Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1680 insertions, 0 deletions

diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
new file mode 100644
index 0000000000..a1af3de9f3
--- /dev/null
+++ b/drivers/input/touchscreen/elants_i2c.c
@@ -0,0 +1,1680 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Elan Microelectronics touch panels with I2C interface
+ *
+ * Copyright (C) 2014 Elan Microelectronics Corporation.
+ * Scott Liu <scott.liu@emc.com.tw>
+ *
+ * This code is partly based on hid-multitouch.c:
+ *
+ *  Copyright (c) 2010-2012 Stephane Chatty <chatty@enac.fr>
+ *  Copyright (c) 2010-2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ *  Copyright (c) 2010-2012 Ecole Nationale de l'Aviation Civile, France
+ *
+ * This code is partly based on i2c-hid.c:
+ *
+ * Copyright (c) 2012 Benjamin Tissoires <benjamin.tissoires@gmail.com>
+ * Copyright (c) 2012 Ecole Nationale de l'Aviation Civile, France
+ * Copyright (c) 2012 Red Hat, Inc
+ */
+
+
+#include <linux/bits.h>
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/platform_device.h>
+#include <linux/async.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/uaccess.h>
+#include <linux/buffer_head.h>
+#include <linux/slab.h>
+#include <linux/firmware.h>
+#include <linux/input/mt.h>
+#include <linux/input/touchscreen.h>
+#include <linux/acpi.h>
+#include <linux/of.h>
+#include <linux/pm_wakeirq.h>
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+#include <linux/uuid.h>
+#include <asm/unaligned.h>
+
+/* Device, Driver information */
+#define DEVICE_NAME	"elants_i2c"
+
+/* Convert from rows or columns into resolution */
+#define ELAN_TS_RESOLUTION(n, m)   (((n) - 1) * (m))
+
+/* FW header data */
+#define HEADER_SIZE		4
+#define FW_HDR_TYPE		0
+#define FW_HDR_COUNT		1
+#define FW_HDR_LENGTH		2
+
+/* Buffer mode Queue Header information */
+#define QUEUE_HEADER_SINGLE	0x62
+#define QUEUE_HEADER_NORMAL	0X63
+#define QUEUE_HEADER_WAIT	0x64
+#define QUEUE_HEADER_NORMAL2	0x66
+
+/* Command header definition */
+#define CMD_HEADER_WRITE	0x54
+#define CMD_HEADER_READ		0x53
+#define CMD_HEADER_6B_READ	0x5B
+#define CMD_HEADER_ROM_READ	0x96
+#define CMD_HEADER_RESP		0x52
+#define CMD_HEADER_6B_RESP	0x9B
+#define CMD_HEADER_ROM_RESP	0x95
+#define CMD_HEADER_HELLO	0x55
+#define CMD_HEADER_REK		0x66
+
+/* FW position data */
+#define PACKET_SIZE_OLD		40
+#define PACKET_SIZE		55
+#define MAX_CONTACT_NUM		10
+#define FW_POS_HEADER		0
+#define FW_POS_STATE		1
+#define FW_POS_TOTAL		2
+#define FW_POS_XY		3
+#define FW_POS_TOOL_TYPE	33
+#define FW_POS_CHECKSUM		34
+#define FW_POS_WIDTH		35
+#define FW_POS_PRESSURE		45
+
+#define HEADER_REPORT_10_FINGER	0x62
+
+/* Header (4 bytes) plus 3 full 10-finger packets */
+#define MAX_PACKET_SIZE		169
+
+#define BOOT_TIME_DELAY_MS	50
+
+/* FW read command, 0x53 0x?? 0x0, 0x01 */
+#define E_ELAN_INFO_FW_VER	0x00
+#define E_ELAN_INFO_BC_VER	0x10
+#define E_ELAN_INFO_X_RES	0x60
+#define E_ELAN_INFO_Y_RES	0x63
+#define E_ELAN_INFO_REK		0xD0
+#define E_ELAN_INFO_TEST_VER	0xE0
+#define E_ELAN_INFO_FW_ID	0xF0
