// SPDX-License-Identifier: GPL-2.0
/*
 * ADIS16550 IMU driver
 *
 * Copyright 2024 Analog Devices Inc.
 */
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/crc32.h>
#include <linux/debugfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/iio.h>
#include <linux/iio/imu/adis.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/lcm.h>
#include <linux/math.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/swab.h>
#include <linux/unaligned.h>

#define ADIS16550_REG_BURST_GYRO_ACCEL		0x0a
#define ADIS16550_REG_BURST_DELTA_ANG_VEL	0x0b
#define ADIS16550_BURST_DATA_GYRO_ACCEL_MASK	GENMASK(6, 1)
#define ADIS16550_BURST_DATA_DELTA_ANG_VEL_MASK	GENMASK(12, 7)

#define ADIS16550_REG_STATUS		0x0e
#define ADIS16550_REG_TEMP		0x10
#define ADIS16550_REG_X_GYRO		0x12
#define ADIS16550_REG_Y_GYRO		0x14
#define ADIS16550_REG_Z_GYRO		0x16
#define ADIS16550_REG_X_ACCEL		0x18
#define ADIS16550_REG_Y_ACCEL		0x1a
#define ADIS16550_REG_Z_ACCEL		0x1c
#define ADIS16550_REG_X_DELTANG_L	0x1E
#define ADIS16550_REG_Y_DELTANG_L	0x20
#define ADIS16550_REG_Z_DELTANG_L	0x22
#define ADIS16550_REG_X_DELTVEL_L	0x24
#define ADIS16550_REG_Y_DELTVEL_L	0x26
#define ADIS16550_REG_Z_DELTVEL_L	0x28
#define ADIS16550_REG_X_GYRO_SCALE	0x30
#define ADIS16550_REG_Y_GYRO_SCALE	0x32
#define ADIS16550_REG_Z_GYRO_SCALE	0x34
#define ADIS16550_REG_X_ACCEL_SCALE	0x36
#define ADIS16550_REG_Y_ACCEL_SCALE	0x38
#define ADIS16550_REG_Z_ACCEL_SCALE	0x3a
#define ADIS16550_REG_X_GYRO_BIAS	0x40
#define ADIS16550_REG_Y_GYRO_BIAS	0x42
#define ADIS16550_REG_Z_GYRO_BIAS	0x44
#define ADIS16550_REG_X_ACCEL_BIAS	0x46
#define ADIS16550_REG_Y_ACCEL_BIAS	0x48
#define ADIS16550_REG_Z_ACCEL_BIAS	0x4a
#define ADIS16550_REG_COMMAND		0x50
#define ADIS16550_REG_CONFIG		0x52
#define ADIS16550_GYRO_FIR_EN_MASK	BIT(3)
#define ADIS16550_ACCL_FIR_EN_MASK	BIT(2)
#define ADIS16550_SYNC_MASK	\
	(ADIS16550_SYNC_EN_MASK | ADIS16550_SYNC_MODE_MASK)
#define ADIS16550_SYNC_MODE_MASK	BIT(1)
#define ADIS16550_SYNC_EN_MASK		BIT(0)
/* max of 4000 SPS in scale sync */
#define ADIS16550_SYNC_SCALE_MAX_RATE	(4000 * 1000)
#define ADIS16550_REG_DEC_RATE		0x54
#define ADIS16550_REG_SYNC_SCALE	0x56
#define ADIS16550_REG_SERIAL_NUM	0x76
#define ADIS16550_REG_FW_REV		0x7A
#define ADIS16550_REG_FW_DATE		0x7C
#define ADIS16550_REG_PROD_ID		0x7E
#define ADIS16550_REG_FLASH_CNT		0x72
/* SPI protocol*/
#define ADIS16550_SPI_DATA_MASK		GENMASK(31, 16)
#define ADIS16550_SPI_REG_MASK		GENMASK(14, 8)
#define ADIS16550_SPI_R_W_MASK		BIT(7)
#define ADIS16550_SPI_CRC_MASK		GENMASK(3, 0)
#define ADIS16550_SPI_SV_MASK		GENMASK(7, 6)
/* burst read */
#define ADIS16550_BURST_N_ELEM		12
#define ADIS16550_BURST_DATA_LEN	(ADIS16550_BURST_N_ELEM * 4)
#define ADIS16550_MAX_SCAN_DATA		12

struct adis16550_sync {
	u16 sync_mode;
	u16 min_rate;
	u16 max_rate;
};

struct adis16550_chip_info {
	const struct iio_chan_spec *channels;
	const struct adis16550_sync *sync_mode;
	char *name;
	u32 num_channels;
	u32 gyro_max_val;
	u32 gyro_max_scale;
	u32 accel_max_val;
	u32 accel_max_scale;
	u32 temp_scale;
	u32 deltang_max_val;
	u32 deltvel_max_val;
	u32 int_clk;
	u16 max_dec;
	u16 num_sync;
};

struct adis16550 {
	const struct adis16550_chip_info *info;
	struct adis adis;
	unsigned long clk_freq_hz;
	u32 sync_mode;
	struct spi_transfer xfer[2];
	u8 buffer[ADIS16550_BURST_DATA_LEN + sizeof(u32)] __aligned(IIO_DMA_MINALIGN);
	__be32 din[2];
	__be32 dout[2];
};

enum {
	ADIS16550_SV_INIT,
	ADIS16550_SV_OK,
	ADIS16550_SV_NOK,
	ADIS16550_SV_SPI_ERROR,
};

