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20#include <linux/module.h>
21#include <linux/init.h>
22#include <linux/slab.h>
23#include <linux/i2c.h>
24#include <linux/hwmon.h>
25#include <linux/hwmon-sysfs.h>
26#include <linux/err.h>
27#include <linux/mutex.h>
28#include <linux/device.h>
29#include <linux/jiffies.h>
30
31#define DRIVER_NAME "tmp102"
32
33#define TMP102_TEMP_REG 0x00
34#define TMP102_CONF_REG 0x01
35
36#define TMP102_CONF_SD 0x0100
37#define TMP102_CONF_TM 0x0200
38#define TMP102_CONF_POL 0x0400
39#define TMP102_CONF_F0 0x0800
40#define TMP102_CONF_F1 0x1000
41#define TMP102_CONF_R0 0x2000
42#define TMP102_CONF_R1 0x4000
43#define TMP102_CONF_OS 0x8000
44#define TMP102_CONF_EM 0x0010
45#define TMP102_CONF_AL 0x0020
46#define TMP102_CONF_CR0 0x0040
47#define TMP102_CONF_CR1 0x0080
48#define TMP102_TLOW_REG 0x02
49#define TMP102_THIGH_REG 0x03
50
51struct tmp102 {
52 struct device *hwmon_dev;
53 struct mutex lock;
54 u16 config_orig;
55 unsigned long last_update;
56 int temp[3];
57};
58
59
60static inline int tmp102_reg_to_mC(s16 val)
61{
62 return ((val & ~0x01) * 1000) / 128;
63}
64
65
66static inline u16 tmp102_mC_to_reg(int val)
67{
68 return (val * 128) / 1000;
69}
70
71static const u8 tmp102_reg[] = {
72 TMP102_TEMP_REG,
73 TMP102_TLOW_REG,
74 TMP102_THIGH_REG,
75};
76
77static struct tmp102 *tmp102_update_device(struct i2c_client *client)
78{
79 struct tmp102 *tmp102 = i2c_get_clientdata(client);
80
81 mutex_lock(&tmp102->lock);
82 if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
83 int i;
84 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
85 int status = i2c_smbus_read_word_swapped(client,
86 tmp102_reg[i]);
87 if (status > -1)
88 tmp102->temp[i] = tmp102_reg_to_mC(status);
89 }
90 tmp102->last_update = jiffies;
91 }
92 mutex_unlock(&tmp102->lock);
93 return tmp102;
94}
95
96static ssize_t tmp102_show_temp(struct device *dev,
97 struct device_attribute *attr,
98 char *buf)
99{
100 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
101 struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
102
103 return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
104}
105
106static ssize_t tmp102_set_temp(struct device *dev,
107 struct device_attribute *attr,
108 const char *buf, size_t count)
109{
110 struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
111 struct i2c_client *client = to_i2c_client(dev);
112 struct tmp102 *tmp102 = i2c_get_clientdata(client);
113 long val;
114 int status;
115
116 if (kstrtol(buf, 10, &val) < 0)
117 return -EINVAL;
118 val = clamp_val(val, -256000, 255000);
119
120 mutex_lock(&tmp102->lock);
121 tmp102->temp[sda->index] = val;
122 status = i2c_smbus_write_word_swapped(client, tmp102_reg[sda->index],
123 tmp102_mC_to_reg(val));
124 mutex_unlock(&tmp102->lock);
125 return status ? : count;
126}
127
128static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
129
130static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
131 tmp102_set_temp, 1);
132
133static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
134 tmp102_set_temp, 2);
135
136static struct attribute *tmp102_attributes[] = {
137 &sensor_dev_attr_temp1_input.dev_attr.attr,
138 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
139 &sensor_dev_attr_temp1_max.dev_attr.attr,
140 NULL
141};
142
143static const struct attribute_group tmp102_attr_group = {
144 .attrs = tmp102_attributes,
145};
146
147#define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
148#define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
149
150static int tmp102_probe(struct i2c_client *client,
151 const struct i2c_device_id *id)
152{
153 struct tmp102 *tmp102;
154 int status;
155
156 if (!i2c_check_functionality(client->adapter,
157 I2C_FUNC_SMBUS_WORD_DATA)) {
158 dev_err(&client->dev,