+#define E_INFO_OSR		0xD6
+#define E_INFO_PHY_SCAN		0xD7
+#define E_INFO_PHY_DRIVER	0xD8
+
+/* FW write command, 0x54 0x?? 0x0, 0x01 */
+#define E_POWER_STATE_SLEEP	0x50
+#define E_POWER_STATE_RESUME	0x58
+
+#define MAX_RETRIES		3
+#define MAX_FW_UPDATE_RETRIES	30
+
+#define ELAN_FW_PAGESIZE	132
+
+/* calibration timeout definition */
+#define ELAN_CALI_TIMEOUT_MSEC	12000
+
+#define ELAN_POWERON_DELAY_USEC	5000
+#define ELAN_RESET_DELAY_MSEC	20
+
+/* FW boot code version */
+#define BC_VER_H_BYTE_FOR_EKTH3900x1_I2C        0x72
+#define BC_VER_H_BYTE_FOR_EKTH3900x2_I2C        0x82
+#define BC_VER_H_BYTE_FOR_EKTH3900x3_I2C        0x92
+#define BC_VER_H_BYTE_FOR_EKTH5312x1_I2C        0x6D
+#define BC_VER_H_BYTE_FOR_EKTH5312x2_I2C        0x6E
+#define BC_VER_H_BYTE_FOR_EKTH5312cx1_I2C       0x77
+#define BC_VER_H_BYTE_FOR_EKTH5312cx2_I2C       0x78
+#define BC_VER_H_BYTE_FOR_EKTH5312x1_I2C_USB    0x67
+#define BC_VER_H_BYTE_FOR_EKTH5312x2_I2C_USB    0x68
+#define BC_VER_H_BYTE_FOR_EKTH5312cx1_I2C_USB   0x74
+#define BC_VER_H_BYTE_FOR_EKTH5312cx2_I2C_USB   0x75
+
+enum elants_chip_id {
+	EKTH3500,
+	EKTF3624,
+};
+
+enum elants_state {
+	ELAN_STATE_NORMAL,
+	ELAN_WAIT_QUEUE_HEADER,
+	ELAN_WAIT_RECALIBRATION,
+};
+
+enum elants_iap_mode {
+	ELAN_IAP_OPERATIONAL,
+	ELAN_IAP_RECOVERY,
+};
+
+/* struct elants_data - represents state of Elan touchscreen device */
+struct elants_data {
+	struct i2c_client *client;
+	struct input_dev *input;
+
+	struct regulator *vcc33;
+	struct regulator *vccio;
+	struct gpio_desc *reset_gpio;
+
+	u16 fw_version;
+	u8 test_version;
+	u8 solution_version;
+	u8 bc_version;
+	u8 iap_version;
+	u16 hw_version;
+	u8 major_res;
+	unsigned int x_res;	/* resolution in units/mm */
+	unsigned int y_res;
+	unsigned int x_max;
+	unsigned int y_max;
+	unsigned int phy_x;
+	unsigned int phy_y;
+	struct touchscreen_properties prop;
+
+	enum elants_state state;
+	enum elants_chip_id chip_id;
+	enum elants_iap_mode iap_mode;
+
+	/* Guards against concurrent access to the device via sysfs */
+	struct mutex sysfs_mutex;
+
+	u8 cmd_resp[HEADER_SIZE];
+	struct completion cmd_done;
+
+	bool keep_power_in_suspend;
+
+	/* Must be last to be used for DMA operations */
+	u8 buf[MAX_PACKET_SIZE] ____cacheline_aligned;
+};
+
+static int elants_i2c_send(struct i2c_client *client,
+			   const void *data, size_t size)
+{
+	int ret;
+
+	ret = i2c_master_send(client, data, size);
+	if (ret == size)
+		return 0;
+
+	if (ret >= 0)
+		ret = -EIO;
+
+	dev_err(&client->dev, "%s failed (%*ph): %d\n",
+		__func__, (int)size, data, ret);
+
+	return ret;
+}
+
+static int elants_i2c_read(struct i2c_client *client, void *data, size_t size)
+{
+	int ret;
+
+	ret = i2c_master_recv(client, data, size);
+	if (ret == size)
+		return 0;
+
+	if (ret >= 0)
+		ret = -EIO;
+
+	dev_err(&client->dev, "%s failed: %d\n", __func__, ret);
+
+	return ret;
+}
+
+static int elants_i2c_execute_command(struct i2c_client *client,
+				      const u8 *cmd, size_t cmd_size,
+				      u8 *resp, size_t resp_size,
+				      int retries, const char *cmd_name)
