/*
 * ADIS16203 Programmable 360 Degrees Inclinometer
 *
 * Copyright 2010 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/delay.h>
#include <linux/device.h>

#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/imu/adis.h>
#include <linux/iio/sysfs.h>

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/sysfs.h>

#define ADIS16203_STARTUP_DELAY 220 /* ms */

/* Flash memory write count */
#define ADIS16203_FLASH_CNT      0x00

/* Output, power supply */
#define ADIS16203_SUPPLY_OUT     0x02

/* Output, auxiliary ADC input */
#define ADIS16203_AUX_ADC        0x08

/* Output, temperature */
#define ADIS16203_TEMP_OUT       0x0A

/* Output, x-axis inclination */
#define ADIS16203_XINCL_OUT      0x0C

/* Output, y-axis inclination */
#define ADIS16203_YINCL_OUT      0x0E

/* Incline null calibration */
#define ADIS16203_INCL_NULL      0x18

/* Alarm 1 amplitude threshold */
#define ADIS16203_ALM_MAG1       0x20

/* Alarm 2 amplitude threshold */
#define ADIS16203_ALM_MAG2       0x22

/* Alarm 1, sample period */
#define ADIS16203_ALM_SMPL1      0x24

/* Alarm 2, sample period */
#define ADIS16203_ALM_SMPL2      0x26

/* Alarm control */
#define ADIS16203_ALM_CTRL       0x28

/* Auxiliary DAC data */
#define ADIS16203_AUX_DAC        0x30

/* General-purpose digital input/output control */
#define ADIS16203_GPIO_CTRL      0x32

/* Miscellaneous control */
#define ADIS16203_MSC_CTRL       0x34

/* Internal sample period (rate) control */
#define ADIS16203_SMPL_PRD       0x36

/* Operation, filter configuration */
#define ADIS16203_AVG_CNT        0x38

/* Operation, sleep mode control */
#define ADIS16203_SLP_CNT        0x3A

/* Diagnostics, system status register */
#define ADIS16203_DIAG_STAT      0x3C

/* Operation, system command register */
#define ADIS16203_GLOB_CMD       0x3E

/* MSC_CTRL */

/* Self-test at power-on: 1 = disabled, 0 = enabled */
#define ADIS16203_MSC_CTRL_PWRUP_SELF_TEST      BIT(10)

/* Reverses rotation of both inclination outputs */
#define ADIS16203_MSC_CTRL_REVERSE_ROT_EN       BIT(9)

/* Self-test enable */
#define ADIS16203_MSC_CTRL_SELF_TEST_EN         BIT(8)

/* Data-ready enable: 1 = enabled, 0 = disabled */
#define ADIS16203_MSC_CTRL_DATA_RDY_EN          BIT(2)

/* Data-ready polarity: 1 = active high, 0 = active low */
#define ADIS16203_MSC_CTRL_ACTIVE_HIGH          BIT(1)

/* Data-ready line selection: 1 = DIO1, 0 = DIO0 */
#define ADIS16203_MSC_CTRL_DATA_RDY_DIO1        BIT(0)

/* DIAG_STAT */

/* Alarm 2 status: 1 = alarm active, 0 = alarm inactive */
#define ADIS16203_DIAG_STAT_ALARM2        BIT(9)

/* Alarm 1 status: 1 = alarm active, 0 = alarm inactive */
#define ADIS16203_DIAG_STAT_ALARM1        BIT(8)

/* Self-test diagnostic error flag */
#define ADIS16203_DIAG_STAT_SELFTEST_FAIL_BIT 5

/* SPI communications failure */
#define ADIS16203_DIAG_STAT_SPI_FAIL_BIT      3

/* Flash update failure */
#define ADIS16203_DIAG_STAT_FLASH_UPT_BIT     2

/* Power supply above 3.625 V */
#define ADIS16203_DIAG_STAT_POWER_HIGH_BIT    1

/* Power supply below 3.15 V */
#define ADIS16203_DIAG_STAT_POWER_LOW_BIT     0

/* GLOB_CMD */

#define ADIS16203_GLOB_CMD_SW_RESET     BIT(7)
#define ADIS16203_GLOB_CMD_CLEAR_STAT   BIT(4)
#define ADIS16203_GLOB_CMD_FACTORY_CAL  BIT(1)

#define ADIS16203_ERROR_ACTIVE          BIT(14)

enum adis16203_scan {
	 ADIS16203_SCAN_INCLI_X,
	 ADIS16203_SCAN_INCLI_Y,
	 ADIS16203_SCAN_SUPPLY,
	 ADIS16203_SCAN_AUX_ADC,
	 ADIS16203_SCAN_TEMP,
};

#define DRIVER_NAME		"adis16203"

static const u8 adis16203_addresses[] = {
	[ADIS16203_SCAN_INCLI_X] = ADIS16203_INCL_NULL,
};

static int adis16203_write_raw(struct iio_dev *indio_dev,
			       struct iio_chan_spec const *chan,
			       int val,
			       int val2,
			       long mask)
{
	struct adis *st = iio_priv(indio_dev);
	/* currently only one writable parameter which keeps this simple */
	u8 addr = adis16203_addresses[chan->scan_index];

