/*
   * Cypress APA trackpad with I2C interface
   *
   * Author: Dudley Du <dudl@cypress.com>
   * Further cleanup and restructuring by:
   *   Daniel Kurtz <djkurtz@chromium.org>
   *   Benson Leung <bleung@chromium.org>
   *
   * Copyright (C) 2011-2015 Cypress Semiconductor, Inc.
   * Copyright (C) 2011-2012 Google, Inc.
   *
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file COPYING in the main directory of this archive for
   * more details.
   */
  
  #include <linux/delay.h>
  #include <linux/i2c.h>
  #include <linux/input.h>
  #include <linux/input/mt.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <asm/unaligned.h>
  #include "cyapa.h"
  
  
  #define GEN3_MAX_FINGERS 5
  #define GEN3_FINGER_NUM(x) (((x) >> 4) & 0x07)
  
  #define BLK_HEAD_BYTES 32
  
  /* Macro for register map group offset. */
  #define PRODUCT_ID_SIZE  16
  #define QUERY_DATA_SIZE  27
  #define REG_PROTOCOL_GEN_QUERY_OFFSET  20
  
  #define REG_OFFSET_DATA_BASE     0x0000
  #define REG_OFFSET_COMMAND_BASE  0x0028
  #define REG_OFFSET_QUERY_BASE    0x002a
  
  #define CYAPA_OFFSET_SOFT_RESET  REG_OFFSET_COMMAND_BASE
  #define OP_RECALIBRATION_MASK    0x80
  #define OP_REPORT_BASELINE_MASK  0x40
  #define REG_OFFSET_MAX_BASELINE  0x0026
  #define REG_OFFSET_MIN_BASELINE  0x0027
  
  #define REG_OFFSET_POWER_MODE (REG_OFFSET_COMMAND_BASE + 1)
  #define SET_POWER_MODE_DELAY   10000  /* Unit: us */
  #define SET_POWER_MODE_TRIES   5
  
  #define GEN3_BL_CMD_CHECKSUM_SEED 0xff
  #define GEN3_BL_CMD_INITIATE_BL   0x38
  #define GEN3_BL_CMD_WRITE_BLOCK   0x39
  #define GEN3_BL_CMD_VERIFY_BLOCK  0x3a
  #define GEN3_BL_CMD_TERMINATE_BL  0x3b
  #define GEN3_BL_CMD_LAUNCH_APP    0xa5
  
  /*
   * CYAPA trackpad device states.
   * Used in register 0x00, bit1-0, DeviceStatus field.
   * Other values indicate device is in an abnormal state and must be reset.
   */
  #define CYAPA_DEV_NORMAL  0x03
  #define CYAPA_DEV_BUSY    0x01
  
  #define CYAPA_FW_BLOCK_SIZE	64
  #define CYAPA_FW_READ_SIZE	16
  #define CYAPA_FW_HDR_START	0x0780
  #define CYAPA_FW_HDR_BLOCK_COUNT  2
  #define CYAPA_FW_HDR_BLOCK_START  (CYAPA_FW_HDR_START / CYAPA_FW_BLOCK_SIZE)
  #define CYAPA_FW_HDR_SIZE	  (CYAPA_FW_HDR_BLOCK_COUNT * \
  					CYAPA_FW_BLOCK_SIZE)
  #define CYAPA_FW_DATA_START	0x0800
  #define CYAPA_FW_DATA_BLOCK_COUNT  480
  #define CYAPA_FW_DATA_BLOCK_START  (CYAPA_FW_DATA_START / CYAPA_FW_BLOCK_SIZE)
  #define CYAPA_FW_DATA_SIZE	(CYAPA_FW_DATA_BLOCK_COUNT * \
  				 CYAPA_FW_BLOCK_SIZE)
  #define CYAPA_FW_SIZE		(CYAPA_FW_HDR_SIZE + CYAPA_FW_DATA_SIZE)
  #define CYAPA_CMD_LEN		16
  
  #define GEN3_BL_IDLE_FW_MAJ_VER_OFFSET 0x0b
  #define GEN3_BL_IDLE_FW_MIN_VER_OFFSET (GEN3_BL_IDLE_FW_MAJ_VER_OFFSET + 1)
  
  
  struct cyapa_touch {
  	/*
  	 * high bits or x/y position value
  	 * bit 7 - 4: high 4 bits of x position value
  	 * bit 3 - 0: high 4 bits of y position value
  	 */
  	u8 xy_hi;
  	u8 x_lo;  /* low 8 bits of x position value. */
  	u8 y_lo;  /* low 8 bits of y position value. */
  	u8 pressure;
  	/* id range is 1 - 15.  It is incremented with every new touch. */
  	u8 id;
  } __packed;
  
  struct cyapa_reg_data {
  	/*
  	 * bit 0 - 1: device status
  	 * bit 3 - 2: power mode
  	 * bit 6 - 4: reserved
  	 * bit 7: interrupt valid bit
  	 */
  	u8 device_status;
  	/*
  	 * bit 7 - 4: number of fingers currently touching pad
  	 * bit 3: valid data check bit
  	 * bit 2: middle mechanism button state if exists
  	 * bit 1: right mechanism button state if exists
  	 * bit 0: left mechanism button state if exists
  	 */
  	u8 finger_btn;
  	/* CYAPA reports up to 5 touches per packet. */
  	struct cyapa_touch touches[5];
  } __packed;
  
  struct gen3_write_block_cmd {
  	u8 checksum_seed;  /* Always be 0xff */
  	u8 cmd_code;       /* command code: 0x39 */
  	u8 key[8];         /* 8-byte security key */
  	__be16 block_num;
  	u8 block_data[CYAPA_FW_BLOCK_SIZE];
  	u8 block_checksum;  /* Calculated using bytes 12 - 75 */
  	u8 cmd_checksum;    /* Calculated using bytes 0-76 */
  } __packed;
  
  static const u8 security_key[] = {
  		0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07 };
  static const u8 bl_activate[] = { 0x00, 0xff, 0x38, 0x00, 0x01, 0x02, 0x03,
  		0x04, 0x05, 0x06, 0x07 };
  static const u8 bl_deactivate[] = { 0x00, 0xff, 0x3b, 0x00, 0x01, 0x02, 0x03,
  		0x04, 0x05, 0x06, 0x07 };
  static const u8 bl_exit[] = { 0x00, 0xff, 0xa5, 0x00, 0x01, 0x02, 0x03, 0x04,
  		0x05, 0x06, 0x07 };
  
