// SPDX-License-Identifier: GPL-2.0+
/*
 * ADIS16460 IMU driver
 *
 * Copyright 2019 Analog Devices Inc.
 */

#include <linux/delay.h>
#include <linux/module.h>
#include <linux/spi/spi.h>

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

#include <linux/debugfs.h>

#define ADIS16460_REG_FLASH_CNT		0x00
#define ADIS16460_REG_DIAG_STAT		0x02
#define ADIS16460_REG_X_GYRO_LOW	0x04
#define ADIS16460_REG_X_GYRO_OUT	0x06
#define ADIS16460_REG_Y_GYRO_LOW	0x08
#define ADIS16460_REG_Y_GYRO_OUT	0x0A
#define ADIS16460_REG_Z_GYRO_LOW	0x0C
#define ADIS16460_REG_Z_GYRO_OUT	0x0E
#define ADIS16460_REG_X_ACCL_LOW	0x10
#define ADIS16460_REG_X_ACCL_OUT	0x12
#define ADIS16460_REG_Y_ACCL_LOW	0x14
#define ADIS16460_REG_Y_ACCL_OUT	0x16
#define ADIS16460_REG_Z_ACCL_LOW	0x18
#define ADIS16460_REG_Z_ACCL_OUT	0x1A
#define ADIS16460_REG_SMPL_CNTR		0x1C
#define ADIS16460_REG_TEMP_OUT		0x1E
#define ADIS16460_REG_X_DELT_ANG	0x24
#define ADIS16460_REG_Y_DELT_ANG	0x26
#define ADIS16460_REG_Z_DELT_ANG	0x28
#define ADIS16460_REG_X_DELT_VEL	0x2A
#define ADIS16460_REG_Y_DELT_VEL	0x2C
#define ADIS16460_REG_Z_DELT_VEL	0x2E
#define ADIS16460_REG_MSC_CTRL		0x32
#define ADIS16460_REG_SYNC_SCAL		0x34
#define ADIS16460_REG_DEC_RATE		0x36
#define ADIS16460_REG_FLTR_CTRL		0x38
#define ADIS16460_REG_GLOB_CMD		0x3E
#define ADIS16460_REG_X_GYRO_OFF	0x40
#define ADIS16460_REG_Y_GYRO_OFF	0x42
#define ADIS16460_REG_Z_GYRO_OFF	0x44
#define ADIS16460_REG_X_ACCL_OFF	0x46
#define ADIS16460_REG_Y_ACCL_OFF	0x48
#define ADIS16460_REG_Z_ACCL_OFF	0x4A
#define ADIS16460_REG_LOT_ID1		0x52
#define ADIS16460_REG_LOT_ID2		0x54
#define ADIS16460_REG_PROD_ID		0x56
#define ADIS16460_REG_SERIAL_NUM	0x58
#define ADIS16460_REG_CAL_SGNTR		0x60
#define ADIS16460_REG_CAL_CRC		0x62
#define ADIS16460_REG_CODE_SGNTR	0x64
#define ADIS16460_REG_CODE_CRC		0x66

struct adis16460_chip_info {
	unsigned int num_channels;
	const struct iio_chan_spec *channels;
	unsigned int gyro_max_val;
	unsigned int gyro_max_scale;
	unsigned int accel_max_val;
	unsigned int accel_max_scale;
};

struct adis16460 {
	const struct adis16460_chip_info *chip_info;
	struct adis adis;
};

#ifdef CONFIG_DEBUG_FS

static int adis16460_show_serial_number(void *arg, u64 *val)
{
	struct adis16460 *adis16460 = arg;
	u16 serial;
	int ret;

	ret = adis_read_reg_16(&adis16460->adis, ADIS16460_REG_SERIAL_NUM,
		&serial);
	if (ret < 0)
		return ret;

	*val = serial;

	return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(adis16460_serial_number_fops,
	adis16460_show_serial_number, NULL, "0x%.4llx\n");

static int adis16460_show_product_id(void *arg, u64 *val)
{
	struct adis16460 *adis16460 = arg;
	u16 prod_id;
	int ret;

	ret = adis_read_reg_16(&adis16460->adis, ADIS16460_REG_PROD_ID,
		&prod_id);
	if (ret < 0)
		return ret;

