// SPDX-License-Identifier: GPL-2.0
/*
 * Parade TrueTouch(TM) Standard Product V5 Module.
 *
 * Copyright (C) 2015 Parade Technologies
 * Copyright (C) 2012-2015 Cypress Semiconductor
 * Copyright (C) 2018 Bootlin
 *
 * Authors: Mylène Josserand <mylene.josserand@bootlin.com>
 *                Alistair Francis <alistair@alistair23.me>
 */

#include <linux/crc-itu-t.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio/consumer.h>
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/interrupt.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/unaligned.h>

#define CYTTSP5_NAME				"cyttsp5"
#define CY_I2C_DATA_SIZE			(2 * 256)
#define HID_VERSION				0x0100
#define CY_MAX_INPUT				512
#define CYTTSP5_PREALLOCATED_CMD_BUFFER		32
#define CY_BITS_PER_BTN				1
#define CY_NUM_BTN_EVENT_ID			GENMASK(CY_BITS_PER_BTN - 1, 0)

#define MAX_AREA				255
#define HID_OUTPUT_BL_SOP			0x1
#define HID_OUTPUT_BL_EOP			0x17
#define HID_OUTPUT_BL_LAUNCH_APP		0x3B
#define HID_OUTPUT_BL_LAUNCH_APP_SIZE		11
#define HID_OUTPUT_GET_SYSINFO			0x2
#define HID_OUTPUT_GET_SYSINFO_SIZE		5
#define HID_OUTPUT_MAX_CMD_SIZE			12

#define HID_DESC_REG				0x1
#define HID_INPUT_REG				0x3
#define HID_OUTPUT_REG				0x4
#define HID_COMMAND_REG				0x5

#define REPORT_ID_TOUCH				0x1
#define REPORT_ID_BTN				0x3
#define REPORT_SIZE_5				5
#define REPORT_SIZE_8				8
#define REPORT_SIZE_16				16

/* Touch reports offsets */
/* Header offsets */
#define TOUCH_REPORT_DESC_HDR_CONTACTCOUNT	16
/* Record offsets */
#define TOUCH_REPORT_DESC_CONTACTID		8
#define TOUCH_REPORT_DESC_X			16
#define TOUCH_REPORT_DESC_Y			32
#define TOUCH_REPORT_DESC_P			48
#define TOUCH_REPORT_DESC_MAJ			56
#define TOUCH_REPORT_DESC_MIN			64

/* HID */
#define HID_TOUCH_REPORT_ID			0x1
#define HID_BTN_REPORT_ID			0x3
#define HID_APP_RESPONSE_REPORT_ID		0x1F
#define HID_APP_OUTPUT_REPORT_ID		0x2F
#define HID_BL_RESPONSE_REPORT_ID		0x30
#define HID_BL_OUTPUT_REPORT_ID			0x40
#define HID_RESPONSE_REPORT_ID			0xF0

#define HID_OUTPUT_RESPONSE_REPORT_OFFSET	2
#define HID_OUTPUT_RESPONSE_CMD_OFFSET		4
#define HID_OUTPUT_RESPONSE_CMD_MASK		GENMASK(6, 0)

#define HID_SYSINFO_SENSING_OFFSET		33
#define HID_SYSINFO_BTN_OFFSET			48
#define HID_SYSINFO_BTN_MASK			GENMASK(7, 0)
#define HID_SYSINFO_MAX_BTN			8

#define HID_CMD_SET_POWER			0x8

#define HID_POWER_ON				0x0
#define HID_POWER_SLEEP				0x1

#define CY_HID_OUTPUT_TIMEOUT_MS		200
#define CY_HID_OUTPUT_GET_SYSINFO_TIMEOUT_MS	3000
#define CY_HID_GET_HID_DESCRIPTOR_TIMEOUT_MS	4000
#define CY_HID_SET_POWER_TIMEOUT		500

/* maximum number of concurrent tracks */
#define TOUCH_REPORT_SIZE			10
#define TOUCH_INPUT_HEADER_SIZE			7
#define BTN_REPORT_SIZE				9
#define BTN_INPUT_HEADER_SIZE			5