  
   /* for byte read/write command */
  #define CMD_RESET      0
  #define CMD_POWER_MODE 1
  #define CMD_DEV_STATUS 2
  #define CMD_REPORT_MAX_BASELINE 3
  #define CMD_REPORT_MIN_BASELINE 4
  #define SMBUS_BYTE_CMD(cmd) (((cmd) & 0x3f) << 1)
  #define CYAPA_SMBUS_RESET         SMBUS_BYTE_CMD(CMD_RESET)
  #define CYAPA_SMBUS_POWER_MODE    SMBUS_BYTE_CMD(CMD_POWER_MODE)
  #define CYAPA_SMBUS_DEV_STATUS    SMBUS_BYTE_CMD(CMD_DEV_STATUS)
  #define CYAPA_SMBUS_MAX_BASELINE  SMBUS_BYTE_CMD(CMD_REPORT_MAX_BASELINE)
  #define CYAPA_SMBUS_MIN_BASELINE  SMBUS_BYTE_CMD(CMD_REPORT_MIN_BASELINE)
  
   /* for group registers read/write command */
  #define REG_GROUP_DATA 0
  #define REG_GROUP_CMD 2
  #define REG_GROUP_QUERY 3
  #define SMBUS_GROUP_CMD(grp) (0x80 | (((grp) & 0x07) << 3))
  #define CYAPA_SMBUS_GROUP_DATA	 SMBUS_GROUP_CMD(REG_GROUP_DATA)
  #define CYAPA_SMBUS_GROUP_CMD	 SMBUS_GROUP_CMD(REG_GROUP_CMD)
  #define CYAPA_SMBUS_GROUP_QUERY	 SMBUS_GROUP_CMD(REG_GROUP_QUERY)
  
   /* for register block read/write command */
  #define CMD_BL_STATUS 0
  #define CMD_BL_HEAD 1
  #define CMD_BL_CMD 2
  #define CMD_BL_DATA 3
  #define CMD_BL_ALL 4
  #define CMD_BLK_PRODUCT_ID 5
  #define CMD_BLK_HEAD 6
  #define SMBUS_BLOCK_CMD(cmd) (0xc0 | (((cmd) & 0x1f) << 1))
  
  /* register block read/write command in bootloader mode */
  #define CYAPA_SMBUS_BL_STATUS  SMBUS_BLOCK_CMD(CMD_BL_STATUS)
  #define CYAPA_SMBUS_BL_HEAD    SMBUS_BLOCK_CMD(CMD_BL_HEAD)
  #define CYAPA_SMBUS_BL_CMD     SMBUS_BLOCK_CMD(CMD_BL_CMD)
  #define CYAPA_SMBUS_BL_DATA    SMBUS_BLOCK_CMD(CMD_BL_DATA)
  #define CYAPA_SMBUS_BL_ALL     SMBUS_BLOCK_CMD(CMD_BL_ALL)
  
  /* register block read/write command in operational mode */
  #define CYAPA_SMBUS_BLK_PRODUCT_ID SMBUS_BLOCK_CMD(CMD_BLK_PRODUCT_ID)
  #define CYAPA_SMBUS_BLK_HEAD SMBUS_BLOCK_CMD(CMD_BLK_HEAD)
  
   /* for byte read/write command */
  #define CMD_RESET 0
  #define CMD_POWER_MODE 1
  #define CMD_DEV_STATUS 2
  #define CMD_REPORT_MAX_BASELINE 3
  #define CMD_REPORT_MIN_BASELINE 4
  #define SMBUS_BYTE_CMD(cmd) (((cmd) & 0x3f) << 1)
  #define CYAPA_SMBUS_RESET         SMBUS_BYTE_CMD(CMD_RESET)
  #define CYAPA_SMBUS_POWER_MODE    SMBUS_BYTE_CMD(CMD_POWER_MODE)
  #define CYAPA_SMBUS_DEV_STATUS    SMBUS_BYTE_CMD(CMD_DEV_STATUS)
  #define CYAPA_SMBUS_MAX_BASELINE  SMBUS_BYTE_CMD(CMD_REPORT_MAX_BASELINE)
  #define CYAPA_SMBUS_MIN_BASELINE  SMBUS_BYTE_CMD(CMD_REPORT_MIN_BASELINE)
  
   /* for group registers read/write command */
  #define REG_GROUP_DATA  0
  #define REG_GROUP_CMD   2
  #define REG_GROUP_QUERY 3
  #define SMBUS_GROUP_CMD(grp) (0x80 | (((grp) & 0x07) << 3))
  #define CYAPA_SMBUS_GROUP_DATA  SMBUS_GROUP_CMD(REG_GROUP_DATA)
  #define CYAPA_SMBUS_GROUP_CMD   SMBUS_GROUP_CMD(REG_GROUP_CMD)
  #define CYAPA_SMBUS_GROUP_QUERY SMBUS_GROUP_CMD(REG_GROUP_QUERY)
  
   /* for register block read/write command */
  #define CMD_BL_STATUS		0
  #define CMD_BL_HEAD		1
  #define CMD_BL_CMD		2
  #define CMD_BL_DATA		3
  #define CMD_BL_ALL		4
  #define CMD_BLK_PRODUCT_ID	5
  #define CMD_BLK_HEAD		6
  #define SMBUS_BLOCK_CMD(cmd) (0xc0 | (((cmd) & 0x1f) << 1))
  
  /* register block read/write command in bootloader mode */
  #define CYAPA_SMBUS_BL_STATUS SMBUS_BLOCK_CMD(CMD_BL_STATUS)
  #define CYAPA_SMBUS_BL_HEAD   SMBUS_BLOCK_CMD(CMD_BL_HEAD)
  #define CYAPA_SMBUS_BL_CMD    SMBUS_BLOCK_CMD(CMD_BL_CMD)
  #define CYAPA_SMBUS_BL_DATA   SMBUS_BLOCK_CMD(CMD_BL_DATA)
  #define CYAPA_SMBUS_BL_ALL    SMBUS_BLOCK_CMD(CMD_BL_ALL)
  
  /* register block read/write command in operational mode */
  #define CYAPA_SMBUS_BLK_PRODUCT_ID SMBUS_BLOCK_CMD(CMD_BLK_PRODUCT_ID)
  #define CYAPA_SMBUS_BLK_HEAD       SMBUS_BLOCK_CMD(CMD_BLK_HEAD)
  
  struct cyapa_cmd_len {
  	u8 cmd;
  	u8 len;
  };
  
