return 0;
95 default:
96 return -EOPNOTSUPP;
97 }
98}
99
100static int tmp102_read_temp(struct device *dev, u32 attr, long *val)
101{
102 struct tmp102 *tmp102 = dev_get_drvdata(dev);
103 unsigned int regval;
104 int err, reg;
105
106 switch (attr) {
107 case hwmon_temp_input:
108 /* Is it too early to return a conversion ? */
109 if (time_before(jiffies, tmp102->ready_time)) {
110 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
111 return -EAGAIN;
112 }
113 reg = TMP102_TEMP_REG;
114 break;
115 case hwmon_temp_max_hyst:
116 reg = TMP102_TLOW_REG;
117 break;
118 case hwmon_temp_max:
119 reg = TMP102_THIGH_REG;
120 break;
121 default:
122 return -EOPNOTSUPP;
123 }
124
125 err = regmap_read(tmp102->regmap, reg, &regval);
126 if (err < 0)
127 return err;
128
129 *val = tmp102_reg_to_mC(regval);
130
131 return 0;
132}
133
134static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
135 u32 attr, int channel, long *val)
136{
137 switch (type) {
138 case hwmon_chip:
139 return tmp102_read_chip(dev, attr, val);
140 case hwmon_temp:
141 return tmp102_read_temp(dev, attr, val);
142 default:
143 return -EOPNOTSUPP;
144 }
145}
146
147static int tmp102_update_interval(struct device *dev, long val)
148{
149 struct tmp102 *tmp102 = dev_get_drvdata(dev);
150 u8 index;
151 s32 err;
152
153 index = find_closest(val, sample_times, NUM_SAMPLE_TIMES);
154
155 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
156 (TMP102_CONF_CR1 | TMP102_CONF_CR0), (3 - index) << 6);
157 if (err < 0)
158 return err;
159 tmp102->sample_time = sample_times[index];
160
161 return 0;
162}
163
164static int tmp102_write_chip(struct device *dev, u32 attr, long val)
165{
166 switch (attr) {
167 case hwmon_chip_update_interval:
168 return tmp102_update_interval(dev, val);
169 default:
170 return -EOPNOTSUPP;
171 }
172 return 0;
173}
174
175static int tmp102_write_temp(struct device *dev, u32 attr, long val)
176{
177 struct tmp102 *tmp102 = dev_get_drvdata(dev);
178 int reg;
179
180 switch (attr) {
181 case hwmon_temp_max_hyst:
182 reg = TMP102_TLOW_REG;
183 break;
184 case hwmon_temp_max:
185 reg = TMP102_THIGH_REG;
186 break;
187 default:
188 return -EOPNOTSUPP;
189 }
190
191 val = clamp_val(val, -256000, 255000);
192 return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(val));
193}
194
195static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
196 u32 attr, int channel, long val)
197{
198 switch (type) {
199 case hwmon_chip:
200 return tmp102_write_chip(dev, attr, val);
201 case hwmon_temp:
202 return tmp102_write_temp(dev, attr, val);
203 default:
204 return -EOPNOTSUPP;
205 }
206 return 0;
207}
208
209static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
210 u32 attr, int channel)
211{
212 const struct tmp102 *tmp102 = data;
213
214 switch (type) {
215 case hwmon_chip:
216 switch (attr) {
217 case hwmon_chip_update_interval:
218 return 0644;
219 default:
220 break;
221 }
222 break;
223 case hwmon_temp:
224 switch (attr) {
225 case hwmon_temp_input:
226 return 0444;
227 case hwmon_temp_label:
228 if (tmp102->label)
229 return 0444;
230 return 0;
231 case hwmon_temp_max_hyst:
232 case hwmon_temp_max:
233 return 0644;
234 default:
235 break;
236 }
237 break;
238 default:
239 break;
240 }
241 return 0;
242}
243
244static const struct hwmon_channel_info * const tmp102_info[] = {
245 HWMON_CHANNEL_INFO(chip,
246 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL),
247 HWMON_CHANNEL_INFO(temp,
248 HWMON_T_INPUT | HWMON_T_LABEL | HWMON_T_MAX | HWMON_T_MAX_HYST),
249 NULL
250};
251
252static const struct hwmon_ops tmp102_hwmon_ops = {
253 .is_visible = tmp102_is_visible,
254 .read_string = tmp102_read_string,
255 .read = tmp102_read,
256 .write = tmp102_write,
257};
258
259static const struct hwmon_chip_info tmp102_chip_info = {
260 .ops = &tmp102_hwmon_ops,
261 .info = tmp102_info,
262};
263
264static void tmp102_restore_config(void *data)
265{
266 struct tmp102 *tmp102 = data;
267
268 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);
269}
270
271static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
272{
