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60994698 RS |
1 | /* |
2 | * ds620.c - Support for temperature sensor and thermostat DS620 | |
3 | * | |
4 | * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de> | |
5 | * | |
6 | * based on ds1621.c by Christian W. Zuckschwerdt <zany@triq.net> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
21 | */ | |
22 | ||
23 | #include <linux/module.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/slab.h> | |
26 | #include <linux/jiffies.h> | |
27 | #include <linux/i2c.h> | |
28 | #include <linux/hwmon.h> | |
29 | #include <linux/hwmon-sysfs.h> | |
30 | #include <linux/err.h> | |
31 | #include <linux/mutex.h> | |
32 | #include <linux/sysfs.h> | |
33 | #include <linux/i2c/ds620.h> | |
34 | ||
35 | /* | |
36 | * Many DS620 constants specified below | |
37 | * 15 14 13 12 11 10 09 08 | |
38 | * |Done|NVB |THF |TLF |R1 |R0 |AUTOC|1SHOT| | |
39 | * | |
40 | * 07 06 05 04 03 02 01 00 | |
41 | * |PO2 |PO1 |A2 |A1 |A0 | | | | | |
42 | */ | |
43 | #define DS620_REG_CONFIG_DONE 0x8000 | |
44 | #define DS620_REG_CONFIG_NVB 0x4000 | |
45 | #define DS620_REG_CONFIG_THF 0x2000 | |
46 | #define DS620_REG_CONFIG_TLF 0x1000 | |
47 | #define DS620_REG_CONFIG_R1 0x0800 | |
48 | #define DS620_REG_CONFIG_R0 0x0400 | |
49 | #define DS620_REG_CONFIG_AUTOC 0x0200 | |
50 | #define DS620_REG_CONFIG_1SHOT 0x0100 | |
51 | #define DS620_REG_CONFIG_PO2 0x0080 | |
52 | #define DS620_REG_CONFIG_PO1 0x0040 | |
53 | #define DS620_REG_CONFIG_A2 0x0020 | |
54 | #define DS620_REG_CONFIG_A1 0x0010 | |
55 | #define DS620_REG_CONFIG_A0 0x0008 | |
56 | ||
57 | /* The DS620 registers */ | |
58 | static const u8 DS620_REG_TEMP[3] = { | |
59 | 0xAA, /* input, word, RO */ | |
60 | 0xA2, /* min, word, RW */ | |
61 | 0xA0, /* max, word, RW */ | |
62 | }; | |
63 | ||
64 | #define DS620_REG_CONF 0xAC /* word, RW */ | |
65 | #define DS620_COM_START 0x51 /* no data */ | |
66 | #define DS620_COM_STOP 0x22 /* no data */ | |
67 | ||
68 | /* Each client has this additional data */ | |
69 | struct ds620_data { | |
70 | struct device *hwmon_dev; | |
71 | struct mutex update_lock; | |
72 | char valid; /* !=0 if following fields are valid */ | |
73 | unsigned long last_updated; /* In jiffies */ | |
74 | ||
cc41d586 | 75 | s16 temp[3]; /* Register values, word */ |
60994698 RS |
76 | }; |
77 | ||
78 | /* | |
79 | * Temperature registers are word-sized. | |
80 | * DS620 uses a high-byte first convention, which is exactly opposite to | |
81 | * the SMBus standard. | |
82 | */ | |
83 | static int ds620_read_temp(struct i2c_client *client, u8 reg) | |
84 | { | |
85 | int ret; | |
86 | ||
87 | ret = i2c_smbus_read_word_data(client, reg); | |
88 | if (ret < 0) | |
89 | return ret; | |
90 | return swab16(ret); | |
91 | } | |
92 | ||
93 | static int ds620_write_temp(struct i2c_client *client, u8 reg, u16 value) | |
94 | { | |
95 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
96 | } | |
97 | ||
98 | static void ds620_init_client(struct i2c_client *client) | |
99 | { | |
100 | struct ds620_platform_data *ds620_info = client->dev.platform_data; | |
101 | u16 conf, new_conf; | |
102 | ||
103 | new_conf = conf = | |
104 | swab16(i2c_smbus_read_word_data(client, DS620_REG_CONF)); | |
105 | ||
106 | /* switch to continuous conversion mode */ | |
107 | new_conf &= ~DS620_REG_CONFIG_1SHOT; | |
108 | /* already high at power-on, but don't trust the BIOS! */ | |
109 | new_conf |= DS620_REG_CONFIG_PO2; | |
110 | /* thermostat mode according to platform data */ | |
111 | if (ds620_info && ds620_info->pomode == 1) | |
