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Staging: iio: add digital compass hmc5843 driver

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Adding support for the Honeywell HMC5843. The interface to the device is
i2c

TODO:
Adding the documentation

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Shubhrajyoti D 2010-07-17 18:32:52 +05:30 • committed by Greg Kroah-Hartman
parent 5fc9e4d527
commit b4e178224c
5 changed files with 646 additions and 0 deletions
drivers/staging/iio
KconfigMakefile
magnetometer
KconfigMakefilehmc5843.c

1
drivers/staging/iio/Kconfig
View file

@ -44,6 +44,7 @@ source "drivers/staging/iio/adc/Kconfig"
source "drivers/staging/iio/gyro/Kconfig"
source "drivers/staging/iio/imu/Kconfig"
source "drivers/staging/iio/light/Kconfig"
source "drivers/staging/iio/magnetometer/Kconfig"
source "drivers/staging/iio/trigger/Kconfig"

1
drivers/staging/iio/Makefile
View file

@ -15,3 +15,4 @@ obj-y += gyro/
obj-y += imu/
obj-y += light/
obj-y += trigger/
obj-y += magnetometer/

15
drivers/staging/iio/magnetometer/Kconfig Normal file
View file

@ -0,0 +1,15 @@
#
# Magnetometer sensors
#
comment "Magnetometer sensors"
config SENSORS_HMC5843
tristate "Honeywell HMC5843 3-Axis Magnetometer"
depends on I2C
help
Say Y here to add support for the Honeywell HMC 5843 3-Axis
Magnetometer (digital compass).
To compile this driver as a module, choose M here: the module
will be called hmc5843

5
drivers/staging/iio/magnetometer/Makefile Normal file
View file

@ -0,0 +1,5 @@
#
# Makefile for industrial I/O Magnetometer sensors
#
obj-$(CONFIG_SENSORS_HMC5843) += hmc5843.o

