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/*
* Driver for the Asahi Kasei EMD Corporation AK8974
* and Aichi Steel AMI305 magnetometer chips.
* Based on a patch from Samu Onkalo and the AK8975 IIO driver.
*
* Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
* Copyright (c) 2010 NVIDIA Corporation.
* Copyright (C) 2016 Linaro Ltd.
*
* Author: Samu Onkalo <samu.p.onkalo@nokia.com>
* Author: Linus Walleij <linus.walleij@linaro.org>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/irq.h> /* For irq_get_irq_data() */
#include <linux/completion.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/random.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
/*
* 16-bit registers are little-endian. LSB is at the address defined below
* and MSB is at the next higher address.
*/
/* These registers are common for AK8974 and AMI30x */
#define AK8974_SELFTEST 0x0C
#define AK8974_SELFTEST_IDLE 0x55
#define AK8974_SELFTEST_OK 0xAA
#define AK8974_INFO 0x0D
#define AK8974_WHOAMI 0x0F
#define AK8974_WHOAMI_VALUE_AMI306 0x46
#define AK8974_WHOAMI_VALUE_AMI305 0x47
#define AK8974_WHOAMI_VALUE_AK8974 0x48
#define AK8974_DATA_X 0x10
#define AK8974_DATA_Y 0x12
#define AK8974_DATA_Z 0x14
#define AK8974_INT_SRC 0x16
#define AK8974_STATUS 0x18
#define AK8974_INT_CLEAR 0x1A
#define AK8974_CTRL1 0x1B
#define AK8974_CTRL2 0x1C
#define AK8974_CTRL3 0x1D
#define AK8974_INT_CTRL 0x1E
#define AK8974_INT_THRES 0x26 /* Absolute any axis value threshold */
#define AK8974_PRESET 0x30
/* AK8974-specific offsets */
#define AK8974_OFFSET_X 0x20
#define AK8974_OFFSET_Y 0x22
#define AK8974_OFFSET_Z 0x24
/* AMI305-specific offsets */
#define AMI305_OFFSET_X 0x6C
#define AMI305_OFFSET_Y 0x72
#define AMI305_OFFSET_Z 0x78
/* Different temperature registers */
#define AK8974_TEMP 0x31
#define AMI305_TEMP 0x60
/* AMI306-specific control register */
#define AMI306_CTRL4 0x5C
/* AMI306 factory calibration data */
/* fine axis sensitivity */
#define AMI306_FINEOUTPUT_X 0x90
#define AMI306_FINEOUTPUT_Y 0x92
#define AMI306_FINEOUTPUT_Z 0x94
/* axis sensitivity */
#define AMI306_SENS_X 0x96
#define AMI306_SENS_Y 0x98
#define AMI306_SENS_Z 0x9A
/* axis cross-interference */
#define AMI306_GAIN_PARA_XZ 0x9C
#define AMI306_GAIN_PARA_XY 0x9D
#define AMI306_GAIN_PARA_YZ 0x9E
#define AMI306_GAIN_PARA_YX 0x9F
#define AMI306_GAIN_PARA_ZY 0xA0
#define AMI306_GAIN_PARA_ZX 0xA1
/* offset at ZERO magnetic field */
#define AMI306_OFFZERO_X 0xF8
#define AMI306_OFFZERO_Y 0xFA
#define AMI306_OFFZERO_Z 0xFC
#define AK8974_INT_X_HIGH BIT(7) /* Axis over +threshold */
#define AK8974_INT_Y_HIGH BIT(6)
#define AK8974_INT_Z_HIGH BIT(5)
#define AK8974_INT_X_LOW BIT(4) /* Axis below -threshold */
#define AK8974_INT_Y_LOW BIT(3)
#define AK8974_INT_Z_LOW BIT(2)
#define AK8974_INT_RANGE BIT(1) /* Range overflow (any axis) */
#define AK8974_STATUS_DRDY BIT(6) /* Data ready */
#define AK8974_STATUS_OVERRUN BIT(5) /* Data overrun */
#define AK8974_STATUS_INT BIT(4) /* Interrupt occurred */
#define AK8974_CTRL1_POWER BIT(7) /* 0 = standby; 1 = active */
#define AK8974_CTRL1_RATE BIT(4) /* 0 = 10 Hz; 1 = 20 Hz */
#define AK8974_CTRL1_FORCE_EN BIT(1) /* 0 = normal; 1 = force */
#define AK8974_CTRL1_MODE2 BIT(0) /* 0 */
#define AK8974_CTRL2_INT_EN BIT(4) /* 1 = enable interrupts */
#define AK8974_CTRL2_DRDY_EN BIT(3) /* 1 = enable data ready signal */
#define AK8974_CTRL2_DRDY_POL BIT(2) /* 1 = data ready active high */
