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   1/*
   2 * Weida HiTech WDT87xx TouchScreen I2C driver
   3 *
   4 * Copyright (c) 2015  Weida Hi-Tech Co., Ltd.
   5 * HN Chen <hn.chen@weidahitech.com>
   6 *
   7 * This software is licensed under the terms of the GNU General Public
   8 * License, as published by the Free Software Foundation, and
   9 * may be copied, distributed, and modified under those terms.
  10 */
  11
  12#include <linux/i2c.h>
  13#include <linux/input.h>
  14#include <linux/interrupt.h>
  15#include <linux/delay.h>
  16#include <linux/irq.h>
  17#include <linux/io.h>
  18#include <linux/module.h>
  19#include <linux/slab.h>
  20#include <linux/firmware.h>
  21#include <linux/input/mt.h>
  22#include <linux/acpi.h>
  23#include <asm/unaligned.h>
  24
  25#define WDT87XX_NAME		"wdt87xx_i2c"
  26#define WDT87XX_FW_NAME		"wdt87xx_fw.bin"
  27#define WDT87XX_CFG_NAME	"wdt87xx_cfg.bin"
  28
  29#define MODE_ACTIVE			0x01
  30#define MODE_READY			0x02
  31#define MODE_IDLE			0x03
  32#define MODE_SLEEP			0x04
  33#define MODE_STOP			0xFF
  34
  35#define WDT_MAX_FINGER			10
  36#define WDT_RAW_BUF_COUNT		54
  37#define WDT_V1_RAW_BUF_COUNT		74
  38#define WDT_FIRMWARE_ID			0xa9e368f5
  39
  40#define PG_SIZE				0x1000
  41#define MAX_RETRIES			3
  42
  43#define MAX_UNIT_AXIS			0x7FFF
  44
  45#define PKT_READ_SIZE			72
  46#define PKT_WRITE_SIZE			80
  47
  48/* the finger definition of the report event */
  49#define FINGER_EV_OFFSET_ID		0
  50#define FINGER_EV_OFFSET_X		1
  51#define FINGER_EV_OFFSET_Y		3
  52#define FINGER_EV_SIZE			5
  53
  54#define FINGER_EV_V1_OFFSET_ID		0
  55#define FINGER_EV_V1_OFFSET_W		1
  56#define FINGER_EV_V1_OFFSET_P		2
  57#define FINGER_EV_V1_OFFSET_X		3
  58#define FINGER_EV_V1_OFFSET_Y		5
  59#define FINGER_EV_V1_SIZE		7
  60
  61/* The definition of a report packet */
  62#define TOUCH_PK_OFFSET_REPORT_ID	0
  63#define TOUCH_PK_OFFSET_EVENT		1
  64#define TOUCH_PK_OFFSET_SCAN_TIME	51
  65#define TOUCH_PK_OFFSET_FNGR_NUM	53
  66
  67#define TOUCH_PK_V1_OFFSET_REPORT_ID	0
  68#define TOUCH_PK_V1_OFFSET_EVENT	1
  69#define TOUCH_PK_V1_OFFSET_SCAN_TIME	71
  70#define TOUCH_PK_V1_OFFSET_FNGR_NUM	73
  71
  72/* The definition of the controller parameters */
  73#define CTL_PARAM_OFFSET_FW_ID		0
  74#define CTL_PARAM_OFFSET_PLAT_ID	2
  75#define CTL_PARAM_OFFSET_XMLS_ID1	4
  76#define CTL_PARAM_OFFSET_XMLS_ID2	6
  77#define CTL_PARAM_OFFSET_PHY_CH_X	8
  78#define CTL_PARAM_OFFSET_PHY_CH_Y	10
  79#define CTL_PARAM_OFFSET_PHY_X0		12
  80#define CTL_PARAM_OFFSET_PHY_X1		14
  81#define CTL_PARAM_OFFSET_PHY_Y0		16
  82#define CTL_PARAM_OFFSET_PHY_Y1		18
  83#define CTL_PARAM_OFFSET_PHY_W		22
  84#define CTL_PARAM_OFFSET_PHY_H		24
  85#define CTL_PARAM_OFFSET_FACTOR		32
  86
  87/* The definition of the device descriptor */
  88#define WDT_GD_DEVICE			1
  89#define DEV_DESC_OFFSET_VID		8
  90#define DEV_DESC_OFFSET_PID		10
  91
  92/* Communication commands */
  93#define PACKET_SIZE			56
  94#define VND_REQ_READ			0x06
  95#define VND_READ_DATA			0x07
  96#define VND_REQ_WRITE			0x08
  97
  98#define VND_CMD_START			0x00
  99#define VND_CMD_STOP			0x01
 100#define VND_CMD_RESET			0x09
 101
 102#define VND_CMD_ERASE			0x1A
 103
 104#define VND_GET_CHECKSUM		0x66
 105
 106#define VND_SET_DATA			0x83
 107#define VND_SET_COMMAND_DATA		0x84
 108#define VND_SET_CHECKSUM_CALC		0x86
 109#define VND_SET_CHECKSUM_LENGTH		0x87
 110
 111#define VND_CMD_SFLCK			0xFC
 112#define VND_CMD_SFUNL			0xFD
 113
 114#define CMD_SFLCK_KEY			0xC39B
 115#define CMD_SFUNL_KEY			0x95DA
 116
 117#define STRIDX_PLATFORM_ID		0x80
 118#define STRIDX_PARAMETERS		0x81
 119
 120#define CMD_BUF_SIZE			8
 121#define PKT_BUF_SIZE			64
 122
 123/* The definition of the command packet */