+{
+	struct i2c_msg msgs[2];
+	int ret;
+	u8 expected_response;
+
+	switch (cmd[0]) {
+	case CMD_HEADER_READ:
+		expected_response = CMD_HEADER_RESP;
+		break;
+
+	case CMD_HEADER_6B_READ:
+		expected_response = CMD_HEADER_6B_RESP;
+		break;
+
+	case CMD_HEADER_ROM_READ:
+		expected_response = CMD_HEADER_ROM_RESP;
+		break;
+
+	default:
+		dev_err(&client->dev, "(%s): invalid command: %*ph\n",
+			cmd_name, (int)cmd_size, cmd);
+		return -EINVAL;
+	}
+
+	for (;;) {
+		msgs[0].addr = client->addr;
+		msgs[0].flags = client->flags & I2C_M_TEN;
+		msgs[0].len = cmd_size;
+		msgs[0].buf = (u8 *)cmd;
+
+		msgs[1].addr = client->addr;
+		msgs[1].flags = (client->flags & I2C_M_TEN) | I2C_M_RD;
+		msgs[1].flags |= I2C_M_RD;
+		msgs[1].len = resp_size;
+		msgs[1].buf = resp;
+
+		ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+		if (ret < 0) {
+			if (--retries > 0) {
+				dev_dbg(&client->dev,
+					"(%s) I2C transfer failed: %pe (retrying)\n",
+					cmd_name, ERR_PTR(ret));
+				continue;
+			}
+
+			dev_err(&client->dev,
+				"(%s) I2C transfer failed: %pe\n",
+				cmd_name, ERR_PTR(ret));
+			return ret;
+		}
+
+		if (ret != ARRAY_SIZE(msgs) ||
+		    resp[FW_HDR_TYPE] != expected_response) {
+			if (--retries > 0) {
+				dev_dbg(&client->dev,
+					"(%s) unexpected response: %*ph (retrying)\n",
+					cmd_name, ret, resp);
+				continue;
+			}
+
+			dev_err(&client->dev,
+				"(%s) unexpected response: %*ph\n",
+				cmd_name, ret, resp);
+			return -EIO;
+		}
+
+		return 0;
+	}
+}
+
+static int elants_i2c_calibrate(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int ret, error;
+	static const u8 w_flashkey[] = { CMD_HEADER_WRITE, 0xC0, 0xE1, 0x5A };
+	static const u8 rek[] = { CMD_HEADER_WRITE, 0x29, 0x00, 0x01 };
+	static const u8 rek_resp[] = { CMD_HEADER_REK, 0x66, 0x66, 0x66 };
+
+	disable_irq(client->irq);
+
+	ts->state = ELAN_WAIT_RECALIBRATION;
+	reinit_completion(&ts->cmd_done);
+
+	elants_i2c_send(client, w_flashkey, sizeof(w_flashkey));
+	elants_i2c_send(client, rek, sizeof(rek));
+
+	enable_irq(client->irq);
+
+	ret = wait_for_completion_interruptible_timeout(&ts->cmd_done,
+				msecs_to_jiffies(ELAN_CALI_TIMEOUT_MSEC));
+
+	ts->state = ELAN_STATE_NORMAL;
+
+	if (ret <= 0) {
+		error = ret < 0 ? ret : -ETIMEDOUT;
+		dev_err(&client->dev,
+			"error while waiting for calibration to complete: %d\n",
+			error);
+		return error;
+	}
+
+	if (memcmp(rek_resp, ts->cmd_resp, sizeof(rek_resp))) {
+		dev_err(&client->dev,
+			"unexpected calibration response: %*ph\n",
+			(int)sizeof(ts->cmd_resp), ts->cmd_resp);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int elants_i2c_sw_reset(struct i2c_client *client)
+{
+	const u8 soft_rst_cmd[] = { 0x77, 0x77, 0x77, 0x77 };
+	int error;
+
+	error = elants_i2c_send(client, soft_rst_cmd,
+				sizeof(soft_rst_cmd));
+	if (error) {
+		dev_err(&client->dev, "software reset failed: %d\n", error);
+		return error;
+	}
+
+	/*
+	 * We should wait at least 10 msec (but no more than 40) before
+	 * sending fastboot or IAP command to the device.
