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/*
* A sensor driver for the magnetometer AK8975.
*
* Magnetic compass sensor driver for monitoring magnetic flux information.
*
* Copyright (c) 2010, NVIDIA Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/acpi.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>
#include <linux/iio/magnetometer/ak8975.h>
/*
* Register definitions, as well as various shifts and masks to get at the
* individual fields of the registers.
*/
#define AK8975_REG_WIA 0x00
#define AK8975_DEVICE_ID 0x48
#define AK8975_REG_INFO 0x01
#define AK8975_REG_ST1 0x02
#define AK8975_REG_ST1_DRDY_SHIFT 0
#define AK8975_REG_ST1_DRDY_MASK (1 << AK8975_REG_ST1_DRDY_SHIFT)
#define AK8975_REG_HXL 0x03
#define AK8975_REG_HXH 0x04
#define AK8975_REG_HYL 0x05
#define AK8975_REG_HYH 0x06
#define AK8975_REG_HZL 0x07
#define AK8975_REG_HZH 0x08
#define AK8975_REG_ST2 0x09
#define AK8975_REG_ST2_DERR_SHIFT 2
#define AK8975_REG_ST2_DERR_MASK (1 << AK8975_REG_ST2_DERR_SHIFT)
#define AK8975_REG_ST2_HOFL_SHIFT 3
#define AK8975_REG_ST2_HOFL_MASK (1 << AK8975_REG_ST2_HOFL_SHIFT)
#define AK8975_REG_CNTL 0x0A
#define AK8975_REG_CNTL_MODE_SHIFT 0
#define AK8975_REG_CNTL_MODE_MASK (0xF << AK8975_REG_CNTL_MODE_SHIFT)
#define AK8975_REG_CNTL_MODE_POWER_DOWN 0x00
#define AK8975_REG_CNTL_MODE_ONCE 0x01
#define AK8975_REG_CNTL_MODE_SELF_TEST 0x08
#define AK8975_REG_CNTL_MODE_FUSE_ROM 0x0F
#define AK8975_REG_RSVC 0x0B
#define AK8975_REG_ASTC 0x0C
#define AK8975_REG_TS1 0x0D
#define AK8975_REG_TS2 0x0E
#define AK8975_REG_I2CDIS 0x0F
#define AK8975_REG_ASAX 0x10
#define AK8975_REG_ASAY 0x11
#define AK8975_REG_ASAZ 0x12
#define AK8975_MAX_REGS AK8975_REG_ASAZ
/*
* AK09912 Register definitions
*/
#define AK09912_REG_WIA1 0x00
#define AK09912_REG_WIA2 0x01
#define AK09912_DEVICE_ID 0x04
#define AK09911_DEVICE_ID 0x05
#define AK09911_REG_INFO1 0x02
#define AK09911_REG_INFO2 0x03
#define AK09912_REG_ST1 0x10
#define AK09912_REG_ST1_DRDY_SHIFT 0
#define AK09912_REG_ST1_DRDY_MASK (1 << AK09912_REG_ST1_DRDY_SHIFT)
#define AK09912_REG_HXL 0x11
#define AK09912_REG_HXH 0x12
#define AK09912_REG_HYL 0x13
#define AK09912_REG_HYH 0x14
#define AK09912_REG_HZL 0x15
#define AK09912_REG_HZH 0x16
#define AK09912_REG_TMPS 0x17
#define AK09912_REG_ST2 0x18
#define AK09912_REG_ST2_HOFL_SHIFT 3
#define AK09912_REG_ST2_HOFL_MASK (1 << AK09912_REG_ST2_HOFL_SHIFT)
#define AK09912_REG_CNTL1 0x30
#define AK09912_REG_CNTL2 0x31
#define AK09912_REG_CNTL_MODE_POWER_DOWN 0x00
#define AK09912_REG_CNTL_MODE_ONCE 0x01
#define AK09912_REG_CNTL_MODE_SELF_TEST 0x10
#define AK09912_REG_CNTL_MODE_FUSE_ROM 0x1F
#define AK09912_REG_CNTL2_MODE_SHIFT 0
#define AK09912_REG_CNTL2_MODE_MASK (0x1F << AK09912_REG_CNTL2_MODE_SHIFT)
#define AK09912_REG_CNTL3 0x32
#define AK09912_REG_TS1 0x33
#define AK09912_REG_TS2 0x34
#define AK09912_REG_TS3 0x35
#define AK09912_REG_I2CDIS 0x36
#define AK09912_REG_TS4 0x37
#define AK09912_REG_ASAX 0x60
#define AK09912_REG_ASAY 0x61
#define AK09912_REG_ASAZ 0x62
#define AK09912_MAX_REGS AK09912_REG_ASAZ
/*
* Miscellaneous values.