112 | new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */ | |
113 | else if (ds620_info && ds620_info->pomode == 2) | |
114 | new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */ | |
115 | else | |
116 | new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */ | |
117 | /* with highest precision */ | |
118 | new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0; | |
119 | ||
120 | if (conf != new_conf) | |
121 | i2c_smbus_write_word_data(client, DS620_REG_CONF, | |
122 | swab16(new_conf)); | |
123 | ||
124 | /* start conversion */ | |
125 | i2c_smbus_write_byte(client, DS620_COM_START); | |
126 | } | |
127 | ||
128 | static struct ds620_data *ds620_update_client(struct device *dev) | |
129 | { | |
130 | struct i2c_client *client = to_i2c_client(dev); | |
131 | struct ds620_data *data = i2c_get_clientdata(client); | |
132 | struct ds620_data *ret = data; | |
133 | ||
134 | mutex_lock(&data->update_lock); | |
135 | ||
136 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
137 | || !data->valid) { | |
138 | int i; | |
139 | int res; | |
140 | ||
141 | dev_dbg(&client->dev, "Starting ds620 update\n"); | |
142 | ||
143 | for (i = 0; i < ARRAY_SIZE(data->temp); i++) { | |
144 | res = ds620_read_temp(client, | |
145 | DS620_REG_TEMP[i]); | |
146 | if (res < 0) { | |
147 | ret = ERR_PTR(res); | |
148 | goto abort; | |
149 | } | |
150 | ||
151 | data->temp[i] = res; | |
152 | } | |
153 | ||
154 | data->last_updated = jiffies; | |
155 | data->valid = 1; | |
156 | } | |
157 | abort: | |
158 | mutex_unlock(&data->update_lock); | |
159 | ||
160 | return ret; | |
161 | } | |
162 | ||
163 | static ssize_t show_temp(struct device *dev, struct device_attribute *da, | |
164 | char *buf) | |
165 | { | |
166 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
167 | struct ds620_data *data = ds620_update_client(dev); | |
168 | ||
169 | if (IS_ERR(data)) | |
170 | return PTR_ERR(data); | |
171 | ||
172 | return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10); | |
173 | } | |
174 | ||
175 | static ssize_t set_temp(struct device *dev, struct device_attribute *da, | |
176 | const char *buf, size_t count) | |
177 | { | |
178 | int res; | |
179 | long val; | |
180 | ||
181 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
182 | struct i2c_client *client = to_i2c_client(dev); | |
183 | struct ds620_data *data = i2c_get_clientdata(client); | |
184 | ||
185 | res = strict_strtol(buf, 10, &val); | |
186 | ||
187 | if (res) | |
188 | return res; | |
189 | ||
190 | val = (val * 10 / 625) * 8; | |
191 | ||
192 | mutex_lock(&data->update_lock); | |
193 | data->temp[attr->index] = val; | |
194 | ds620_write_temp(client, DS620_REG_TEMP[attr->index], | |
195 | data->temp[attr->index]); | |
196 | mutex_unlock(&data->update_lock); | |
197 | return count; | |
198 | } | |
199 | ||
200 | static ssize_t show_alarm(struct device *dev, struct device_attribute *da, | |
201 | char *buf) | |
202 | { | |
203 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
204 | struct ds620_data *data = ds620_update_client(dev); | |
205 | struct i2c_client *client = to_i2c_client(dev); | |
206 | u16 conf, new_conf; | |
207 | int res; | |
208 | ||
209 | if (IS_ERR(data)) | |
210 | return PTR_ERR(data); | |
211 | ||
212 | /* reset alarms if necessary */ | |
213 | res = i2c_smbus_read_word_data(client, DS620_REG_CONF); | |
214 | if (res < 0) | |
215 | return res; | |
216 | ||
217 | conf = swab16(res); | |
218 | new_conf = conf; | |
219 | new_conf &= ~attr->index; | |
220 | if (conf != new_conf) { | |
221 | res = i2c_smbus_write_word_data(client, DS620_REG_CONF, | |