624
drivers/staging/iio/magnetometer/hmc5843.c Normal file
View file

@ -0,0 +1,624 @@
/* Copyright (C) 2010 Texas Instruments
Author: Shubhrajyoti Datta <shubhrajyoti@ti.com>
Acknowledgement: Jonathan Cameron <jic23@cam.ac.uk> for valuable inputs.
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/i2c.h>
#include <linux/slab.h>
#include <linux/types.h>
#include "../iio.h"
#include "../sysfs.h"
#include "magnet.h"
#define HMC5843_I2C_ADDRESS 0x1E
#define HMC5843_CONFIG_REG_A 0x00
#define HMC5843_CONFIG_REG_B 0x01
#define HMC5843_MODE_REG 0x02
#define HMC5843_DATA_OUT_X_MSB_REG 0x03
#define HMC5843_DATA_OUT_X_LSB_REG 0x04
#define HMC5843_DATA_OUT_Y_MSB_REG 0x05
#define HMC5843_DATA_OUT_Y_LSB_REG 0x06
#define HMC5843_DATA_OUT_Z_MSB_REG 0x07
#define HMC5843_DATA_OUT_Z_LSB_REG 0x08
#define HMC5843_STATUS_REG 0x09
#define HMC5843_ID_REG_A 0x0A
#define HMC5843_ID_REG_B 0x0B
#define HMC5843_ID_REG_C 0x0C
#define HMC5843_ID_REG_LENGTH 0x03
#define HMC5843_ID_STRING "H43"
/*
* Range settings in (+-)Ga
* */
#define RANGE_GAIN_OFFSET 0x05
#define RANGE_0_7 0x00
#define RANGE_1_0 0x01 /* default */
#define RANGE_1_5 0x02
#define RANGE_2_0 0x03
#define RANGE_3_2 0x04
#define RANGE_3_8 0x05
#define RANGE_4_5 0x06
#define RANGE_6_5 0x07 /* Not recommended */
/*
* Device status
*/
#define DATA_READY 0x01
#define DATA_OUTPUT_LOCK 0x02
#define VOLTAGE_REGULATOR_ENABLED 0x04
/*
* Mode register configuration
*/
#define MODE_CONVERSION_CONTINUOUS 0x00
#define MODE_CONVERSION_SINGLE 0x01
#define MODE_IDLE 0x02
#define MODE_SLEEP 0x03
/* Minimum Data Output Rate in 1/10 Hz */
#define RATE_OFFSET 0x02
#define RATE_BITMASK 0x1C
#define RATE_5 0x00
#define RATE_10 0x01
#define RATE_20 0x02
#define RATE_50 0x03
#define RATE_100 0x04
#define RATE_200 0x05
#define RATE_500 0x06
#define RATE_NOT_USED 0x07
/*
* Device Configutration
*/
#define CONF_NORMAL 0x00
#define CONF_POSITIVE_BIAS 0x01
#define CONF_NEGATIVE_BIAS 0x02
#define CONF_NOT_USED 0x03
#define MEAS_CONF_MASK 0x03
static const int regval_to_counts_per_mg[] = {
1620,
1300,
970,
780,
530,
460,
390,
280
};
static const int regval_to_input_field_mg[] = {
700,
1000,
1500,
2000,
3200,
3800,
4500,
6500
};
static const char *regval_to_samp_freq[] = {
"0.5",
"1",
"2",
"5",
"10",
"20",
"50",
};
/* Addresses to scan: 0x1E */
static const unsigned short normal_i2c[] = { HMC5843_I2C_ADDRESS,
I2C_CLIENT_END };
/* Each client has this additional data */
struct hmc5843_data {
struct iio_dev *indio_dev;
struct mutex lock;
u8 rate;
u8 meas_conf;
u8 operating_mode;
u8 range;
};
static void hmc5843_init_client(struct i2c_client *client);
static s32 hmc5843_configure(struct i2c_client *client,
u8 operating_mode)
{
/* The lower two bits contain the current conversion mode */
return i2c_smbus_write_byte_data(client,
HMC5843_MODE_REG,
(operating_mode & 0x03));
}
/* Return the measurement value from the specified channel */
static ssize_t hmc5843_read_measurement(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
s16 coordinate_val;
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
struct hmc5843_data *data = indio_dev->dev_data;
s32 result;
mutex_lock(&data->lock);
result = i2c_smbus_read_byte_data(client, HMC5843_STATUS_REG);
while (!(result & DATA_READY))
result = i2c_smbus_read_byte_data(client, HMC5843_STATUS_REG);
result = i2c_smbus_read_word_data(client, this_attr->address);
mutex_unlock(&data->lock);
if (result < 0)
return -EINVAL;
coordinate_val = (s16)swab16((u16)result);