	return adis_write_reg_16(st, addr, val & 0x3FFF);
}

static int adis16203_read_raw(struct iio_dev *indio_dev,
			      struct iio_chan_spec const *chan,
			      int *val, int *val2,
			      long mask)
{
	struct adis *st = iio_priv(indio_dev);
	int ret;
	int bits;
	u8 addr;
	s16 val16;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		return adis_single_conversion(indio_dev, chan,
				ADIS16203_ERROR_ACTIVE, val);
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_VOLTAGE:
			if (chan->channel == 0) {
				*val = 1;
				*val2 = 220000; /* 1.22 mV */
			} else {
				*val = 0;
				*val2 = 610000; /* 0.61 mV */
			}
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_TEMP:
			*val = -470; /* -0.47 C */
			*val2 = 0;
			return IIO_VAL_INT_PLUS_MICRO;
		case IIO_INCLI:
			*val = 0;
			*val2 = 25000; /* 0.025 degree */
			return IIO_VAL_INT_PLUS_MICRO;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_OFFSET:
		*val = 25000 / -470 - 1278; /* 25 C = 1278 */
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_CALIBBIAS:
		bits = 14;
		addr = adis16203_addresses[chan->scan_index];
		ret = adis_read_reg_16(st, addr, &val16);
		if (ret)
			return ret;
		val16 &= (1 << bits) - 1;
		val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
		*val = val16;
		return IIO_VAL_INT;
	default:
		return -EINVAL;
	}
}

static const struct iio_chan_spec adis16203_channels[] = {
	ADIS_SUPPLY_CHAN(ADIS16203_SUPPLY_OUT, ADIS16203_SCAN_SUPPLY, 0, 12),
	ADIS_AUX_ADC_CHAN(ADIS16203_AUX_ADC, ADIS16203_SCAN_AUX_ADC, 0, 12),
	ADIS_INCLI_CHAN(X, ADIS16203_XINCL_OUT, ADIS16203_SCAN_INCLI_X,
			BIT(IIO_CHAN_INFO_CALIBBIAS), 0, 14),
	/* Fixme: Not what it appears to be - see data sheet */
	ADIS_INCLI_CHAN(Y, ADIS16203_YINCL_OUT, ADIS16203_SCAN_INCLI_Y,
			0, 0, 14),
	ADIS_TEMP_CHAN(ADIS16203_TEMP_OUT, ADIS16203_SCAN_TEMP, 0, 12),
	IIO_CHAN_SOFT_TIMESTAMP(5),
};

static const struct iio_info adis16203_info = {
	.read_raw = adis16203_read_raw,
	.write_raw = adis16203_write_raw,
	.update_scan_mode = adis_update_scan_mode,
	.driver_module = THIS_MODULE,
};

static const char * const adis16203_status_error_msgs[] = {
	[ADIS16203_DIAG_STAT_SELFTEST_FAIL_BIT] = "Self test failure",
	[ADIS16203_DIAG_STAT_SPI_FAIL_BIT] = "SPI failure",
	[ADIS16203_DIAG_STAT_FLASH_UPT_BIT] = "Flash update failed",
	[ADIS16203_DIAG_STAT_POWER_HIGH_BIT] = "Power supply above 3.625V",
	[ADIS16203_DIAG_STAT_POWER_LOW_BIT] = "Power supply below 3.15V",
};

static const struct adis_data adis16203_data = {
	.read_delay = 20,
	.msc_ctrl_reg = ADIS16203_MSC_CTRL,
	.glob_cmd_reg = ADIS16203_GLOB_CMD,
	.diag_stat_reg = ADIS16203_DIAG_STAT,

	.self_test_mask = ADIS16203_MSC_CTRL_SELF_TEST_EN,
	.self_test_no_autoclear = true,
	.startup_delay = ADIS16203_STARTUP_DELAY,

	.status_error_msgs = adis16203_status_error_msgs,
	.status_error_mask = BIT(ADIS16203_DIAG_STAT_SELFTEST_FAIL_BIT) |
		BIT(ADIS16203_DIAG_STAT_SPI_FAIL_BIT) |
		BIT(ADIS16203_DIAG_STAT_FLASH_UPT_BIT) |
		BIT(ADIS16203_DIAG_STAT_POWER_HIGH_BIT) |
		BIT(ADIS16203_DIAG_STAT_POWER_LOW_BIT),
};

static int adis16203_probe(struct spi_device *spi)
{
	int ret;
	struct iio_dev *indio_dev;
	struct adis *st;

	/* setup the industrialio driver allocated elements */
	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;
	st = iio_priv(indio_dev);
	/* this is only used for removal purposes */
	spi_set_drvdata(spi, indio_dev);

	indio_dev->name = spi->dev.driver->name;
	indio_dev->dev.parent = &spi->dev;
	indio_dev->channels = adis16203_channels;
	indio_dev->num_channels = ARRAY_SIZE(adis16203_channels);
	indio_dev->info = &adis16203_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = adis_init(st, indio_dev, spi, &adis16203_data);
	if (ret)
		return ret;

	ret = adis_setup_buffer_and_trigger(st, indio_dev, NULL);
	if (ret)
		return ret;

	/* Get the device into a sane initial state */
	ret = adis_initial_startup(st);
	if (ret)
		goto error_cleanup_buffer_trigger;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto error_cleanup_buffer_trigger;

	return 0;

error_cleanup_buffer_trigger:
	adis_cleanup_buffer_and_trigger(st, indio_dev);
	return ret;
}

static int adis16203_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct adis *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	adis_cleanup_buffer_and_trigger(st, indio_dev);

	return 0;
}

static struct spi_driver adis16203_driver = {
	.driver = {
		.name = "adis16203",
	},
	.probe = adis16203_probe,
	.remove = adis16203_remove,
};
module_spi_driver(adis16203_driver);

MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_DESCRIPTION("Analog Devices ADIS16203 Programmable 360 Degrees Inclinometer");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("spi:adis16203");