hwmon: tegra: tsensor: lp0 save/restore configuration
[linux-2.6.git] / drivers / hwmon / tmp102.c
1 /* Texas Instruments TMP102 SMBus temperature sensor driver
2  *
3  * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License as published by
7  * the Free Software Foundation; either version 2 of the License, or
8  * (at your option) any later version.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
18  */
19
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
30 #define DRIVER_NAME "tmp102"
31
32 #define TMP102_TEMP_REG                 0x00
33 #define TMP102_CONF_REG                 0x01
34 /* note: these bit definitions are byte swapped */
35 #define         TMP102_CONF_SD          0x0100
36 #define         TMP102_CONF_TM          0x0200
37 #define         TMP102_CONF_POL         0x0400
38 #define         TMP102_CONF_F0          0x0800
39 #define         TMP102_CONF_F1          0x1000
40 #define         TMP102_CONF_R0          0x2000
41 #define         TMP102_CONF_R1          0x4000
42 #define         TMP102_CONF_OS          0x8000
43 #define         TMP102_CONF_EM          0x0010
44 #define         TMP102_CONF_AL          0x0020
45 #define         TMP102_CONF_CR0         0x0040
46 #define         TMP102_CONF_CR1         0x0080
47 #define TMP102_TLOW_REG                 0x02
48 #define TMP102_THIGH_REG                0x03
49
50 struct tmp102 {
51         struct device *hwmon_dev;
52         struct mutex lock;
53         u16 config_orig;
54         unsigned long last_update;
55         int temp[3];
56 };
57
58 /* SMBus specifies low byte first, but the TMP102 returns high byte first,
59  * so we have to swab16 the values */
60 static inline int tmp102_read_reg(struct i2c_client *client, u8 reg)
61 {
62         int result = i2c_smbus_read_word_data(client, reg);
63         return result < 0 ? result : swab16(result);
64 }
65
66 static inline int tmp102_write_reg(struct i2c_client *client, u8 reg, u16 val)
67 {
68         return i2c_smbus_write_word_data(client, reg, swab16(val));
69 }
70
71 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
72 static inline int tmp102_reg_to_mC(s16 val)
73 {
74         return ((val & ~0x01) * 1000) / 128;
75 }
76
77 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
78 static inline u16 tmp102_mC_to_reg(int val)
79 {
80         return (val * 128) / 1000;
81 }
82
83 static const u8 tmp102_reg[] = {
84         TMP102_TEMP_REG,
85         TMP102_TLOW_REG,
86         TMP102_THIGH_REG,
87 };
88
89 static struct tmp102 *tmp102_update_device(struct i2c_client *client)
90 {
91         struct tmp102 *tmp102 = i2c_get_clientdata(client);
92
93         mutex_lock(&tmp102->lock);
94         if (time_after(jiffies, tmp102->last_update + HZ / 3)) {
95                 int i;
96                 for (i = 0; i < ARRAY_SIZE(tmp102->temp); ++i) {
97                         int status = tmp102_read_reg(client, tmp102_reg[i]);
98                         if (status > -1)
99                                 tmp102->temp[i] = tmp102_reg_to_mC(status);
100                 }
101                 tmp102->last_update = jiffies;
102         }
103         mutex_unlock(&tmp102->lock);
104         return tmp102;
105 }
106
107 static ssize_t tmp102_show_temp(struct device *dev,
108                                 struct device_attribute *attr,
109                                 char *buf)
110 {
111         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
112         struct tmp102 *tmp102 = tmp102_update_device(to_i2c_client(dev));
113
114         return sprintf(buf, "%d\n", tmp102->temp[sda->index]);
115 }
116
117 static ssize_t tmp102_set_temp(struct device *dev,
118                                struct device_attribute *attr,
119                                const char *buf, size_t count)
120 {
121         struct sensor_device_attribute *sda = to_sensor_dev_attr(attr);
122         struct i2c_client *client = to_i2c_client(dev);
123         struct tmp102 *tmp102 = i2c_get_clientdata(client);
124         long val;
125         int status;
126
127         if (strict_strtol(buf, 10, &val) < 0)
128                 return -EINVAL;
129         val = SENSORS_LIMIT(val, -256000, 255000);
130
131         mutex_lock(&tmp102->lock);
132         tmp102->temp[sda->index] = val;
133         status = tmp102_write_reg(client, tmp102_reg[sda->index],
134                                   tmp102_mC_to_reg(val));
135         mutex_unlock(&tmp102->lock);
136         return status ? : count;
137 }
138
139 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, tmp102_show_temp, NULL , 0);
140
141 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, tmp102_show_temp,
142                           tmp102_set_temp, 1);
143
144 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, tmp102_show_temp,
145                           tmp102_set_temp, 2);
146
147 static struct attribute *tmp102_attributes[] = {
148         &sensor_dev_attr_temp1_input.dev_attr.attr,
149         &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
150         &sensor_dev_attr_temp1_max.dev_attr.attr,
151         NULL
152 };
153
154 static const struct attribute_group tmp102_attr_group = {
155         .attrs = tmp102_attributes,
156 };
157
158 #define TMP102_CONFIG  (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
159 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
160