/*
 * This is a simplified implementation of lib/crc4.c. It could not be used
 * directly since the polynomial used is different from the one used by the
 * 16550 which is 0b10001
 */
static u8 spi_crc4(const u32 val)
{
	int i;
	const int bits = 28;
	u8 crc = 0xa;
	/* ignore 4lsb */
	const u32 __val = val >> 4;

	/* Calculate crc4 over four-bit nibbles, starting at the MSbit */
	for (i = bits - 4; i >= 0; i -= 4)
		crc = crc ^ ((__val >> i) & 0xf);

	return crc;
}

static int adis16550_spi_validate(const struct adis *adis, __be32 dout,
				  u16 *data)
{
	u32 __dout;
	u8 crc, crc_rcv, sv;

	__dout = be32_to_cpu(dout);

	/* validate received message */
	crc_rcv = FIELD_GET(ADIS16550_SPI_CRC_MASK, __dout);
	crc = spi_crc4(__dout);
	if (crc_rcv != crc) {
		dev_err(&adis->spi->dev,
			"Invalid crc, rcv: 0x%02x, calc: 0x%02x!\n",
			crc_rcv, crc);
		return -EIO;
	}
	sv = FIELD_GET(ADIS16550_SPI_SV_MASK, __dout);
	if (sv >= ADIS16550_SV_NOK) {
		dev_err(&adis->spi->dev,
			"State vector error detected: %02X", sv);
		return -EIO;
	}
	*data = FIELD_GET(ADIS16550_SPI_DATA_MASK, __dout);

	return 0;
}

static void adis16550_spi_msg_prepare(const u32 reg, const bool write,
				      const u16 data, __be32 *din)
{
	u8 crc;
	u32 __din;

	__din = FIELD_PREP(ADIS16550_SPI_REG_MASK, reg);

	if (write) {
		__din |= FIELD_PREP(ADIS16550_SPI_R_W_MASK, 1);
		__din |= FIELD_PREP(ADIS16550_SPI_DATA_MASK, data);
	}

	crc = spi_crc4(__din);
	__din |= FIELD_PREP(ADIS16550_SPI_CRC_MASK, crc);

	*din = cpu_to_be32(__din);
}

static int adis16550_spi_xfer(const struct adis *adis, u32 reg, u32 len,
			      u32 *readval, u32 writeval)
{
	int ret;
	u16 data = 0;
	struct spi_message msg;
	bool wr = readval ? false : true;
	struct spi_device *spi = adis->spi;
	struct adis16550 *st = container_of(adis, struct adis16550, adis);
	struct spi_transfer xfers[] = {
		{
			.tx_buf = &st->din[0],
			.len = 4,
			.cs_change = 1,
		}, {
			.tx_buf = &st->din[1],
			.len = 4,
			.cs_change = 1,
			.rx_buf = st->dout,
		}, {
			.tx_buf = &st->din[1],
			.rx_buf = &st->dout[1],
			.len = 4,
		},
	};

	spi_message_init(&msg);

	switch (len) {
	case 4:
		adis16550_spi_msg_prepare(reg + 1, wr, writeval >> 16,
					  &st->din[0]);
		spi_message_add_tail(&xfers[0], &msg);
		fallthrough;
	case 2:
		adis16550_spi_msg_prepare(reg, wr, writeval, &st->din[1]);
		spi_message_add_tail(&xfers[1], &msg);
		spi_message_add_tail(&xfers[2], &msg);
		break;
	default:
		return -EINVAL;
	}

	ret = spi_sync(spi, &msg);
	if (ret) {
		dev_err(&spi->dev, "Spi failure %d\n", ret);
		return ret;
	}
	/*
	 * When writing a register, the device will reply with a readback on the
	 * transfer so that we can validate if our data was actually written..
	 */
	switch (len) {
	case 4:
		ret = adis16550_spi_validate(adis, st->dout[0], &data);
		if (ret)
			return ret;

		if (readval) {
			*readval = data << 16;
		} else if ((writeval >> 16) != data && reg != ADIS16550_REG_COMMAND) {
			dev_err(&spi->dev,
				"Data not written: wr: 0x%04X, rcv: 0x%04X\n",
				writeval >> 16, data);
			return -EIO;
		}

		fallthrough;
	case 2:
		ret = adis16550_spi_validate(adis, st->dout[1], &data);
		if (ret)
			return ret;

		if (readval) {
			*readval = (*readval & GENMASK(31, 16)) | data;
		} else if ((writeval & GENMASK(15, 0)) != data && reg != ADIS16550_REG_COMMAND) {
			dev_err(&spi->dev,
				"Data not written: wr: 0x%04X, rcv: 0x%04X\n",
				(u16)writeval, data);
			return -EIO;
		}
	}

	return 0;
}

static int adis16550_spi_read(struct adis *adis, const u32 reg,
			      u32 *value, const u32 len)
{
	return adis16550_spi_xfer(adis, reg, len, value, 0);
}

static int adis16550_spi_write(struct adis *adis, const u32 reg,
			       const u32 value, const u32 len)
{
	return adis16550_spi_xfer(adis, reg, len, NULL, value);
}

static ssize_t adis16550_show_firmware_revision(struct file *file,
						char __user *userbuf,
						size_t count, loff_t *ppos)
{
	struct adis16550 *st = file->private_data;
	char buf[7];
	size_t len;
	u16 rev;
	int ret;

	ret = adis_read_reg_16(&st->adis, ADIS16550_REG_FW_REV, &rev);
	if (ret)
		return ret;

	len = scnprintf(buf, sizeof(buf), "%x.%x\n", rev >> 8, rev & 0xff);

