summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/lm73.c
blob: 5166a8e3a06100794d4e3591e360093f9453289b (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
/*
 * LM73 Sensor driver
 * Based on LM75
 *
 * Copyright (C) 2007, CenoSYS (www.cenosys.com).
 * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu).
 *
 * Guillaume Ligneul <guillaume.ligneul@gmail.com>
 * Adrien Demarez <adrien.demarez@bolloretelecom.eu>
 * Jeremy Laine <jeremy.laine@bolloretelecom.eu>
 *
 * This software program is licensed subject to the GNU General Public License
 * (GPL).Version 2,June 1991, available at
 * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>


/* Addresses scanned */
static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c,
					0x4d, 0x4e, I2C_CLIENT_END };

/* LM73 registers */
#define LM73_REG_INPUT		0x00
#define LM73_REG_CONF		0x01
#define LM73_REG_MAX		0x02
#define LM73_REG_MIN		0x03
#define LM73_REG_CTRL		0x04
#define LM73_REG_ID		0x07

#define LM73_ID			0x9001	/* 0x0190, byte-swapped */
#define DRVNAME			"lm73"
#define LM73_TEMP_MIN		(-40)
#define LM73_TEMP_MAX		150

/*-----------------------------------------------------------------------*/


static ssize_t set_temp(struct device *dev, struct device_attribute *da,
			const char *buf, size_t count)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct i2c_client *client = to_i2c_client(dev);
	long temp;
	short value;
	s32 err;

	int status = kstrtol(buf, 10, &temp);
	if (status < 0)
		return status;

	/* Write value */
	value = (short) clamp_val(temp / 250, LM73_TEMP_MIN * 4,
				  LM73_TEMP_MAX * 4) << 5;
	err = i2c_smbus_write_word_swapped(client, attr->index, value);
	return (err < 0) ? err : count;
}

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 i2c_client *client = to_i2c_client(dev);
	int temp;

	s32 err = i2c_smbus_read_word_swapped(client, attr->index);
	if (err < 0)
		return err;

	/* use integer division instead of equivalent right shift to
	   guarantee arithmetic shift and preserve the sign */
	temp = (((s16) err) * 250) / 32;
	return scnprintf(buf, PAGE_SIZE, "%d\n", temp);
}


/*-----------------------------------------------------------------------*/

/* sysfs attributes for hwmon */

static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
			show_temp, set_temp, LM73_REG_MAX);
static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
			show_temp, set_temp, LM73_REG_MIN);
static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO,
			show_temp, NULL, LM73_REG_INPUT);


static struct attribute *lm73_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_max.dev_attr.attr,
	&sensor_dev_attr_temp1_min.dev_attr.attr,

	NULL
};

static const struct attribute_group lm73_group = {
	.attrs = lm73_attributes,
};

/*-----------------------------------------------------------------------*/

/* device probe and removal */

static int
lm73_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
	struct device *hwmon_dev;
	int status;

	/* Register sysfs hooks */
	status = sysfs_create_group(&client->dev.kobj, &lm73_group);
	if (status)
		return status;

	hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(hwmon_dev)) {
		status = PTR_ERR(hwmon_dev);
		goto exit_remove;
	}
	i2c_set_clientdata(client, hwmon_dev);

	dev_info(&client->dev, "%s: sensor '%s'\n",
		 dev_name(hwmon_dev), client->name);

	return 0;

exit_remove:
	sysfs_remove_group(&client->dev.kobj, &lm73_group);
	return status;
}

static int lm73_remove(struct i2c_client *client)
{
	struct device *hwmon_dev = i2c_get_clientdata(client);

	hwmon_device_unregister(hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm73_group);
	return 0;
}

static const struct i2c_device_id lm73_ids[] = {
	{ "lm73", 0 },
	{ /* LIST END */ }
};
MODULE_DEVICE_TABLE(i2c, lm73_ids);

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm73_detect(struct i2c_client *new_client,
			struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;
	int id, ctrl, conf;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
					I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	/*
	 * Do as much detection as possible with byte reads first, as word
	 * reads can confuse other devices.
	 */
	ctrl = i2c_smbus_read_byte_data(new_client, LM73_REG_CTRL);
	if (ctrl < 0 || (ctrl & 0x10))
		return -ENODEV;

	conf = i2c_smbus_read_byte_data(new_client, LM73_REG_CONF);
	if (conf < 0 || (conf & 0x0c))
		return -ENODEV;

	id = i2c_smbus_read_byte_data(new_client, LM73_REG_ID);
	if (id < 0 || id != (LM73_ID & 0xff))
		return -ENODEV;

	/* Check device ID */
	id = i2c_smbus_read_word_data(new_client, LM73_REG_ID);
	if (id < 0 || id != LM73_ID)
		return -ENODEV;

	strlcpy(info->type, "lm73", I2C_NAME_SIZE);

	return 0;
}

static struct i2c_driver lm73_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm73",
	},
	.probe		= lm73_probe,
	.remove		= lm73_remove,
	.id_table	= lm73_ids,
	.detect		= lm73_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(lm73_driver);

MODULE_AUTHOR("Guillaume Ligneul <guillaume.ligneul@gmail.com>");
MODULE_DESCRIPTION("LM73 driver");
MODULE_LICENSE("GPL");