	*val = prod_id;

	return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(adis16460_product_id_fops,
	adis16460_show_product_id, NULL, "%llu\n");

static int adis16460_show_flash_count(void *arg, u64 *val)
{
	struct adis16460 *adis16460 = arg;
	u32 flash_count;
	int ret;

	ret = adis_read_reg_32(&adis16460->adis, ADIS16460_REG_FLASH_CNT,
		&flash_count);
	if (ret < 0)
		return ret;

	*val = flash_count;

	return 0;
}
DEFINE_SIMPLE_ATTRIBUTE(adis16460_flash_count_fops,
	adis16460_show_flash_count, NULL, "%lld\n");

static int adis16460_debugfs_init(struct iio_dev *indio_dev)
{
	struct adis16460 *adis16460 = iio_priv(indio_dev);

	debugfs_create_file("serial_number", 0400, indio_dev->debugfs_dentry,
		adis16460, &adis16460_serial_number_fops);
	debugfs_create_file("product_id", 0400, indio_dev->debugfs_dentry,
		adis16460, &adis16460_product_id_fops);
	debugfs_create_file("flash_count", 0400, indio_dev->debugfs_dentry,
		adis16460, &adis16460_flash_count_fops);

	return 0;
}

#else

static int adis16460_debugfs_init(struct iio_dev *indio_dev)
{
	return 0;
}

#endif

static int adis16460_set_freq(struct iio_dev *indio_dev, int val, int val2)
{
	struct adis16460 *st = iio_priv(indio_dev);
	unsigned int t;

	t =  val * 1000 + val2 / 1000;
	if (t <= 0)
		return -EINVAL;

	t = 2048000 / t;
	if (t > 2048)
		t = 2048;

	if (t != 0)
		t--;

	return adis_write_reg_16(&st->adis, ADIS16460_REG_DEC_RATE, t);
}

static int adis16460_get_freq(struct iio_dev *indio_dev, int *val, int *val2)
{
	struct adis16460 *st = iio_priv(indio_dev);
	uint16_t t;
	int ret;
	unsigned int freq;

	ret = adis_read_reg_16(&st->adis, ADIS16460_REG_DEC_RATE, &t);
	if (ret < 0)
		return ret;

	freq = 2048000 / (t + 1);
	*val = freq / 1000;
	*val2 = (freq % 1000) * 1000;

	return IIO_VAL_INT_PLUS_MICRO;
}

static int adis16460_read_raw(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, int *val, int *val2, long info)
{
	struct adis16460 *st = iio_priv(indio_dev);

	switch (info) {
	case IIO_CHAN_INFO_RAW:
		return adis_single_conversion(indio_dev, chan, 0, val);
	case IIO_CHAN_INFO_SCALE:
		switch (chan->type) {
		case IIO_ANGL_VEL:
			*val = st->chip_info->gyro_max_scale;
			*val2 = st->chip_info->gyro_max_val;
			return IIO_VAL_FRACTIONAL;
		case IIO_ACCEL:
			*val = st->chip_info->accel_max_scale;
			*val2 = st->chip_info->accel_max_val;
			return IIO_VAL_FRACTIONAL;
		case IIO_TEMP:
			*val = 50; /* 50 milli degrees Celsius/LSB */
			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_OFFSET:
		*val = 500; /* 25 degrees Celsius = 0x0000 */
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SAMP_FREQ:
		return adis16460_get_freq(indio_dev, val, val2);
	default:
		return -EINVAL;
	}
}

static int adis16460_write_raw(struct iio_dev *indio_dev,
	const struct iio_chan_spec *chan, int val, int val2, long info)
{
	switch (info) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		return adis16460_set_freq(indio_dev, val, val2);
	default:
		return -EINVAL;
	}
}

enum {
	ADIS16460_SCAN_GYRO_X,
	ADIS16460_SCAN_GYRO_Y,
	ADIS16460_SCAN_GYRO_Z,
	ADIS16460_SCAN_ACCEL_X,
	ADIS16460_SCAN_ACCEL_Y,
	ADIS16460_SCAN_ACCEL_Z,
	ADIS16460_SCAN_TEMP,
};