+	 */
+	msleep(30);
+
+	return 0;
+}
+
+static u16 elants_i2c_parse_version(u8 *buf)
+{
+	return get_unaligned_be32(buf) >> 4;
+}
+
+static int elants_i2c_query_hw_version(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int retry_cnt = MAX_RETRIES;
+	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
+	u8 resp[HEADER_SIZE];
+	int error;
+
+	while (retry_cnt--) {
+		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+						   resp, sizeof(resp), 1,
+						   "read fw id");
+		if (error)
+			return error;
+
+		ts->hw_version = elants_i2c_parse_version(resp);
+		if (ts->hw_version != 0xffff)
+			return 0;
+	}
+
+	dev_err(&client->dev, "Invalid fw id: %#04x\n", ts->hw_version);
+
+	return -EINVAL;
+}
+
+static int elants_i2c_query_fw_version(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int retry_cnt = MAX_RETRIES;
+	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
+	u8 resp[HEADER_SIZE];
+	int error;
+
+	while (retry_cnt--) {
+		error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+						   resp, sizeof(resp), 1,
+						   "read fw version");
+		if (error)
+			return error;
+
+		ts->fw_version = elants_i2c_parse_version(resp);
+		if (ts->fw_version != 0x0000 && ts->fw_version != 0xffff)
+			return 0;
+
+		dev_dbg(&client->dev, "(read fw version) resp %*phC\n",
+			(int)sizeof(resp), resp);
+	}
+
+	dev_err(&client->dev, "Invalid fw ver: %#04x\n", ts->fw_version);
+
+	return -EINVAL;
+}
+
+static int elants_i2c_query_test_version(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int error;
+	u16 version;
+	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
+	u8 resp[HEADER_SIZE];
+
+	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+					   resp, sizeof(resp), MAX_RETRIES,
+					   "read test version");
+	if (error) {
+		dev_err(&client->dev, "Failed to read test version\n");
+		return error;
+	}
+
+	version = elants_i2c_parse_version(resp);
+	ts->test_version = version >> 8;
+	ts->solution_version = version & 0xff;
+
+	return 0;
+}
+
+static int elants_i2c_query_bc_version(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_BC_VER, 0x00, 0x01 };
+	u8 resp[HEADER_SIZE];
+	u16 version;
+	int error;
+
+	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+					   resp, sizeof(resp), 1,
+					   "read BC version");
+	if (error)
+		return error;
+
+	version = elants_i2c_parse_version(resp);
+	ts->bc_version = version >> 8;
+	ts->iap_version = version & 0xff;
+
+	return 0;
+}
+
+static int elants_i2c_query_ts_info_ektf(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int error;
+	u8 resp[4];
+	u16 phy_x, phy_y;
+	const u8 get_xres_cmd[] = {
+		CMD_HEADER_READ, E_ELAN_INFO_X_RES, 0x00, 0x00
+	};
+	const u8 get_yres_cmd[] = {
+		CMD_HEADER_READ, E_ELAN_INFO_Y_RES, 0x00, 0x00
+	};
+
+	/* Get X/Y size in mm */
+	error = elants_i2c_execute_command(client, get_xres_cmd,
+					   sizeof(get_xres_cmd),
+					   resp, sizeof(resp), 1,
+					   "get X size");
+	if (error)
+		return error;
+
+	phy_x = resp[2] | ((resp[3] & 0xF0) << 4);
+
+	error = elants_i2c_execute_command(client, get_yres_cmd,
+					   sizeof(get_yres_cmd),
+					   resp, sizeof(resp), 1,
+					   "get Y size");
+	if (error)
+		return error;
+
+	phy_y = resp[2] | ((resp[3] & 0xF0) << 4);
+
+	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
