156 lines
4.0 KiB
C
156 lines
4.0 KiB
C
/*
|
|
* hmc6352.c - Honeywell Compass Driver
|
|
*
|
|
* Copyright (C) 2009 Intel Corp
|
|
*
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
*
|
|
* 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; version 2 of the License.
|
|
*
|
|
* 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.,
|
|
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
|
|
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
*
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/i2c.h>
|
|
#include <linux/err.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/sysfs.h>
|
|
|
|
static DEFINE_MUTEX(compass_mutex);
|
|
|
|
static int compass_command(struct i2c_client *c, u8 cmd)
|
|
{
|
|
int ret = i2c_master_send(c, &cmd, 1);
|
|
if (ret < 0)
|
|
dev_warn(&c->dev, "command '%c' failed.\n", cmd);
|
|
return ret;
|
|
}
|
|
|
|
static int compass_store(struct device *dev, const char *buf, size_t count,
|
|
const char *map)
|
|
{
|
|
struct i2c_client *c = to_i2c_client(dev);
|
|
int ret;
|
|
unsigned long val;
|
|
|
|
ret = kstrtoul(buf, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
if (val >= strlen(map))
|
|
return -EINVAL;
|
|
mutex_lock(&compass_mutex);
|
|
ret = compass_command(c, map[val]);
|
|
mutex_unlock(&compass_mutex);
|
|
if (ret < 0)
|
|
return ret;
|
|
return count;
|
|
}
|
|
|
|
static ssize_t compass_calibration_store(struct device *dev,
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
return compass_store(dev, buf, count, "EC");
|
|
}
|
|
|
|
static ssize_t compass_power_mode_store(struct device *dev,
|
|
struct device_attribute *attr, const char *buf, size_t count)
|
|
{
|
|
return compass_store(dev, buf, count, "SW");
|
|
}
|
|
|
|
static ssize_t compass_heading_data_show(struct device *dev,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
struct i2c_client *client = to_i2c_client(dev);
|
|
unsigned char i2c_data[2];
|
|
int ret;
|
|
|
|
mutex_lock(&compass_mutex);
|
|
ret = compass_command(client, 'A');
|
|
if (ret != 1) {
|
|
mutex_unlock(&compass_mutex);
|
|
return ret;
|
|
}
|
|
msleep(10); /* sending 'A' cmd we need to wait for 7-10 millisecs */
|
|
ret = i2c_master_recv(client, i2c_data, 2);
|
|
mutex_unlock(&compass_mutex);
|
|
if (ret < 0) {
|
|
dev_warn(dev, "i2c read data cmd failed\n");
|
|
return ret;
|
|
}
|
|
ret = (i2c_data[0] << 8) | i2c_data[1];
|
|
return sprintf(buf, "%d.%d\n", ret/10, ret%10);
|
|
}
|
|
|
|
|
|
static DEVICE_ATTR(heading0_input, S_IRUGO, compass_heading_data_show, NULL);
|
|
static DEVICE_ATTR(calibration, S_IWUSR, NULL, compass_calibration_store);
|
|
static DEVICE_ATTR(power_state, S_IWUSR, NULL, compass_power_mode_store);
|
|
|
|
static struct attribute *mid_att_compass[] = {
|
|
&dev_attr_heading0_input.attr,
|
|
&dev_attr_calibration.attr,
|
|
&dev_attr_power_state.attr,
|
|
NULL
|
|
};
|
|
|
|
static const struct attribute_group m_compass_gr = {
|
|
.name = "hmc6352",
|
|
.attrs = mid_att_compass
|
|
};
|
|
|
|
static int hmc6352_probe(struct i2c_client *client,
|
|
const struct i2c_device_id *id)
|
|
{
|
|
int res;
|
|
|
|
res = sysfs_create_group(&client->dev.kobj, &m_compass_gr);
|
|
if (res) {
|
|
dev_err(&client->dev, "device_create_file failed\n");
|
|
return res;
|
|
}
|
|
dev_info(&client->dev, "%s HMC6352 compass chip found\n",
|
|
client->name);
|
|
return 0;
|
|
}
|
|
|
|
static int hmc6352_remove(struct i2c_client *client)
|
|
{
|
|
sysfs_remove_group(&client->dev.kobj, &m_compass_gr);
|
|
return 0;
|
|
}
|
|
|
|
static struct i2c_device_id hmc6352_id[] = {
|
|
{ "hmc6352", 0 },
|
|
{ }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(i2c, hmc6352_id);
|
|
|
|
static struct i2c_driver hmc6352_driver = {
|
|
.driver = {
|
|
.name = "hmc6352",
|
|
},
|
|
.probe = hmc6352_probe,
|
|
.remove = hmc6352_remove,
|
|
.id_table = hmc6352_id,
|
|
};
|
|
|
|
module_i2c_driver(hmc6352_driver);
|
|
|
|
MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
|
|
MODULE_DESCRIPTION("hmc6352 Compass Driver");
|
|
MODULE_LICENSE("GPL v2");
|