return sprintf(buf, "%d\n", coordinate_val);
}
static IIO_DEV_ATTR_MAGN_X(hmc5843_read_measurement,
HMC5843_DATA_OUT_X_MSB_REG);
static IIO_DEV_ATTR_MAGN_Y(hmc5843_read_measurement,
HMC5843_DATA_OUT_Y_MSB_REG);
static IIO_DEV_ATTR_MAGN_Z(hmc5843_read_measurement,
HMC5843_DATA_OUT_Z_MSB_REG);
/*
* From the datasheet
* 0 - Continuous-Conversion Mode: In continuous-conversion mode, the
* device continuously performs conversions an places the result in the
* data register.
*
* 1 - Single-Conversion Mode : device performs a single measurement,
* sets RDY high and returned to sleep mode
*
* 2 - Idle Mode : Device is placed in idle mode.
*
* 3 - Sleep Mode. Device is placed in sleep mode.
*
*/
static ssize_t hmc5843_show_operating_mode(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct hmc5843_data *data = indio_dev->dev_data;
return sprintf(buf, "%d\n", data->operating_mode);
}
static ssize_t hmc5843_set_operating_mode(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
struct hmc5843_data *data = indio_dev->dev_data;
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
unsigned long operating_mode = 0;
s32 status;
int error;
mutex_lock(&data->lock);
error = strict_strtoul(buf, 10, &operating_mode);
if (error)
return error;
dev_dbg(dev, "set Conversion mode to %lu\n", operating_mode);
if (operating_mode > MODE_SLEEP)
return -EINVAL;
status = i2c_smbus_write_byte_data(client, this_attr->address,
operating_mode);
if (status) {
count = -EINVAL;
goto exit;
}
data->operating_mode = operating_mode;
exit:
mutex_unlock(&data->lock);
return count;
}
static IIO_DEVICE_ATTR(operating_mode,
S_IWUSR | S_IRUGO,
hmc5843_show_operating_mode,
hmc5843_set_operating_mode,
HMC5843_MODE_REG);
/*
* API for setting the measurement configuration to
* Normal, Positive bias and Negative bias
* From the datasheet
*
* Normal measurement configuration (default): In normal measurement
* configuration the device follows normal measurement flow. Pins BP and BN
* are left floating and high impedance.
*
* Positive bias configuration: In positive bias configuration, a positive
* current is forced across the resistive load on pins BP and BN.
*
* Negative bias configuration. In negative bias configuration, a negative
* current is forced across the resistive load on pins BP and BN.
*
*/
static s32 hmc5843_set_meas_conf(struct i2c_client *client,
u8 meas_conf)
{
struct hmc5843_data *data = i2c_get_clientdata(client);
u8 reg_val;
reg_val = (meas_conf & MEAS_CONF_MASK) | (data->rate << RATE_OFFSET);
return i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_A, reg_val);
}
static ssize_t hmc5843_show_measurement_configuration(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct hmc5843_data *data = indio_dev->dev_data;
return sprintf(buf, "%d\n", data->meas_conf);
}
static ssize_t hmc5843_set_measurement_configuration(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
struct hmc5843_data *data = i2c_get_clientdata(client);
unsigned long meas_conf = 0;
int error = strict_strtoul(buf, 10, &meas_conf);
if (error)
return error;
mutex_lock(&data->lock);
dev_dbg(dev, "set mode to %lu\n", meas_conf);
if (hmc5843_set_meas_conf(client, meas_conf)) {
count = -EINVAL;
goto exit;
}
data->meas_conf = meas_conf;
exit:
mutex_unlock(&data->lock);
return count;
}
static IIO_DEVICE_ATTR(meas_conf,
S_IWUSR | S_IRUGO,
hmc5843_show_measurement_configuration,
hmc5843_set_measurement_configuration,
0);
/*
* From Datasheet