#define MAX_CY_TCH_T_IDS			32

/* All usage pages for Touch Report */
#define TOUCH_REPORT_USAGE_PG_X			0x00010030
#define TOUCH_REPORT_USAGE_PG_Y			0x00010031
#define TOUCH_REPORT_USAGE_PG_P			0x000D0030
#define TOUCH_REPORT_USAGE_PG_CONTACTID		0x000D0051
#define TOUCH_REPORT_USAGE_PG_CONTACTCOUNT	0x000D0054
#define TOUCH_REPORT_USAGE_PG_MAJ		0xFF010062
#define TOUCH_REPORT_USAGE_PG_MIN		0xFF010063
#define TOUCH_COL_USAGE_PG			0x000D0022

#define SET_CMD_LOW(byte, bits) \
	((byte) = (((byte) & 0xF0) | ((bits) & 0x0F)))
#define SET_CMD_HIGH(byte, bits)\
	((byte) = (((byte) & 0x0F) | ((bits) & 0xF0)))
#define SET_CMD_OPCODE(byte, opcode) SET_CMD_LOW(byte, opcode)
#define SET_CMD_REPORT_TYPE(byte, type) SET_CMD_HIGH(byte, ((type) << 4))
#define SET_CMD_REPORT_ID(byte, id) SET_CMD_LOW(byte, id)

/* System Information interface definitions */
struct cyttsp5_sensing_conf_data_dev {
	u8 electrodes_x;
	u8 electrodes_y;
	__le16 len_x;
	__le16 len_y;
	__le16 res_x;
	__le16 res_y;
	__le16 max_z;
	u8 origin_x;
	u8 origin_y;
	u8 panel_id;
	u8 btn;
	u8 scan_mode;
	u8 max_num_of_tch_per_refresh_cycle;
} __packed;

struct cyttsp5_sensing_conf_data {
	u16 res_x;
	u16 res_y;
	u16 max_z;
	u16 len_x;
	u16 len_y;
	u8 origin_x;
	u8 origin_y;
	u8 max_tch;
};

enum cyttsp5_tch_abs {	/* for ordering within the extracted touch data array */
	CY_TCH_X,	/* X */
	CY_TCH_Y,	/* Y */
	CY_TCH_P,	/* P (Z) */
	CY_TCH_T,	/* TOUCH ID */
	CY_TCH_MAJ,	/* TOUCH_MAJOR */
	CY_TCH_MIN,	/* TOUCH_MINOR */
	CY_TCH_NUM_ABS
};

struct cyttsp5_tch_abs_params {
	size_t ofs;	/* abs byte offset */
	size_t size;	/* size in bits */
	size_t min;	/* min value */
	size_t max;	/* max value */
	size_t bofs;	/* bit offset */
};

struct cyttsp5_touch {
	int abs[CY_TCH_NUM_ABS];
};

struct cyttsp5_sysinfo {
	struct cyttsp5_sensing_conf_data sensing_conf_data;
	int num_btns;
	struct cyttsp5_tch_abs_params tch_hdr;
	struct cyttsp5_tch_abs_params tch_abs[CY_TCH_NUM_ABS];
	u32 key_code[HID_SYSINFO_MAX_BTN];
};

struct cyttsp5_hid_desc {
	__le16 hid_desc_len;
	u8 packet_id;
	u8 reserved_byte;
	__le16 bcd_version;
	__le16 report_desc_len;
	__le16 report_desc_register;
	__le16 input_register;
	__le16 max_input_len;
	__le16 output_register;
	__le16 max_output_len;
	__le16 command_register;
	__le16 data_register;
	__le16 vendor_id;
	__le16 product_id;
	__le16 version_id;
	u8 reserved[4];
} __packed;

struct cyttsp5 {
	struct device *dev;
	struct completion cmd_done;
	struct cyttsp5_sysinfo sysinfo;
	struct cyttsp5_hid_desc hid_desc;
	u8 cmd_buf[CYTTSP5_PREALLOCATED_CMD_BUFFER];
	u8 input_buf[CY_MAX_INPUT];
	u8 response_buf[CY_MAX_INPUT];
	struct gpio_desc *reset_gpio;
	struct input_dev *input;
	char phys[NAME_MAX];
	int num_prv_rec;
	struct regmap *regmap;
	struct touchscreen_properties prop;
	struct regulator_bulk_data supplies[2];
};

/*
 * For what is understood in the datasheet, the register does not
 * matter. For consistency, use the Input Register address
 * but it does mean anything to the device. The important data
 * to send is the I2C address
 */
static int cyttsp5_read(struct cyttsp5 *ts, u8 *buf, u32 max)
{
	int error;
	u32 size;
	u8 temp[2];

