summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/ds620.c
blob: f1d6b422cf0682b43ed6b4354481d97de240fcef (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/*
 *  ds620.c - Support for temperature sensor and thermostat DS620
 *
 *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
 *
 *  based on ds1621.c by Christian W. Zuckschwerdt  <zany@triq.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/sysfs.h>
#include <linux/i2c/ds620.h>

/*
 * Many DS620 constants specified below
 *  15   14   13   12   11   10   09    08
 * |Done|NVB |THF |TLF |R1  |R0  |AUTOC|1SHOT|
 *
 *  07   06   05   04   03   02   01    00
 * |PO2 |PO1 |A2  |A1  |A0  |    |     |     |
 */
#define DS620_REG_CONFIG_DONE		0x8000
#define DS620_REG_CONFIG_NVB		0x4000
#define DS620_REG_CONFIG_THF		0x2000
#define DS620_REG_CONFIG_TLF		0x1000
#define DS620_REG_CONFIG_R1		0x0800
#define DS620_REG_CONFIG_R0		0x0400
#define DS620_REG_CONFIG_AUTOC		0x0200
#define DS620_REG_CONFIG_1SHOT		0x0100
#define DS620_REG_CONFIG_PO2		0x0080
#define DS620_REG_CONFIG_PO1		0x0040
#define DS620_REG_CONFIG_A2		0x0020
#define DS620_REG_CONFIG_A1		0x0010
#define DS620_REG_CONFIG_A0		0x0008

/* The DS620 registers */
static const u8 DS620_REG_TEMP[3] = {
	0xAA,			/* input, word, RO */
	0xA2,			/* min, word, RW */
	0xA0,			/* max, word, RW */
};

#define DS620_REG_CONF		0xAC	/* word, RW */
#define DS620_COM_START		0x51	/* no data */
#define DS620_COM_STOP		0x22	/* no data */

/* Each client has this additional data */
struct ds620_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	char valid;		/* !=0 if following fields are valid */
	unsigned long last_updated;	/* In jiffies */

	s16 temp[3];		/* Register values, word */
};

static void ds620_init_client(struct i2c_client *client)
{
	struct ds620_platform_data *ds620_info = client->dev.platform_data;
	u16 conf, new_conf;

	new_conf = conf =
	    i2c_smbus_read_word_swapped(client, DS620_REG_CONF);

	/* switch to continuous conversion mode */
	new_conf &= ~DS620_REG_CONFIG_1SHOT;
	/* already high at power-on, but don't trust the BIOS! */
	new_conf |= DS620_REG_CONFIG_PO2;
	/* thermostat mode according to platform data */
	if (ds620_info && ds620_info->pomode == 1)
		new_conf &= ~DS620_REG_CONFIG_PO1; /* PO_LOW */
	else if (ds620_info && ds620_info->pomode == 2)
		new_conf |= DS620_REG_CONFIG_PO1; /* PO_HIGH */
	else
		new_conf &= ~DS620_REG_CONFIG_PO2; /* always low */
	/* with highest precision */
	new_conf |= DS620_REG_CONFIG_R1 | DS620_REG_CONFIG_R0;

	if (conf != new_conf)
		i2c_smbus_write_word_swapped(client, DS620_REG_CONF, new_conf);

	/* start conversion */
	i2c_smbus_write_byte(client, DS620_COM_START);
}

static struct ds620_data *ds620_update_client(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ds620_data *data = i2c_get_clientdata(client);
	struct ds620_data *ret = data;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
	    || !data->valid) {
		int i;
		int res;

		dev_dbg(&client->dev, "Starting ds620 update\n");

		for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
			res = i2c_smbus_read_word_swapped(client,
							  DS620_REG_TEMP[i]);
			if (res < 0) {
				ret = ERR_PTR(res);
				goto abort;
			}

			data->temp[i] = res;
		}

		data->last_updated = jiffies;
		data->valid = 1;
	}
abort:
	mutex_unlock(&data->update_lock);

	return ret;
}

static ssize_t show_temp(struct device *dev, struct device_attribute *da,
			 char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ds620_data *data = ds620_update_client(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return sprintf(buf, "%d\n", ((data->temp[attr->index] / 8) * 625) / 10);
}

static ssize_t set_temp(struct device *dev, struct device_attribute *da,
			const char *buf, size_t count)
{
	int res;
	long val;

	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct i2c_client *client = to_i2c_client(dev);
	struct ds620_data *data = i2c_get_clientdata(client);

	res = kstrtol(buf, 10, &val);

	if (res)
		return res;

	val = (val * 10 / 625) * 8;

	mutex_lock(&data->update_lock);
	data->temp[attr->index] = val;
	i2c_smbus_write_word_swapped(client, DS620_REG_TEMP[attr->index],
				     data->temp[attr->index]);
	mutex_unlock(&data->update_lock);
	return count;
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
			  char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ds620_data *data = ds620_update_client(dev);
	struct i2c_client *client = to_i2c_client(dev);
	u16 conf, new_conf;
	int res;

	if (IS_ERR(data))
		return PTR_ERR(data);

	/* reset alarms if necessary */
	res = i2c_smbus_read_word_swapped(client, DS620_REG_CONF);
	if (res < 0)
		return res;

	new_conf = conf = res;
	new_conf &= ~attr->index;
	if (conf != new_conf) {
		res = i2c_smbus_write_word_swapped(client, DS620_REG_CONF,
						   new_conf);
		if (res < 0)
			return res;
	}

	return sprintf(buf, "%d\n", !!(conf & attr->index));
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
			  DS620_REG_CONFIG_TLF);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
			  DS620_REG_CONFIG_THF);

static struct attribute *ds620_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group ds620_group = {
	.attrs = ds620_attributes,
};

static int ds620_probe(struct i2c_client *client,
		       const struct i2c_device_id *id)
{
	struct ds620_data *data;
	int err;

	data = devm_kzalloc(&client->dev, sizeof(struct ds620_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* Initialize the DS620 chip */
	ds620_init_client(client);

	/* Register sysfs hooks */
	err = sysfs_create_group(&client->dev.kobj, &ds620_group);
	if (err)
		return err;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto exit_remove_files;
	}

	dev_info(&client->dev, "temperature sensor found\n");

	return 0;

exit_remove_files:
	sysfs_remove_group(&client->dev.kobj, &ds620_group);
	return err;
}

static int ds620_remove(struct i2c_client *client)
{
	struct ds620_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &ds620_group);

	return 0;
}

static const struct i2c_device_id ds620_id[] = {
	{"ds620", 0},
	{}
};

MODULE_DEVICE_TABLE(i2c, ds620_id);

/* This is the driver that will be inserted */
static struct i2c_driver ds620_driver = {
	.class = I2C_CLASS_HWMON,
	.driver = {
		   .name = "ds620",
	},
	.probe = ds620_probe,
	.remove = ds620_remove,
	.id_table = ds620_id,
};

module_i2c_driver(ds620_driver);

MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
MODULE_DESCRIPTION("DS620 driver");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud