linux-imx

/**

 * Sensortek STK8BA50 3-Axis Accelerometer

 *

 * Copyright (c) 2015, 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.

 *

 * STK8BA50 7-bit I2C address: 0x18.

 */

​

#include <linux/acpi.h>

#include <linux/i2c.h>

#include <linux/interrupt.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/iio/trigger.h>

#include <linux/iio/triggered_buffer.h>

#include <linux/iio/trigger_consumer.h>

​

#define STK8BA50_REG_XOUT           0x02

#define STK8BA50_REG_YOUT           0x04

#define STK8BA50_REG_ZOUT           0x06

#define STK8BA50_REG_RANGE          0x0F

#define STK8BA50_REG_BWSEL          0x10

#define STK8BA50_REG_POWMODE            0x11

#define STK8BA50_REG_SWRST          0x14

#define STK8BA50_REG_INTEN2         0x17

#define STK8BA50_REG_INTMAP2            0x1A

​

#define STK8BA50_MODE_NORMAL            0

#define STK8BA50_MODE_SUSPEND           1

#define STK8BA50_MODE_POWERBIT          BIT(7)

#define STK8BA50_DATA_SHIFT         6

#define STK8BA50_RESET_CMD          0xB6

#define STK8BA50_SR_1792HZ_IDX          7

#define STK8BA50_DREADY_INT_MASK        0x10

#define STK8BA50_DREADY_INT_MAP         0x81

#define STK8BA50_ALL_CHANNEL_MASK       7

#define STK8BA50_ALL_CHANNEL_SIZE       6

​

#define STK8BA50_DRIVER_NAME            "stk8ba50"

#define STK8BA50_IRQ_NAME           "stk8ba50_event"

​

#define STK8BA50_SCALE_AVAIL            "0.0384 0.0767 0.1534 0.3069"

​

/*

 * The accelerometer has four measurement ranges:

 * +/-2g; +/-4g; +/-8g; +/-16g

 *

 * Acceleration values are 10-bit, 2's complement.

 * Scales are calculated as following:

 *

 * scale1 = (2 + 2) * 9.81 / (2^10 - 1)   = 0.0384

 * scale2 = (4 + 4) * 9.81 / (2^10 - 1)   = 0.0767

 * etc.

 *

 * Scales are stored in this format:

 * { <register value>, <scale value> }

 *

 * Locally, the range is stored as a table index.

 */

static const struct {

    u8 reg_val;

    u32 scale_val;

} stk8ba50_scale_table[] = {

    {3, 38400}, {5, 76700}, {8, 153400}, {12, 306900}

};

​

/* Sample rates are stored as { <register value>, <Hz value> } */

static const struct {

    u8 reg_val;

    u16 samp_freq;

} stk8ba50_samp_freq_table[] = {

    {0x08, 14},  {0x09, 25},  {0x0A, 56},  {0x0B, 112},

    {0x0C, 224}, {0x0D, 448}, {0x0E, 896}, {0x0F, 1792}

};

​

/* Used to map scan mask bits to their corresponding channel register. */

static const int stk8ba50_channel_table[] = {

    STK8BA50_REG_XOUT,

    STK8BA50_REG_YOUT,

    STK8BA50_REG_ZOUT

};

​

struct stk8ba50_data {

    struct i2c_client *client;

    struct mutex lock;