	/* Read the frame to retrieve the size */
	error = regmap_bulk_read(ts->regmap, HID_INPUT_REG, temp, sizeof(temp));
	if (error)
		return error;

	size = get_unaligned_le16(temp);
	if (!size || size == 2)
		return 0;

	if (size > max)
		return -EINVAL;

	/* Get the real value */
	return regmap_bulk_read(ts->regmap, HID_INPUT_REG, buf, size);
}

static int cyttsp5_write(struct cyttsp5 *ts, unsigned int reg, u8 *data,
			 size_t size)
{
	u8 cmd[HID_OUTPUT_MAX_CMD_SIZE];

	if (size + 1 > HID_OUTPUT_MAX_CMD_SIZE)
		return -E2BIG;

	/* High bytes of register address needed as first byte of cmd */
	cmd[0] = (reg >> 8) & 0xFF;

	/* Copy the rest of the data */
	if (data)
		memcpy(&cmd[1], data, size);

	/*
	 * The hardware wants to receive a frame with the address register
	 * contained in the first two bytes. As the regmap_write function
	 * add the register adresse in the frame, we use the low byte as
	 * first frame byte for the address register and the first
	 * data byte is the high register + left of the cmd to send
	 */
	return regmap_bulk_write(ts->regmap, reg & 0xFF, cmd, size + 1);
}

static void cyttsp5_get_touch_axis(int *axis, int size, int max, u8 *xy_data,
				   int bofs)
{
	int nbyte;

	for (nbyte = 0, *axis = 0; nbyte < size; nbyte++)
		*axis += ((xy_data[nbyte] >> bofs) << (nbyte * 8));

	*axis &= max - 1;
}

static void cyttsp5_get_touch_record(struct cyttsp5 *ts,
				     struct cyttsp5_touch *touch, u8 *xy_data)
{
	struct cyttsp5_sysinfo *si = &ts->sysinfo;
	enum cyttsp5_tch_abs abs;

	for (abs = CY_TCH_X; abs < CY_TCH_NUM_ABS; abs++)
		cyttsp5_get_touch_axis(&touch->abs[abs],
				       si->tch_abs[abs].size,
				       si->tch_abs[abs].max,
				       xy_data + si->tch_abs[abs].ofs,
				       si->tch_abs[abs].bofs);
}

static void cyttsp5_get_mt_touches(struct cyttsp5 *ts,
				   struct cyttsp5_touch *tch, int num_cur_tch)
{
	struct cyttsp5_sysinfo *si = &ts->sysinfo;
	int i, t = 0, offset = 0;
	DECLARE_BITMAP(ids, MAX_CY_TCH_T_IDS);
	u8 *tch_addr;
	int tmp;

	bitmap_zero(ids, MAX_CY_TCH_T_IDS);
	memset(tch->abs, 0, sizeof(tch->abs));

	switch (ts->input_buf[2]) {
	case HID_TOUCH_REPORT_ID:
		offset = TOUCH_INPUT_HEADER_SIZE;
		break;
	case HID_BTN_REPORT_ID:
		offset = BTN_INPUT_HEADER_SIZE;
		break;
	}

	for (i = 0; i < num_cur_tch; i++) {
		tch_addr = ts->input_buf + offset + (i * TOUCH_REPORT_SIZE);
		cyttsp5_get_touch_record(ts, tch, tch_addr);

		/* Convert MAJOR/MINOR from mm to resolution */
		tmp = tch->abs[CY_TCH_MAJ] * 100 * si->sensing_conf_data.res_x;
		tch->abs[CY_TCH_MAJ] = tmp / si->sensing_conf_data.len_x;
		tmp = tch->abs[CY_TCH_MIN] * 100 * si->sensing_conf_data.res_x;
		tch->abs[CY_TCH_MIN] = tmp / si->sensing_conf_data.len_x;

		t = tch->abs[CY_TCH_T];
		input_mt_slot(ts->input, t);
		input_mt_report_slot_state(ts->input, MT_TOOL_FINGER, true);
		__set_bit(t, ids);

		/* position and pressure fields */
		touchscreen_report_pos(ts->input, &ts->prop,
				       tch->abs[CY_TCH_X], tch->abs[CY_TCH_Y],
				       true);
		input_report_abs(ts->input, ABS_MT_PRESSURE,
				 tch->abs[CY_TCH_P]);