*/
#define AK8975_MAX_CONVERSION_TIMEOUT 500
#define AK8975_CONVERSION_DONE_POLL_TIME 10
#define AK8975_DATA_READY_TIMEOUT ((100*HZ)/1000)
/*
* Precalculate scale factor (in Gauss units) for each axis and
* store in the device data.
*
* This scale factor is axis-dependent, and is derived from 3 calibration
* factors ASA(x), ASA(y), and ASA(z).
*
* These ASA values are read from the sensor device at start of day, and
* cached in the device context struct.
*
* Adjusting the flux value with the sensitivity adjustment value should be
* done via the following formula:
*
* Hadj = H * ( ( ( (ASA-128)*0.5 ) / 128 ) + 1 )
* where H is the raw value, ASA is the sensitivity adjustment, and Hadj
* is the resultant adjusted value.
*
* We reduce the formula to:
*
* Hadj = H * (ASA + 128) / 256
*
* H is in the range of -4096 to 4095. The magnetometer has a range of
* +-1229uT. To go from the raw value to uT is:
*
* HuT = H * 1229/4096, or roughly, 3/10.
*
* Since 1uT = 0.01 gauss, our final scale factor becomes:
*
* Hadj = H * ((ASA + 128) / 256) * 3/10 * 1/100
* Hadj = H * ((ASA + 128) * 0.003) / 256
*
* Since ASA doesn't change, we cache the resultant scale factor into the
* device context in ak8975_setup().
*
* Given we use IIO_VAL_INT_PLUS_MICRO bit when displaying the scale, we
* multiply the stored scale value by 1e6.
*/
static long ak8975_raw_to_gauss(u16 data)
{
return (((long)data + 128) * 3000) / 256;
}
/*
* For AK8963 and AK09911, same calculation, but the device is less sensitive:
*
* H is in the range of +-8190. The magnetometer has a range of
* +-4912uT. To go from the raw value to uT is:
*
* HuT = H * 4912/8190, or roughly, 6/10, instead of 3/10.
*/
static long ak8963_09911_raw_to_gauss(u16 data)
{
return (((long)data + 128) * 6000) / 256;
}
/*
* For AK09912, same calculation, except the device is more sensitive:
*
* H is in the range of -32752 to 32752. The magnetometer has a range of
* +-4912uT. To go from the raw value to uT is:
*
* HuT = H * 4912/32752, or roughly, 3/20, instead of 3/10.
*/
static long ak09912_raw_to_gauss(u16 data)
{
return (((long)data + 128) * 1500) / 256;
}
/* Compatible Asahi Kasei Compass parts */
enum asahi_compass_chipset {
AK8975,
AK8963,
AK09911,
AK09912,
AK_MAX_TYPE
};
enum ak_ctrl_reg_addr {
ST1,
ST2,
CNTL,
ASA_BASE,
MAX_REGS,
REGS_END,
};
enum ak_ctrl_reg_mask {
ST1_DRDY,
ST2_HOFL,
ST2_DERR,
CNTL_MODE,
MASK_END,
};
enum ak_ctrl_mode {
POWER_DOWN,
MODE_ONCE,
SELF_TEST,
FUSE_ROM,
MODE_END,
};
struct ak_def {
enum asahi_compass_chipset type;
long (*raw_to_gauss)(u16 data);
u16 range;
u8 ctrl_regs[REGS_END];
u8 ctrl_masks[MASK_END];
u8 ctrl_modes[MODE_END];
u8 data_regs[3];
};
static const struct ak_def ak_def_array[AK_MAX_TYPE] = {
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