#define ADIS16460_MOD_CHANNEL(_type, _mod, _address, _si, _bits) \
	{ \
		.type = (_type), \
		.modified = 1, \
		.channel2 = (_mod), \
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
		.address = (_address), \
		.scan_index = (_si), \
		.scan_type = { \
			.sign = 's', \
			.realbits = (_bits), \
			.storagebits = (_bits), \
			.endianness = IIO_BE, \
		}, \
	}

#define ADIS16460_GYRO_CHANNEL(_mod) \
	ADIS16460_MOD_CHANNEL(IIO_ANGL_VEL, IIO_MOD_ ## _mod, \
	ADIS16460_REG_ ## _mod ## _GYRO_LOW, ADIS16460_SCAN_GYRO_ ## _mod, \
	32)

#define ADIS16460_ACCEL_CHANNEL(_mod) \
	ADIS16460_MOD_CHANNEL(IIO_ACCEL, IIO_MOD_ ## _mod, \
	ADIS16460_REG_ ## _mod ## _ACCL_LOW, ADIS16460_SCAN_ACCEL_ ## _mod, \
	32)

#define ADIS16460_TEMP_CHANNEL() { \
		.type = IIO_TEMP, \
		.indexed = 1, \
		.channel = 0, \
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
			BIT(IIO_CHAN_INFO_SCALE) | \
			BIT(IIO_CHAN_INFO_OFFSET), \
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
		.address = ADIS16460_REG_TEMP_OUT, \
		.scan_index = ADIS16460_SCAN_TEMP, \
		.scan_type = { \
			.sign = 's', \
			.realbits = 16, \
			.storagebits = 16, \
			.endianness = IIO_BE, \
		}, \
	}

static const struct iio_chan_spec adis16460_channels[] = {
	ADIS16460_GYRO_CHANNEL(X),
	ADIS16460_GYRO_CHANNEL(Y),
	ADIS16460_GYRO_CHANNEL(Z),
	ADIS16460_ACCEL_CHANNEL(X),
	ADIS16460_ACCEL_CHANNEL(Y),
	ADIS16460_ACCEL_CHANNEL(Z),
	ADIS16460_TEMP_CHANNEL(),
	IIO_CHAN_SOFT_TIMESTAMP(7)
};

static const struct adis16460_chip_info adis16460_chip_info = {
	.channels = adis16460_channels,
	.num_channels = ARRAY_SIZE(adis16460_channels),
	/*
	 * storing the value in rad/degree and the scale in degree
	 * gives us the result in rad and better precession than
	 * storing the scale directly in rad.
	 */
	.gyro_max_val = IIO_RAD_TO_DEGREE(200 << 16),
	.gyro_max_scale = 1,
	.accel_max_val = IIO_M_S_2_TO_G(20000 << 16),
	.accel_max_scale = 5,
};

static const struct iio_info adis16460_info = {
	.read_raw = &adis16460_read_raw,
	.write_raw = &adis16460_write_raw,
	.update_scan_mode = adis_update_scan_mode,
	.debugfs_reg_access = adis_debugfs_reg_access,
};

static int adis16460_enable_irq(struct adis *adis, bool enable)
{
	/*
	 * There is no way to gate the data-ready signal internally inside the
	 * ADIS16460 :(
	 */
	if (enable)
		enable_irq(adis->spi->irq);
	else
		disable_irq(adis->spi->irq);

	return 0;
}

static int adis16460_initial_setup(struct iio_dev *indio_dev)
{
	struct adis16460 *st = iio_priv(indio_dev);
	uint16_t prod_id;
	unsigned int device_id;
	int ret;

	adis_reset(&st->adis);
	msleep(222);

	ret = adis_write_reg_16(&st->adis, ADIS16460_REG_GLOB_CMD, BIT(1));
	if (ret)
		return ret;
	msleep(75);

	ret = adis_check_status(&st->adis);
	if (ret)
		return ret;

	ret = adis_read_reg_16(&st->adis, ADIS16460_REG_PROD_ID, &prod_id);
	if (ret)
		return ret;

	ret = sscanf(indio_dev->name, "adis%u\n", &device_id);
	if (ret != 1)
		return -EINVAL;

