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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
Roland Stiggecc41d582011-09-21 13:06:11 -040075 s16 temp[3]; /* Register values, word */
Roland Stigge60994692011-01-09 09:31:39 -050076};
77
Roland Stigge60994692011-01-09 09:31:39 -050078static void ds620_init_client(struct i2c_client *client)
79{
80 struct ds620_platform_data *ds620_info = client->dev.platform_data;
81 u16 conf, new_conf;
82
83 new_conf = conf =
Jean Delvare90f41022011-11-04 12:00:47 +010084 i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
Roland Stigge60994692011-01-09 09:31:39 -050085
86 /* switch to continuous conversion mode */
87 new_conf &= ~DS620_REG_CONFIG_1SHOT;
88 /* already high at power-on, but don't trust the BIOS! */
89 new_conf |= DS620_REG_CONFIG_PO2;
90 /* thermostat mode according to platform data */
91 if (ds620_info && ds620_info->pomode == 1)
92 new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */
93 else if (ds620_info && ds620_info->pomode == 2)
94 new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */
95 else
96 new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */
97 /* with highest precision */
98 new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0;
99
100 if (conf != new_conf)
Jean Delvare90f41022011-11-04 12:00:47 +0100101 i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf);
Roland Stigge60994692011-01-09 09:31:39 -0500102
103 /* start conversion */
104 i2c_smbus_write_byte(client, DS620_COM_START);
105}
106
107static struct ds620_data *ds620_update_client(struct device *dev)
108{
109 struct i2c_client *client = to_i2c_client(dev);
110 struct ds620_data *data = i2c_get_clientdata(client);
111 struct ds620_data *ret = data;
112
113 mutex_lock(&data->update_lock);
114
115 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
116 || !data->valid) {
117 int i;
118 int res;
119
120 dev_dbg(&client->dev, "Starting ds620 update\n");
121
122 for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
Jean Delvare90f41022011-11-04 12:00:47 +0100123 res = i2c_smbus_read_word_swapped(client,
124 DS620_REG_TEMP[i]);
Roland Stigge60994692011-01-09 09:31:39 -0500125 if (res < 0) {
126 ret = ERR_PTR(res);
127 goto abort;
128 }
129
130 data->temp[i] = res;
131 }
132
133 data->last_updated = jiffies;
134 data->valid = 1;
135 }
136abort:
137 mutex_unlock(&data->update_lock);
138
139 return ret;
140}
141
142static ssize_t show_temp(struct device *dev, struct device_attribute *da,
143 char *buf)
144{
145 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
146 struct ds620_data *data = ds620_update_client(dev);
147
148 if (IS_ERR(data))
149 return PTR_ERR(data);
150
151 return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10);
152}
153
154static ssize_t set_temp(struct device *dev, struct device_attribute *da,
155 const char *buf, size_t count)
156{
157 int res;
158 long val;
159
160 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
161 struct i2c_client *client = to_i2c_client(dev);
162 struct ds620_data *data = i2c_get_clientdata(client);
163
Frans Meulenbroeks179c4fd2012-01-04 20:58:52 +0100164 res = kstrtol(buf, 10, &val);
Roland Stigge60994692011-01-09 09:31:39 -0500165
166 if (res)
167 return res;
168
169 val = (val * 10 / 625) * 8;
170
171 mutex_lock(&data->update_lock);
172 data->temp[attr->index] = val;
Jean Delvare90f41022011-11-04 12:00:47 +0100173 i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index],
174 data->temp[attr->index]);
Roland Stigge60994692011-01-09 09:31:39 -0500175 mutex_unlock(&data->update_lock);
176 return count;
177}
178
179static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
180 char *buf)
181{
182 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
183 struct ds620_data *data = ds620_update_client(dev);
184 struct i2c_client *client = to_i2c_client(dev);
185 u16 conf, new_conf;
186 int res;
187
188 if (IS_ERR(data))
189 return PTR_ERR(data);
190
191 /* reset alarms if necessary */
Jean Delvare90f41022011-11-04 12:00:47 +0100192 res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
Roland Stigge60994692011-01-09 09:31:39 -0500193 if (res < 0)
194 return res;
195
Jean Delvare90f41022011-11-04 12:00:47 +0100196 new_conf = conf = res;
Roland Stigge60994692011-01-09 09:31:39 -0500197 new_conf &= ~attr->index;
198 if (conf != new_conf) {
Jean Delvare90f41022011-11-04 12:00:47 +0100199 res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF,
200 new_conf);
Roland Stigge60994692011-01-09 09:31:39 -0500201 if (res < 0)
202 return res;
203 }
204
205 return sprintf(buf, "%d\n", !!(conf & attr->index));
206}
207
208static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
209static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
210static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
211static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
212 DS620_REG_CONFIG_TLF);
213static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
214 DS620_REG_CONFIG_THF);
215
216static struct attribute *ds620_attributes[] = {
217 &sensor_dev_attr_temp1_input.dev_attr.attr,
218 &sensor_dev_attr_temp1_min.dev_attr.attr,
219 &sensor_dev_attr_temp1_max.dev_attr.attr,
220 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
221 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
222 NULL
223};
224
225static const struct attribute_group ds620_group = {
226 .attrs = ds620_attributes,
227};
228
229static int ds620_probe(struct i2c_client *client,
230 const struct i2c_device_id *id)
231{
232 struct ds620_data *data;
233 int err;
234
235 data = kzalloc(sizeof(struct ds620_data), GFP_KERNEL);
236 if (!data) {
237 err = -ENOMEM;
238 goto exit;
239 }
240
241 i2c_set_clientdata(client, data);
242 mutex_init(&data->update_lock);
243
244 /* Initialize the DS620 chip */
245 ds620_init_client(client);
246
247 /* Register sysfs hooks */
248 err = sysfs_create_group(&client->dev.kobj, &ds620_group);
249 if (err)
250 goto exit_free;
251
252 data->hwmon_dev = hwmon_device_register(&client->dev);
253 if (IS_ERR(data->hwmon_dev)) {
254 err = PTR_ERR(data->hwmon_dev);
255 goto exit_remove_files;
256 }
257
258 dev_info(&client->dev, "temperature sensor found\n");
259
260 return 0;
261
262exit_remove_files:
263 sysfs_remove_group(&client->dev.kobj, &ds620_group);
264exit_free:
265 kfree(data);
266exit:
267 return err;
268}
269
270static int ds620_remove(struct i2c_client *client)
271{
272 struct ds620_data *data = i2c_get_clientdata(client);
273
274 hwmon_device_unregister(data->hwmon_dev);
275 sysfs_remove_group(&client->dev.kobj, &ds620_group);
276
277 kfree(data);
278
279 return 0;
280}
281
282static const struct i2c_device_id ds620_id[] = {
283 {"ds620", 0},
284 {}
285};
286
287MODULE_DEVICE_TABLE(i2c, ds620_id);
288
289/* This is the driver that will be inserted */
290static struct i2c_driver ds620_driver = {
291 .class = I2C_CLASS_HWMON,
292 .driver = {
293 .name = "ds620",
294 },
295 .probe = ds620_probe,
296 .remove = ds620_remove,
297 .id_table = ds620_id,
298};
299
300static int __init ds620_init(void)
301{
302 return i2c_add_driver(&ds620_driver);
303}
304
305static void __exit ds620_exit(void)
306{
307 i2c_del_driver(&ds620_driver);
308}
309
310MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
311MODULE_DESCRIPTION("DS620 driver");
312MODULE_LICENSE("GPL");
313
314module_init(ds620_init);
315module_exit(ds620_exit);