  /* maps generic CYAPA_CMD_* code to the I2C equivalent */
  static const struct cyapa_cmd_len cyapa_i2c_cmds[] = {
  	{ CYAPA_OFFSET_SOFT_RESET, 1 },		/* CYAPA_CMD_SOFT_RESET */
  	{ REG_OFFSET_COMMAND_BASE + 1, 1 },	/* CYAPA_CMD_POWER_MODE */
  	{ REG_OFFSET_DATA_BASE, 1 },		/* CYAPA_CMD_DEV_STATUS */
  	{ REG_OFFSET_DATA_BASE, sizeof(struct cyapa_reg_data) },
  						/* CYAPA_CMD_GROUP_DATA */
  	{ REG_OFFSET_COMMAND_BASE, 0 },		/* CYAPA_CMD_GROUP_CMD */
  	{ REG_OFFSET_QUERY_BASE, QUERY_DATA_SIZE }, /* CYAPA_CMD_GROUP_QUERY */
  	{ BL_HEAD_OFFSET, 3 },			/* CYAPA_CMD_BL_STATUS */
  	{ BL_HEAD_OFFSET, 16 },			/* CYAPA_CMD_BL_HEAD */
  	{ BL_HEAD_OFFSET, 16 },			/* CYAPA_CMD_BL_CMD */
  	{ BL_DATA_OFFSET, 16 },			/* CYAPA_CMD_BL_DATA */
  	{ BL_HEAD_OFFSET, 32 },			/* CYAPA_CMD_BL_ALL */
  	{ REG_OFFSET_QUERY_BASE, PRODUCT_ID_SIZE },
  						/* CYAPA_CMD_BLK_PRODUCT_ID */
  	{ REG_OFFSET_DATA_BASE, 32 },		/* CYAPA_CMD_BLK_HEAD */
  	{ REG_OFFSET_MAX_BASELINE, 1 },		/* CYAPA_CMD_MAX_BASELINE */
  	{ REG_OFFSET_MIN_BASELINE, 1 },		/* CYAPA_CMD_MIN_BASELINE */
  };
  
  static const struct cyapa_cmd_len cyapa_smbus_cmds[] = {
  	{ CYAPA_SMBUS_RESET, 1 },		/* CYAPA_CMD_SOFT_RESET */
  	{ CYAPA_SMBUS_POWER_MODE, 1 },		/* CYAPA_CMD_POWER_MODE */
  	{ CYAPA_SMBUS_DEV_STATUS, 1 },		/* CYAPA_CMD_DEV_STATUS */
  	{ CYAPA_SMBUS_GROUP_DATA, sizeof(struct cyapa_reg_data) },
  						/* CYAPA_CMD_GROUP_DATA */
  	{ CYAPA_SMBUS_GROUP_CMD, 2 },		/* CYAPA_CMD_GROUP_CMD */
  	{ CYAPA_SMBUS_GROUP_QUERY, QUERY_DATA_SIZE },
  						/* CYAPA_CMD_GROUP_QUERY */
  	{ CYAPA_SMBUS_BL_STATUS, 3 },		/* CYAPA_CMD_BL_STATUS */
  	{ CYAPA_SMBUS_BL_HEAD, 16 },		/* CYAPA_CMD_BL_HEAD */
  	{ CYAPA_SMBUS_BL_CMD, 16 },		/* CYAPA_CMD_BL_CMD */
  	{ CYAPA_SMBUS_BL_DATA, 16 },		/* CYAPA_CMD_BL_DATA */
  	{ CYAPA_SMBUS_BL_ALL, 32 },		/* CYAPA_CMD_BL_ALL */
  	{ CYAPA_SMBUS_BLK_PRODUCT_ID, PRODUCT_ID_SIZE },
  						/* CYAPA_CMD_BLK_PRODUCT_ID */
  	{ CYAPA_SMBUS_BLK_HEAD, 16 },		/* CYAPA_CMD_BLK_HEAD */
  	{ CYAPA_SMBUS_MAX_BASELINE, 1 },	/* CYAPA_CMD_MAX_BASELINE */
  	{ CYAPA_SMBUS_MIN_BASELINE, 1 },	/* CYAPA_CMD_MIN_BASELINE */
  };
  
  
  /*
   * cyapa_smbus_read_block - perform smbus block read command
   * @cyapa  - private data structure of the driver
   * @cmd    - the properly encoded smbus command
   * @len    - expected length of smbus command result
   * @values - buffer to store smbus command result
   *
   * Returns negative errno, else the number of bytes written.
   *
   * Note:
   * In trackpad device, the memory block allocated for I2C register map
   * is 256 bytes, so the max read block for I2C bus is 256 bytes.
   */
  ssize_t cyapa_smbus_read_block(struct cyapa *cyapa, u8 cmd, size_t len,
  				      u8 *values)
  {
  	ssize_t ret;
  	u8 index;
  	u8 smbus_cmd;
  	u8 *buf;
  	struct i2c_client *client = cyapa->client;
  
  	if (!(SMBUS_BYTE_BLOCK_CMD_MASK & cmd))
  		return -EINVAL;
  
  	if (SMBUS_GROUP_BLOCK_CMD_MASK & cmd) {
  		/* read specific block registers command. */
  		smbus_cmd = SMBUS_ENCODE_RW(cmd, SMBUS_READ);
  		ret = i2c_smbus_read_block_data(client, smbus_cmd, values);
  		goto out;
  	}
  
  	ret = 0;
  	for (index = 0; index * I2C_SMBUS_BLOCK_MAX < len; index++) {
  		smbus_cmd = SMBUS_ENCODE_IDX(cmd, index);
  		smbus_cmd = SMBUS_ENCODE_RW(smbus_cmd, SMBUS_READ);
  		buf = values + I2C_SMBUS_BLOCK_MAX * index;
  		ret = i2c_smbus_read_block_data(client, smbus_cmd, buf);
  		if (ret < 0)
  			goto out;
  	}
  
  out:
  	return ret > 0 ? len : ret;
  }
  
  static s32 cyapa_read_byte(struct cyapa *cyapa, u8 cmd_idx)
  {
  	u8 cmd;
  
  	if (cyapa->smbus) {
  		cmd = cyapa_smbus_cmds[cmd_idx].cmd;
  		cmd = SMBUS_ENCODE_RW(cmd, SMBUS_READ);
  	} else {
  		cmd = cyapa_i2c_cmds[cmd_idx].cmd;
  	}
  	return i2c_smbus_read_byte_data(cyapa->client, cmd);
  }
  
  static s32 cyapa_write_byte(struct cyapa *cyapa, u8 cmd_idx, u8 value)
  {
  	u8 cmd;
  
  	if (cyapa->smbus) {
  		cmd = cyapa_smbus_cmds[cmd_idx].cmd;
  		cmd = SMBUS_ENCODE_RW(cmd, SMBUS_WRITE);
  	} else {
  		cmd = cyapa_i2c_cmds[cmd_idx].cmd;
  	}
  	return i2c_smbus_write_byte_data(cyapa->client, cmd, value);
  }
  
  ssize_t cyapa_i2c_reg_read_block(struct cyapa *cyapa, u8 reg, size_t len,
  					u8 *values)
  {
  	return i2c_smbus_read_i2c_block_data(cyapa->client, reg, len, values);
  }
  
  static ssize_t cyapa_i2c_reg_write_block(struct cyapa *cyapa, u8 reg,
  					 size_t len, const u8 *values)
  {
  	return i2c_smbus_write_i2c_block_data(cyapa->client, reg, len, values);
  }
  
  ssize_t cyapa_read_block(struct cyapa *cyapa, u8 cmd_idx, u8 *values)
  {
  	u8 cmd;
  	size_t len;
  
  	if (cyapa->smbus) {
  		cmd = cyapa_smbus_cmds[cmd_idx].cmd;
  		len = cyapa_smbus_cmds[cmd_idx].len;
  		return cyapa_smbus_read_block(cyapa, cmd, len, values);
  	}
  	cmd = cyapa_i2c_cmds[cmd_idx].cmd;
  	len = cyapa_i2c_cmds[cmd_idx].len;
  	return cyapa_i2c_reg_read_block(cyapa, cmd, len, values);
  }
  