	if (prod_id != device_id)
		dev_warn(&indio_dev->dev, "Device ID(%u) and product ID(%u) do not match.",
				device_id, prod_id);

	return 0;
}

#define ADIS16460_DIAG_STAT_IN_CLK_OOS	7
#define ADIS16460_DIAG_STAT_FLASH_MEM	6
#define ADIS16460_DIAG_STAT_SELF_TEST	5
#define ADIS16460_DIAG_STAT_OVERRANGE	4
#define ADIS16460_DIAG_STAT_SPI_COMM	3
#define ADIS16460_DIAG_STAT_FLASH_UPT	2

static const char * const adis16460_status_error_msgs[] = {
	[ADIS16460_DIAG_STAT_IN_CLK_OOS] = "Input clock out of sync",
	[ADIS16460_DIAG_STAT_FLASH_MEM] = "Flash memory failure",
	[ADIS16460_DIAG_STAT_SELF_TEST] = "Self test diagnostic failure",
	[ADIS16460_DIAG_STAT_OVERRANGE] = "Sensor overrange",
	[ADIS16460_DIAG_STAT_SPI_COMM] = "SPI communication failure",
	[ADIS16460_DIAG_STAT_FLASH_UPT] = "Flash update failure",
};

static const struct adis_data adis16460_data = {
	.diag_stat_reg = ADIS16460_REG_DIAG_STAT,
	.glob_cmd_reg = ADIS16460_REG_GLOB_CMD,
	.has_paging = false,
	.read_delay = 5,
	.write_delay = 5,
	.cs_change_delay = 16,
	.status_error_msgs = adis16460_status_error_msgs,
	.status_error_mask = BIT(ADIS16460_DIAG_STAT_IN_CLK_OOS) |
		BIT(ADIS16460_DIAG_STAT_FLASH_MEM) |
		BIT(ADIS16460_DIAG_STAT_SELF_TEST) |
		BIT(ADIS16460_DIAG_STAT_OVERRANGE) |
		BIT(ADIS16460_DIAG_STAT_SPI_COMM) |
		BIT(ADIS16460_DIAG_STAT_FLASH_UPT),
	.enable_irq = adis16460_enable_irq,
};

static int adis16460_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct adis16460 *st;
	int ret;

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
	if (indio_dev == NULL)
		return -ENOMEM;

	spi_set_drvdata(spi, indio_dev);

	st = iio_priv(indio_dev);

	st->chip_info = &adis16460_chip_info;
	indio_dev->dev.parent = &spi->dev;
	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->channels = st->chip_info->channels;
	indio_dev->num_channels = st->chip_info->num_channels;
	indio_dev->info = &adis16460_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = adis_init(&st->adis, indio_dev, spi, &adis16460_data);
	if (ret)
		return ret;

	ret = adis_setup_buffer_and_trigger(&st->adis, indio_dev, NULL);
	if (ret)
		return ret;

	adis16460_enable_irq(&st->adis, 0);

	ret = adis16460_initial_setup(indio_dev);
	if (ret)
		goto error_cleanup_buffer;

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

	adis16460_debugfs_init(indio_dev);

	return 0;

error_cleanup_buffer:
	adis_cleanup_buffer_and_trigger(&st->adis, indio_dev);
	return ret;
}

static int adis16460_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct adis16460 *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	adis_cleanup_buffer_and_trigger(&st->adis, indio_dev);

	return 0;
}

static const struct spi_device_id adis16460_ids[] = {
	{ "adis16460", 0 },
	{}
};
MODULE_DEVICE_TABLE(spi, adis16460_ids);

static const struct of_device_id adis16460_of_match[] = {
	{ .compatible = "adi,adis16460" },
	{}
};
MODULE_DEVICE_TABLE(of, adis16460_of_match);

static struct spi_driver adis16460_driver = {
	.driver = {
		.name = "adis16460",
		.of_match_table = adis16460_of_match,
	},
	.id_table = adis16460_ids,
	.probe = adis16460_probe,
	.remove = adis16460_remove,
};
module_spi_driver(adis16460_driver);

MODULE_AUTHOR("Dragos Bogdan <dragos.bogdan@analog.com>");
MODULE_DESCRIPTION("Analog Devices ADIS16460 IMU driver");
MODULE_LICENSE("GPL");