	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}

static const struct file_operations adis16550_firmware_revision_fops = {
	.open = simple_open,
	.read = adis16550_show_firmware_revision,
	.llseek = default_llseek,
	.owner = THIS_MODULE,
};

static ssize_t adis16550_show_firmware_date(struct file *file,
					    char __user *userbuf,
					    size_t count, loff_t *ppos)
{
	struct adis16550 *st = file->private_data;
	char buf[12];
	size_t len;
	u32 date;
	int ret;

	ret = adis_read_reg_32(&st->adis, ADIS16550_REG_FW_DATE, &date);
	if (ret)
		return ret;

	len = scnprintf(buf, sizeof(buf), "%.2x-%.2x-%.4x\n", date & 0xff,
			(date >> 8) & 0xff, date >> 16);

	return simple_read_from_buffer(userbuf, count, ppos, buf, len);
}

static const struct file_operations adis16550_firmware_date_fops = {
	.open = simple_open,
	.read = adis16550_show_firmware_date,
	.llseek = default_llseek,
	.owner = THIS_MODULE,
};

static int adis16550_show_serial_number(void *arg, u64 *val)
{
	struct adis16550 *st = arg;
	u32 serial;
	int ret;

	ret = adis_read_reg_32(&st->adis, ADIS16550_REG_SERIAL_NUM, &serial);
	if (ret)
		return ret;

	*val = serial;

	return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(adis16550_serial_number_fops,
			 adis16550_show_serial_number, NULL, "0x%.8llx\n");

static int adis16550_show_product_id(void *arg, u64 *val)
{
	struct adis16550 *st = arg;
	u16 prod_id;
	int ret;

	ret = adis_read_reg_16(&st->adis, ADIS16550_REG_PROD_ID, &prod_id);
	if (ret)
		return ret;

	*val = prod_id;

	return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(adis16550_product_id_fops,
			 adis16550_show_product_id, NULL, "%llu\n");

static int adis16550_show_flash_count(void *arg, u64 *val)
{
	struct adis16550 *st = arg;
	u16 flash_count;
	int ret;

	ret = adis_read_reg_16(&st->adis, ADIS16550_REG_FLASH_CNT, &flash_count);
	if (ret)
		return ret;

	*val = flash_count;

	return 0;
}
DEFINE_DEBUGFS_ATTRIBUTE(adis16550_flash_count_fops,
			 adis16550_show_flash_count, NULL, "%lld\n");

static void adis16550_debugfs_init(struct iio_dev *indio_dev)
{
	struct adis16550 *st = iio_priv(indio_dev);
	struct dentry *d = iio_get_debugfs_dentry(indio_dev);

	debugfs_create_file_unsafe("serial_number", 0400, d, st,
				   &adis16550_serial_number_fops);
	debugfs_create_file_unsafe("product_id", 0400, d, st,
				   &adis16550_product_id_fops);
	debugfs_create_file("firmware_revision", 0400, d, st,
			    &adis16550_firmware_revision_fops);
	debugfs_create_file("firmware_date", 0400, d, st,
			    &adis16550_firmware_date_fops);
	debugfs_create_file_unsafe("flash_count", 0400, d, st,
				   &adis16550_flash_count_fops);
}

enum {
	ADIS16550_SYNC_MODE_DIRECT,
	ADIS16550_SYNC_MODE_SCALED,
};

static int adis16550_get_freq(struct adis16550 *st, u32 *freq)
{
	int ret;
	u16 dec = 0;
	u32 sample_rate = st->clk_freq_hz;

	adis_dev_auto_lock(&st->adis);

	if (st->sync_mode == ADIS16550_SYNC_MODE_SCALED) {
		u16 sync_scale;

		ret = __adis_read_reg_16(&st->adis, ADIS16550_REG_SYNC_SCALE, &sync_scale);
		if (ret)
			return ret;

		sample_rate = st->clk_freq_hz * sync_scale;
	}

	ret = __adis_read_reg_16(&st->adis, ADIS16550_REG_DEC_RATE, &dec);
	if (ret)
		return -EINVAL;
	*freq = DIV_ROUND_CLOSEST(sample_rate, dec + 1);

	return 0;
}

static int adis16550_set_freq_hz(struct adis16550 *st, u32 freq_hz)
{
	u16 dec;
	int ret;
	u32 sample_rate = st->clk_freq_hz;
	/*
	 * The optimal sample rate for the supported IMUs is between
	 * int_clk - 1000 and int_clk + 500.
	 */
	u32 max_sample_rate = st->info->int_clk * 1000 + 500000;
	u32 min_sample_rate = st->info->int_clk * 1000 - 1000000;

	if (!freq_hz)
		return -EINVAL;

	adis_dev_auto_lock(&st->adis);

	if (st->sync_mode == ADIS16550_SYNC_MODE_SCALED) {
		unsigned long scaled_rate = lcm(st->clk_freq_hz, freq_hz);
		int sync_scale;

