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/**
* IIO driver for the 3-axis accelerometer Domintech ARD10.
*
* Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
* Copyright (c) 2012 Domintech Technology Co., Ltd
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/byteorder/generic.h>
#define DMARD10_REG_ACTR 0x00
#define DMARD10_REG_AFEM 0x0c
#define DMARD10_REG_STADR 0x12
#define DMARD10_REG_STAINT 0x1c
#define DMARD10_REG_MISC2 0x1f
#define DMARD10_REG_PD 0x21
#define DMARD10_MODE_OFF 0x00
#define DMARD10_MODE_STANDBY 0x02
#define DMARD10_MODE_ACTIVE 0x06
#define DMARD10_MODE_READ_OTP 0x12
#define DMARD10_MODE_RESET_DATA_PATH 0x82
/* AFEN set 1, ATM[2:0]=b'000 (normal), EN_Z/Y/X/T=1 */
#define DMARD10_VALUE_AFEM_AFEN_NORMAL 0x8f
/* ODR[3:0]=b'0111 (100Hz), CCK[3:0]=b'0100 (204.8kHZ) */
#define DMARD10_VALUE_CKSEL_ODR_100_204 0x74
/* INTC[6:5]=b'00 */
#define DMARD10_VALUE_INTC 0x00
/* TAP1/TAP2 Average 2 */
#define DMARD10_VALUE_TAPNS_AVE_2 0x11
#define DMARD10_VALUE_STADR 0x55
#define DMARD10_VALUE_STAINT 0xaa
#define DMARD10_VALUE_MISC2_OSCA_EN 0x08
#define DMARD10_VALUE_PD_RST 0x52
/* Offsets into the buffer read in dmard10_read_raw() */
#define DMARD10_X_OFFSET 1
#define DMARD10_Y_OFFSET 2
#define DMARD10_Z_OFFSET 3
/*
* a value of + or -128 corresponds to + or - 1G
* scale = 9.81 / 128 = 0.076640625
*/
static const int dmard10_nscale = 76640625;
#define DMARD10_CHANNEL(reg, axis) { \
.type = IIO_ACCEL, \
.address = reg, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec dmard10_channels[] = {
DMARD10_CHANNEL(DMARD10_X_OFFSET, X),
DMARD10_CHANNEL(DMARD10_Y_OFFSET, Y),
DMARD10_CHANNEL(DMARD10_Z_OFFSET, Z),
};
struct dmard10_data {
struct i2c_client *client;
};
/* Init sequence taken from the android driver */
static int dmard10_reset(struct i2c_client *client)
{
unsigned char buffer[7];
int ret;
/* 1. Powerdown reset */
ret = i2c_smbus_write_byte_data(client, DMARD10_REG_PD,
DMARD10_VALUE_PD_RST);
if (ret < 0)
return ret;
/*
* 2. ACTR => Standby mode => Download OTP to parameter reg =>
* Standby mode => Reset data path => Standby mode
*/
buffer[0] = DMARD10_REG_ACTR;
buffer[1] = DMARD10_MODE_STANDBY;
buffer[2] = DMARD10_MODE_READ_OTP;
buffer[3] = DMARD10_MODE_STANDBY;
buffer[4] = DMARD10_MODE_RESET_DATA_PATH;
buffer[5] = DMARD10_MODE_STANDBY;
ret = i2c_master_send(client, buffer, 6);
if (ret < 0)
return ret;
/* 3. OSCA_EN = 1, TSTO = b'000 (INT1 = normal, TEST0 = normal) */
ret = i2c_smbus_write_byte_data(client, DMARD10_REG_MISC2,
DMARD10_VALUE_MISC2_OSCA_EN);
if (ret < 0)
return ret;
/* 4. AFEN = 1 (AFE will powerdown after ADC) */
buffer[0] = DMARD10_REG_AFEM;
buffer[1] = DMARD10_VALUE_AFEM_AFEN_NORMAL;
buffer[2] = DMARD10_VALUE_CKSEL_ODR_100_204;
buffer[3] = DMARD10_VALUE_INTC;
buffer[4] = DMARD10_VALUE_TAPNS_AVE_2;
buffer[5] = 0x00; /* DLYC, no delay timing */
buffer[6] = 0x07; /* INTD=1 push-pull, INTA=1 active high, AUTOT=1 */
ret = i2c_master_send(client, buffer, 7);
if (ret < 0)
return ret;
/* 5. Activation mode */
ret = i2c_smbus_write_byte_data(client, DMARD10_REG_ACTR,
DMARD10_MODE_ACTIVE);
if (ret < 0)
return ret;
return 0;
}
/* Shutdown sequence taken from the android driver */
static int dmard10_shutdown(struct i2c_client *client)
{
unsigned char buffer[3];
buffer[0] = DMARD10_REG_ACTR;
buffer[1] = DMARD10_MODE_STANDBY;
buffer[2] = DMARD10_MODE_OFF;
return i2c_master_send(client, buffer, 3);
}
static int dmard10_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct dmard10_data *data = iio_priv(indio_dev);
__le16 buf[4];
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
/*
* Read 8 bytes starting at the REG_STADR register, trying to
* read the individual X, Y, Z registers will always read 0.
*/
ret = i2c_smbus_read_i2c_block_data(data->client,
DMARD10_REG_STADR,
sizeof(buf), (u8 *)buf);
if (ret < 0)
return ret;
ret = le16_to_cpu(buf[chan->address]);
*val = sign_extend32(ret, 12);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = dmard10_nscale;
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
}
static const struct iio_info dmard10_info = {
.driver_module = THIS_MODULE,
.read_raw = dmard10_read_raw,
};
static int dmard10_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct dmard10_data *data;
/* These 2 registers have special POR reset values used for id */
ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STADR);
if (ret != DMARD10_VALUE_STADR)
return (ret < 0) ? ret : -ENODEV;
ret = i2c_smbus_read_byte_data(client, DMARD10_REG_STAINT);
if (ret != DMARD10_VALUE_STAINT)
return (ret < 0) ? ret : -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev) {
dev_err(&client->dev, "iio allocation failed!\n");
return -ENOMEM;
}
data = iio_priv(indio_dev);
data->client = client;
i2c_set_clientdata(client, indio_dev);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &dmard10_info;
indio_dev->name = "dmard10";
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = dmard10_channels;
indio_dev->num_channels = ARRAY_SIZE(dmard10_channels);
ret = dmard10_reset(client);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
dmard10_shutdown(client);
}
return ret;
}
static int dmard10_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
return dmard10_shutdown(client);
}
#ifdef CONFIG_PM_SLEEP
static int dmard10_suspend(struct device *dev)
{
return dmard10_shutdown(to_i2c_client(dev));
}
static int dmard10_resume(struct device *dev)
{
return dmard10_reset(to_i2c_client(dev));
}
#endif
static SIMPLE_DEV_PM_OPS(dmard10_pm_ops, dmard10_suspend, dmard10_resume);
static const struct i2c_device_id dmard10_i2c_id[] = {
{"dmard10", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, dmard10_i2c_id);
static struct i2c_driver dmard10_driver = {
.driver = {
.name = "dmard10",
.pm = &dmard10_pm_ops,
},
.probe = dmard10_probe,
.remove = dmard10_remove,
.id_table = dmard10_i2c_id,
};
module_i2c_driver(dmard10_driver);
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("Domintech ARD10 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
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