* The table shows the minimum data output
* Value | Minimum data output rate(Hz)
* 0 | 0.5
* 1 | 1
* 2 | 2
* 3 | 5
* 4 | 10 (default)
* 5 | 20
* 6 | 50
* 7 | Not used
*/
static IIO_CONST_ATTR_AVAIL_SAMP_FREQ("0.5 1 2 5 10 20 50");
static s32 hmc5843_set_rate(struct i2c_client *client,
u8 rate)
{
struct hmc5843_data *data = i2c_get_clientdata(client);
u8 reg_val;
reg_val = (data->meas_conf) | (rate << RATE_OFFSET);
if (rate >= RATE_NOT_USED) {
dev_err(&client->dev,
"This data output rate is not supported \n");
return -EINVAL;
}
return i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_A, reg_val);
}
static ssize_t set_sampling_frequency(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
struct hmc5843_data *data = indio_dev->dev_data;
unsigned long rate = 0;
if (strncmp(buf, "0.5" , 3) == 0)
rate = RATE_5;
else if (strncmp(buf, "1" , 1) == 0)
rate = RATE_10;
else if (strncmp(buf, "2", 1) == 0)
rate = RATE_20;
else if (strncmp(buf, "5", 1) == 0)
rate = RATE_50;
else if (strncmp(buf, "10", 2) == 0)
rate = RATE_100;
else if (strncmp(buf, "20" , 2) == 0)
rate = RATE_200;
else if (strncmp(buf, "50" , 2) == 0)
rate = RATE_500;
else
return -EINVAL;
mutex_lock(&data->lock);
dev_dbg(dev, "set rate to %lu\n", rate);
if (hmc5843_set_rate(client, rate)) {
count = -EINVAL;
goto exit;
}
data->rate = rate;
exit:
mutex_unlock(&data->lock);
return count;
}
static ssize_t show_sampling_frequency(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
u32 rate;
rate = i2c_smbus_read_byte_data(client, this_attr->address);
if (rate < 0)
return -EINVAL;
rate = (rate & RATE_BITMASK) >> RATE_OFFSET;
return sprintf(buf, "%s\n", regval_to_samp_freq[rate]);
}
static IIO_DEVICE_ATTR(sampling_frequency,
S_IWUSR | S_IRUGO,
show_sampling_frequency,
set_sampling_frequency,
HMC5843_CONFIG_REG_A);
/*
* From Datasheet
* Nominal gain settings
* Value | Sensor Input Field Range(Ga) | Gain(counts/ milli-gauss)
*0 |(+-)0.7 |1620
*1 |(+-)1.0 |1300
*2 |(+-)1.5 |970
*3 |(+-)2.0 |780
*4 |(+-)3.2 |530
*5 |(+-)3.8 |460
*6 |(+-)4.5 |390
*7 |(+-)6.5 |280
*/
static ssize_t show_range(struct device *dev,
struct device_attribute *attr,
char *buf)
{
u8 range;
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct hmc5843_data *data = indio_dev->dev_data;
range = data->range;
return sprintf(buf, "%d\n", regval_to_input_field_mg[range]);
}
static ssize_t set_range(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t count)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct i2c_client *client = to_i2c_client(indio_dev->dev.parent);
struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
struct hmc5843_data *data = indio_dev->dev_data;
unsigned long range = 0;
int error;
mutex_lock(&data->lock);
error = strict_strtoul(buf, 10, &range);
if (error)
return error;
dev_dbg(dev, "set range to %lu\n", range);
if (range > RANGE_6_5)
return -EINVAL;
data->range = range;
range = range << RANGE_GAIN_OFFSET;
if (i2c_smbus_write_byte_data(client, this_attr->address, range))
count = -EINVAL;
mutex_unlock(&data->lock);
return count;
}
static IIO_DEVICE_ATTR(magn_range,
S_IWUSR | S_IRUGO,
show_range,
set_range,
HMC5843_CONFIG_REG_B);
static ssize_t show_gain(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct hmc5843_data *data = indio_dev->dev_data;
return sprintf(buf, "%d\n", regval_to_counts_per_mg[data->range]);
}
static IIO_DEVICE_ATTR(magn_gain,
S_IRUGO,
show_gain,
NULL , 0);
static struct attribute *hmc5843_attributes[] = {
&iio_dev_attr_meas_conf.dev_attr.attr,