		/* Get the extended touch fields */
		input_report_abs(ts->input, ABS_MT_TOUCH_MAJOR,
				 tch->abs[CY_TCH_MAJ]);
		input_report_abs(ts->input, ABS_MT_TOUCH_MINOR,
				 tch->abs[CY_TCH_MIN]);
	}

	ts->num_prv_rec = num_cur_tch;
}

static int cyttsp5_mt_attention(struct device *dev)
{
	struct cyttsp5 *ts = dev_get_drvdata(dev);
	struct cyttsp5_sysinfo *si = &ts->sysinfo;
	int max_tch = si->sensing_conf_data.max_tch;
	struct cyttsp5_touch tch;
	int num_cur_tch;

	cyttsp5_get_touch_axis(&num_cur_tch, si->tch_hdr.size,
			       si->tch_hdr.max,
			       ts->input_buf + 3 + si->tch_hdr.ofs,
			       si->tch_hdr.bofs);

	if (num_cur_tch > max_tch) {
		dev_err(dev, "Num touch err detected (n=%d)\n", num_cur_tch);
		num_cur_tch = max_tch;
	}

	if (num_cur_tch == 0 && ts->num_prv_rec == 0)
		return 0;

	/* extract xy_data for all currently reported touches */
	if (num_cur_tch)
		cyttsp5_get_mt_touches(ts, &tch, num_cur_tch);

	input_mt_sync_frame(ts->input);
	input_sync(ts->input);

	return 0;
}

static int cyttsp5_setup_input_device(struct device *dev)
{
	struct cyttsp5 *ts = dev_get_drvdata(dev);
	struct cyttsp5_sysinfo *si = &ts->sysinfo;
	int max_x, max_y, max_p;
	int max_x_tmp, max_y_tmp;
	int error;

	max_x_tmp = si->sensing_conf_data.res_x;
	max_y_tmp = si->sensing_conf_data.res_y;
	max_x = max_x_tmp - 1;
	max_y = max_y_tmp - 1;
	max_p = si->sensing_conf_data.max_z;

	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, max_x, 0, 0);
	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, max_y, 0, 0);
	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, max_p, 0, 0);

	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, MAX_AREA, 0, 0);
	input_set_abs_params(ts->input, ABS_MT_TOUCH_MINOR, 0, MAX_AREA, 0, 0);

	error = input_mt_init_slots(ts->input, si->tch_abs[CY_TCH_T].max,
				    INPUT_MT_DROP_UNUSED | INPUT_MT_DIRECT);
	if (error)
		return error;

	error = input_register_device(ts->input);
	if (error) {
		dev_err(dev, "failed to register input device: %d\n", error);
		return error;
	}

	return error;
}

static int cyttsp5_parse_dt_key_code(struct device *dev)
{
	struct cyttsp5 *ts = dev_get_drvdata(dev);
	struct cyttsp5_sysinfo *si = &ts->sysinfo;

	if (!si->num_btns)
		return 0;

	/* Initialize the button to RESERVED */
	memset32(si->key_code, KEY_RESERVED,  si->num_btns);

	return device_property_read_u32_array(dev, "linux,keycodes",
					      si->key_code, si->num_btns);
}

static int cyttsp5_btn_attention(struct device *dev)
{
	struct cyttsp5 *ts = dev_get_drvdata(dev);
	struct cyttsp5_sysinfo *si = &ts->sysinfo;
	int cur_btn, offset = 0;
	int cur_btn_state;

	switch (ts->input_buf[2]) {
	case HID_TOUCH_REPORT_ID:
		offset = TOUCH_INPUT_HEADER_SIZE;
		break;
	case HID_BTN_REPORT_ID:
		offset = BTN_INPUT_HEADER_SIZE;
		break;
	}

	if (ts->input_buf[2] != HID_BTN_REPORT_ID)
		return 0;

	/* extract button press/release touch information */
	for (cur_btn = 0; cur_btn < si->num_btns; cur_btn++) {
		/* Get current button state */
		cur_btn_state = (ts->input_buf[offset] >> (cur_btn * CY_BITS_PER_BTN))
				& CY_NUM_BTN_EVENT_ID;

		input_report_key(ts->input, si->key_code[cur_btn],
				 cur_btn_state);
		input_sync(ts->input);
	}

	return 0;
}

static int cyttsp5_validate_cmd_response(struct cyttsp5 *ts, u8 code)
{
	u16 size, crc;
	u8 status, report_id;
	int command_code;

	size = get_unaligned_le16(&ts->response_buf[0]);
	if (!size)
		return 0;

	report_id = ts->response_buf[HID_OUTPUT_RESPONSE_REPORT_OFFSET];

