blob: 257957c69d9229f8ffa76cec6d303a01f0d8d2e5 [file] [log] [blame]
Roland Stigge60994692011-01-09 09:31:39 -05001/*
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 */
58static 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 */
69struct 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
75 u16 temp[3]; /* Register values, word */
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 */
83static 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
93static 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
98static 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
128static 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 }
157abort:
158 mutex_unlock(&data->update_lock);
159
160 return ret;
161}
162
163static 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
175static 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
200static 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
230static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
231static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
232static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
233static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
234 DS620_REG_CONFIG_TLF);
235static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
236 DS620_REG_CONFIG_THF);
237
238static 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
247static const struct attribute_group ds620_group = {
248 .attrs = ds620_attributes,
249};
250
251static 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
284exit_remove_files:
285 sysfs_remove_group(&client->dev.kobj, &ds620_group);
286exit_free:
287 kfree(data);
288exit:
289 return err;
290}
291
292static 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
304static const struct i2c_device_id ds620_id[] = {
305 {"ds620", 0},
306 {}
307};
308
309MODULE_DEVICE_TABLE(i2c, ds620_id);
310
311/* This is the driver that will be inserted */
312static 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
322static int __init ds620_init(void)
323{
324 return i2c_add_driver(&ds620_driver);
325}
326
327static void __exit ds620_exit(void)
328{
329 i2c_del_driver(&ds620_driver);
330}
331
332MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
333MODULE_DESCRIPTION("DS620 driver");
334MODULE_LICENSE("GPL");
335
336module_init(ds620_init);
337module_exit(ds620_exit);