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