	switch (report_id) {
	case HID_BL_RESPONSE_REPORT_ID:
		if (ts->response_buf[4] != HID_OUTPUT_BL_SOP) {
			dev_err(ts->dev, "HID output response, wrong SOP\n");
			return -EPROTO;
		}

		if (ts->response_buf[size - 1] != HID_OUTPUT_BL_EOP) {
			dev_err(ts->dev, "HID output response, wrong EOP\n");
			return -EPROTO;
		}

		crc = crc_itu_t(0xFFFF, &ts->response_buf[4], size - 7);
		if (get_unaligned_le16(&ts->response_buf[size - 3]) != crc) {
			dev_err(ts->dev,
				"HID output response, wrong CRC 0x%X\n",
				crc);
			return -EPROTO;
		}

		status = ts->response_buf[5];
		if (status) {
			dev_err(ts->dev, "HID output response, ERROR:%d\n",
				status);
			return -EPROTO;
		}
		break;

	case HID_APP_RESPONSE_REPORT_ID:
		command_code = ts->response_buf[HID_OUTPUT_RESPONSE_CMD_OFFSET]
			& HID_OUTPUT_RESPONSE_CMD_MASK;
		if (command_code != code) {
			dev_err(ts->dev,
				"HID output response, wrong command_code:%X\n",
				command_code);
			return -EPROTO;
		}
		break;
	}

	return 0;
}

static void cyttsp5_si_get_btn_data(struct cyttsp5 *ts)
{
	struct cyttsp5_sysinfo *si = &ts->sysinfo;
	unsigned int btns = ts->response_buf[HID_SYSINFO_BTN_OFFSET] &
				HID_SYSINFO_BTN_MASK;

	si->num_btns = hweight8(btns);
}

static int cyttsp5_get_sysinfo_regs(struct cyttsp5 *ts)
{
	struct cyttsp5_sensing_conf_data *scd = &ts->sysinfo.sensing_conf_data;
	struct cyttsp5_sensing_conf_data_dev *scd_dev =
		(struct cyttsp5_sensing_conf_data_dev *)
		&ts->response_buf[HID_SYSINFO_SENSING_OFFSET];

	cyttsp5_si_get_btn_data(ts);

	scd->max_tch = scd_dev->max_num_of_tch_per_refresh_cycle;
	scd->res_x = get_unaligned_le16(&scd_dev->res_x);
	scd->res_y = get_unaligned_le16(&scd_dev->res_y);
	scd->max_z = get_unaligned_le16(&scd_dev->max_z);
	scd->len_x = get_unaligned_le16(&scd_dev->len_x);
	scd->len_y = get_unaligned_le16(&scd_dev->len_y);

	return 0;
}

static int cyttsp5_hid_output_get_sysinfo(struct cyttsp5 *ts)
{
	int rc;
	u8 cmd[HID_OUTPUT_GET_SYSINFO_SIZE];

	/* HI bytes of Output register address */
	put_unaligned_le16(HID_OUTPUT_GET_SYSINFO_SIZE, cmd);
	cmd[2] = HID_APP_OUTPUT_REPORT_ID;
	cmd[3] = 0x0; /* Reserved */
	cmd[4] = HID_OUTPUT_GET_SYSINFO;

	rc = cyttsp5_write(ts, HID_OUTPUT_REG, cmd,
			   HID_OUTPUT_GET_SYSINFO_SIZE);
	if (rc) {
		dev_err(ts->dev, "Failed to write command %d", rc);
		return rc;
	}

	rc = wait_for_completion_interruptible_timeout(&ts->cmd_done,
						msecs_to_jiffies(CY_HID_OUTPUT_GET_SYSINFO_TIMEOUT_MS));
	if (rc <= 0) {
		dev_err(ts->dev, "HID output cmd execution timed out\n");
		rc = -ETIMEDOUT;
		return rc;
	}

	rc = cyttsp5_validate_cmd_response(ts, HID_OUTPUT_GET_SYSINFO);
	if (rc) {
		dev_err(ts->dev, "Validation of the response failed\n");
		return rc;
	}

	return cyttsp5_get_sysinfo_regs(ts);
}

static int cyttsp5_power_control(struct cyttsp5 *ts, bool on)
{
	u8 state = on ? HID_POWER_ON : HID_POWER_SLEEP;
	u8 cmd[2] = { 0 };
	int rc;