		if (scaled_rate > max_sample_rate)
			scaled_rate = max_sample_rate / st->clk_freq_hz * st->clk_freq_hz;
		else
			scaled_rate = max_sample_rate / scaled_rate * scaled_rate;

		if (scaled_rate < min_sample_rate)
			scaled_rate = roundup(min_sample_rate, st->clk_freq_hz);

		sync_scale = scaled_rate / st->clk_freq_hz;
		ret = __adis_write_reg_16(&st->adis, ADIS16550_REG_SYNC_SCALE,
					  sync_scale);
		if (ret)
			return ret;

		sample_rate = scaled_rate;
	}

	dec = DIV_ROUND_CLOSEST(sample_rate, freq_hz);

	if (dec)
		dec--;

	dec = min(dec, st->info->max_dec);

	return __adis_write_reg_16(&st->adis, ADIS16550_REG_DEC_RATE, dec);
}

static int adis16550_get_accl_filter_freq(struct adis16550 *st, int *freq_hz)
{
	int ret;
	u16 config = 0;

	ret = adis_read_reg_16(&st->adis, ADIS16550_REG_CONFIG, &config);
	if (ret)
		return -EINVAL;

	if (FIELD_GET(ADIS16550_ACCL_FIR_EN_MASK, config))
		*freq_hz = 100;
	else
		*freq_hz = 0;

	return 0;
}

static int adis16550_set_accl_filter_freq(struct adis16550 *st, int freq_hz)
{
	u8 en = freq_hz ? 1 : 0;
	u16 val = FIELD_PREP(ADIS16550_ACCL_FIR_EN_MASK, en);

	return __adis_update_bits(&st->adis, ADIS16550_REG_CONFIG,
				  ADIS16550_ACCL_FIR_EN_MASK, val);
}

static int adis16550_get_gyro_filter_freq(struct adis16550 *st, int *freq_hz)
{
	int ret;
	u16 config = 0;

	ret = adis_read_reg_16(&st->adis, ADIS16550_REG_CONFIG, &config);
	if (ret)
		return -EINVAL;

	if (FIELD_GET(ADIS16550_GYRO_FIR_EN_MASK, config))
		*freq_hz = 100;
	else
		*freq_hz = 0;

	return 0;
}

static int adis16550_set_gyro_filter_freq(struct adis16550 *st, int freq_hz)
{
	u8 en = freq_hz ? 1 : 0;
	u16 val = FIELD_PREP(ADIS16550_GYRO_FIR_EN_MASK, en);

	return __adis_update_bits(&st->adis, ADIS16550_REG_CONFIG,
				  ADIS16550_GYRO_FIR_EN_MASK, val);
}

enum {
	ADIS16550_SCAN_TEMP,
	ADIS16550_SCAN_GYRO_X,
	ADIS16550_SCAN_GYRO_Y,
	ADIS16550_SCAN_GYRO_Z,
	ADIS16550_SCAN_ACCEL_X,
	ADIS16550_SCAN_ACCEL_Y,
	ADIS16550_SCAN_ACCEL_Z,
	ADIS16550_SCAN_DELTANG_X,
	ADIS16550_SCAN_DELTANG_Y,
	ADIS16550_SCAN_DELTANG_Z,
	ADIS16550_SCAN_DELTVEL_X,
	ADIS16550_SCAN_DELTVEL_Y,
	ADIS16550_SCAN_DELTVEL_Z,
};

static const u32 adis16550_calib_bias[] = {
	[ADIS16550_SCAN_GYRO_X] = ADIS16550_REG_X_GYRO_BIAS,
	[ADIS16550_SCAN_GYRO_Y] = ADIS16550_REG_Y_GYRO_BIAS,
	[ADIS16550_SCAN_GYRO_Z] = ADIS16550_REG_Z_GYRO_BIAS,
	[ADIS16550_SCAN_ACCEL_X] = ADIS16550_REG_X_ACCEL_BIAS,
	[ADIS16550_SCAN_ACCEL_Y] = ADIS16550_REG_Y_ACCEL_BIAS,
	[ADIS16550_SCAN_ACCEL_Z] = ADIS16550_REG_Z_ACCEL_BIAS,

};

static const u32 adis16550_calib_scale[] = {
	[ADIS16550_SCAN_GYRO_X] = ADIS16550_REG_X_GYRO_SCALE,
	[ADIS16550_SCAN_GYRO_Y] = ADIS16550_REG_Y_GYRO_SCALE,
	[ADIS16550_SCAN_GYRO_Z] = ADIS16550_REG_Z_GYRO_SCALE,
	[ADIS16550_SCAN_ACCEL_X] = ADIS16550_REG_X_ACCEL_SCALE,
	[ADIS16550_SCAN_ACCEL_Y] = ADIS16550_REG_Y_ACCEL_SCALE,
	[ADIS16550_SCAN_ACCEL_Z] = ADIS16550_REG_Z_ACCEL_SCALE,
};

static int adis16550_read_raw(struct iio_dev *indio_dev,
			      const struct iio_chan_spec *chan,
			      int *val, int *val2, long info)
{
	struct adis16550 *st = iio_priv(indio_dev);
	const int idx = chan->scan_index;
	u16 scale;
	int ret;
	u32 tmp;

