1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Texas Instruments TMP102 SMBus temperature sensor driver
3 *
4 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
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/hwmon-sysfs.h>
14 #include <linux/err.h>
15 #include <linux/mutex.h>
16 #include <linux/device.h>
17 #include <linux/jiffies.h>
18 #include <linux/regmap.h>
19 #include <linux/regulator/consumer.h>
20 #include <linux/of.h>
21
22 #define DRIVER_NAME "tmp102"
23
24 #define TMP102_TEMP_REG 0x00
25 #define TMP102_CONF_REG 0x01
26 /* note: these bit definitions are byte swapped */
27 #define TMP102_CONF_SD 0x0100
28 #define TMP102_CONF_TM 0x0200
29 #define TMP102_CONF_POL 0x0400
30 #define TMP102_CONF_F0 0x0800
31 #define TMP102_CONF_F1 0x1000
32 #define TMP102_CONF_R0 0x2000
33 #define TMP102_CONF_R1 0x4000
34 #define TMP102_CONF_OS 0x8000
35 #define TMP102_CONF_EM 0x0010
36 #define TMP102_CONF_AL 0x0020
37 #define TMP102_CONF_CR0 0x0040
38 #define TMP102_CONF_CR1 0x0080
39 #define TMP102_TLOW_REG 0x02
40 #define TMP102_THIGH_REG 0x03
41
42 #define TMP102_CONFREG_MASK (TMP102_CONF_SD | TMP102_CONF_TM | \
43 TMP102_CONF_POL | TMP102_CONF_F0 | \
44 TMP102_CONF_F1 | TMP102_CONF_OS | \
45 TMP102_CONF_EM | TMP102_CONF_AL | \
46 TMP102_CONF_CR0 | TMP102_CONF_CR1)
47
48 #define TMP102_CONFIG_CLEAR (TMP102_CONF_SD | TMP102_CONF_OS | \
49 TMP102_CONF_CR0)
50 #define TMP102_CONFIG_SET (TMP102_CONF_TM | TMP102_CONF_EM | \
51 TMP102_CONF_CR1)
52
53 #define CONVERSION_TIME_MS 35 /* in milli-seconds */
54
55 struct tmp102 {
56 struct regmap *regmap;
57 u16 config_orig;
58 unsigned long ready_time;
59 };
60
61 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
tmp102_reg_to_mC(s16 val)62 static inline int tmp102_reg_to_mC(s16 val)
63 {
64 return ((val & ~0x01) * 1000) / 128;
65 }
66
67 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
tmp102_mC_to_reg(int val)68 static inline u16 tmp102_mC_to_reg(int val)
69 {
70 return (val * 128) / 1000;
71 }
72
tmp102_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * temp)73 static int tmp102_read(struct device *dev, enum hwmon_sensor_types type,
74 u32 attr, int channel, long *temp)
75 {
76 struct tmp102 *tmp102 = dev_get_drvdata(dev);
77 unsigned int regval;
78 int err, reg;
79
80 switch (attr) {
81 case hwmon_temp_input:
82 /* Is it too early to return a conversion ? */
83 if (time_before(jiffies, tmp102->ready_time)) {
84 dev_dbg(dev, "%s: Conversion not ready yet..\n", __func__);
85 return -EAGAIN;
86 }
87 reg = TMP102_TEMP_REG;
88 break;
89 case hwmon_temp_max_hyst:
90 reg = TMP102_TLOW_REG;
91 break;
92 case hwmon_temp_max:
93 reg = TMP102_THIGH_REG;
94 break;
95 default:
96 return -EOPNOTSUPP;
97 }
98
99 err = regmap_read(tmp102->regmap, reg, ®val);
100 if (err < 0)
101 return err;
102 *temp = tmp102_reg_to_mC(regval);
103
104 return 0;
105 }
106
tmp102_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long temp)107 static int tmp102_write(struct device *dev, enum hwmon_sensor_types type,
108 u32 attr, int channel, long temp)
109 {
110 struct tmp102 *tmp102 = dev_get_drvdata(dev);
111 int reg;
112
113 switch (attr) {
114 case hwmon_temp_max_hyst:
115 reg = TMP102_TLOW_REG;
116 break;
117 case hwmon_temp_max:
118 reg = TMP102_THIGH_REG;
119 break;
120 default:
121 return -EOPNOTSUPP;
122 }
123
124 temp = clamp_val(temp, -256000, 255000);
125 return regmap_write(tmp102->regmap, reg, tmp102_mC_to_reg(temp));
126 }
127
tmp102_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)128 static umode_t tmp102_is_visible(const void *data, enum hwmon_sensor_types type,
129 u32 attr, int channel)
130 {
131 if (type != hwmon_temp)
132 return 0;
133
134 switch (attr) {
135 case hwmon_temp_input:
136 return 0444;
137 case hwmon_temp_max_hyst:
138 case hwmon_temp_max:
139 return 0644;
140 default:
141 return 0;
142 }
143 }
144
145 static const struct hwmon_channel_info * const tmp102_info[] = {
146 HWMON_CHANNEL_INFO(chip,
147 HWMON_C_REGISTER_TZ),
148 HWMON_CHANNEL_INFO(temp,
149 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST),
150 NULL
151 };
152
153 static const struct hwmon_ops tmp102_hwmon_ops = {
154 .is_visible = tmp102_is_visible,
155 .read = tmp102_read,
156 .write = tmp102_write,
157 };
158
159 static const struct hwmon_chip_info tmp102_chip_info = {
160 .ops = &tmp102_hwmon_ops,
161 .info = tmp102_info,
162 };
163
tmp102_restore_config(void * data)164 static void tmp102_restore_config(void *data)