	SET_CMD_REPORT_TYPE(cmd[0], 0);
	SET_CMD_REPORT_ID(cmd[0], state);
	SET_CMD_OPCODE(cmd[1], HID_CMD_SET_POWER);

	rc = cyttsp5_write(ts, HID_COMMAND_REG, cmd, sizeof(cmd));
	if (rc) {
		dev_err(ts->dev, "Failed to write power command %d", rc);
		return rc;
	}

	rc = wait_for_completion_interruptible_timeout(&ts->cmd_done,
				msecs_to_jiffies(CY_HID_SET_POWER_TIMEOUT));
	if (rc <= 0) {
		dev_err(ts->dev, "HID power cmd execution timed out\n");
		return -ETIMEDOUT;
	}

	if (ts->response_buf[2] != HID_RESPONSE_REPORT_ID ||
	    (ts->response_buf[3] & 0x03) != state ||
	    (ts->response_buf[4] & 0x0f) != HID_CMD_SET_POWER) {
		dev_err(ts->dev, "Validation of the %s response failed\n",
			on ? "wakeup" : "sleep");
		return -EINVAL;
	}

	return 0;
}

static int cyttsp5_hid_output_bl_launch_app(struct cyttsp5 *ts)
{
	int rc;
	u8 cmd[HID_OUTPUT_BL_LAUNCH_APP_SIZE];
	u16 crc;

	put_unaligned_le16(HID_OUTPUT_BL_LAUNCH_APP_SIZE, cmd);
	cmd[2] = HID_BL_OUTPUT_REPORT_ID;
	cmd[3] = 0x0; /* Reserved */
	cmd[4] = HID_OUTPUT_BL_SOP;
	cmd[5] = HID_OUTPUT_BL_LAUNCH_APP;
	put_unaligned_le16(0x00, &cmd[6]);
	crc = crc_itu_t(0xFFFF, &cmd[4], 4);
	put_unaligned_le16(crc, &cmd[8]);
	cmd[10] = HID_OUTPUT_BL_EOP;

	rc = cyttsp5_write(ts, HID_OUTPUT_REG, cmd,
			   HID_OUTPUT_BL_LAUNCH_APP_SIZE);
	if (rc) {
		dev_err(ts->dev, "Failed to write command %d", rc);
		return rc;
	}

	rc = wait_for_completion_interruptible_timeout(&ts->cmd_done,
				msecs_to_jiffies(CY_HID_OUTPUT_TIMEOUT_MS));
	if (rc <= 0) {
		dev_err(ts->dev, "HID output cmd execution timed out\n");
		rc = -ETIMEDOUT;
		return rc;
	}

	rc = cyttsp5_validate_cmd_response(ts, HID_OUTPUT_BL_LAUNCH_APP);
	if (rc) {
		dev_err(ts->dev, "Validation of the response failed\n");
		return rc;
	}

	return 0;
}

static int cyttsp5_get_hid_descriptor(struct cyttsp5 *ts,
				      struct cyttsp5_hid_desc *desc)
{
	struct device *dev = ts->dev;
	int rc;

	rc = cyttsp5_write(ts, HID_DESC_REG, NULL, 0);
	if (rc) {
		dev_err(dev, "Failed to get HID descriptor, rc=%d\n", rc);
		return rc;
	}

	rc = wait_for_completion_interruptible_timeout(&ts->cmd_done,
			msecs_to_jiffies(CY_HID_GET_HID_DESCRIPTOR_TIMEOUT_MS));
	if (rc <= 0) {
		dev_err(ts->dev, "HID get descriptor timed out\n");
		rc = -ETIMEDOUT;
		return rc;
	}

	memcpy(desc, ts->response_buf, sizeof(*desc));

	/* Check HID descriptor length and version */
	if (le16_to_cpu(desc->hid_desc_len) != sizeof(*desc) ||
	    le16_to_cpu(desc->bcd_version) != HID_VERSION) {
		dev_err(dev, "Unsupported HID version\n");
		return -ENODEV;
	}

	return 0;
}

static int fill_tch_abs(struct cyttsp5_tch_abs_params *tch_abs, int report_size,
			int offset)
{
	tch_abs->ofs = offset / 8;
	tch_abs->size = report_size / 8;
	if (report_size % 8)
		tch_abs->size += 1;
	tch_abs->min = 0;
	tch_abs->max = 1 << report_size;
	tch_abs->bofs = offset - (tch_abs->ofs << 3);

	return 0;
}

static irqreturn_t cyttsp5_handle_irq(int irq, void *handle)
{
	struct cyttsp5 *ts = handle;
	int report_id;
	int size;
	int error;

