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/platform_data/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 i2c_client *client;
71 struct mutex update_lock;
72 char valid; /* !=0 if following fields are valid */
73 unsigned long last_updated; /* In jiffies */
74
75 s16 temp[3]; /* Register values, word */
76};
77
78static void ds620_init_client(struct i2c_client *client)
79{
80 struct ds620_platform_data *ds620_info = dev_get_platdata(&client->dev);
81 u16 conf, new_conf;
82
83 new_conf = conf =
84 i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
85
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)
101 i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf);
102
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 ds620_data *data = dev_get_drvdata(dev);
110 struct i2c_client *client = data->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++) {
123 res = i2c_smbus_read_word_swapped(client,
124 DS620_REG_TEMP[i]);
125 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 temp_show(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 temp_store(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 ds620_data *data = dev_get_drvdata(dev);
162 struct i2c_client *client = data->client;
163
164 res = kstrtol(buf, 10, &val);
165
166 if (res)
167 return res;
168
169 val = (clamp_val(val, -128000, 128000) * 10 / 625) * 8;
170
171 mutex_lock(&data->update_lock);
172 data->temp[attr->index] = val;
173 i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index],
174 data->temp[attr->index]);
175 mutex_unlock(&data->update_lock);
176 return count;
177}
178
179static ssize_t alarm_show(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;
185 u16 conf, new_conf;
186 int res;
187
188 if (IS_ERR(data))
189 return PTR_ERR(data);
190
191 client = data->client;
192
193 /* reset alarms if necessary */
194 res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
195 if (res < 0)
196 return res;
197
198 new_conf = conf = res;
199 new_conf &= ~attr->index;
200 if (conf != new_conf) {
201 res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF,
202 new_conf);
203 if (res < 0)
204 return res;
205 }
206
207 return sprintf(buf, "%d\n", !!(conf & attr->index));
208}
209
210static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
211static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, 1);
212static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 2);
213static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, DS620_REG_CONFIG_TLF);
214static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, DS620_REG_CONFIG_THF);
215
216static struct attribute *ds620_attrs[] = {
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
225ATTRIBUTE_GROUPS(ds620);
226
227static int ds620_probe(struct i2c_client *client,
228 const struct i2c_device_id *id)
229{
230 struct device *dev = &client->dev;
231 struct device *hwmon_dev;
232 struct ds620_data *data;
233
234 data = devm_kzalloc(dev, sizeof(struct ds620_data), GFP_KERNEL);
235 if (!data)
236 return -ENOMEM;
237
238 data->client = client;
239 mutex_init(&data->update_lock);
240
241 /* Initialize the DS620 chip */
242 ds620_init_client(client);
243
244 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
245 data, ds620_groups);
246 return PTR_ERR_OR_ZERO(hwmon_dev);
247}
248
249static const struct i2c_device_id ds620_id[] = {
250 {"ds620", 0},
251 {}
252};
253
254MODULE_DEVICE_TABLE(i2c, ds620_id);
255
256/* This is the driver that will be inserted */
257static struct i2c_driver ds620_driver = {
258 .class = I2C_CLASS_HWMON,
259 .driver = {
260 .name = "ds620",
261 },
262 .probe = ds620_probe,
263 .id_table = ds620_id,
264};
265
266module_i2c_driver(ds620_driver);
267
268MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
269MODULE_DESCRIPTION("DS620 driver");
270MODULE_LICENSE("GPL");
271