  /*
   * Determine the Gen3 trackpad device's current operating state.
   *
   */
  static int cyapa_gen3_state_parse(struct cyapa *cyapa, u8 *reg_data, int len)
  {
  	cyapa->state = CYAPA_STATE_NO_DEVICE;
  
  	/* Parse based on Gen3 characteristic registers and bits */
  	if (reg_data[REG_BL_FILE] == BL_FILE &&
  		reg_data[REG_BL_ERROR] == BL_ERROR_NO_ERR_IDLE &&
  		(reg_data[REG_BL_STATUS] ==
  			(BL_STATUS_RUNNING | BL_STATUS_CSUM_VALID) ||
  			reg_data[REG_BL_STATUS] == BL_STATUS_RUNNING)) {
  		/*
  		 * Normal state after power on or reset,
  		 * REG_BL_STATUS == 0x11, firmware image checksum is valid.
  		 * REG_BL_STATUS == 0x10, firmware image checksum is invalid.
  		 */
  		cyapa->gen = CYAPA_GEN3;
  		cyapa->state = CYAPA_STATE_BL_IDLE;
  	} else if (reg_data[REG_BL_FILE] == BL_FILE &&
  		(reg_data[REG_BL_STATUS] & BL_STATUS_RUNNING) ==
  			BL_STATUS_RUNNING) {
  		cyapa->gen = CYAPA_GEN3;
  		if (reg_data[REG_BL_STATUS] & BL_STATUS_BUSY) {
  			cyapa->state = CYAPA_STATE_BL_BUSY;
  		} else {
  			if ((reg_data[REG_BL_ERROR] & BL_ERROR_BOOTLOADING) ==
  					BL_ERROR_BOOTLOADING)
  				cyapa->state = CYAPA_STATE_BL_ACTIVE;
  			else
  				cyapa->state = CYAPA_STATE_BL_IDLE;
  		}
  	} else if ((reg_data[REG_OP_STATUS] & OP_STATUS_SRC) &&
  			(reg_data[REG_OP_DATA1] & OP_DATA_VALID)) {
  		/*
  		 * Normal state when running in operational mode,
  		 * may also not in full power state or
  		 * busying in command process.
  		 */
  		if (GEN3_FINGER_NUM(reg_data[REG_OP_DATA1]) <=
  				GEN3_MAX_FINGERS) {
  			/* Finger number data is valid. */
  			cyapa->gen = CYAPA_GEN3;
  			cyapa->state = CYAPA_STATE_OP;
  		}
  	} else if (reg_data[REG_OP_STATUS] == 0x0C &&
  			reg_data[REG_OP_DATA1] == 0x08) {
  		/* Op state when first two registers overwritten with 0x00 */
  		cyapa->gen = CYAPA_GEN3;
  		cyapa->state = CYAPA_STATE_OP;
  	} else if (reg_data[REG_BL_STATUS] &
  			(BL_STATUS_RUNNING | BL_STATUS_BUSY)) {
  		cyapa->gen = CYAPA_GEN3;
  		cyapa->state = CYAPA_STATE_BL_BUSY;
  	}
  
  	if (cyapa->gen == CYAPA_GEN3 && (cyapa->state == CYAPA_STATE_OP ||
  		cyapa->state == CYAPA_STATE_BL_IDLE ||
  		cyapa->state == CYAPA_STATE_BL_ACTIVE ||
  		cyapa->state == CYAPA_STATE_BL_BUSY))
  		return 0;
  
  	return -EAGAIN;
  }
  
  /*
   * Enter bootloader by soft resetting the device.
   *
   * If device is already in the bootloader, the function just returns.
   * Otherwise, reset the device; after reset, device enters bootloader idle
   * state immediately.
   *
   * Returns:
   *   0        on success
   *   -EAGAIN  device was reset, but is not now in bootloader idle state
   *   < 0      if the device never responds within the timeout
   */
  static int cyapa_gen3_bl_enter(struct cyapa *cyapa)
  {
  	int error;
  	int waiting_time;
  
  	error = cyapa_poll_state(cyapa, 500);
  	if (error)
  		return error;
  	if (cyapa->state == CYAPA_STATE_BL_IDLE) {
  		/* Already in BL_IDLE. Skipping reset. */
  		return 0;
  	}
  
  	if (cyapa->state != CYAPA_STATE_OP)
  		return -EAGAIN;
  
  	cyapa->operational = false;
  	cyapa->state = CYAPA_STATE_NO_DEVICE;
  	error = cyapa_write_byte(cyapa, CYAPA_CMD_SOFT_RESET, 0x01);
  	if (error)
  		return -EIO;
  
  	usleep_range(25000, 50000);
  	waiting_time = 2000;  /* For some shipset, max waiting time is 1~2s. */
  	do {
  		error = cyapa_poll_state(cyapa, 500);
  		if (error) {
  			if (error == -ETIMEDOUT) {
  				waiting_time -= 500;
  				continue;
  			}
  			return error;
  		}
  
  		if ((cyapa->state == CYAPA_STATE_BL_IDLE) &&
  			!(cyapa->status[REG_BL_STATUS] & BL_STATUS_WATCHDOG))
  			break;
  
  		msleep(100);
  		waiting_time -= 100;
  	} while (waiting_time > 0);
  
  	if ((cyapa->state != CYAPA_STATE_BL_IDLE) ||
  		(cyapa->status[REG_BL_STATUS] & BL_STATUS_WATCHDOG))
  		return -EAGAIN;
  
  	return 0;
  }
  
  static int cyapa_gen3_bl_activate(struct cyapa *cyapa)
  {
  	int error;
  
  	error = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_activate),
  					bl_activate);
  	if (error)
  		return error;
  
  	/* Wait for bootloader to activate; takes between 2 and 12 seconds */
  	msleep(2000);
  	error = cyapa_poll_state(cyapa, 11000);
  	if (error)
  		return error;
  	if (cyapa->state != CYAPA_STATE_BL_ACTIVE)
  		return -EAGAIN;
  
  	return 0;
  }
  
  static int cyapa_gen3_bl_deactivate(struct cyapa *cyapa)
  {
  	int error;
  
  	error = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_deactivate),
  					bl_deactivate);
  	if (error)
  		return error;
  
  	/* Wait for bootloader to switch to idle state; should take < 100ms */
  	msleep(100);
  	error = cyapa_poll_state(cyapa, 500);
  	if (error)
  		return error;
  	if (cyapa->state != CYAPA_STATE_BL_IDLE)
  		return -EAGAIN;
  	return 0;
  }
  