 124#define CMD_REPORT_ID_OFFSET		0x0
 125#define CMD_TYPE_OFFSET			0x1
 126#define CMD_INDEX_OFFSET		0x2
 127#define CMD_KEY_OFFSET			0x3
 128#define CMD_LENGTH_OFFSET		0x4
 129#define CMD_DATA_OFFSET			0x8
 130
 131/* The definition of firmware chunk tags */
 132#define FOURCC_ID_RIFF			0x46464952
 133#define FOURCC_ID_WHIF			0x46494857
 134#define FOURCC_ID_FRMT			0x544D5246
 135#define FOURCC_ID_FRWR			0x52575246
 136#define FOURCC_ID_CNFG			0x47464E43
 137
 138#define CHUNK_ID_FRMT			FOURCC_ID_FRMT
 139#define CHUNK_ID_FRWR			FOURCC_ID_FRWR
 140#define CHUNK_ID_CNFG			FOURCC_ID_CNFG
 141
 142#define FW_FOURCC1_OFFSET		0
 143#define FW_SIZE_OFFSET			4
 144#define FW_FOURCC2_OFFSET		8
 145#define FW_PAYLOAD_OFFSET		40
 146
 147#define FW_CHUNK_ID_OFFSET		0
 148#define FW_CHUNK_SIZE_OFFSET		4
 149#define FW_CHUNK_TGT_START_OFFSET	8
 150#define FW_CHUNK_PAYLOAD_LEN_OFFSET	12
 151#define FW_CHUNK_SRC_START_OFFSET	16
 152#define FW_CHUNK_VERSION_OFFSET		20
 153#define FW_CHUNK_ATTR_OFFSET		24
 154#define FW_CHUNK_PAYLOAD_OFFSET		32
 155
 156/* Controller requires minimum 300us between commands */
 157#define WDT_COMMAND_DELAY_MS		2
 158#define WDT_FLASH_WRITE_DELAY_MS	4
 159#define WDT_FLASH_ERASE_DELAY_MS	200
 160#define WDT_FW_RESET_TIME		2500
 161
 162struct wdt87xx_sys_param {
 163	u16	fw_id;
 164	u16	plat_id;
 165	u16	xmls_id1;
 166	u16	xmls_id2;
 167	u16	phy_ch_x;
 168	u16	phy_ch_y;
 169	u16	phy_w;
 170	u16	phy_h;
 171	u16	scaling_factor;
 172	u32	max_x;
 173	u32	max_y;
 174	u16	vendor_id;
 175	u16	product_id;
 176};
 177
 178struct wdt87xx_data {
 179	struct i2c_client		*client;
 180	struct input_dev		*input;
 181	/* Mutex for fw update to prevent concurrent access */
 182	struct mutex			fw_mutex;
 183	struct wdt87xx_sys_param	param;
 184	u8				phys[32];
 185};
 186
 187static int wdt87xx_i2c_xfer(struct i2c_client *client,
 188			    void *txdata, size_t txlen,
 189			    void *rxdata, size_t rxlen)
 190{
 191	struct i2c_msg msgs[] = {
 192		{
 193			.addr	= client->addr,
 194			.flags	= 0,
 195			.len	= txlen,
 196			.buf	= txdata,
 197		},
 198		{
 199			.addr	= client->addr,
 200			.flags	= I2C_M_RD,
 201			.len	= rxlen,
 202			.buf	= rxdata,
 203		},
 204	};
 205	int error;
 206	int ret;
 207
 208	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 209	if (ret != ARRAY_SIZE(msgs)) {
 210		error = ret < 0 ? ret : -EIO;
 211		dev_err(&client->dev, "%s: i2c transfer failed: %d\n",
 212			__func__, error);
 213		return error;
 214	}
 215
 216	return 0;
 217}
 218
 219static int wdt87xx_get_desc(struct i2c_client *client, u8 desc_idx,
 220			    u8 *buf, size_t len)
 221{
 222	u8 tx_buf[] = { 0x22, 0x00, 0x10, 0x0E, 0x23, 0x00 };
 223	int error;
 224
 225	tx_buf[2] |= desc_idx & 0xF;
 226
 227	error = wdt87xx_i2c_xfer(client, tx_buf, sizeof(tx_buf),
 228				 buf, len);
 229	if (error) {
 230		dev_err(&client->dev, "get desc failed: %d\n", error);
 231		return error;
 232	}
 233
 234	if (buf[0] != len) {
 235		dev_err(&client->dev, "unexpected response to get desc: %d\n",
 236			buf[0]);
 237		return -EINVAL;
 238	}
 239
 240	mdelay(WDT_COMMAND_DELAY_MS);
 241
 242	return 0;
 243}
 244
 245static int wdt87xx_get_string(struct i2c_client *client, u8 str_idx,
 246			      u8 *buf, size_t len)
 247{
 248	u8 tx_buf[] = { 0x22, 0x00, 0x13, 0x0E, str_idx, 0x23, 0x00 };
 249	u8 rx_buf[PKT_WRITE_SIZE];
 250	size_t rx_len = len + 2;
 251	int error;
 252
 253	if (rx_len > sizeof(rx_buf))
 254		return -EINVAL;
 255
 256	error = wdt87xx_i2c_xfer(client, tx_buf, sizeof(tx_buf),
 257				 rx_buf, rx_len);
 258	if (error) {
 259		dev_err(&client->dev, "get string failed: %d\n", error);
 260		return error;
 261	}
 262
 263	if (rx_buf[1] != 0x03) {
 264		dev_err(&client->dev, "unexpected response to get string: %d\n",
 265			rx_buf[1]);