&iio_dev_attr_operating_mode.dev_attr.attr,
&iio_dev_attr_sampling_frequency.dev_attr.attr,
&iio_dev_attr_magn_range.dev_attr.attr,
&iio_dev_attr_magn_gain.dev_attr.attr,
&iio_dev_attr_magn_x_raw.dev_attr.attr,
&iio_dev_attr_magn_y_raw.dev_attr.attr,
&iio_dev_attr_magn_z_raw.dev_attr.attr,
&iio_const_attr_available_sampling_frequency.dev_attr.attr,
NULL
};
static const struct attribute_group hmc5843_group = {
.attrs = hmc5843_attributes,
};
static int hmc5843_detect(struct i2c_client *client,
struct i2c_board_info *info)
{
unsigned char id_str[HMC5843_ID_REG_LENGTH];
if (client->addr != HMC5843_I2C_ADDRESS)
return -ENODEV;
if (i2c_smbus_read_i2c_block_data(client, HMC5843_ID_REG_A,
HMC5843_ID_REG_LENGTH, id_str)
!= HMC5843_ID_REG_LENGTH)
return -ENODEV;
if (0 != strncmp(id_str, HMC5843_ID_STRING, HMC5843_ID_REG_LENGTH))
return -ENODEV;
return 0;
}
/* Called when we have found a new HMC5843. */
static void hmc5843_init_client(struct i2c_client *client)
{
struct hmc5843_data *data = i2c_get_clientdata(client);
hmc5843_set_meas_conf(client, data->meas_conf);
hmc5843_set_rate(client, data->rate);
hmc5843_configure(client, data->operating_mode);
i2c_smbus_write_byte_data(client, HMC5843_CONFIG_REG_B, data->range);
mutex_init(&data->lock);
pr_info("HMC5843 initialized\n");
}
static int hmc5843_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct hmc5843_data *data;
int err = 0;
data = kzalloc(sizeof(struct hmc5843_data), GFP_KERNEL);
if (!data) {
err = -ENOMEM;
goto exit;
}
/* default settings at probe */
data->meas_conf = CONF_NORMAL;
data->range = RANGE_1_0;
data->operating_mode = MODE_CONVERSION_CONTINUOUS;
i2c_set_clientdata(client, data);
/* Initialize the HMC5843 chip */
hmc5843_init_client(client);
data->indio_dev = iio_allocate_device();
if (!data->indio_dev) {
err = -ENOMEM;
goto exit_free1;
}
data->indio_dev->attrs = &hmc5843_group;
data->indio_dev->dev.parent = &client->dev;
data->indio_dev->dev_data = (void *)(data);
data->indio_dev->driver_module = THIS_MODULE;
data->indio_dev->modes = INDIO_DIRECT_MODE;
err = iio_device_register(data->indio_dev);
if (err)
goto exit_free2;
return 0;
exit_free2:
iio_free_device(data->indio_dev);
exit_free1:
kfree(data);
exit:
return err;
}
static int hmc5843_remove(struct i2c_client *client)
{
struct hmc5843_data *data = i2c_get_clientdata(client);
/* sleep mode to save power */
hmc5843_configure(client, MODE_SLEEP);
iio_device_unregister(data->indio_dev);
kfree(i2c_get_clientdata(client));
return 0;
}
static int hmc5843_suspend(struct i2c_client *client, pm_message_t mesg)
{
hmc5843_configure(client, MODE_SLEEP);
return 0;
}
static int hmc5843_resume(struct i2c_client *client)
{
struct hmc5843_data *data = i2c_get_clientdata(client);
hmc5843_configure(client, data->operating_mode);
return 0;
}
static const struct i2c_device_id hmc5843_id[] = {
{ "hmc5843", 0 },
{ }
};
static struct i2c_driver hmc5843_driver = {
.driver = {
.name = "hmc5843",
},
.id_table = hmc5843_id,
.probe = hmc5843_probe,
.remove = hmc5843_remove,
.detect = hmc5843_detect,
.address_list = normal_i2c,
.suspend = hmc5843_suspend,
.resume = hmc5843_resume,
};
static int __init hmc5843_init(void)
{
return i2c_add_driver(&hmc5843_driver);
}
static void __exit hmc5843_exit(void)
{
i2c_del_driver(&hmc5843_driver);
}
MODULE_AUTHOR("Shubhrajyoti Datta <shubhrajyoti@ti.com");
MODULE_DESCRIPTION("HMC5843 driver");
MODULE_LICENSE("GPL");
module_init(hmc5843_init);
module_exit(hmc5843_exit);