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hmc6352: add driver for the HMC6352 compass

This driver will report the heading values in degrees to the sysfs
interface.  The values returned are headings .  e.g.  245.6

Alan: Cleanups requested now all folded in and a sysfs description to keep
Andrew happy. The sysfs description now resembles hwmon.

Signed-off-by: Kalhan Trisal <kalhan.trisal@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kalhan Trisal 2010-08-09 17:21:05 -07:00 committed by Linus Torvalds
parent 5f1209a1a4
commit cfa3b24c38
4 changed files with 195 additions and 0 deletions

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@ -0,0 +1,21 @@
Where: /sys/bus/i2c/devices/.../heading0_input
Date: April 2010
Kernel Version: 2.6.36?
Contact: alan.cox@intel.com
Description: Reports the current heading from the compass as a floating
point value in degrees.
Where: /sys/bus/i2c/devices/.../power_state
Date: April 2010
Kernel Version: 2.6.36?
Contact: alan.cox@intel.com
Description: Sets the power state of the device. 0 sets the device into
sleep mode, 1 wakes it up.
Where: /sys/bus/i2c/devices/.../calibration
Date: April 2010
Kernel Version: 2.6.36?
Contact: alan.cox@intel.com
Description: Sets the calibration on or off (1 = on, 0 = off). See the
chip data sheet.

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@ -314,6 +314,13 @@ config SENSORS_BH1780
This driver can also be built as a module. If so, the module
will be called bh1780gli.
config HMC6352
tristate "Honeywell HMC6352 compass"
depends on I2C
help
This driver provides support for the Honeywell HMC6352 compass,
providing configuration and heading data via sysfs.
config EP93XX_PWM
tristate "EP93xx PWM support"
depends on ARCH_EP93XX

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@ -30,6 +30,7 @@ obj-$(CONFIG_DS1682) += ds1682.o
obj-$(CONFIG_TI_DAC7512) += ti_dac7512.o
obj-$(CONFIG_C2PORT) += c2port/
obj-$(CONFIG_IWMC3200TOP) += iwmc3200top/
obj-$(CONFIG_HMC6352) += hmc6352.o
obj-y += eeprom/
obj-y += cb710/
obj-$(CONFIG_VMWARE_BALLOON) += vmware_balloon.o

166
drivers/misc/hmc6352.c Normal file
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@ -0,0 +1,166 @@
/*
* 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/init.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;
if (strict_strtoul(buf, 10, &val))
return -EINVAL;
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];
unsigned 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 != 1) {
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,
};
static int __init sensor_hmc6352_init(void)
{
return i2c_add_driver(&hmc6352_driver);
}
static void __exit sensor_hmc6352_exit(void)
{
i2c_del_driver(&hmc6352_driver);
}
module_init(sensor_hmc6352_init);
module_exit(sensor_hmc6352_exit);
MODULE_AUTHOR("Kalhan Trisal <kalhan.trisal@intel.com");
MODULE_DESCRIPTION("hmc6352 Compass Driver");
MODULE_LICENSE("GPL v2");