 266		return -EINVAL;
 267	}
 268
 269	rx_len = min_t(size_t, len, rx_buf[0]);
 270	memcpy(buf, &rx_buf[2], rx_len);
 271
 272	mdelay(WDT_COMMAND_DELAY_MS);
 273
 274	return 0;
 275}
 276
 277static int wdt87xx_get_feature(struct i2c_client *client,
 278			       u8 *buf, size_t buf_size)
 279{
 280	u8 tx_buf[8];
 281	u8 rx_buf[PKT_WRITE_SIZE];
 282	size_t tx_len = 0;
 283	size_t rx_len = buf_size + 2;
 284	int error;
 285
 286	if (rx_len > sizeof(rx_buf))
 287		return -EINVAL;
 288
 289	/* Get feature command packet */
 290	tx_buf[tx_len++] = 0x22;
 291	tx_buf[tx_len++] = 0x00;
 292	if (buf[CMD_REPORT_ID_OFFSET] > 0xF) {
 293		tx_buf[tx_len++] = 0x30;
 294		tx_buf[tx_len++] = 0x02;
 295		tx_buf[tx_len++] = buf[CMD_REPORT_ID_OFFSET];
 296	} else {
 297		tx_buf[tx_len++] = 0x30 | buf[CMD_REPORT_ID_OFFSET];
 298		tx_buf[tx_len++] = 0x02;
 299	}
 300	tx_buf[tx_len++] = 0x23;
 301	tx_buf[tx_len++] = 0x00;
 302
 303	error = wdt87xx_i2c_xfer(client, tx_buf, tx_len, rx_buf, rx_len);
 304	if (error) {
 305		dev_err(&client->dev, "get feature failed: %d\n", error);
 306		return error;
 307	}
 308
 309	rx_len = min_t(size_t, buf_size, get_unaligned_le16(rx_buf));
 310	memcpy(buf, &rx_buf[2], rx_len);
 311
 312	mdelay(WDT_COMMAND_DELAY_MS);
 313
 314	return 0;
 315}
 316
 317static int wdt87xx_set_feature(struct i2c_client *client,
 318			       const u8 *buf, size_t buf_size)
 319{
 320	u8 tx_buf[PKT_WRITE_SIZE];
 321	int tx_len = 0;
 322	int error;
 323
 324	/* Set feature command packet */
 325	tx_buf[tx_len++] = 0x22;
 326	tx_buf[tx_len++] = 0x00;
 327	if (buf[CMD_REPORT_ID_OFFSET] > 0xF) {
 328		tx_buf[tx_len++] = 0x30;
 329		tx_buf[tx_len++] = 0x03;
 330		tx_buf[tx_len++] = buf[CMD_REPORT_ID_OFFSET];
 331	} else {
 332		tx_buf[tx_len++] = 0x30 | buf[CMD_REPORT_ID_OFFSET];
 333		tx_buf[tx_len++] = 0x03;
 334	}
 335	tx_buf[tx_len++] = 0x23;
 336	tx_buf[tx_len++] = 0x00;
 337	tx_buf[tx_len++] = (buf_size & 0xFF);
 338	tx_buf[tx_len++] = ((buf_size & 0xFF00) >> 8);
 339
 340	if (tx_len + buf_size > sizeof(tx_buf))
 341		return -EINVAL;
 342
 343	memcpy(&tx_buf[tx_len], buf, buf_size);
 344	tx_len += buf_size;
 345
 346	error = i2c_master_send(client, tx_buf, tx_len);
 347	if (error < 0) {
 348		dev_err(&client->dev, "set feature failed: %d\n", error);
 349		return error;
 350	}
 351
 352	mdelay(WDT_COMMAND_DELAY_MS);
 353
 354	return 0;
 355}
 356
 357static int wdt87xx_send_command(struct i2c_client *client, int cmd, int value)
 358{
 359	u8 cmd_buf[CMD_BUF_SIZE];
 360
 361	/* Set the command packet */
 362	cmd_buf[CMD_REPORT_ID_OFFSET] = VND_REQ_WRITE;
 363	cmd_buf[CMD_TYPE_OFFSET] = VND_SET_COMMAND_DATA;
 364	put_unaligned_le16((u16)cmd, &cmd_buf[CMD_INDEX_OFFSET]);
 365
 366	switch (cmd) {
 367	case VND_CMD_START:
 368	case VND_CMD_STOP:
 369	case VND_CMD_RESET:
 370		/* Mode selector */
 371		put_unaligned_le32((value & 0xFF), &cmd_buf[CMD_LENGTH_OFFSET]);
 372		break;
 373
 374	case VND_CMD_SFLCK:
 375		put_unaligned_le16(CMD_SFLCK_KEY, &cmd_buf[CMD_KEY_OFFSET]);
 376		break;
 377
 378	case VND_CMD_SFUNL:
 379		put_unaligned_le16(CMD_SFUNL_KEY, &cmd_buf[CMD_KEY_OFFSET]);
 380		break;
 381
 382	case VND_CMD_ERASE:
 383	case VND_SET_CHECKSUM_CALC:
 384	case VND_SET_CHECKSUM_LENGTH:
 385		put_unaligned_le32(value, &cmd_buf[CMD_KEY_OFFSET]);
 386		break;
 387
 388	default:
 389		cmd_buf[CMD_REPORT_ID_OFFSET] = 0;
 390		dev_err(&client->dev, "Invalid command: %d\n", cmd);
 391		return -EINVAL;
 392	}
 393
 394	return wdt87xx_set_feature(client, cmd_buf, sizeof(cmd_buf));
 395}
 396
 397static int wdt87xx_sw_reset(struct i2c_client *client)
 398{
 399	int error;
 400
 401	dev_dbg(&client->dev, "resetting device now\n");
 402
 403	error = wdt87xx_send_command(client, VND_CMD_RESET, 0);
 404	if (error) {
