linux-imx

/**

 * BMA220 Digital triaxial acceleration sensor driver

 *

 * Copyright (c) 2016, Intel Corporation.

 *

 * This file is subject to the terms and conditions of version 2 of

 * the GNU General Public License. See the file COPYING in the main

 * directory of this archive for more details.

 */

​

#include <linux/acpi.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/iio/buffer.h>

#include <linux/iio/iio.h>

#include <linux/iio/sysfs.h>

#include <linux/spi/spi.h>

#include <linux/iio/trigger_consumer.h>

#include <linux/iio/triggered_buffer.h>

​

#define BMA220_REG_ID               0x00

#define BMA220_REG_ACCEL_X          0x02

#define BMA220_REG_ACCEL_Y          0x03

#define BMA220_REG_ACCEL_Z          0x04

#define BMA220_REG_RANGE            0x11

#define BMA220_REG_SUSPEND          0x18

​

#define BMA220_CHIP_ID              0xDD

#define BMA220_READ_MASK            0x80

#define BMA220_RANGE_MASK           0x03

#define BMA220_DATA_SHIFT           2

#define BMA220_SUSPEND_SLEEP            0xFF

#define BMA220_SUSPEND_WAKE         0x00

​

#define BMA220_DEVICE_NAME          "bma220"

#define BMA220_SCALE_AVAILABLE          "0.623 1.248 2.491 4.983"

​

#define BMA220_ACCEL_CHANNEL(index, 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),       \

    .scan_index = index,                        \

    .scan_type = {                          \

        .sign = 's',                        \

        .realbits = 6,                      \

        .storagebits = 8,                   \

        .shift = BMA220_DATA_SHIFT,             \

        .endianness = IIO_CPU,                  \

    },                              \

}

​

enum bma220_axis {

    AXIS_X,

    AXIS_Y,

    AXIS_Z,

};

​

static IIO_CONST_ATTR(in_accel_scale_available, BMA220_SCALE_AVAILABLE);

​

static struct attribute *bma220_attributes[] = {

    &iio_const_attr_in_accel_scale_available.dev_attr.attr,

    NULL,

};

​

static const struct attribute_group bma220_attribute_group = {

    .attrs = bma220_attributes,

};

​

static const int bma220_scale_table[][4] = {

    {0, 623000}, {1, 248000}, {2, 491000}, {4, 983000}

};

​

struct bma220_data {

    struct spi_device *spi_device;

    struct mutex lock;

    s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */

    u8 tx_buf[2] ____cacheline_aligned;

};

​

static const struct iio_chan_spec bma220_channels[] = {

    BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),

    BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),

    BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),

    IIO_CHAN_SOFT_TIMESTAMP(3),

};

​

static inline int bma220_read_reg(struct spi_device *spi, u8 reg)

{

    return spi_w8r8(spi, reg | BMA220_READ_MASK);