	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->info->gyro_max_val;
			*val2 = st->info->gyro_max_scale;
			return IIO_VAL_FRACTIONAL;
		case IIO_ACCEL:
			*val = st->info->accel_max_val;
			*val2 = st->info->accel_max_scale;
			return IIO_VAL_FRACTIONAL;
		case IIO_TEMP:
			*val = st->info->temp_scale;
			return IIO_VAL_INT;
		case IIO_DELTA_ANGL:
			*val = st->info->deltang_max_val;
			*val2 = 31;
			return IIO_VAL_FRACTIONAL_LOG2;
		case IIO_DELTA_VELOCITY:
			*val = st->info->deltvel_max_val;
			*val2 = 31;
			return IIO_VAL_FRACTIONAL_LOG2;
		default:
			return -EINVAL;
		}
	case IIO_CHAN_INFO_OFFSET:
		/* temperature centered at 25°C */
		*val = DIV_ROUND_CLOSEST(25000, st->info->temp_scale);
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_CALIBBIAS:
		ret = adis_read_reg_32(&st->adis,
				       adis16550_calib_bias[idx], val);
		if (ret)
			return ret;

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_CALIBSCALE:
		ret = adis_read_reg_16(&st->adis,
				       adis16550_calib_scale[idx], &scale);
		if (ret)
			return ret;

		*val = scale;
		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SAMP_FREQ:
		ret = adis16550_get_freq(st, &tmp);
		if (ret)
			return ret;

		*val = tmp / 1000;
		*val2 = (tmp % 1000) * 1000;
		return IIO_VAL_INT_PLUS_MICRO;
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		switch (chan->type) {
		case IIO_ANGL_VEL:
			ret = adis16550_get_gyro_filter_freq(st, val);
			if (ret)
				return ret;
			return IIO_VAL_INT;
		case IIO_ACCEL:
			ret = adis16550_get_accl_filter_freq(st, val);
			if (ret)
				return ret;
			return IIO_VAL_INT;
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

static int adis16550_write_raw(struct iio_dev *indio_dev,
			       const struct iio_chan_spec *chan,
			       int val, int val2, long info)
{
	struct adis16550 *st = iio_priv(indio_dev);
	const int idx = chan->scan_index;
	u32 tmp;

	switch (info) {
	case IIO_CHAN_INFO_SAMP_FREQ:
		tmp = val * 1000 + val2 / 1000;
		return adis16550_set_freq_hz(st, tmp);
	case IIO_CHAN_INFO_CALIBBIAS:
		return adis_write_reg_32(&st->adis, adis16550_calib_bias[idx],
					 val);
	case IIO_CHAN_INFO_CALIBSCALE:
		return adis_write_reg_16(&st->adis, adis16550_calib_scale[idx],
					 val);
	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
		switch (chan->type) {
		case IIO_ANGL_VEL:
			return adis16550_set_gyro_filter_freq(st, val);
		case IIO_ACCEL:
			return adis16550_set_accl_filter_freq(st, val);
		default:
			return -EINVAL;
		}
	default:
		return -EINVAL;
	}
}

#define ADIS16550_MOD_CHAN(_type, _mod, _address, _si) \
	{ \
		.type = (_type), \
		.modified = 1, \
		.channel2 = (_mod), \
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
			BIT(IIO_CHAN_INFO_CALIBBIAS) | \
			BIT(IIO_CHAN_INFO_CALIBSCALE), \
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
					    BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY), \
		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
		.address = (_address), \
		.scan_index = (_si), \
		.scan_type = { \
			.sign = 's', \
			.realbits = 32, \
			.storagebits = 32, \
			.endianness = IIO_BE, \
		}, \
	}

#define ADIS16550_GYRO_CHANNEL(_mod) \
	ADIS16550_MOD_CHAN(IIO_ANGL_VEL, IIO_MOD_ ## _mod, \
	ADIS16550_REG_ ## _mod ## _GYRO, ADIS16550_SCAN_GYRO_ ## _mod)

#define ADIS16550_ACCEL_CHANNEL(_mod) \
	ADIS16550_MOD_CHAN(IIO_ACCEL, IIO_MOD_ ## _mod, \
	ADIS16550_REG_ ## _mod ## _ACCEL, ADIS16550_SCAN_ACCEL_ ## _mod)

#define ADIS16550_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 = ADIS16550_REG_TEMP, \
		.scan_index = ADIS16550_SCAN_TEMP, \
		.scan_type = { \
			.sign = 's', \
			.realbits = 16, \
			.storagebits = 32, \
			.endianness = IIO_BE, \
		}, \
	}

#define ADIS16550_MOD_CHAN_DELTA(_type, _mod, _address, _si) { \
		.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 = 32, \
			.storagebits = 32, \
			.endianness = IIO_BE, \
		}, \
	}

#define ADIS16550_DELTANG_CHAN(_mod) \
	ADIS16550_MOD_CHAN_DELTA(IIO_DELTA_ANGL, IIO_MOD_ ## _mod, \
			   ADIS16550_REG_ ## _mod ## _DELTANG_L, ADIS16550_SCAN_DELTANG_ ## _mod)

#define ADIS16550_DELTVEL_CHAN(_mod) \
	ADIS16550_MOD_CHAN_DELTA(IIO_DELTA_VELOCITY, IIO_MOD_ ## _mod, \
			   ADIS16550_REG_ ## _mod ## _DELTVEL_L, ADIS16550_SCAN_DELTVEL_ ## _mod)