 405		dev_err(&client->dev, "reset failed\n");
 406		return error;
 407	}
 408
 409	/* Wait the device to be ready */
 410	msleep(WDT_FW_RESET_TIME);
 411
 412	return 0;
 413}
 414
 415static const void *wdt87xx_get_fw_chunk(const struct firmware *fw, u32 id)
 416{
 417	size_t pos = FW_PAYLOAD_OFFSET;
 418	u32 chunk_id, chunk_size;
 419
 420	while (pos < fw->size) {
 421		chunk_id = get_unaligned_le32(fw->data +
 422					      pos + FW_CHUNK_ID_OFFSET);
 423		if (chunk_id == id)
 424			return fw->data + pos;
 425
 426		chunk_size = get_unaligned_le32(fw->data +
 427						pos + FW_CHUNK_SIZE_OFFSET);
 428		pos += chunk_size + 2 * sizeof(u32); /* chunk ID + size */
 429	}
 430
 431	return NULL;
 432}
 433
 434static int wdt87xx_get_sysparam(struct i2c_client *client,
 435				struct wdt87xx_sys_param *param)
 436{
 437	u8 buf[PKT_READ_SIZE];
 438	int error;
 439
 440	error = wdt87xx_get_desc(client, WDT_GD_DEVICE, buf, 18);
 441	if (error) {
 442		dev_err(&client->dev, "failed to get device desc\n");
 443		return error;
 444	}
 445
 446	param->vendor_id = get_unaligned_le16(buf + DEV_DESC_OFFSET_VID);
 447	param->product_id = get_unaligned_le16(buf + DEV_DESC_OFFSET_PID);
 448
 449	error = wdt87xx_get_string(client, STRIDX_PARAMETERS, buf, 34);
 450	if (error) {
 451		dev_err(&client->dev, "failed to get parameters\n");
 452		return error;
 453	}
 454
 455	param->xmls_id1 = get_unaligned_le16(buf + CTL_PARAM_OFFSET_XMLS_ID1);
 456	param->xmls_id2 = get_unaligned_le16(buf + CTL_PARAM_OFFSET_XMLS_ID2);
 457	param->phy_ch_x = get_unaligned_le16(buf + CTL_PARAM_OFFSET_PHY_CH_X);
 458	param->phy_ch_y = get_unaligned_le16(buf + CTL_PARAM_OFFSET_PHY_CH_Y);
 459	param->phy_w = get_unaligned_le16(buf + CTL_PARAM_OFFSET_PHY_W) / 10;
 460	param->phy_h = get_unaligned_le16(buf + CTL_PARAM_OFFSET_PHY_H) / 10;
 461
 462	/* Get the scaling factor of pixel to logical coordinate */
 463	param->scaling_factor =
 464			get_unaligned_le16(buf + CTL_PARAM_OFFSET_FACTOR);
 465
 466	param->max_x = MAX_UNIT_AXIS;
 467	param->max_y = DIV_ROUND_CLOSEST(MAX_UNIT_AXIS * param->phy_h,
 468					 param->phy_w);
 469
 470	error = wdt87xx_get_string(client, STRIDX_PLATFORM_ID, buf, 8);
 471	if (error) {
 472		dev_err(&client->dev, "failed to get platform id\n");
 473		return error;
 474	}
 475
 476	param->plat_id = buf[1];
 477
 478	buf[0] = 0xf2;
 479	error = wdt87xx_get_feature(client, buf, 16);
 480	if (error) {
 481		dev_err(&client->dev, "failed to get firmware id\n");
 482		return error;
 483	}
 484
 485	if (buf[0] != 0xf2) {
 486		dev_err(&client->dev, "wrong id of fw response: 0x%x\n",
 487			buf[0]);
 488		return -EINVAL;
 489	}
 490
 491	param->fw_id = get_unaligned_le16(&buf[1]);
 492
 493	dev_info(&client->dev,
 494		 "fw_id: 0x%x, plat_id: 0x%x, xml_id1: %04x, xml_id2: %04x\n",
 495		 param->fw_id, param->plat_id,
 496		 param->xmls_id1, param->xmls_id2);
 497
 498	return 0;
 499}
 500
 501static int wdt87xx_validate_firmware(struct wdt87xx_data *wdt,
 502				     const struct firmware *fw)
 503{
 504	const void *fw_chunk;
 505	u32 data1, data2;
 506	u32 size;
 507	u8 fw_chip_id;
 508	u8 chip_id;
 509
 510	data1 = get_unaligned_le32(fw->data + FW_FOURCC1_OFFSET);
 511	data2 = get_unaligned_le32(fw->data + FW_FOURCC2_OFFSET);
 512	if (data1 != FOURCC_ID_RIFF || data2 != FOURCC_ID_WHIF) {
 513		dev_err(&wdt->client->dev, "check fw tag failed\n");
 514		return -EINVAL;
 515	}
 516
 517	size = get_unaligned_le32(fw->data + FW_SIZE_OFFSET);
 518	if (size != fw->size) {
 519		dev_err(&wdt->client->dev,
 520			"fw size mismatch: expected %d, actual %zu\n",
 521			size, fw->size);
 522		return -EINVAL;
 523	}
 524
 525	/*
 526	 * Get the chip_id from the firmware. Make sure that it is the
 527	 * right controller to do the firmware and config update.