	error = cyttsp5_read(ts, ts->input_buf, CY_MAX_INPUT);
	if (error)
		return IRQ_HANDLED;

	size = get_unaligned_le16(&ts->input_buf[0]);
	if (size == 0) {
		/* reset */
		report_id = 0;
		size = 2;
	} else {
		report_id = ts->input_buf[2];
	}

	switch (report_id) {
	case HID_TOUCH_REPORT_ID:
		cyttsp5_mt_attention(ts->dev);
		break;
	case HID_BTN_REPORT_ID:
		cyttsp5_btn_attention(ts->dev);
		break;
	case HID_RESPONSE_REPORT_ID:
		memcpy(ts->response_buf, ts->input_buf, size);
		complete(&ts->cmd_done);
		break;
	default:
		/* It is not an input but a command response */
		memcpy(ts->response_buf, ts->input_buf, size);
		complete(&ts->cmd_done);
	}

	return IRQ_HANDLED;
}

static int cyttsp5_deassert_int(struct cyttsp5 *ts)
{
	u16 size;
	u8 buf[2];
	int error;

	error = regmap_bulk_read(ts->regmap, HID_INPUT_REG, buf, sizeof(buf));
	if (error < 0)
		return error;

	size = get_unaligned_le16(&buf[0]);
	if (size == 2 || size == 0)
		return 0;

	return -EINVAL;
}

static int cyttsp5_fill_all_touch(struct cyttsp5 *ts)
{
	struct cyttsp5_sysinfo *si = &ts->sysinfo;

	fill_tch_abs(&si->tch_abs[CY_TCH_X], REPORT_SIZE_16,
		     TOUCH_REPORT_DESC_X);
	fill_tch_abs(&si->tch_abs[CY_TCH_Y], REPORT_SIZE_16,
		     TOUCH_REPORT_DESC_Y);
	fill_tch_abs(&si->tch_abs[CY_TCH_P], REPORT_SIZE_8,
		     TOUCH_REPORT_DESC_P);
	fill_tch_abs(&si->tch_abs[CY_TCH_T], REPORT_SIZE_5,
		     TOUCH_REPORT_DESC_CONTACTID);
	fill_tch_abs(&si->tch_hdr, REPORT_SIZE_5,
		     TOUCH_REPORT_DESC_HDR_CONTACTCOUNT);
	fill_tch_abs(&si->tch_abs[CY_TCH_MAJ], REPORT_SIZE_8,
		     TOUCH_REPORT_DESC_MAJ);
	fill_tch_abs(&si->tch_abs[CY_TCH_MIN], REPORT_SIZE_8,
		     TOUCH_REPORT_DESC_MIN);

	return 0;
}

static int cyttsp5_startup(struct cyttsp5 *ts)
{
	int error;

	error = cyttsp5_deassert_int(ts);
	if (error) {
		dev_err(ts->dev, "Error on deassert int r=%d\n", error);
		return -ENODEV;
	}

	/*
	 * Launch the application as the device starts in bootloader mode
	 * because of a power-on-reset
	 */
	error = cyttsp5_hid_output_bl_launch_app(ts);
	if (error < 0) {
		dev_err(ts->dev, "Error on launch app r=%d\n", error);
		return error;
	}

	error = cyttsp5_get_hid_descriptor(ts, &ts->hid_desc);
	if (error < 0) {
		dev_err(ts->dev, "Error on getting HID descriptor r=%d\n", error);
		return error;
	}

	error = cyttsp5_fill_all_touch(ts);
	if (error < 0) {
		dev_err(ts->dev, "Error on report descriptor r=%d\n", error);
		return error;
	}

	error = cyttsp5_hid_output_get_sysinfo(ts);
	if (error) {
		dev_err(ts->dev, "Error on getting sysinfo r=%d\n", error);
		return error;
	}

	return error;
}

static void cyttsp5_cleanup(void *data)
{
	struct cyttsp5 *ts = data;

	regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
}

static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
			 const char *name)
{
	struct cyttsp5 *ts;
	struct cyttsp5_sysinfo *si;
	int error, i;

	ts = devm_kzalloc(dev, sizeof(*ts), GFP_KERNEL);
	if (!ts)
		return -ENOMEM;

	/* Initialize device info */
	ts->regmap = regmap;
	ts->dev = dev;
	si = &ts->sysinfo;
	dev_set_drvdata(dev, ts);

	init_completion(&ts->cmd_done);