165 {
166 struct tmp102 *tmp102 = data;
167
168 regmap_write(tmp102->regmap, TMP102_CONF_REG, tmp102->config_orig);
169 }
170
tmp102_is_writeable_reg(struct device * dev,unsigned int reg)171 static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
172 {
173 return reg != TMP102_TEMP_REG;
174 }
175
tmp102_is_volatile_reg(struct device * dev,unsigned int reg)176 static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
177 {
178 return reg == TMP102_TEMP_REG;
179 }
180
181 static const struct regmap_config tmp102_regmap_config = {
182 .reg_bits = 8,
183 .val_bits = 16,
184 .max_register = TMP102_THIGH_REG,
185 .writeable_reg = tmp102_is_writeable_reg,
186 .volatile_reg = tmp102_is_volatile_reg,
187 .val_format_endian = REGMAP_ENDIAN_BIG,
188 .cache_type = REGCACHE_MAPLE,
189 .use_single_read = true,
190 .use_single_write = true,
191 };
192
tmp102_probe(struct i2c_client * client)193 static int tmp102_probe(struct i2c_client *client)
194 {
195 struct device *dev = &client->dev;
196 struct device *hwmon_dev;
197 struct tmp102 *tmp102;
198 unsigned int regval;
199 int err;
200
201 if (!i2c_check_functionality(client->adapter,
202 I2C_FUNC_SMBUS_WORD_DATA)) {
203 dev_err(dev,
204 "adapter doesn't support SMBus word transactions\n");
205 return -ENODEV;
206 }
207
208 err = devm_regulator_get_enable_optional(dev, "vcc");
209 if (err < 0 && err != -ENODEV)
210 return dev_err_probe(dev, err, "Failed to enable regulator\n");
211
212 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
213 if (!tmp102)
214 return -ENOMEM;
215
216 i2c_set_clientdata(client, tmp102);
217
218 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
219 if (IS_ERR(tmp102->regmap))
220 return PTR_ERR(tmp102->regmap);
221
222 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val);
223 if (err < 0) {
224 dev_err(dev, "error reading config register\n");
225 return err;
226 }
227
228 if ((regval & ~TMP102_CONFREG_MASK) !=
229 (TMP102_CONF_R0 | TMP102_CONF_R1)) {
230 dev_err(dev, "unexpected config register value\n");
231 return -ENODEV;
232 }
233
234 tmp102->config_orig = regval;
235
236 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
237 if (err)
238 return err;
239
240 regval &= ~TMP102_CONFIG_CLEAR;
241 regval |= TMP102_CONFIG_SET;
242
243 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
244 if (err < 0) {
245 dev_err(dev, "error writing config register\n");
246 return err;
247 }
248
249 /*
250 * Mark that we are not ready with data until the first
251 * conversion is complete
252 */
253 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
254
255 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
256 tmp102,
257 &tmp102_chip_info,
258 NULL);
259 if (IS_ERR(hwmon_dev)) {
260 dev_dbg(dev, "unable to register hwmon device\n");
261 return PTR_ERR(hwmon_dev);
262 }
263 dev_info(dev, "initialized\n");
264
265 return 0;
266 }
267
tmp102_suspend(struct device * dev)268 static int tmp102_suspend(struct device *dev)
269 {
270 struct i2c_client *client = to_i2c_client(dev);
271 struct tmp102 *tmp102 = i2c_get_clientdata(client);
272
273 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
274 TMP102_CONF_SD, TMP102_CONF_SD);
275 }
276
tmp102_resume(struct device * dev)277 static int tmp102_resume(struct device *dev)
278 {
279 struct i2c_client *client = to_i2c_client(dev);
280 struct tmp102 *tmp102 = i2c_get_clientdata(client);
281 int err;
282
283 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
284 TMP102_CONF_SD, 0);
285
286 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
287
288 return err;
289 }
290
291 static DEFINE_SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
292
293 static const struct i2c_device_id tmp102_id[] = {
294 { "tmp102" },
295 { }
296 };
297 MODULE_DEVICE_TABLE(i2c, tmp102_id);
298
299 static const struct of_device_id __maybe_unused tmp102_of_match[] = {
300 { .compatible = "ti,tmp102" },
301 { },
302 };
303 MODULE_DEVICE_TABLE(of, tmp102_of_match);
304
305 static struct i2c_driver tmp102_driver = {
306 .driver.name = DRIVER_NAME,
307 .driver.of_match_table = of_match_ptr(tmp102_of_match),
308 .driver.pm = pm_sleep_ptr(&tmp102_dev_pm_ops),
309 .probe = tmp102_probe,
310 .id_table = tmp102_id,
311 };
312
313 module_i2c_driver(tmp102_driver);
314
315 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
316 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
317 MODULE_LICENSE("GPL");
318