 528	 */
 529	fw_chunk = wdt87xx_get_fw_chunk(fw, CHUNK_ID_FRWR);
 530	if (!fw_chunk) {
 531		dev_err(&wdt->client->dev,
 532			"unable to locate firmware chunk\n");
 533		return -EINVAL;
 534	}
 535
 536	fw_chip_id = (get_unaligned_le32(fw_chunk +
 537					 FW_CHUNK_VERSION_OFFSET) >> 12) & 0xF;
 538	chip_id = (wdt->param.fw_id >> 12) & 0xF;
 539
 540	if (fw_chip_id != chip_id) {
 541		dev_err(&wdt->client->dev,
 542			"fw version mismatch: fw %d vs. chip %d\n",
 543			fw_chip_id, chip_id);
 544		return -ENODEV;
 545	}
 546
 547	return 0;
 548}
 549
 550static int wdt87xx_validate_fw_chunk(const void *data, int id)
 551{
 552	if (id == CHUNK_ID_FRWR) {
 553		u32 fw_id;
 554
 555		fw_id = get_unaligned_le32(data + FW_CHUNK_PAYLOAD_OFFSET);
 556		if (fw_id != WDT_FIRMWARE_ID)
 557			return -EINVAL;
 558	}
 559
 560	return 0;
 561}
 562
 563static int wdt87xx_write_data(struct i2c_client *client, const char *data,
 564			      u32 address, int length)
 565{
 566	u16 packet_size;
 567	int count = 0;
 568	int error;
 569	u8 pkt_buf[PKT_BUF_SIZE];
 570
 571	/* Address and length should be 4 bytes aligned */
 572	if ((address & 0x3) != 0 || (length & 0x3) != 0) {
 573		dev_err(&client->dev,
 574			"addr & len must be 4 bytes aligned %x, %x\n",
 575			address, length);
 576		return -EINVAL;
 577	}
 578
 579	while (length) {
 580		packet_size = min(length, PACKET_SIZE);
 581
 582		pkt_buf[CMD_REPORT_ID_OFFSET] = VND_REQ_WRITE;
 583		pkt_buf[CMD_TYPE_OFFSET] = VND_SET_DATA;
 584		put_unaligned_le16(packet_size, &pkt_buf[CMD_INDEX_OFFSET]);
 585		put_unaligned_le32(address, &pkt_buf[CMD_LENGTH_OFFSET]);
 586		memcpy(&pkt_buf[CMD_DATA_OFFSET], data, packet_size);
 587
 588		error = wdt87xx_set_feature(client, pkt_buf, sizeof(pkt_buf));
 589		if (error)
 590			return error;
 591
 592		length -= packet_size;
 593		data += packet_size;
 594		address += packet_size;
 595
 596		/* Wait for the controller to finish the write */
 597		mdelay(WDT_FLASH_WRITE_DELAY_MS);
 598
 599		if ((++count % 32) == 0) {
 600			/* Delay for fw to clear watch dog */
 601			msleep(20);
 602		}
 603	}
 604
 605	return 0;
 606}
 607
 608static u16 misr(u16 cur_value, u8 new_value)
 609{
 610	u32 a, b;
 611	u32 bit0;
 612	u32 y;
 613
 614	a = cur_value;
 615	b = new_value;
 616	bit0 = a ^ (b & 1);
 617	bit0 ^= a >> 1;
 618	bit0 ^= a >> 2;
 619	bit0 ^= a >> 4;
 620	bit0 ^= a >> 5;
 621	bit0 ^= a >> 7;
 622	bit0 ^= a >> 11;
 623	bit0 ^= a >> 15;
 624	y = (a << 1) ^ b;
 625	y = (y & ~1) | (bit0 & 1);
 626
 627	return (u16)y;
 628}
 629
 630static u16 wdt87xx_calculate_checksum(const u8 *data, size_t length)
 631{
 632	u16 checksum = 0;
 633	size_t i;
 634
 635	for (i = 0; i < length; i++)
 636		checksum = misr(checksum, data[i]);
 637
 638	return checksum;
 639}
 640
 641static int wdt87xx_get_checksum(struct i2c_client *client, u16 *checksum,
 642				u32 address, int length)
 643{
 644	int error;
 645	int time_delay;
 646	u8 pkt_buf[PKT_BUF_SIZE];
 647	u8 cmd_buf[CMD_BUF_SIZE];
 648
 649	error = wdt87xx_send_command(client, VND_SET_CHECKSUM_LENGTH, length);
 650	if (error) {
 651		dev_err(&client->dev, "failed to set checksum length\n");
 652		return error;
 653	}
 654
 655	error = wdt87xx_send_command(client, VND_SET_CHECKSUM_CALC, address);
 656	if (error) {
 657		dev_err(&client->dev, "failed to set checksum address\n");
 658		return error;
 659	}
 660
 661	/* Wait the operation to complete */
 662	time_delay = DIV_ROUND_UP(length, 1024);
 663	msleep(time_delay * 30);
 664
 665	memset(cmd_buf, 0, sizeof(cmd_buf));
 666	cmd_buf[CMD_REPORT_ID_OFFSET] = VND_REQ_READ;
 667	cmd_buf[CMD_TYPE_OFFSET] = VND_GET_CHECKSUM;
 668	error = wdt87xx_set_feature(client, cmd_buf, sizeof(cmd_buf));
 669	if (error) {
 670		dev_err(&client->dev, "failed to request checksum\n");
 671		return error;
 672	}
 673
 674	memset(pkt_buf, 0, sizeof(pkt_buf));
 675	pkt_buf[CMD_REPORT_ID_OFFSET] = VND_READ_DATA;
 676	error = wdt87xx_get_feature(client, pkt_buf, sizeof(pkt_buf));
 677	if (error) {
 678		dev_err(&client->dev, "failed to read checksum\n");
 679		return error;
 680	}
 681
 682	*checksum = get_unaligned_le16(&pkt_buf[CMD_DATA_OFFSET]);
 683	return 0;
 684}
 685
 686static int wdt87xx_write_firmware(struct i2c_client *client, const void *chunk)
 687{
 688	u32 start_addr = get_unaligned_le32(chunk + FW_CHUNK_TGT_START_OFFSET);
 689	u32 size = get_unaligned_le32(chunk + FW_CHUNK_PAYLOAD_LEN_OFFSET);
 690	const void *data = chunk + FW_CHUNK_PAYLOAD_OFFSET;
 691	int error;
 692	int err1;
 693	int page_size;
 694	int retry = 0;