#define ADIS16550_DELTANG_CHAN_NO_SCAN(_mod) \
	ADIS16550_MOD_CHAN_DELTA(IIO_DELTA_ANGL, IIO_MOD_ ## _mod, \
			   ADIS16550_REG_ ## _mod ## _DELTANG_L, -1)

#define ADIS16550_DELTVEL_CHAN_NO_SCAN(_mod) \
	ADIS16550_MOD_CHAN_DELTA(IIO_DELTA_VELOCITY, IIO_MOD_ ## _mod, \
			   ADIS16550_REG_ ## _mod ## _DELTVEL_L, -1)

static const struct iio_chan_spec adis16550_channels[] = {
	ADIS16550_TEMP_CHANNEL(),
	ADIS16550_GYRO_CHANNEL(X),
	ADIS16550_GYRO_CHANNEL(Y),
	ADIS16550_GYRO_CHANNEL(Z),
	ADIS16550_ACCEL_CHANNEL(X),
	ADIS16550_ACCEL_CHANNEL(Y),
	ADIS16550_ACCEL_CHANNEL(Z),
	ADIS16550_DELTANG_CHAN(X),
	ADIS16550_DELTANG_CHAN(Y),
	ADIS16550_DELTANG_CHAN(Z),
	ADIS16550_DELTVEL_CHAN(X),
	ADIS16550_DELTVEL_CHAN(Y),
	ADIS16550_DELTVEL_CHAN(Z),
	IIO_CHAN_SOFT_TIMESTAMP(13),
};

static const struct adis16550_sync adis16550_sync_modes[] = {
	{ ADIS16550_SYNC_MODE_DIRECT, 3000, 4500 },
	{ ADIS16550_SYNC_MODE_SCALED, 1, 128 },
};

static const struct adis16550_chip_info adis16550_chip_info = {
	.num_channels = ARRAY_SIZE(adis16550_channels),
	.channels = adis16550_channels,
	.name = "adis16550",
	.gyro_max_val = 1,
	.gyro_max_scale = IIO_RAD_TO_DEGREE(80 << 16),
	.accel_max_val = 1,
	.accel_max_scale = IIO_M_S_2_TO_G(102400000),
	.temp_scale = 4,
	.deltang_max_val = IIO_DEGREE_TO_RAD(720),
	.deltvel_max_val = 125,
	.int_clk = 4000,
	.max_dec = 4095,
	.sync_mode = adis16550_sync_modes,
	.num_sync = ARRAY_SIZE(adis16550_sync_modes),
};

static u32 adis16550_validate_crc(__be32 *buffer, const u8 n_elem)
{
	int i;
	u32 crc_calc;
	u32 crc_buf[ADIS16550_BURST_N_ELEM - 2];
	u32 crc = be32_to_cpu(buffer[ADIS16550_BURST_N_ELEM - 1]);
	/*
	 * The crc calculation of the data is done in little endian. Hence, we
	 * always swap the 32bit elements making sure that the data LSB is
	 * always on address 0...
	 */
	for (i = 0; i < n_elem; i++)
		crc_buf[i] = be32_to_cpu(buffer[i]);

	crc_calc = crc32(~0, crc_buf, n_elem * 4);
	crc_calc ^= ~0;

	return (crc_calc == crc);
}

static irqreturn_t adis16550_trigger_handler(int irq, void *p)
{
	int ret;
	u16 dummy;
	bool valid;
	struct iio_poll_func *pf = p;
	__be32 data[ADIS16550_MAX_SCAN_DATA] __aligned(8);
	struct iio_dev *indio_dev = pf->indio_dev;
	struct adis16550 *st = iio_priv(indio_dev);
	struct adis *adis = iio_device_get_drvdata(indio_dev);
	__be32 *buffer = (__be32 *)st->buffer;

	ret = spi_sync(adis->spi, &adis->msg);
	if (ret)
		goto done;
	/*
	 * Validate the header. The header is a normal spi reply with state
	 * vector and crc4.
	 */
	ret = adis16550_spi_validate(&st->adis, buffer[0], &dummy);
	if (ret)
		goto done;

	/* the header is not included in the crc */
	valid = adis16550_validate_crc(buffer, ADIS16550_BURST_N_ELEM - 2);
	if (!valid) {
		dev_err(&adis->spi->dev, "Burst Invalid crc!\n");
		goto done;
	}

	/* copy the temperature together with sensor data */
	memcpy(data, &buffer[3],
	       (ADIS16550_SCAN_ACCEL_Z - ADIS16550_SCAN_GYRO_X + 2) *
	       sizeof(__be32));
	iio_push_to_buffers_with_timestamp(indio_dev, data, pf->timestamp);
done:
	iio_trigger_notify_done(indio_dev->trig);
	return IRQ_HANDLED;
}

static const unsigned long adis16550_channel_masks[] = {
	ADIS16550_BURST_DATA_GYRO_ACCEL_MASK | BIT(ADIS16550_SCAN_TEMP),
	ADIS16550_BURST_DATA_DELTA_ANG_VEL_MASK | BIT(ADIS16550_SCAN_TEMP),
	0
};