  /*
   * Exit bootloader
   *
   * Send bl_exit command, then wait 50 - 100 ms to let device transition to
   * operational mode.  If this is the first time the device's firmware is
   * running, it can take up to 2 seconds to calibrate its sensors.  So, poll
   * the device's new state for up to 2 seconds.
   *
   * Returns:
   *   -EIO    failure while reading from device
   *   -EAGAIN device is stuck in bootloader, b/c it has invalid firmware
   *   0       device is supported and in operational mode
   */
  static int cyapa_gen3_bl_exit(struct cyapa *cyapa)
  {
  	int error;
  
  	error = cyapa_i2c_reg_write_block(cyapa, 0, sizeof(bl_exit), bl_exit);
  	if (error)
  		return error;
  
  	/*
  	 * Wait for bootloader to exit, and operation mode to start.
  	 * Normally, this takes at least 50 ms.
  	 */
  	usleep_range(50000, 100000);
  	/*
  	 * In addition, when a device boots for the first time after being
  	 * updated to new firmware, it must first calibrate its sensors, which
  	 * can take up to an additional 2 seconds. If the device power is
  	 * running low, this may take even longer.
  	 */
  	error = cyapa_poll_state(cyapa, 4000);
  	if (error < 0)
  		return error;
  	if (cyapa->state != CYAPA_STATE_OP)
  		return -EAGAIN;
  
  	return 0;
  }
  
  static u16 cyapa_gen3_csum(const u8 *buf, size_t count)
  {
  	int i;
  	u16 csum = 0;
  
  	for (i = 0; i < count; i++)
  		csum += buf[i];
  
  	return csum;
  }
  
  /*
   * Verify the integrity of a CYAPA firmware image file.
   *
   * The firmware image file is 30848 bytes, composed of 482 64-byte blocks.
   *
   * The first 2 blocks are the firmware header.
   * The next 480 blocks are the firmware image.
   *
   * The first two bytes of the header hold the header checksum, computed by
   * summing the other 126 bytes of the header.
   * The last two bytes of the header hold the firmware image checksum, computed
   * by summing the 30720 bytes of the image modulo 0xffff.
   *
   * Both checksums are stored little-endian.
   */
  static int cyapa_gen3_check_fw(struct cyapa *cyapa, const struct firmware *fw)
  {
  	struct device *dev = &cyapa->client->dev;
  	u16 csum;
  	u16 csum_expected;
  
  	/* Firmware must match exact 30848 bytes = 482 64-byte blocks. */
  	if (fw->size != CYAPA_FW_SIZE) {
  		dev_err(dev, "invalid firmware size = %zu, expected %u.
  ",
  			fw->size, CYAPA_FW_SIZE);
  		return -EINVAL;
  	}
  
  	/* Verify header block */
  	csum_expected = (fw->data[0] << 8) | fw->data[1];
  	csum = cyapa_gen3_csum(&fw->data[2], CYAPA_FW_HDR_SIZE - 2);
  	if (csum != csum_expected) {
  		dev_err(dev, "%s %04x, expected: %04x
  ",
  			"invalid firmware header checksum = ",
  			csum, csum_expected);
  		return -EINVAL;
  	}
  
  	/* Verify firmware image */
  	csum_expected = (fw->data[CYAPA_FW_HDR_SIZE - 2] << 8) |
  			 fw->data[CYAPA_FW_HDR_SIZE - 1];
  	csum = cyapa_gen3_csum(&fw->data[CYAPA_FW_HDR_SIZE],
  			CYAPA_FW_DATA_SIZE);
  	if (csum != csum_expected) {
  		dev_err(dev, "%s %04x, expected: %04x
  ",
  			"invalid firmware header checksum = ",
  			csum, csum_expected);
  		return -EINVAL;
  	}
  	return 0;
  }
  
  /*
   * Write a |len| byte long buffer |buf| to the device, by chopping it up into a
   * sequence of smaller |CYAPA_CMD_LEN|-length write commands.
   *
   * The data bytes for a write command are prepended with the 1-byte offset
   * of the data relative to the start of |buf|.
   */
  static int cyapa_gen3_write_buffer(struct cyapa *cyapa,
  		const u8 *buf, size_t len)
  {
  	int error;
  	size_t i;
  	unsigned char cmd[CYAPA_CMD_LEN + 1];
  	size_t cmd_len;
  
  	for (i = 0; i < len; i += CYAPA_CMD_LEN) {
  		const u8 *payload = &buf[i];
  
  		cmd_len = (len - i >= CYAPA_CMD_LEN) ? CYAPA_CMD_LEN : len - i;
  		cmd[0] = i;
  		memcpy(&cmd[1], payload, cmd_len);
  
  		error = cyapa_i2c_reg_write_block(cyapa, 0, cmd_len + 1, cmd);
  		if (error)
  			return error;
  	}
  	return 0;
  }
  
  /*
   * A firmware block write command writes 64 bytes of data to a single flash
   * page in the device.  The 78-byte block write command has the format:
   *   <0xff> <CMD> <Key> <Start> <Data> <Data-Checksum> <CMD Checksum>
   *
   *  <0xff>  - every command starts with 0xff
   *  <CMD>   - the write command value is 0x39
   *  <Key>   - write commands include an 8-byte key: { 00 01 02 03 04 05 06 07 }
   *  <Block> - Memory Block number (address / 64) (16-bit, big-endian)
   *  <Data>  - 64 bytes of firmware image data
   *  <Data Checksum> - sum of 64 <Data> bytes, modulo 0xff
   *  <CMD Checksum> - sum of 77 bytes, from 0xff to <Data Checksum>
   *
   * Each write command is split into 5 i2c write transactions of up to 16 bytes.
   * Each transaction starts with an i2c register offset: (00, 10, 20, 30, 40).
   */
  static int cyapa_gen3_write_fw_block(struct cyapa *cyapa,
  		u16 block, const u8 *data)
  {
  	int ret;
  	struct gen3_write_block_cmd write_block_cmd;
  	u8 status[BL_STATUS_SIZE];
  	int tries;
  	u8 bl_status, bl_error;
  
  	/* Set write command and security key bytes. */
  	write_block_cmd.checksum_seed = GEN3_BL_CMD_CHECKSUM_SEED;
  	write_block_cmd.cmd_code = GEN3_BL_CMD_WRITE_BLOCK;
  	memcpy(write_block_cmd.key, security_key, sizeof(security_key));
  	put_unaligned_be16(block, &write_block_cmd.block_num);
  	memcpy(write_block_cmd.block_data, data, CYAPA_FW_BLOCK_SIZE);
  	write_block_cmd.block_checksum = cyapa_gen3_csum(
  			write_block_cmd.block_data, CYAPA_FW_BLOCK_SIZE);
  	write_block_cmd.cmd_checksum = cyapa_gen3_csum((u8 *)&write_block_cmd,
  			sizeof(write_block_cmd) - 1);
  
  	ret = cyapa_gen3_write_buffer(cyapa, (u8 *)&write_block_cmd,
  			sizeof(write_block_cmd));
  	if (ret)
  		return ret;
  