 695	u16 device_checksum, firmware_checksum;
 696
 697	dev_dbg(&client->dev, "start 4k page program\n");
 698
 699	error = wdt87xx_send_command(client, VND_CMD_STOP, MODE_STOP);
 700	if (error) {
 701		dev_err(&client->dev, "stop report mode failed\n");
 702		return error;
 703	}
 704
 705	error = wdt87xx_send_command(client, VND_CMD_SFUNL, 0);
 706	if (error) {
 707		dev_err(&client->dev, "unlock failed\n");
 708		goto out_enable_reporting;
 709	}
 710
 711	mdelay(10);
 712
 713	while (size) {
 714		dev_dbg(&client->dev, "%s: %x, %x\n", __func__,
 715			start_addr, size);
 716
 717		page_size = min_t(u32, size, PG_SIZE);
 718		size -= page_size;
 719
 720		for (retry = 0; retry < MAX_RETRIES; retry++) {
 721			error = wdt87xx_send_command(client, VND_CMD_ERASE,
 722						     start_addr);
 723			if (error) {
 724				dev_err(&client->dev,
 725					"erase failed at %#08x\n", start_addr);
 726				break;
 727			}
 728
 729			msleep(WDT_FLASH_ERASE_DELAY_MS);
 730
 731			error = wdt87xx_write_data(client, data, start_addr,
 732						   page_size);
 733			if (error) {
 734				dev_err(&client->dev,
 735					"write failed at %#08x (%d bytes)\n",
 736					start_addr, page_size);
 737				break;
 738			}
 739
 740			error = wdt87xx_get_checksum(client, &device_checksum,
 741						     start_addr, page_size);
 742			if (error) {
 743				dev_err(&client->dev,
 744					"failed to retrieve checksum for %#08x (len: %d)\n",
 745					start_addr, page_size);
 746				break;
 747			}
 748
 749			firmware_checksum =
 750				wdt87xx_calculate_checksum(data, page_size);
 751
 752			if (device_checksum == firmware_checksum)
 753				break;
 754
 755			dev_err(&client->dev,
 756				"checksum fail: %d vs %d, retry %d\n",
 757				device_checksum, firmware_checksum, retry);
 758		}
 759
 760		if (retry == MAX_RETRIES) {
 761			dev_err(&client->dev, "page write failed\n");
 762			error = -EIO;
 763			goto out_lock_device;
 764		}
 765
 766		start_addr = start_addr + page_size;
 767		data = data + page_size;
 768	}
 769
 770out_lock_device:
 771	err1 = wdt87xx_send_command(client, VND_CMD_SFLCK, 0);
 772	if (err1)
 773		dev_err(&client->dev, "lock failed\n");
 774
 775	mdelay(10);
 776
 777out_enable_reporting:
 778	err1 = wdt87xx_send_command(client, VND_CMD_START, 0);
 779	if (err1)
 780		dev_err(&client->dev, "start to report failed\n");
 781
 782	return error ? error : err1;
 783}
 784
 785static int wdt87xx_load_chunk(struct i2c_client *client,
 786			      const struct firmware *fw, u32 ck_id)
 787{
 788	const void *chunk;
 789	int error;
 790
 791	chunk = wdt87xx_get_fw_chunk(fw, ck_id);
 792	if (!chunk) {
 793		dev_err(&client->dev, "unable to locate chunk (type %d)\n",
 794			ck_id);
 795		return -EINVAL;
 796	}
 797
 798	error = wdt87xx_validate_fw_chunk(chunk, ck_id);
 799	if (error) {
 800		dev_err(&client->dev, "invalid chunk (type %d): %d\n",
 801			ck_id, error);
 802		return error;
 803	}
 804
 805	error = wdt87xx_write_firmware(client, chunk);
 806	if (error) {
 807		dev_err(&client->dev,
 808			"failed to write fw chunk (type %d): %d\n",
 809			ck_id, error);
 810		return error;
 811	}
 812
 813	return 0;
 814}
 815
 816static int wdt87xx_do_update_firmware(struct i2c_client *client,
 817				      const struct firmware *fw,
 818				      unsigned int chunk_id)
 819{
 820	struct wdt87xx_data *wdt = i2c_get_clientdata(client);
 821	int error;
 822
 823	error = wdt87xx_validate_firmware(wdt, fw);
 824	if (error)
 825		return error;
 826
 827	error = mutex_lock_interruptible(&wdt->fw_mutex);
 828	if (error)
 829		return error;
 830
 831	disable_irq(client->irq);
 832
 833	error = wdt87xx_load_chunk(client, fw, chunk_id);
 834	if (error) {
 835		dev_err(&client->dev,
 836			"firmware load failed (type: %d): %d\n",
 837			chunk_id, error);
 838		goto out;
 839	}
 840
 841	error = wdt87xx_sw_reset(client);
 842	if (error) {
 843		dev_err(&client->dev, "soft reset failed: %d\n", error);
 844		goto out;
 845	}
 846
 847	/* Refresh the parameters */
 848	error = wdt87xx_get_sysparam(client, &wdt->param);
 849	if (error)
 850		dev_err(&client->dev,
 851			"failed to refresh system parameters: %d\n", error);
 852out:
 853	enable_irq(client->irq);
 854	mutex_unlock(&wdt->fw_mutex);
 855
 856	return error ? error : 0;
 857}
 858
 859static int wdt87xx_update_firmware(struct device *dev,
 860				   const char *fw_name, unsigned int chunk_id)
 861{
 862	struct i2c_client *client = to_i2c_client(dev);
 863	const struct firmware *fw;
 864	int error;
 865
 866	error = request_firmware(&fw, fw_name, dev);
