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/*
* kxsd9.c simple support for the Kionix KXSD9 3D
* accelerometer.
*
* Copyright (c) 2008-2009 Jonathan Cameron <jic23@kernel.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* The i2c interface is very similar, so shouldn't be a problem once
* I have a suitable wire made up.
*
* TODO: Support the motion detector
* Uses register address incrementing so could have a
* heavily optimized ring buffer access function.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/sysfs.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include "kxsd9.h"
#define KXSD9_REG_X 0x00
#define KXSD9_REG_Y 0x02
#define KXSD9_REG_Z 0x04
#define KXSD9_REG_AUX 0x06
#define KXSD9_REG_RESET 0x0a
#define KXSD9_REG_CTRL_C 0x0c
#define KXSD9_FS_MASK 0x03
#define KXSD9_REG_CTRL_B 0x0d
#define KXSD9_REG_CTRL_A 0x0e
/**
* struct kxsd9_state - device related storage
* @map: regmap to the device
*/
struct kxsd9_state {
struct regmap *map;
};
#define KXSD9_SCALE_2G "0.011978"
#define KXSD9_SCALE_4G "0.023927"
#define KXSD9_SCALE_6G "0.035934"
#define KXSD9_SCALE_8G "0.047853"
/* reverse order */
static const int kxsd9_micro_scales[4] = { 47853, 35934, 23927, 11978 };
#define KXSD9_ZERO_G_OFFSET -2048
static int kxsd9_write_scale(struct iio_dev *indio_dev, int micro)
{
int ret, i;
struct kxsd9_state *st = iio_priv(indio_dev);
bool foundit = false;
unsigned int val;
for (i = 0; i < 4; i++)
if (micro == kxsd9_micro_scales[i]) {
foundit = true;
break;
}
if (!foundit)
return -EINVAL;
ret = regmap_read(st->map,
KXSD9_REG_CTRL_C,
&val);
if (ret < 0)
goto error_ret;
ret = regmap_write(st->map,
KXSD9_REG_CTRL_C,
(val & ~KXSD9_FS_MASK) | i);
error_ret:
return ret;
}
static IIO_CONST_ATTR(accel_scale_available,
KXSD9_SCALE_2G " "
KXSD9_SCALE_4G " "
KXSD9_SCALE_6G " "
KXSD9_SCALE_8G);
static struct attribute *kxsd9_attributes[] = {
&iio_const_attr_accel_scale_available.dev_attr.attr,
NULL,
};
static int kxsd9_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
int ret = -EINVAL;
if (mask == IIO_CHAN_INFO_SCALE) {
/* Check no integer component */
if (val)
return -EINVAL;
ret = kxsd9_write_scale(indio_dev, val2);
}
return ret;
}
static int kxsd9_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
int ret = -EINVAL;
struct kxsd9_state *st = iio_priv(indio_dev);
unsigned int regval;
__be16 raw_val;
u16 nval;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = regmap_bulk_read(st->map, chan->address, &raw_val,
sizeof(raw_val));
if (ret)
goto error_ret;
nval = be16_to_cpu(raw_val);
/* Only 12 bits are valid */
nval >>= 4;
*val = nval;
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_OFFSET:
/* This has a bias of -2048 */
*val = KXSD9_ZERO_G_OFFSET;
ret = IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
ret = regmap_read(st->map,
KXSD9_REG_CTRL_C,
®val);
if (ret < 0)
goto error_ret;
*val = 0;
*val2 = kxsd9_micro_scales[regval & KXSD9_FS_MASK];
ret = IIO_VAL_INT_PLUS_MICRO;
break;
}
error_ret:
return ret;
};
#define KXSD9_ACCEL_CHAN(axis) \
{ \
.type = IIO_ACCEL, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
BIT(IIO_CHAN_INFO_OFFSET), \
.address = KXSD9_REG_##axis, \
}
static const struct iio_chan_spec kxsd9_channels[] = {
KXSD9_ACCEL_CHAN(X), KXSD9_ACCEL_CHAN(Y), KXSD9_ACCEL_CHAN(Z),
{
.type = IIO_VOLTAGE,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.indexed = 1,
.address = KXSD9_REG_AUX,
}
};
static const struct attribute_group kxsd9_attribute_group = {
.attrs = kxsd9_attributes,
};
static int kxsd9_power_up(struct kxsd9_state *st)
{
int ret;
ret = regmap_write(st->map, KXSD9_REG_CTRL_B, 0x40);
if (ret)
return ret;
return regmap_write(st->map, KXSD9_REG_CTRL_C, 0x9b);
};
static const struct iio_info kxsd9_info = {
.read_raw = &kxsd9_read_raw,
.write_raw = &kxsd9_write_raw,
.attrs = &kxsd9_attribute_group,
.driver_module = THIS_MODULE,
};
int kxsd9_common_probe(struct device *parent,
struct regmap *map,
const char *name)
{
struct iio_dev *indio_dev;
struct kxsd9_state *st;
int ret;
indio_dev = devm_iio_device_alloc(parent, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->map = map;
indio_dev->channels = kxsd9_channels;
indio_dev->num_channels = ARRAY_SIZE(kxsd9_channels);
indio_dev->name = name;
indio_dev->dev.parent = parent;
indio_dev->info = &kxsd9_info;
indio_dev->modes = INDIO_DIRECT_MODE;
kxsd9_power_up(st);
ret = iio_device_register(indio_dev);
if (ret)
return ret;
dev_set_drvdata(parent, indio_dev);
return 0;
}
EXPORT_SYMBOL(kxsd9_common_probe);
int kxsd9_common_remove(struct device *parent)
{
struct iio_dev *indio_dev = dev_get_drvdata(parent);
iio_device_unregister(indio_dev);
return 0;
}
EXPORT_SYMBOL(kxsd9_common_remove);
MODULE_AUTHOR("Jonathan Cameron <jic23@kernel.org>");
MODULE_DESCRIPTION("Kionix KXSD9 driver");
MODULE_LICENSE("GPL v2");
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