1
2
3
4
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
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
53
54struct tmp102 {
55 struct regmap *regmap;
56 u16 config_orig;
57 unsigned long ready_time;
58};
59
60
61static inline int tmp102_reg_to_mC(s16 val)
62{
63 return ((val & ~0x01) * 1000) / 128;
64}
65
66
67static inline u16 tmp102_mC_to_reg(int val)
68{
69 return (val * 128) / 1000;
70}
71
72static 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
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
106static 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
127static 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
144static 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
152static const struct hwmon_ops tmp102_hwmon_ops = {
153 .is_visible = tmp102_is_visible,
154 .read = tmp102_read,
155 .write = tmp102_write,
156};
157
158static const struct hwmon_chip_info tmp102_chip_info = {
159 .ops = &tmp102_hwmon_ops,
160 .info = tmp102_info,
161};
162
163static 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
170static bool tmp102_is_writeable_reg(struct device *dev, unsigned int reg)
171{
172 return reg != TMP102_TEMP_REG;
173}
174
175static bool tmp102_is_volatile_reg(struct device *dev, unsigned int reg)
176{
177 return reg == TMP102_TEMP_REG;
178}
179
180static 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
192static int tmp102_probe(struct i2c_client *client)
193{
194 struct device *dev = &client->dev;
195 struct device *hwmon_dev;
196 struct tmp102 *tmp102;
197 unsigned int regval;
198 int err;
199
200 if (!i2c_check_functionality(client->adapter,
201 I2C_FUNC_SMBUS_WORD_DATA)) {
202 dev_err(dev,
203 "adapter doesn't support SMBus word transactions\n");
204 return -ENODEV;
205 }
206
207 tmp102 = devm_kzalloc(dev, sizeof(*tmp102), GFP_KERNEL);
208 if (!tmp102)
209 return -ENOMEM;
210
211 i2c_set_clientdata(client, tmp102);
212
213 tmp102->regmap = devm_regmap_init_i2c(client, &tmp102_regmap_config);
214 if (IS_ERR(tmp102->regmap))
215 return PTR_ERR(tmp102->regmap);
216
217 err = regmap_read(tmp102->regmap, TMP102_CONF_REG, ®val);
218 if (err < 0) {
219 dev_err(dev, "error reading config register\n");
220 return err;
221 }
222
223 if ((regval & ~TMP102_CONFREG_MASK) !=
224 (TMP102_CONF_R0 | TMP102_CONF_R1)) {
225 dev_err(dev, "unexpected config register value\n");
226 return -ENODEV;
227 }
228
229 tmp102->config_orig = regval;
230
231 err = devm_add_action_or_reset(dev, tmp102_restore_config, tmp102);
232 if (err)
233 return err;
234
235 regval &= ~TMP102_CONFIG_CLEAR;
236 regval |= TMP102_CONFIG_SET;
237
238 err = regmap_write(tmp102->regmap, TMP102_CONF_REG, regval);
239 if (err < 0) {
240 dev_err(dev, "error writing config register\n");
241 return err;
242 }
243
244
245
246
247
248 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
249
250 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
251 tmp102,
252 &tmp102_chip_info,
253 NULL);
254 if (IS_ERR(hwmon_dev)) {
255 dev_dbg(dev, "unable to register hwmon device\n");
256 return PTR_ERR(hwmon_dev);
257 }
258 dev_info(dev, "initialized\n");
259
260 return 0;
261}
262
263#ifdef CONFIG_PM_SLEEP
264static int tmp102_suspend(struct device *dev)
265{
266 struct i2c_client *client = to_i2c_client(dev);
267 struct tmp102 *tmp102 = i2c_get_clientdata(client);
268
269 return regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
270 TMP102_CONF_SD, TMP102_CONF_SD);
271}
272
273static int tmp102_resume(struct device *dev)
274{
275 struct i2c_client *client = to_i2c_client(dev);
276 struct tmp102 *tmp102 = i2c_get_clientdata(client);
277 int err;
278
279 err = regmap_update_bits(tmp102->regmap, TMP102_CONF_REG,
280 TMP102_CONF_SD, 0);
281
282 tmp102->ready_time = jiffies + msecs_to_jiffies(CONVERSION_TIME_MS);
283
284 return err;
285}
286#endif
287
288static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops, tmp102_suspend, tmp102_resume);
289
290static const struct i2c_device_id tmp102_id[] = {
291 { "tmp102", 0 },
292 { }
293};
294MODULE_DEVICE_TABLE(i2c, tmp102_id);
295
296static const struct of_device_id __maybe_unused tmp102_of_match[] = {
297 { .compatible = "ti,tmp102" },
298 { },
299};
300MODULE_DEVICE_TABLE(of, tmp102_of_match);
301
302static struct i2c_driver tmp102_driver = {
303 .driver.name = DRIVER_NAME,
304 .driver.of_match_table = of_match_ptr(tmp102_of_match),
305 .driver.pm = &tmp102_dev_pm_ops,
306 .probe_new = tmp102_probe,
307 .id_table = tmp102_id,
308};
309
310module_i2c_driver(tmp102_driver);
311
312MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
313MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
314MODULE_LICENSE("GPL");
315