 867	if (error) {
 868		dev_err(&client->dev, "unable to retrieve firmware %s: %d\n",
 869			fw_name, error);
 870		return error;
 871	}
 872
 873	error = wdt87xx_do_update_firmware(client, fw, chunk_id);
 874
 875	release_firmware(fw);
 876
 877	return error ? error : 0;
 878}
 879
 880static ssize_t config_csum_show(struct device *dev,
 881				struct device_attribute *attr, char *buf)
 882{
 883	struct i2c_client *client = to_i2c_client(dev);
 884	struct wdt87xx_data *wdt = i2c_get_clientdata(client);
 885	u32 cfg_csum;
 886
 887	cfg_csum = wdt->param.xmls_id1;
 888	cfg_csum = (cfg_csum << 16) | wdt->param.xmls_id2;
 889
 890	return scnprintf(buf, PAGE_SIZE, "%x\n", cfg_csum);
 891}
 892
 893static ssize_t fw_version_show(struct device *dev,
 894			       struct device_attribute *attr, char *buf)
 895{
 896	struct i2c_client *client = to_i2c_client(dev);
 897	struct wdt87xx_data *wdt = i2c_get_clientdata(client);
 898
 899	return scnprintf(buf, PAGE_SIZE, "%x\n", wdt->param.fw_id);
 900}
 901
 902static ssize_t plat_id_show(struct device *dev,
 903			    struct device_attribute *attr, char *buf)
 904{
 905	struct i2c_client *client = to_i2c_client(dev);
 906	struct wdt87xx_data *wdt = i2c_get_clientdata(client);
 907
 908	return scnprintf(buf, PAGE_SIZE, "%x\n", wdt->param.plat_id);
 909}
 910
 911static ssize_t update_config_store(struct device *dev,
 912				   struct device_attribute *attr,
 913				   const char *buf, size_t count)
 914{
 915	int error;
 916
 917	error = wdt87xx_update_firmware(dev, WDT87XX_CFG_NAME, CHUNK_ID_CNFG);
 918
 919	return error ? error : count;
 920}
 921
 922static ssize_t update_fw_store(struct device *dev,
 923			       struct device_attribute *attr,
 924			       const char *buf, size_t count)
 925{
 926	int error;
 927
 928	error = wdt87xx_update_firmware(dev, WDT87XX_FW_NAME, CHUNK_ID_FRWR);
 929
 930	return error ? error : count;
 931}
 932
 933static DEVICE_ATTR_RO(config_csum);
 934static DEVICE_ATTR_RO(fw_version);
 935static DEVICE_ATTR_RO(plat_id);
 936static DEVICE_ATTR_WO(update_config);
 937static DEVICE_ATTR_WO(update_fw);
 938
 939static struct attribute *wdt87xx_attrs[] = {
 940	&dev_attr_config_csum.attr,
 941	&dev_attr_fw_version.attr,
 942	&dev_attr_plat_id.attr,
 943	&dev_attr_update_config.attr,
 944	&dev_attr_update_fw.attr,
 945	NULL
 946};
 947
 948static const struct attribute_group wdt87xx_attr_group = {
 949	.attrs = wdt87xx_attrs,
 950};
 951
 952static void wdt87xx_report_contact(struct input_dev *input,
 953				   struct wdt87xx_sys_param *param,
 954				   u8 *buf)
 955{
 956	int finger_id;
 957	u32 x, y, w;
 958	u8 p;
 959
 960	finger_id = (buf[FINGER_EV_V1_OFFSET_ID] >> 3) - 1;
 961	if (finger_id < 0)
 962		return;
 963
 964	/* Check if this is an active contact */
 965	if (!(buf[FINGER_EV_V1_OFFSET_ID] & 0x1))
 966		return;
 967
 968	w = buf[FINGER_EV_V1_OFFSET_W];
 969	w *= param->scaling_factor;
 970
 971	p = buf[FINGER_EV_V1_OFFSET_P];
 972
 973	x = get_unaligned_le16(buf + FINGER_EV_V1_OFFSET_X);
 974
 975	y = get_unaligned_le16(buf + FINGER_EV_V1_OFFSET_Y);
 976	y = DIV_ROUND_CLOSEST(y * param->phy_h, param->phy_w);
 977
 978	/* Refuse incorrect coordinates */
 979	if (x > param->max_x || y > param->max_y)
 980		return;
 981
 982	dev_dbg(input->dev.parent, "tip on (%d), x(%d), y(%d)\n",
 983		finger_id, x, y);
 984
 985	input_mt_slot(input, finger_id);
 986	input_mt_report_slot_state(input, MT_TOOL_FINGER, 1);
 987	input_report_abs(input, ABS_MT_TOUCH_MAJOR, w);
 988	input_report_abs(input, ABS_MT_PRESSURE, p);
 989	input_report_abs(input, ABS_MT_POSITION_X, x);
 990	input_report_abs(input, ABS_MT_POSITION_Y, y);
 991}
 992
 993static irqreturn_t wdt87xx_ts_interrupt(int irq, void *dev_id)
 994{
 995	struct wdt87xx_data *wdt = dev_id;
 996	struct i2c_client *client = wdt->client;
 997	int i, fingers;
 998	int error;
 999	u8 raw_buf[WDT_V1_RAW_BUF_COUNT] = {0};
1000
1001	error = i2c_master_recv(client, raw_buf, WDT_V1_RAW_BUF_COUNT);
1002	if (error < 0) {
1003		dev_err(&client->dev, "read v1 raw data failed: %d\n", error);
1004		goto irq_exit;
1005	}
1006
1007	fingers = raw_buf[TOUCH_PK_V1_OFFSET_FNGR_NUM];
1008	if (!fingers)
1009		goto irq_exit;
1010
1011	for (i = 0; i < WDT_MAX_FINGER; i++)
1012		wdt87xx_report_contact(wdt->input,
1013				       &wdt->param,
1014				       &raw_buf[TOUCH_PK_V1_OFFSET_EVENT +
1015						i * FINGER_EV_V1_SIZE]);
1016
1017	input_mt_sync_frame(wdt->input);
1018	input_sync(wdt->input);
1019
1020irq_exit:
1021	return IRQ_HANDLED;
1022}
1023