161 static int __devinit tmp102_probe(struct i2c_client *client,
162                                   const struct i2c_device_id *id)
163 {
164         struct tmp102 *tmp102;
165         int status;
166
167         if (!i2c_check_functionality(client->adapter,
168                                      I2C_FUNC_SMBUS_WORD_DATA)) {
169                 dev_err(&client->dev, "adapter doesn't support SMBus word "
170                         "transactions\n");
171                 return -ENODEV;
172         }
173
174         tmp102 = kzalloc(sizeof(*tmp102), GFP_KERNEL);
175         if (!tmp102) {
176                 dev_dbg(&client->dev, "kzalloc failed\n");
177                 return -ENOMEM;
178         }
179         i2c_set_clientdata(client, tmp102);
180
181         status = tmp102_read_reg(client, TMP102_CONF_REG);
182         if (status < 0) {
183                 dev_err(&client->dev, "error reading config register\n");
184                 goto fail_free;
185         }
186         tmp102->config_orig = status;
187         status = tmp102_write_reg(client, TMP102_CONF_REG, TMP102_CONFIG);
188         if (status < 0) {
189                 dev_err(&client->dev, "error writing config register\n");
190                 goto fail_restore_config;
191         }
192         status = tmp102_read_reg(client, TMP102_CONF_REG);
193         if (status < 0) {
194                 dev_err(&client->dev, "error reading config register\n");
195                 goto fail_restore_config;
196         }
197         status &= ~TMP102_CONFIG_RD_ONLY;
198         if (status != TMP102_CONFIG) {
199                 dev_err(&client->dev, "config settings did not stick\n");
200                 status = -ENODEV;
201                 goto fail_restore_config;
202         }
203         tmp102->last_update = jiffies - HZ;
204         mutex_init(&tmp102->lock);
205
206         status = sysfs_create_group(&client->dev.kobj, &tmp102_attr_group);
207         if (status) {
208                 dev_dbg(&client->dev, "could not create sysfs files\n");
209                 goto fail_restore_config;
210         }
211         tmp102->hwmon_dev = hwmon_device_register(&client->dev);
212         if (IS_ERR(tmp102->hwmon_dev)) {
213                 dev_dbg(&client->dev, "unable to register hwmon device\n");
214                 status = PTR_ERR(tmp102->hwmon_dev);
215                 goto fail_remove_sysfs;
216         }
217
218         dev_info(&client->dev, "initialized\n");
219
220         return 0;
221
222 fail_remove_sysfs:
223         sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
224 fail_restore_config:
225         tmp102_write_reg(client, TMP102_CONF_REG, tmp102->config_orig);
226 fail_free:
227         kfree(tmp102);
228
229         return status;
230 }
231
232 static int __devexit tmp102_remove(struct i2c_client *client)
233 {
234         struct tmp102 *tmp102 = i2c_get_clientdata(client);
235
236         hwmon_device_unregister(tmp102->hwmon_dev);
237         sysfs_remove_group(&client->dev.kobj, &tmp102_attr_group);
238
239         /* Stop monitoring if device was stopped originally */
240         if (tmp102->config_orig & TMP102_CONF_SD) {
241                 int config;
242
243                 config = tmp102_read_reg(client, TMP102_CONF_REG);
244                 if (config >= 0)
245                         tmp102_write_reg(client, TMP102_CONF_REG,
246                                          config | TMP102_CONF_SD);
247         }
248
249         kfree(tmp102);
250
251         return 0;
252 }
253
254 #ifdef CONFIG_PM
255 static int tmp102_suspend(struct device *dev)
256 {
257         struct i2c_client *client = to_i2c_client(dev);
258         int config;
259
260         config = tmp102_read_reg(client, TMP102_CONF_REG);
261         if (config < 0)
262                 return config;
263
264         config |= TMP102_CONF_SD;
265         return tmp102_write_reg(client, TMP102_CONF_REG, config);
266 }
267
268 static int tmp102_resume(struct device *dev)
269 {
270         struct i2c_client *client = to_i2c_client(dev);
271         int config;
272
273         config = tmp102_read_reg(client, TMP102_CONF_REG);
274         if (config < 0)
275                 return config;
276
277         config &= ~TMP102_CONF_SD;
278         return tmp102_write_reg(client, TMP102_CONF_REG, config);
279 }
280
281 static const struct dev_pm_ops tmp102_dev_pm_ops = {
282         .suspend        = tmp102_suspend,
283         .resume         = tmp102_resume,
284 };
285
286 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
287 #else
288 #define TMP102_DEV_PM_OPS NULL
289 #endif /* CONFIG_PM */
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 struct i2c_driver tmp102_driver = {
298         .driver.name    = DRIVER_NAME,
299         .driver.pm      = TMP102_DEV_PM_OPS,
300         .probe          = tmp102_probe,
301         .remove         = __devexit_p(tmp102_remove),
302         .id_table       = tmp102_id,
303 };
304
305 static int __init tmp102_init(void)
306 {
307         return i2c_add_driver(&tmp102_driver);
308 }
309 module_init(tmp102_init);
310
311 static void __exit tmp102_exit(void)
312 {
313         i2c_del_driver(&tmp102_driver);
314 }
315 module_exit(tmp102_exit);
316
317 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
318 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
319 MODULE_LICENSE("GPL");