static int adis16550_update_scan_mode(struct iio_dev *indio_dev,
				      const unsigned long *scan_mask)
{
	u16 burst_length = ADIS16550_BURST_DATA_LEN;
	struct adis16550 *st = iio_priv(indio_dev);
	u8 burst_cmd;
	u8 *tx;

	memset(st->buffer, 0, burst_length + sizeof(u32));

	if (*scan_mask & ADIS16550_BURST_DATA_GYRO_ACCEL_MASK)
		burst_cmd = ADIS16550_REG_BURST_GYRO_ACCEL;
	else
		burst_cmd = ADIS16550_REG_BURST_DELTA_ANG_VEL;

	tx = st->buffer + burst_length;
	tx[0] = 0x00;
	tx[1] = 0x00;
	tx[2] = burst_cmd;
	/* crc4 is 0 on burst command */
	tx[3] = spi_crc4(get_unaligned_le32(tx));

	return 0;
}

static int adis16550_reset(struct adis *adis)
{
	return __adis_write_reg_16(adis, ADIS16550_REG_COMMAND, BIT(15));
}

static int adis16550_config_sync(struct adis16550 *st)
{
	struct device *dev = &st->adis.spi->dev;
	const struct adis16550_sync *sync_mode_data;
	struct clk *clk;
	int ret, i;
	u16 mode;

	clk = devm_clk_get_optional_enabled(dev, NULL);
	if (IS_ERR(clk))
		return PTR_ERR(clk);
	if (!clk) {
		st->clk_freq_hz = st->info->int_clk * 1000;
		return 0;
	}

	st->clk_freq_hz = clk_get_rate(clk);

	for (i = 0; i < st->info->num_sync; i++) {
		if (st->clk_freq_hz >= st->info->sync_mode[i].min_rate &&
		    st->clk_freq_hz <= st->info->sync_mode[i].max_rate) {
			sync_mode_data = &st->info->sync_mode[i];
			break;
		}
	}

	if (i == st->info->num_sync)
		return dev_err_probe(dev, -EINVAL, "Clk rate: %lu not in a valid range",
				     st->clk_freq_hz);

	if (sync_mode_data->sync_mode == ADIS16550_SYNC_MODE_SCALED) {
		u16 sync_scale;
		/*
		 * In sps scaled sync we must scale the input clock to a range
		 * of [3000 4500].
		 */

		sync_scale = DIV_ROUND_CLOSEST(st->info->int_clk, st->clk_freq_hz);

		if (3000 > sync_scale || 4500 < sync_scale)
			return dev_err_probe(dev, -EINVAL,
					     "Invalid value:%u for sync_scale",
					     sync_scale);

		ret = adis_write_reg_16(&st->adis, ADIS16550_REG_SYNC_SCALE,
					sync_scale);
		if (ret)
			return ret;

		st->clk_freq_hz = st->info->int_clk;
	}

	st->clk_freq_hz *= 1000;

	mode = FIELD_PREP(ADIS16550_SYNC_MODE_MASK, sync_mode_data->sync_mode) |
	       FIELD_PREP(ADIS16550_SYNC_EN_MASK, true);

	return __adis_update_bits(&st->adis, ADIS16550_REG_CONFIG,
				  ADIS16550_SYNC_MASK, mode);
}

static const struct iio_info adis16550_info = {
	.read_raw = &adis16550_read_raw,
	.write_raw = &adis16550_write_raw,
	.update_scan_mode = adis16550_update_scan_mode,
	.debugfs_reg_access = adis_debugfs_reg_access,
};

enum {
	ADIS16550_STATUS_CRC_CODE,
	ADIS16550_STATUS_CRC_CONFIG,
	ADIS16550_STATUS_FLASH_UPDATE,
	ADIS16550_STATUS_INERIAL,
	ADIS16550_STATUS_SENSOR,
	ADIS16550_STATUS_TEMPERATURE,
	ADIS16550_STATUS_SPI,
	ADIS16550_STATUS_PROCESSING,
	ADIS16550_STATUS_POWER,
	ADIS16550_STATUS_BOOT,
	ADIS16550_STATUS_WATCHDOG = 15,
	ADIS16550_STATUS_REGULATOR = 28,
	ADIS16550_STATUS_SENSOR_SUPPLY,
	ADIS16550_STATUS_CPU_SUPPLY,
	ADIS16550_STATUS_5V_SUPPLY,
};

static const char * const adis16550_status_error_msgs[] = {
	[ADIS16550_STATUS_CRC_CODE] = "Code CRC Error",
	[ADIS16550_STATUS_CRC_CONFIG] = "Configuration/Calibration CRC Error",
	[ADIS16550_STATUS_FLASH_UPDATE] = "Flash Update Error",
	[ADIS16550_STATUS_INERIAL] = "Overrange for Inertial Signals",
	[ADIS16550_STATUS_SENSOR] = "Sensor failure",
	[ADIS16550_STATUS_TEMPERATURE] = "Temperature Error",
	[ADIS16550_STATUS_SPI] = "SPI Communication Error",
	[ADIS16550_STATUS_PROCESSING] = "Processing Overrun Error",
	[ADIS16550_STATUS_POWER] = "Power Supply Failure",
	[ADIS16550_STATUS_BOOT] = "Boot Memory Failure",
	[ADIS16550_STATUS_WATCHDOG] = "Watchdog timer flag",
	[ADIS16550_STATUS_REGULATOR] = "Internal Regulator Error",
	[ADIS16550_STATUS_SENSOR_SUPPLY] = "Internal Sensor Supply Error.",
	[ADIS16550_STATUS_CPU_SUPPLY] = "Internal Processor Supply Error.",
	[ADIS16550_STATUS_5V_SUPPLY] = "External 5V Supply Error",
};