#define AK8974_CTRL2_RESDEF (AK8974_CTRL2_DRDY_POL)
#define AK8974_CTRL3_RESET BIT(7) /* Software reset */
#define AK8974_CTRL3_FORCE BIT(6) /* Start forced measurement */
#define AK8974_CTRL3_SELFTEST BIT(4) /* Set selftest register */
#define AK8974_CTRL3_RESDEF 0x00
#define AK8974_INT_CTRL_XEN BIT(7) /* Enable interrupt for this axis */
#define AK8974_INT_CTRL_YEN BIT(6)
#define AK8974_INT_CTRL_ZEN BIT(5)
#define AK8974_INT_CTRL_XYZEN (BIT(7)|BIT(6)|BIT(5))
#define AK8974_INT_CTRL_POL BIT(3) /* 0 = active low; 1 = active high */
#define AK8974_INT_CTRL_PULSE BIT(1) /* 0 = latched; 1 = pulse (50 usec) */
#define AK8974_INT_CTRL_RESDEF (AK8974_INT_CTRL_XYZEN | AK8974_INT_CTRL_POL)
/* The AMI305 has elaborate FW version and serial number registers */
#define AMI305_VER 0xE8
#define AMI305_SN 0xEA
#define AK8974_MAX_RANGE 2048
#define AK8974_POWERON_DELAY 50
#define AK8974_ACTIVATE_DELAY 1
#define AK8974_SELFTEST_DELAY 1
/*
* Set the autosuspend to two orders of magnitude larger than the poweron
* delay to make sane reasonable power tradeoff savings (5 seconds in
* this case).
*/
#define AK8974_AUTOSUSPEND_DELAY 5000
#define AK8974_MEASTIME 3
#define AK8974_PWR_ON 1
#define AK8974_PWR_OFF 0
/**
* struct ak8974 - state container for the AK8974 driver
* @i2c: parent I2C client
* @orientation: mounting matrix, flipped axis etc
* @map: regmap to access the AK8974 registers over I2C
* @regs: the avdd and dvdd power regulators
* @name: the name of the part
* @variant: the whoami ID value (for selecting code paths)
* @lock: locks the magnetometer for exclusive use during a measurement
* @drdy_irq: uses the DRDY IRQ line
* @drdy_complete: completion for DRDY
* @drdy_active_low: the DRDY IRQ is active low
*/
struct ak8974 {
struct i2c_client *i2c;
struct iio_mount_matrix orientation;
struct regmap *map;
struct regulator_bulk_data regs[2];
const char *name;
u8 variant;
struct mutex lock;
bool drdy_irq;
struct completion drdy_complete;
bool drdy_active_low;
};
static const char ak8974_reg_avdd[] = "avdd";
static const char ak8974_reg_dvdd[] = "dvdd";
static int ak8974_get_u16_val(struct ak8974 *ak8974, u8 reg, u16 *val)
{
int ret;
__le16 bulk;
ret = regmap_bulk_read(ak8974->map, reg, &bulk, 2);
if (ret)
return ret;
*val = le16_to_cpu(bulk);
return 0;
}
static int ak8974_set_u16_val(struct ak8974 *ak8974, u8 reg, u16 val)
{
__le16 bulk = cpu_to_le16(val);
return regmap_bulk_write(ak8974->map, reg, &bulk, 2);
}
static int ak8974_set_power(struct ak8974 *ak8974, bool mode)
{
int ret;
u8 val;
val = mode ? AK8974_CTRL1_POWER : 0;
val |= AK8974_CTRL1_FORCE_EN;
ret = regmap_write(ak8974->map, AK8974_CTRL1, val);
if (ret < 0)
return ret;
if (mode)
msleep(AK8974_ACTIVATE_DELAY);
return 0;
}
static int ak8974_reset(struct ak8974 *ak8974)
{
int ret;
/* Power on to get register access. Sets CTRL1 reg to reset state */
ret = ak8974_set_power(ak8974, AK8974_PWR_ON);
if (ret)
return ret;
ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_RESDEF);
if (ret)
return ret;
ret = regmap_write(ak8974->map, AK8974_CTRL3, AK8974_CTRL3_RESDEF);
if (ret)
return ret;
ret = regmap_write(ak8974->map, AK8974_INT_CTRL,
AK8974_INT_CTRL_RESDEF);
if (ret)
return ret;
/* After reset, power off is default state */
return ak8974_set_power(ak8974, AK8974_PWR_OFF);
}
static int ak8974_configure(struct ak8974 *ak8974)
{
int ret;
ret = regmap_write(ak8974->map, AK8974_CTRL2, AK8974_CTRL2_DRDY_EN
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