	/* Power up the device */
	ts->supplies[0].supply = "vdd";
	ts->supplies[1].supply = "vddio";
	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
					ts->supplies);
	if (error) {
		dev_err(ts->dev, "Failed to get regulators, error %d\n", error);
		return error;
	}

	error = devm_add_action_or_reset(dev, cyttsp5_cleanup, ts);
	if (error)
		return error;

	error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
	if (error) {
		dev_err(ts->dev, "Failed to enable regulators, error %d\n", error);
		return error;
	}

	ts->input = devm_input_allocate_device(dev);
	if (!ts->input) {
		dev_err(dev, "Error, failed to allocate input device\n");
		return -ENODEV;
	}

	ts->input->name = "cyttsp5";
	scnprintf(ts->phys, sizeof(ts->phys), "%s/input0", dev_name(dev));
	ts->input->phys = ts->phys;
	input_set_drvdata(ts->input, ts);

	/* Assert gpio to be in a reset state */
	ts->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
	if (IS_ERR(ts->reset_gpio)) {
		error = PTR_ERR(ts->reset_gpio);
		dev_err(dev, "Failed to request reset gpio, error %d\n", error);
		return error;
	}

	fsleep(10); /* Ensure long-enough reset pulse (minimum 10us). */

	gpiod_set_value_cansleep(ts->reset_gpio, 0);

	/* Need a delay to have device up */
	msleep(20);

	error = devm_request_threaded_irq(dev, irq, NULL, cyttsp5_handle_irq,
					  IRQF_ONESHOT, name, ts);
	if (error) {
		dev_err(dev, "unable to request IRQ\n");
		return error;
	}

	error = cyttsp5_startup(ts);
	if (error) {
		dev_err(ts->dev, "Fail initial startup r=%d\n", error);
		return error;
	}

	error = cyttsp5_parse_dt_key_code(dev);
	if (error < 0) {
		dev_err(ts->dev, "Error while parsing dts %d\n", error);
		return error;
	}

	touchscreen_parse_properties(ts->input, true, &ts->prop);

	__set_bit(EV_KEY, ts->input->evbit);
	for (i = 0; i < si->num_btns; i++)
		__set_bit(si->key_code[i], ts->input->keybit);

	return cyttsp5_setup_input_device(dev);
}

static int cyttsp5_i2c_probe(struct i2c_client *client)
{
	struct regmap *regmap;
	static const struct regmap_config config = {
		.reg_bits = 8,
		.val_bits = 8,
	};

	regmap = devm_regmap_init_i2c(client, &config);
	if (IS_ERR(regmap)) {
		dev_err(&client->dev, "regmap allocation failed: %ld\n",
			PTR_ERR(regmap));
		return PTR_ERR(regmap);
	}

	return cyttsp5_probe(&client->dev, regmap, client->irq, client->name);
}

static const struct of_device_id cyttsp5_of_match[] = {
	{ .compatible = "cypress,tt21000", },
	{ }
};
MODULE_DEVICE_TABLE(of, cyttsp5_of_match);

static const struct i2c_device_id cyttsp5_i2c_id[] = {
	{ CYTTSP5_NAME },
	{ }
};
MODULE_DEVICE_TABLE(i2c, cyttsp5_i2c_id);

static int __maybe_unused cyttsp5_suspend(struct device *dev)
{
	struct cyttsp5 *ts = dev_get_drvdata(dev);

	if (!device_may_wakeup(dev))
		cyttsp5_power_control(ts, false);

	return 0;
}

static int __maybe_unused cyttsp5_resume(struct device *dev)
{
	struct cyttsp5 *ts = dev_get_drvdata(dev);

	if (!device_may_wakeup(dev))
		cyttsp5_power_control(ts, true);

	return 0;
}

static SIMPLE_DEV_PM_OPS(cyttsp5_pm, cyttsp5_suspend, cyttsp5_resume);

static struct i2c_driver cyttsp5_i2c_driver = {
	.driver = {
		.name = CYTTSP5_NAME,
		.of_match_table = cyttsp5_of_match,
		.pm = &cyttsp5_pm,
	},
	.probe = cyttsp5_i2c_probe,
	.id_table = cyttsp5_i2c_id,
};
module_i2c_driver(cyttsp5_i2c_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Touchscreen driver for Cypress TrueTouch Gen 5 Product");
MODULE_AUTHOR("Mylène Josserand <mylene.josserand@bootlin.com>");