1024static int wdt87xx_ts_create_input_device(struct wdt87xx_data *wdt)
1025{
1026	struct device *dev = &wdt->client->dev;
1027	struct input_dev *input;
1028	unsigned int res = DIV_ROUND_CLOSEST(MAX_UNIT_AXIS, wdt->param.phy_w);
1029	int error;
1030
1031	input = devm_input_allocate_device(dev);
1032	if (!input) {
1033		dev_err(dev, "failed to allocate input device\n");
1034		return -ENOMEM;
1035	}
1036	wdt->input = input;
1037
1038	input->name = "WDT87xx Touchscreen";
1039	input->id.bustype = BUS_I2C;
1040	input->id.vendor = wdt->param.vendor_id;
1041	input->id.product = wdt->param.product_id;
1042	input->phys = wdt->phys;
1043
1044	input_set_abs_params(input, ABS_MT_POSITION_X, 0,
1045			     wdt->param.max_x, 0, 0);
1046	input_set_abs_params(input, ABS_MT_POSITION_Y, 0,
1047			     wdt->param.max_y, 0, 0);
1048	input_abs_set_res(input, ABS_MT_POSITION_X, res);
1049	input_abs_set_res(input, ABS_MT_POSITION_Y, res);
1050
1051	input_set_abs_params(input, ABS_MT_TOUCH_MAJOR,
1052			     0, wdt->param.max_x, 0, 0);
1053	input_set_abs_params(input, ABS_MT_PRESSURE, 0, 0xFF, 0, 0);
1054
1055	input_mt_init_slots(input, WDT_MAX_FINGER,
1056			    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
1057
1058	error = input_register_device(input);
1059	if (error) {
1060		dev_err(dev, "failed to register input device: %d\n", error);
1061		return error;
1062	}
1063
1064	return 0;
1065}
1066
1067static int wdt87xx_ts_probe(struct i2c_client *client)
1068{
1069	struct wdt87xx_data *wdt;
1070	int error;
1071
1072	dev_dbg(&client->dev, "adapter=%d, client irq: %d\n",
1073		client->adapter->nr, client->irq);
1074
1075	/* Check if the I2C function is ok in this adaptor */
1076	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
1077		return -ENXIO;
1078
1079	wdt = devm_kzalloc(&client->dev, sizeof(*wdt), GFP_KERNEL);
1080	if (!wdt)
1081		return -ENOMEM;
1082
1083	wdt->client = client;
1084	mutex_init(&wdt->fw_mutex);
1085	i2c_set_clientdata(client, wdt);
1086
1087	snprintf(wdt->phys, sizeof(wdt->phys), "i2c-%u-%04x/input0",
1088		 client->adapter->nr, client->addr);
1089
1090	error = wdt87xx_get_sysparam(client, &wdt->param);
1091	if (error)
1092		return error;
1093
1094	error = wdt87xx_ts_create_input_device(wdt);
1095	if (error)
1096		return error;
1097
1098	error = devm_request_threaded_irq(&client->dev, client->irq,
1099					  NULL, wdt87xx_ts_interrupt,
1100					  IRQF_ONESHOT,
1101					  client->name, wdt);
1102	if (error) {
1103		dev_err(&client->dev, "request irq failed: %d\n", error);
1104		return error;
1105	}
1106
1107	error = devm_device_add_group(&client->dev, &wdt87xx_attr_group);
1108	if (error) {
1109		dev_err(&client->dev, "create sysfs failed: %d\n", error);
1110		return error;
1111	}
1112
1113	return 0;
1114}
1115
1116static int __maybe_unused wdt87xx_suspend(struct device *dev)
1117{
1118	struct i2c_client *client = to_i2c_client(dev);
1119	int error;
1120
1121	disable_irq(client->irq);
1122
1123	error = wdt87xx_send_command(client, VND_CMD_STOP, MODE_IDLE);
1124	if (error) {
1125		enable_irq(client->irq);
1126		dev_err(&client->dev,
1127			"failed to stop device when suspending: %d\n",
1128			error);
1129		return error;
1130	}
1131
1132	return 0;
1133}
1134
1135static int __maybe_unused wdt87xx_resume(struct device *dev)
1136{
1137	struct i2c_client *client = to_i2c_client(dev);
1138	int error;
1139
1140	/*
1141	 * The chip may have been reset while system is resuming,
1142	 * give it some time to settle.
1143	 */
1144	msleep(100);
1145
1146	error = wdt87xx_send_command(client, VND_CMD_START, 0);
1147	if (error)
1148		dev_err(&client->dev,
1149			"failed to start device when resuming: %d\n",
1150			error);
1151
1152	enable_irq(client->irq);
1153
1154	return 0;
1155}
1156
1157static SIMPLE_DEV_PM_OPS(wdt87xx_pm_ops, wdt87xx_suspend, wdt87xx_resume);
1158
1159static const struct i2c_device_id wdt87xx_dev_id[] = {
1160	{ WDT87XX_NAME, 0 },
1161	{ }
1162};
1163MODULE_DEVICE_TABLE(i2c, wdt87xx_dev_id);
1164
1165static const struct acpi_device_id wdt87xx_acpi_id[] = {
1166	{ "WDHT0001", 0 },
1167	{ }
1168};
1169MODULE_DEVICE_TABLE(acpi, wdt87xx_acpi_id);
1170
1171static struct i2c_driver wdt87xx_driver = {
1172	.probe_new	= wdt87xx_ts_probe,
1173	.id_table	= wdt87xx_dev_id,
1174	.driver	= {
1175		.name	= WDT87XX_NAME,
1176		.pm     = &wdt87xx_pm_ops,
1177		.acpi_match_table = ACPI_PTR(wdt87xx_acpi_id),
1178	},
1179};
1180module_i2c_driver(wdt87xx_driver);
1181
1182MODULE_AUTHOR("HN Chen <hn.chen@weidahitech.com>");
1183MODULE_DESCRIPTION("WeidaHiTech WDT87XX Touchscreen driver");
1184MODULE_LICENSE("GPL");