  	/* Wait for write to finish */
  	tries = 11;  /* Programming for one block can take about 100ms. */
  	do {
  		usleep_range(10000, 20000);
  
  		/* Check block write command result status. */
  		ret = cyapa_i2c_reg_read_block(cyapa, BL_HEAD_OFFSET,
  					       BL_STATUS_SIZE, status);
  		if (ret != BL_STATUS_SIZE)
  			return (ret < 0) ? ret : -EIO;
  	} while ((status[REG_BL_STATUS] & BL_STATUS_BUSY) && --tries);
  
  	/* Ignore WATCHDOG bit and reserved bits. */
  	bl_status = status[REG_BL_STATUS] & ~BL_STATUS_REV_MASK;
  	bl_error = status[REG_BL_ERROR] & ~BL_ERROR_RESERVED;
  
  	if (bl_status & BL_STATUS_BUSY)
  		ret = -ETIMEDOUT;
  	else if (bl_status != BL_STATUS_RUNNING ||
  		bl_error != BL_ERROR_BOOTLOADING)
  		ret = -EIO;
  	else
  		ret = 0;
  
  	return ret;
  }
  
  static int cyapa_gen3_write_blocks(struct cyapa *cyapa,
  		size_t start_block, size_t block_count,
  		const u8 *image_data)
  {
  	int error;
  	int i;
  
  	for (i = 0; i < block_count; i++) {
  		size_t block = start_block + i;
  		size_t addr = i * CYAPA_FW_BLOCK_SIZE;
  		const u8 *data = &image_data[addr];
  
  		error = cyapa_gen3_write_fw_block(cyapa, block, data);
  		if (error)
  			return error;
  	}
  	return 0;
  }
  
  static int cyapa_gen3_do_fw_update(struct cyapa *cyapa,
  		const struct firmware *fw)
  {
  	struct device *dev = &cyapa->client->dev;
  	int error;
  
  	/* First write data, starting at byte 128 of fw->data */
  	error = cyapa_gen3_write_blocks(cyapa,
  		CYAPA_FW_DATA_BLOCK_START, CYAPA_FW_DATA_BLOCK_COUNT,
  		&fw->data[CYAPA_FW_HDR_BLOCK_COUNT * CYAPA_FW_BLOCK_SIZE]);
  	if (error) {
  		dev_err(dev, "FW update aborted, write image: %d
  ", error);
  		return error;
  	}
  
  	/* Then write checksum */
  	error = cyapa_gen3_write_blocks(cyapa,
  		CYAPA_FW_HDR_BLOCK_START, CYAPA_FW_HDR_BLOCK_COUNT,
  		&fw->data[0]);
  	if (error) {
  		dev_err(dev, "FW update aborted, write checksum: %d
  ", error);
  		return error;
  	}
  
  	return 0;
  }
  
  static ssize_t cyapa_gen3_do_calibrate(struct device *dev,
  				     struct device_attribute *attr,
  				     const char *buf, size_t count)
  {
  	struct cyapa *cyapa = dev_get_drvdata(dev);
  	int tries;
  	int ret;
  
  	ret = cyapa_read_byte(cyapa, CYAPA_CMD_DEV_STATUS);
  	if (ret < 0) {
  		dev_err(dev, "Error reading dev status: %d
  ", ret);
  		goto out;
  	}
  	if ((ret & CYAPA_DEV_NORMAL) != CYAPA_DEV_NORMAL) {
  		dev_warn(dev, "Trackpad device is busy, device state: 0x%02x
  ",
  			 ret);
  		ret = -EAGAIN;
  		goto out;
  	}
  
  	ret = cyapa_write_byte(cyapa, CYAPA_CMD_SOFT_RESET,
  			       OP_RECALIBRATION_MASK);
  	if (ret < 0) {
  		dev_err(dev, "Failed to send calibrate command: %d
  ",
  			ret);
  		goto out;
  	}
  
  	tries = 20;  /* max recalibration timeout 2s. */
  	do {
  		/*
  		 * For this recalibration, the max time will not exceed 2s.
  		 * The average time is approximately 500 - 700 ms, and we
  		 * will check the status every 100 - 200ms.
  		 */
  		usleep_range(100000, 200000);
  
  		ret = cyapa_read_byte(cyapa, CYAPA_CMD_DEV_STATUS);
  		if (ret < 0) {
  			dev_err(dev, "Error reading dev status: %d
  ",
  				ret);
  			goto out;
  		}
  		if ((ret & CYAPA_DEV_NORMAL) == CYAPA_DEV_NORMAL)
  			break;
  	} while (--tries);
  
  	if (tries == 0) {
  		dev_err(dev, "Failed to calibrate. Timeout.
  ");
  		ret = -ETIMEDOUT;
  		goto out;
  	}
  	dev_dbg(dev, "Calibration successful.
  ");
  
  out:
  	return ret < 0 ? ret : count;
  }
  
  static ssize_t cyapa_gen3_show_baseline(struct device *dev,
  				   struct device_attribute *attr, char *buf)
  {
  	struct cyapa *cyapa = dev_get_drvdata(dev);
  	int max_baseline, min_baseline;
  	int tries;
  	int ret;
  
  	ret = cyapa_read_byte(cyapa, CYAPA_CMD_DEV_STATUS);
  	if (ret < 0) {
  		dev_err(dev, "Error reading dev status. err = %d
  ", ret);
  		goto out;
  	}
  	if ((ret & CYAPA_DEV_NORMAL) != CYAPA_DEV_NORMAL) {
  		dev_warn(dev, "Trackpad device is busy. device state = 0x%x
  ",
  			 ret);
  		ret = -EAGAIN;
  		goto out;
  	}
  
  	ret = cyapa_write_byte(cyapa, CYAPA_CMD_SOFT_RESET,
  			       OP_REPORT_BASELINE_MASK);
  	if (ret < 0) {
  		dev_err(dev, "Failed to send report baseline command. %d
  ",
  			ret);
  		goto out;
  	}
  
  	tries = 3;  /* Try for 30 to 60 ms */
  	do {
  		usleep_range(10000, 20000);
  
  		ret = cyapa_read_byte(cyapa, CYAPA_CMD_DEV_STATUS);
  		if (ret < 0) {
  			dev_err(dev, "Error reading dev status. err = %d
  ",
  				ret);
  			goto out;
  		}
  		if ((ret & CYAPA_DEV_NORMAL) == CYAPA_DEV_NORMAL)
  			break;
  	} while (--tries);
  
  	if (tries == 0) {
  		dev_err(dev, "Device timed out going to Normal state.
  ");
  		ret = -ETIMEDOUT;
  		goto out;
  	}
  
  	ret = cyapa_read_byte(cyapa, CYAPA_CMD_MAX_BASELINE);
  	if (ret < 0) {
  		dev_err(dev, "Failed to read max baseline. err = %d
  ", ret);
  		goto out;
  	}
  	max_baseline = ret;
  