159 "adapter doesn't support SMBus word transactions\n");
160 return -ENODEV;
161 }
162
163 tmp102 = devm_kzalloc(&client->dev, sizeof(*tmp102), GFP_KERNEL);
164 if (!tmp102)
165 return -ENOMEM;
166
167 i2c_set_clientdata(client, tmp102);
168
169 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
170 if (status < 0) {
171 dev_err(&client->dev, "error reading config register\n");
172 return status;
173 }
174 tmp102->config_orig = status;
175 status = i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
176 TMP102_CONFIG);
177 if (status < 0) {
178 dev_err(&client->dev, "error writing config register\n");
179 goto fail_restore_config;
180 }
181 status = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
182 if (status < 0) {
183 dev_err(&client->dev, "error reading config register\n");
184 goto fail_restore_config;
185 }
186 status &= ~TMP102_CONFIG_RD_ONLY;
187 if (status != TMP102_CONFIG) {
188 dev_err(&client->dev, "config settings did not stick\n");
189 status = -ENODEV;
190 goto fail_restore_config;
191 }
192 tmp102->last_update = jiffies - HZ;
193 mutex_init(&tmp102->lock);
194
195 status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
196 if (status) {
197 dev_dbg(&client->dev, "could not create sysfs files\n");
198 goto fail_restore_config;
199 }
200 tmp102->hwmon_dev = hwmon_device_register(&client->dev);
201 if (IS_ERR(tmp102->hwmon_dev)) {
202 dev_dbg(&client->dev, "unable to register hwmon device\n");
203 status = PTR_ERR(tmp102->hwmon_dev);
204 goto fail_remove_sysfs;
205 }
206
207 dev_info(&client->dev, "initialized\n");
208
209 return 0;
210
211fail_remove_sysfs:
212 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
213fail_restore_config:
214 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
215 tmp102->config_orig);
216 return status;
217}
218
219static int tmp102_remove(struct i2c_client *client)
220{
221 struct tmp102 *tmp102 = i2c_get_clientdata(client);
222
223 hwmon_device_unregister(tmp102->hwmon_dev);
224 sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
225
226
227 if (tmp102->config_orig & TMP102_CONF_SD) {
228 int config;
229
230 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
231 if (config >= 0)
232 i2c_smbus_write_word_swapped(client, TMP102_CONF_REG,
233 config | TMP102_CONF_SD);
234 }
235
236 return 0;
237}
238
239#ifdef CONFIG_PM
240static int tmp102_suspend(struct device *dev)
241{
242 struct i2c_client *client = to_i2c_client(dev);
243 int config;
244
245 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
246 if (config < 0)
247 return config;
248
249 config |= TMP102_CONF_SD;
250 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
251}
252
253static int tmp102_resume(struct device *dev)
254{
255 struct i2c_client *client = to_i2c_client(dev);
256 int config;
257
258 config = i2c_smbus_read_word_swapped(client, TMP102_CONF_REG);
259 if (config < 0)
260 return config;
261
262 config &= ~TMP102_CONF_SD;
263 return i2c_smbus_write_word_swapped(client, TMP102_CONF_REG, config);
264}
265
266static const struct dev_pm_ops tmp102_dev_pm_ops = {
267 .suspend = tmp102_suspend,
268 .resume = tmp102_resume,
269};
270
271#define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
272#else
273#define TMP102_DEV_PM_OPS NULL
274#endif
275
276static const struct i2c_device_id tmp102_id[] = {
277 { "tmp102", 0 },
278 { }
279};
280MODULE_DEVICE_TABLE(i2c, tmp102_id);
281
282static struct i2c_driver tmp102_driver = {
283 .driver.name = DRIVER_NAME,
284 .driver.pm = TMP102_DEV_PM_OPS,
285 .probe = tmp102_probe,
286 .remove = tmp102_remove,
287 .id_table = tmp102_id,
288};
289
290module_i2c_driver(tmp102_driver);
291
292MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
293MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
294MODULE_LICENSE("GPL");
295