273 return reg != TMP102_TEMP_REG;
274}
275
276static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
277{
278 return reg == TMP102_TEMP_REG;
279}
280
281static const struct regmap_config tmp102_regmap_config = {
282 .reg_bits = 8,
283 .val_bits = 16,
284 .max_register = TMP102_THIGH_REG,
285 .writeable_reg = tmp102_is_writeable_reg,
286 .volatile_reg = tmp102_is_volatile_reg,
287 .val_format_endian = REGMAP_ENDIAN_BIG,
288 .cache_type = REGCACHE_MAPLE,
289 .use_single_read = true,
290 .use_single_write = true,
291};
292
293static int tmp102_probe(struct i2c_client *client)
294{
295 struct device *dev = &client->dev;
296 struct device *hwmon_dev;
297 struct tmp102 *tmp102;
298 unsigned int regval;
299 int err;
300
301 if (!i2c_check_functionality(client->adapter,
302 I2C_FUNC_SMBUS_WORD_DATA)) {
303 dev_err(dev,
304 "adapter doesn't support SMBus word transactions\n");
305 return -ENODEV;
306 }
307
308 err = devm_regulator_get_enable_optional(dev, "vcc");
309 if (err < 0 && err != -ENODEV)
310 return dev_err_probe(dev, err, "Failed to enable regulator\n");
311
312 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
313 if (!tmp102)
314 return -ENOMEM;
315
316 device_property_read_string(dev, "label", &tmp102->label);
317
318 i2c_set_clientdata(client, tmp102);
319
320 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
321 if (IS_ERR(tmp102->regmap))
322 return PTR_ERR(tmp102->regmap);
323
324 tmp102->sample_time = DEFAULT_SAMPLE_TIME_MS;
325
326 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, &regval);
327 if (err < 0) {
328 dev_err(dev, "error reading config register\n");
329 return err;
330 }
331
332 if ((regval & ~TMP102_CONFREG_MASK) !=
333 (TMP102_CONF_R0 | TMP102_CONF_R1)) {
334 dev_err(dev, "unexpected config register value\n");
335 return -ENODEV;
336 }
337
338 tmp102->config_orig = regval;
339
340 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
341 if (err)
342 return err;
343
344 regval &= ~TMP102_CONFIG_CLEAR;
345 regval |= TMP102_CONFIG_SET;
346
347 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
348 if (err < 0) {
349 dev_err(dev, "error writing config register\n");
350 return err;
351 }
352
353 /*
354 * Mark that we are not ready with data until the first
355 * conversion is complete
356 */
357 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
358
359 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
360 tmp102,
361 &tmp102_chip_info,
362 NULL);
363 if (IS_ERR(hwmon_dev)) {
364 dev_dbg(dev, "unable to register hwmon device\n");
365 return PTR_ERR(hwmon_dev);
366 }
367 dev_info(dev, "initialized\n");
368
369 return 0;
370}
371
372static int tmp102_suspend(struct device *dev)
373{
374 struct i2c_client *client = to_i2c_client(dev);
375 struct tmp102 *tmp102 = i2c_get_clientdata(client);
376
377 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
378 TMP102_CONF_SD, TMP102_CONF_SD);
379}
380
381static int tmp102_resume(struct device *dev)
382{
383 struct i2c_client *client = to_i2c_client(dev);
384 struct tmp102 *tmp102 = i2c_get_clientdata(client);
385 int err;
386
387 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
388 TMP102_CONF_SD, 0);
389
390 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
391
392 return err;
393}
394
395static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
396
397static const struct i2c_device_id tmp102_id[] = {
398 { .name = "tmp102" },
399 { .name = "tmp110" },
400 { .name = "tmp113" },
401 { }
402};
403MODULE_DEVICE_TABLE(i2c, tmp102_id);
404
405static const struct of_device_id tmp102_of_match[] = {
406 { .compatible = "ti,tmp102" },
407 { },
408};
409MODULE_DEVICE_TABLE(of, tmp102_of_match);
410
411static struct i2c_driver tmp102_driver = {
412 .driver.name = DRIVER_NAME,
413 .driver.of_match_table = tmp102_of_match,
414 .driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops),
415 .probe = tmp102_probe,
416 .id_table = tmp102_id,
417};
418
419module_i2c_driver(tmp102_driver);
420
421MODULE_AUTHOR("Steven King <[email protected]>");
422MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
423MODULE_LICENSE("GPL");