  	ret = cyapa_read_byte(cyapa, CYAPA_CMD_MIN_BASELINE);
  	if (ret < 0) {
  		dev_err(dev, "Failed to read min baseline. err = %d
  ", ret);
  		goto out;
  	}
  	min_baseline = ret;
  
  	dev_dbg(dev, "Baseline report successful. Max: %d Min: %d
  ",
  		max_baseline, min_baseline);
  	ret = scnprintf(buf, PAGE_SIZE, "%d %d
  ", max_baseline, min_baseline);
  
  out:
  	return ret;
  }
  
  /*
   * cyapa_get_wait_time_for_pwr_cmd
   *
   * Compute the amount of time we need to wait after updating the touchpad
   * power mode. The touchpad needs to consume the incoming power mode set
   * command at the current clock rate.
   */
  
  static u16 cyapa_get_wait_time_for_pwr_cmd(u8 pwr_mode)
  {
  	switch (pwr_mode) {
  	case PWR_MODE_FULL_ACTIVE: return 20;
  	case PWR_MODE_BTN_ONLY: return 20;
  	case PWR_MODE_OFF: return 20;
  	default: return cyapa_pwr_cmd_to_sleep_time(pwr_mode) + 50;
  	}
  }
  
  /*
   * Set device power mode
   *
   * Write to the field to configure power state. Power states include :
   *   Full : Max scans and report rate.
   *   Idle : Report rate set by user specified time.
   *   ButtonOnly : No scans for fingers. When the button is triggered,
   *     a slave interrupt is asserted to notify host to wake up.
   *   Off : Only awake for i2c commands from host. No function for button
   *     or touch sensors.
   *
   * The power_mode command should conform to the following :
   *   Full : 0x3f
   *   Idle : Configurable from 20 to 1000ms. See note below for
   *     cyapa_sleep_time_to_pwr_cmd and cyapa_pwr_cmd_to_sleep_time
   *   ButtonOnly : 0x01
   *   Off : 0x00
   *
   * Device power mode can only be set when device is in operational mode.
   */
  static int cyapa_gen3_set_power_mode(struct cyapa *cyapa, u8 power_mode,
  		u16 always_unused, bool is_suspend_unused)
  {
  	int ret;
  	u8 power;
  	int tries;
  	u16 sleep_time;
  
  	if (cyapa->state != CYAPA_STATE_OP)
  		return 0;
  
  	tries = SET_POWER_MODE_TRIES;
  	while (tries--) {
  		ret = cyapa_read_byte(cyapa, CYAPA_CMD_POWER_MODE);
  		if (ret >= 0)
  			break;
  		usleep_range(SET_POWER_MODE_DELAY, 2 * SET_POWER_MODE_DELAY);
  	}
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * Return early if the power mode to set is the same as the current
  	 * one.
  	 */
  	if ((ret & PWR_MODE_MASK) == power_mode)
  		return 0;
  
  	sleep_time = cyapa_get_wait_time_for_pwr_cmd(ret & PWR_MODE_MASK);
  	power = ret;
  	power &= ~PWR_MODE_MASK;
  	power |= power_mode & PWR_MODE_MASK;
  	tries = SET_POWER_MODE_TRIES;
  	while (tries--) {
  		ret = cyapa_write_byte(cyapa, CYAPA_CMD_POWER_MODE, power);
  		if (!ret)
  			break;
  		usleep_range(SET_POWER_MODE_DELAY, 2 * SET_POWER_MODE_DELAY);
  	}
  
  	/*
  	 * Wait for the newly set power command to go in at the previous
  	 * clock speed (scanrate) used by the touchpad firmware. Not
  	 * doing so before issuing the next command may result in errors
  	 * depending on the command's content.
  	 */
  	msleep(sleep_time);
  	return ret;
  }
  
  static int cyapa_gen3_set_proximity(struct cyapa *cyapa, bool enable)
  {
  	return -EOPNOTSUPP;
  }
  
  static int cyapa_gen3_get_query_data(struct cyapa *cyapa)
  {
  	u8 query_data[QUERY_DATA_SIZE];
  	int ret;
  
  	if (cyapa->state != CYAPA_STATE_OP)
  		return -EBUSY;
  
  	ret = cyapa_read_block(cyapa, CYAPA_CMD_GROUP_QUERY, query_data);
  	if (ret != QUERY_DATA_SIZE)
  		return (ret < 0) ? ret : -EIO;
  
  	memcpy(&cyapa->product_id[0], &query_data[0], 5);
  	cyapa->product_id[5] = '-';
  	memcpy(&cyapa->product_id[6], &query_data[5], 6);
  	cyapa->product_id[12] = '-';
  	memcpy(&cyapa->product_id[13], &query_data[11], 2);
  	cyapa->product_id[15] = '\0';
  
  	cyapa->fw_maj_ver = query_data[15];
  	cyapa->fw_min_ver = query_data[16];
  
  	cyapa->btn_capability = query_data[19] & CAPABILITY_BTN_MASK;
  
  	cyapa->gen = query_data[20] & 0x0f;
  
  	cyapa->max_abs_x = ((query_data[21] & 0xf0) << 4) | query_data[22];
  	cyapa->max_abs_y = ((query_data[21] & 0x0f) << 8) | query_data[23];
  
  	cyapa->physical_size_x =
  		((query_data[24] & 0xf0) << 4) | query_data[25];
  	cyapa->physical_size_y =
  		((query_data[24] & 0x0f) << 8) | query_data[26];
  
  	cyapa->max_z = 255;
  
  	return 0;
  }
  
  static int cyapa_gen3_bl_query_data(struct cyapa *cyapa)
  {
  	u8 bl_data[CYAPA_CMD_LEN];
  	int ret;
  
  	ret = cyapa_i2c_reg_read_block(cyapa, 0, CYAPA_CMD_LEN, bl_data);
  	if (ret != CYAPA_CMD_LEN)
  		return (ret < 0) ? ret : -EIO;
  
  	/*
  	 * This value will be updated again when entered application mode.
  	 * If TP failed to enter application mode, this fw version values
  	 * can be used as a reference.
  	 * This firmware version valid when fw image checksum is valid.
  	 */
  	if (bl_data[REG_BL_STATUS] ==
  			(BL_STATUS_RUNNING | BL_STATUS_CSUM_VALID)) {
  		cyapa->fw_maj_ver = bl_data[GEN3_BL_IDLE_FW_MAJ_VER_OFFSET];
  		cyapa->fw_min_ver = bl_data[GEN3_BL_IDLE_FW_MIN_VER_OFFSET];
  	}
  
  	return 0;
  }
  
  /*
   * Check if device is operational.
   *
   * An operational device is responding, has exited bootloader, and has
   * firmware supported by this driver.
   *
   * Returns:
   *   -EBUSY  no device or in bootloader
   *   -EIO    failure while reading from device
   *   -EAGAIN device is still in bootloader
   *           if ->state = CYAPA_STATE_BL_IDLE, device has invalid firmware
   *   -EINVAL device is in operational mode, but not supported by this driver
   *   0       device is supported
   */
  static int cyapa_gen3_do_operational_check(struct cyapa *cyapa)
  {
  	struct device *dev = &cyapa->client->dev;
  	int error;
  
  	switch (cyapa->state) {
  	case CYAPA_STATE_BL_ACTIVE:
  		error = cyapa_gen3_bl_deactivate(cyapa);
  		if (error) {
  			dev_err(dev, "failed to bl_deactivate: %d
  ", error);
  			return error;
  		}
  
