blob: 170bd3daf33699598a794e4a58a9df19a917c279 [file] [log] [blame]
Kalhan Trisalcfa3b242010-08-09 17:21:05 -07001/*
2 * hmc6352.c - Honeywell Compass Driver
3 *
4 * Copyright (C) 2009 Intel Corp
5 *
6 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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; version 2 of the License.
11 *
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
20 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21 *
22 */
23
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/i2c.h>
28#include <linux/err.h>
29#include <linux/delay.h>
30#include <linux/sysfs.h>
31
32static DEFINE_MUTEX(compass_mutex);
33
34static int compass_command(struct i2c_client *c, u8 cmd)
35{
36 int ret = i2c_master_send(c, &cmd, 1);
37 if (ret < 0)
38 dev_warn(&c->dev, "command '%c' failed.\n", cmd);
39 return ret;
40}
41
42static int compass_store(struct device *dev, const char *buf, size_t count,
43 const char *map)
44{
45 struct i2c_client *c = to_i2c_client(dev);
46 int ret;
47 unsigned long val;
48
Jingoo Hanf7b41272013-06-04 13:15:16 +090049 ret = kstrtoul(buf, 10, &val);
50 if (ret)
51 return ret;
Kalhan Trisalcfa3b242010-08-09 17:21:05 -070052 if (val >= strlen(map))
53 return -EINVAL;
54 mutex_lock(&compass_mutex);
55 ret = compass_command(c, map[val]);
56 mutex_unlock(&compass_mutex);
57 if (ret < 0)
58 return ret;
59 return count;
60}
61
62static ssize_t compass_calibration_store(struct device *dev,
63 struct device_attribute *attr, const char *buf, size_t count)
64{
65 return compass_store(dev, buf, count, "EC");
66}
67
68static ssize_t compass_power_mode_store(struct device *dev,
69 struct device_attribute *attr, const char *buf, size_t count)
70{
71 return compass_store(dev, buf, count, "SW");
72}
73
74static ssize_t compass_heading_data_show(struct device *dev,
75 struct device_attribute *attr, char *buf)
76{
77 struct i2c_client *client = to_i2c_client(dev);
78 unsigned char i2c_data[2];
Axel Lin6f7d4852011-03-22 16:34:00 -070079 int ret;
Kalhan Trisalcfa3b242010-08-09 17:21:05 -070080
81 mutex_lock(&compass_mutex);
82 ret = compass_command(client, 'A');
83 if (ret != 1) {
84 mutex_unlock(&compass_mutex);
85 return ret;
86 }
87 msleep(10); /* sending 'A' cmd we need to wait for 7-10 millisecs */
88 ret = i2c_master_recv(client, i2c_data, 2);
89 mutex_unlock(&compass_mutex);
Axel Lin6f7d4852011-03-22 16:34:00 -070090 if (ret < 0) {
Kalhan Trisalcfa3b242010-08-09 17:21:05 -070091 dev_warn(dev, "i2c read data cmd failed\n");
92 return ret;
93 }
94 ret = (i2c_data[0] << 8) | i2c_data[1];
95 return sprintf(buf, "%d.%d\n", ret/10, ret%10);
96}
97
98
99static DEVICE_ATTR(heading0_input, S_IRUGO, compass_heading_data_show, NULL);
100static DEVICE_ATTR(calibration, S_IWUSR, NULL, compass_calibration_store);
101static DEVICE_ATTR(power_state, S_IWUSR, NULL, compass_power_mode_store);
102
103static struct attribute *mid_att_compass[] = {
104 &dev_attr_heading0_input.attr,
105 &dev_attr_calibration.attr,
106 &dev_attr_power_state.attr,
107 NULL
108};
109
110static const struct attribute_group m_compass_gr = {
111 .name = "hmc6352",
112 .attrs = mid_att_compass
113};
114
115static int hmc6352_probe(struct i2c_client *client,
116 const struct i2c_device_id *id)
117{
118 int res;
119
120 res = sysfs_create_group(&client->dev.kobj, &m_compass_gr);
121 if (res) {
122 dev_err(&client->dev, "device_create_file failed\n");
123 return res;
124 }
125 dev_info(&client->dev, "%s HMC6352 compass chip found\n",
126 client->name);
127 return 0;
128}
129
130static int hmc6352_remove(struct i2c_client *client)
131{
132 sysfs_remove_group(&client->dev.kobj, &m_compass_gr);
133 return 0;
134}
135
136static struct i2c_device_id hmc6352_id[] = {
137 { "hmc6352", 0 },
138 { }
139};
140
141MODULE_DEVICE_TABLE(i2c, hmc6352_id);
142
143static struct i2c_driver hmc6352_driver = {
144 .driver = {
145 .name = "hmc6352",
146 },
147 .probe = hmc6352_probe,
148 .remove = hmc6352_remove,
149 .id_table = hmc6352_id,
150};
151
Axel Lina64fe2e2012-01-22 15:36:45 +0800152module_i2c_driver(hmc6352_driver);
Kalhan Trisalcfa3b242010-08-09 17:21:05 -0700153
154MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
155MODULE_DESCRIPTION("hmc6352 Compass Driver");
156MODULE_LICENSE("GPL v2");