222 | swab16(new_conf)); | |
223 | if (res < 0) | |
224 | return res; | |
225 | } | |
226 | ||
227 | return sprintf(buf, "%d\n", !!(conf & attr->index)); | |
228 | } | |
229 | ||
230 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); | |
231 | static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1); | |
232 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2); | |
233 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, | |
234 | DS620_REG_CONFIG_TLF); | |
235 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, | |
236 | DS620_REG_CONFIG_THF); | |
237 | ||
238 | static struct attribute *ds620_attributes[] = { | |
239 | &sensor_dev_attr_temp1_input.dev_attr.attr, | |
240 | &sensor_dev_attr_temp1_min.dev_attr.attr, | |
241 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
242 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
243 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
244 | NULL | |
245 | }; | |
246 | ||
247 | static const struct attribute_group ds620_group = { | |
248 | .attrs = ds620_attributes, | |
249 | }; | |
250 | ||
251 | static int ds620_probe(struct i2c_client *client, | |
252 | const struct i2c_device_id *id) | |
253 | { | |
254 | struct ds620_data *data; | |
255 | int err; | |
256 | ||
257 | data = kzalloc(sizeof(struct ds620_data), GFP_KERNEL); | |
258 | if (!data) { | |
259 | err = -ENOMEM; | |
260 | goto exit; | |
261 | } | |
262 | ||
263 | i2c_set_clientdata(client, data); | |
264 | mutex_init(&data->update_lock); | |
265 | ||
266 | /* Initialize the DS620 chip */ | |
267 | ds620_init_client(client); | |
268 | ||
269 | /* Register sysfs hooks */ | |
270 | err = sysfs_create_group(&client->dev.kobj, &ds620_group); | |
271 | if (err) | |
272 | goto exit_free; | |
273 | ||
274 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
275 | if (IS_ERR(data->hwmon_dev)) { | |
276 | err = PTR_ERR(data->hwmon_dev); | |
277 | goto exit_remove_files; | |
278 | } | |
279 | ||
280 | dev_info(&client->dev, "temperature sensor found\n"); | |
281 | ||
282 | return 0; | |
283 | ||
284 | exit_remove_files: | |
285 | sysfs_remove_group(&client->dev.kobj, &ds620_group); | |
286 | exit_free: | |
287 | kfree(data); | |
288 | exit: | |
289 | return err; | |
290 | } | |
291 | ||
292 | static int ds620_remove(struct i2c_client *client) | |
293 | { | |
294 | struct ds620_data *data = i2c_get_clientdata(client); | |
295 | ||
296 | hwmon_device_unregister(data->hwmon_dev); | |
297 | sysfs_remove_group(&client->dev.kobj, &ds620_group); | |
298 | ||
299 | kfree(data); | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | static const struct i2c_device_id ds620_id[] = { | |
305 | {"ds620", 0}, | |
306 | {} | |
307 | }; | |
308 | ||
309 | MODULE_DEVICE_TABLE(i2c, ds620_id); | |
310 | ||
311 | /* This is the driver that will be inserted */ | |
312 | static struct i2c_driver ds620_driver = { | |
313 | .class = I2C_CLASS_HWMON, | |
314 | .driver = { | |
315 | .name = "ds620", | |
316 | }, | |
317 | .probe = ds620_probe, | |
318 | .remove = ds620_remove, | |
319 | .id_table = ds620_id, | |
320 | }; | |
321 | ||
322 | static int __init ds620_init(void) | |
323 | { | |
324 | return i2c_add_driver(&ds620_driver); | |
325 | } | |
326 | ||
327 | static void __exit ds620_exit(void) | |
328 | { | |
329 | i2c_del_driver(&ds620_driver); | |
330 | } | |
331 | ||
332 | MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>"); | |
333 | MODULE_DESCRIPTION("DS620 driver"); | |
334 | MODULE_LICENSE("GPL"); | |
335 | ||
336 | module_init(ds620_init); | |
337 | module_exit(ds620_exit); |