  	/* Fallthrough state */
  	case CYAPA_STATE_BL_IDLE:
  		/* Try to get firmware version in bootloader mode. */
  		cyapa_gen3_bl_query_data(cyapa);
  
  		error = cyapa_gen3_bl_exit(cyapa);
  		if (error) {
  			dev_err(dev, "failed to bl_exit: %d
  ", error);
  			return error;
  		}
  
  	/* Fallthrough state */
  	case CYAPA_STATE_OP:
  		/*
  		 * Reading query data before going back to the full mode
  		 * may cause problems, so we set the power mode first here.
  		 */
  		error = cyapa_gen3_set_power_mode(cyapa,
  				PWR_MODE_FULL_ACTIVE, 0, false);
  		if (error)
  			dev_err(dev, "%s: set full power mode failed: %d
  ",
  				__func__, error);
  		error = cyapa_gen3_get_query_data(cyapa);
  		if (error < 0)
  			return error;
  
  		/* Only support firmware protocol gen3 */
  		if (cyapa->gen != CYAPA_GEN3) {
  			dev_err(dev, "unsupported protocol version (%d)",
  				cyapa->gen);
  			return -EINVAL;
  		}
  
  		/* Only support product ID starting with CYTRA */
  		if (memcmp(cyapa->product_id, product_id,
  				strlen(product_id)) != 0) {
  			dev_err(dev, "unsupported product ID (%s)
  ",
  				cyapa->product_id);
  			return -EINVAL;
  		}
  
  		return 0;
  
  	default:
  		return -EIO;
  	}
  	return 0;
  }
  
  /*
   * Return false, do not continue process
   * Return true, continue process.
   */
  static bool cyapa_gen3_irq_cmd_handler(struct cyapa *cyapa)
  {
  	/* Not gen3 irq command response, skip for continue. */
  	if (cyapa->gen != CYAPA_GEN3)
  		return true;
  
  	if (cyapa->operational)
  		return true;
  
  	/*
  	 * Driver in detecting or other interface function processing,
  	 * so, stop cyapa_gen3_irq_handler to continue process to
  	 * avoid unwanted to error detecting and processing.
  	 *
  	 * And also, avoid the periodically asserted interrupts to be processed
  	 * as touch inputs when gen3 failed to launch into application mode,
  	 * which will cause gen3 stays in bootloader mode.
  	 */
  	return false;
  }
  
  static int cyapa_gen3_irq_handler(struct cyapa *cyapa)
  {
  	struct input_dev *input = cyapa->input;
  	struct device *dev = &cyapa->client->dev;
  	struct cyapa_reg_data data;
  	int num_fingers;
  	int ret;
  	int i;
  
  	ret = cyapa_read_block(cyapa, CYAPA_CMD_GROUP_DATA, (u8 *)&data);
  	if (ret != sizeof(data)) {
  		dev_err(dev, "failed to read report data, (%d)
  ", ret);
  		return -EINVAL;
  	}
  
  	if ((data.device_status & OP_STATUS_SRC) != OP_STATUS_SRC ||
  	    (data.device_status & OP_STATUS_DEV) != CYAPA_DEV_NORMAL ||
  	    (data.finger_btn & OP_DATA_VALID) != OP_DATA_VALID) {
  		dev_err(dev, "invalid device state bytes, %02x %02x
  ",
  			data.device_status, data.finger_btn);
  		return -EINVAL;
  	}
  
  	num_fingers = (data.finger_btn >> 4) & 0x0f;
  	for (i = 0; i < num_fingers; i++) {
  		const struct cyapa_touch *touch = &data.touches[i];
  		/* Note: touch->id range is 1 to 15; slots are 0 to 14. */
  		int slot = touch->id - 1;
  
  		input_mt_slot(input, slot);
  		input_mt_report_slot_state(input, MT_TOOL_FINGER, true);
  		input_report_abs(input, ABS_MT_POSITION_X,
  				 ((touch->xy_hi & 0xf0) << 4) | touch->x_lo);
  		input_report_abs(input, ABS_MT_POSITION_Y,
  				 ((touch->xy_hi & 0x0f) << 8) | touch->y_lo);
  		input_report_abs(input, ABS_MT_PRESSURE, touch->pressure);
  	}
  
  	input_mt_sync_frame(input);
  
  	if (cyapa->btn_capability & CAPABILITY_LEFT_BTN_MASK)
  		input_report_key(input, BTN_LEFT,
  				 !!(data.finger_btn & OP_DATA_LEFT_BTN));
  	if (cyapa->btn_capability & CAPABILITY_MIDDLE_BTN_MASK)
  		input_report_key(input, BTN_MIDDLE,
  				 !!(data.finger_btn & OP_DATA_MIDDLE_BTN));
  	if (cyapa->btn_capability & CAPABILITY_RIGHT_BTN_MASK)
  		input_report_key(input, BTN_RIGHT,
  				 !!(data.finger_btn & OP_DATA_RIGHT_BTN));
  	input_sync(input);
  
  	return 0;
  }
  
  static int cyapa_gen3_initialize(struct cyapa *cyapa) { return 0; }
  static int cyapa_gen3_bl_initiate(struct cyapa *cyapa,
  		const struct firmware *fw) { return 0; }
  static int cyapa_gen3_empty_output_data(struct cyapa *cyapa,
  		u8 *buf, int *len, cb_sort func) { return 0; }
  
  const struct cyapa_dev_ops cyapa_gen3_ops = {
  	.check_fw = cyapa_gen3_check_fw,
  	.bl_enter = cyapa_gen3_bl_enter,
  	.bl_activate = cyapa_gen3_bl_activate,
  	.update_fw = cyapa_gen3_do_fw_update,
  	.bl_deactivate = cyapa_gen3_bl_deactivate,
  	.bl_initiate = cyapa_gen3_bl_initiate,
  
  	.show_baseline = cyapa_gen3_show_baseline,
  	.calibrate_store = cyapa_gen3_do_calibrate,
  
  	.initialize = cyapa_gen3_initialize,
  
  	.state_parse = cyapa_gen3_state_parse,
  	.operational_check = cyapa_gen3_do_operational_check,
  
  	.irq_handler = cyapa_gen3_irq_handler,
  	.irq_cmd_handler = cyapa_gen3_irq_cmd_handler,
  	.sort_empty_output_data = cyapa_gen3_empty_output_data,
  	.set_power_mode = cyapa_gen3_set_power_mode,
  
  	.set_proximity = cyapa_gen3_set_proximity,
  };