static const struct adis_timeout adis16550_timeouts = {
	.reset_ms = 1000,
	.sw_reset_ms = 1000,
	.self_test_ms = 1000,
};

static const struct adis_data adis16550_data = {
	.diag_stat_reg = ADIS16550_REG_STATUS,
	.diag_stat_size = 4,
	.prod_id_reg = ADIS16550_REG_PROD_ID,
	.prod_id = 16550,
	.self_test_mask = BIT(1),
	.self_test_reg = ADIS16550_REG_COMMAND,
	.cs_change_delay = 5,
	.unmasked_drdy = true,
	.status_error_msgs = adis16550_status_error_msgs,
	.status_error_mask = BIT(ADIS16550_STATUS_CRC_CODE) |
			BIT(ADIS16550_STATUS_CRC_CONFIG) |
			BIT(ADIS16550_STATUS_FLASH_UPDATE) |
			BIT(ADIS16550_STATUS_INERIAL) |
			BIT(ADIS16550_STATUS_SENSOR) |
			BIT(ADIS16550_STATUS_TEMPERATURE) |
			BIT(ADIS16550_STATUS_SPI) |
			BIT(ADIS16550_STATUS_PROCESSING) |
			BIT(ADIS16550_STATUS_POWER) |
			BIT(ADIS16550_STATUS_BOOT) |
			BIT(ADIS16550_STATUS_WATCHDOG) |
			BIT(ADIS16550_STATUS_REGULATOR) |
			BIT(ADIS16550_STATUS_SENSOR_SUPPLY) |
			BIT(ADIS16550_STATUS_CPU_SUPPLY) |
			BIT(ADIS16550_STATUS_5V_SUPPLY),
	.timeouts = &adis16550_timeouts,
};

static const struct adis_ops adis16550_ops = {
	.write = adis16550_spi_write,
	.read = adis16550_spi_read,
	.reset = adis16550_reset,
};

static int adis16550_probe(struct spi_device *spi)
{
	u16 burst_length = ADIS16550_BURST_DATA_LEN;
	struct device *dev = &spi->dev;
	struct iio_dev *indio_dev;
	struct adis16550 *st;
	struct adis *adis;
	int ret;

	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
	if (!indio_dev)
		return -ENOMEM;

	st = iio_priv(indio_dev);
	st->info = spi_get_device_match_data(spi);
	if (!st->info)
		return -EINVAL;
	adis = &st->adis;
	indio_dev->name = st->info->name;
	indio_dev->channels = st->info->channels;
	indio_dev->num_channels = st->info->num_channels;
	indio_dev->available_scan_masks = adis16550_channel_masks;
	indio_dev->info = &adis16550_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	st->adis.ops = &adis16550_ops;
	st->xfer[0].tx_buf = st->buffer + burst_length;
	st->xfer[0].len = 4;
	st->xfer[0].cs_change = 1;
	st->xfer[0].delay.value = 8;
	st->xfer[0].delay.unit = SPI_DELAY_UNIT_USECS;
	st->xfer[1].rx_buf = st->buffer;
	st->xfer[1].len = burst_length;

	spi_message_init_with_transfers(&adis->msg, st->xfer, 2);

	ret = devm_regulator_get_enable(dev, "vdd");
	if (ret)
		return dev_err_probe(dev, ret, "Failed to get vdd regulator\n");

	ret = adis_init(&st->adis, indio_dev, spi, &adis16550_data);
	if (ret)
		return ret;

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

	ret = adis16550_config_sync(st);
	if (ret)
		return ret;

	ret = devm_adis_setup_buffer_and_trigger(&st->adis, indio_dev,
						 adis16550_trigger_handler);
	if (ret)
		return ret;

	ret = devm_iio_device_register(dev, indio_dev);
	if (ret)
		return ret;

	adis16550_debugfs_init(indio_dev);

	return 0;
}

static const struct spi_device_id adis16550_id[] = {
	{ "adis16550",  (kernel_ulong_t)&adis16550_chip_info},
	{ }
};
MODULE_DEVICE_TABLE(spi, adis16550_id);

static const struct of_device_id adis16550_of_match[] = {
	{ .compatible = "adi,adis16550", .data = &adis16550_chip_info },
	{ }
};
MODULE_DEVICE_TABLE(of, adis16550_of_match);

static struct spi_driver adis16550_driver = {
	.driver = {
		.name = "adis16550",
		.of_match_table = adis16550_of_match,
	},
	.probe = adis16550_probe,
	.id_table = adis16550_id,
};
module_spi_driver(adis16550_driver);

MODULE_AUTHOR("Nuno Sa <nuno.sa@analog.com>");
MODULE_AUTHOR("Ramona Gradinariu <ramona.gradinariu@analog.com>");
MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
MODULE_AUTHOR("Robert Budai <robert.budai@analog.com>");
MODULE_DESCRIPTION("Analog Devices ADIS16550 IMU driver");
MODULE_IMPORT_NS("IIO_ADISLIB");
MODULE_LICENSE("GPL");