+
+	ts->phy_x = phy_x;
+	ts->phy_y = phy_y;
+
+	/* eKTF doesn't report max size, set it to default values */
+	ts->x_max = 2240 - 1;
+	ts->y_max = 1408 - 1;
+
+	return 0;
+}
+
+static int elants_i2c_query_ts_info_ekth(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int error;
+	u8 resp[17];
+	u16 phy_x, phy_y, rows, cols, osr;
+	const u8 get_resolution_cmd[] = {
+		CMD_HEADER_6B_READ, 0x00, 0x00, 0x00, 0x00, 0x00
+	};
+	const u8 get_osr_cmd[] = {
+		CMD_HEADER_READ, E_INFO_OSR, 0x00, 0x01
+	};
+	const u8 get_physical_scan_cmd[] = {
+		CMD_HEADER_READ, E_INFO_PHY_SCAN, 0x00, 0x01
+	};
+	const u8 get_physical_drive_cmd[] = {
+		CMD_HEADER_READ, E_INFO_PHY_DRIVER, 0x00, 0x01
+	};
+
+	/* Get trace number */
+	error = elants_i2c_execute_command(client,
+					   get_resolution_cmd,
+					   sizeof(get_resolution_cmd),
+					   resp, sizeof(resp), 1,
+					   "get resolution");
+	if (error)
+		return error;
+
+	rows = resp[2] + resp[6] + resp[10];
+	cols = resp[3] + resp[7] + resp[11];
+
+	/* Get report resolution value of ABS_MT_TOUCH_MAJOR */
+	ts->major_res = resp[16];
+
+	/* Process mm_to_pixel information */
+	error = elants_i2c_execute_command(client,
+					   get_osr_cmd, sizeof(get_osr_cmd),
+					   resp, sizeof(resp), 1, "get osr");
+	if (error)
+		return error;
+
+	osr = resp[3];
+
+	error = elants_i2c_execute_command(client,
+					   get_physical_scan_cmd,
+					   sizeof(get_physical_scan_cmd),
+					   resp, sizeof(resp), 1,
+					   "get physical scan");
+	if (error)
+		return error;
+
+	phy_x = get_unaligned_be16(&resp[2]);
+
+	error = elants_i2c_execute_command(client,
+					   get_physical_drive_cmd,
+					   sizeof(get_physical_drive_cmd),
+					   resp, sizeof(resp), 1,
+					   "get physical drive");
+	if (error)
+		return error;
+
+	phy_y = get_unaligned_be16(&resp[2]);
+
+	dev_dbg(&client->dev, "phy_x=%d, phy_y=%d\n", phy_x, phy_y);
+
+	if (rows == 0 || cols == 0 || osr == 0) {
+		dev_warn(&client->dev,
+			 "invalid trace number data: %d, %d, %d\n",
+			 rows, cols, osr);
+	} else {
+		/* translate trace number to TS resolution */
+		ts->x_max = ELAN_TS_RESOLUTION(rows, osr);
+		ts->x_res = DIV_ROUND_CLOSEST(ts->x_max, phy_x);
+		ts->y_max = ELAN_TS_RESOLUTION(cols, osr);
+		ts->y_res = DIV_ROUND_CLOSEST(ts->y_max, phy_y);
+		ts->phy_x = phy_x;
+		ts->phy_y = phy_y;
+	}
+
+	return 0;
+}
+
+static int elants_i2c_fastboot(struct i2c_client *client)
+{
+	const u8 boot_cmd[] = { 0x4D, 0x61, 0x69, 0x6E };
+	int error;
+
+	error = elants_i2c_send(client, boot_cmd, sizeof(boot_cmd));
+	if (error) {
+		dev_err(&client->dev, "boot failed: %d\n", error);
+		return error;
+	}
+
+	dev_dbg(&client->dev, "boot success -- 0x%x\n", client->addr);
+	return 0;
+}
+
+static int elants_i2c_initialize(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	int error, error2, retry_cnt;
+	const u8 hello_packet[] = { 0x55, 0x55, 0x55, 0x55 };
+	const u8 recov_packet[] = { 0x55, 0x55, 0x80, 0x80 };
+	u8 buf[HEADER_SIZE];
+
+	for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
+		error = elants_i2c_sw_reset(client);
+		if (error) {
+			/* Continue initializing if it's the last try */
+			if (retry_cnt < MAX_RETRIES - 1)
+				continue;
+		}
+
+		error = elants_i2c_fastboot(client);
+		if (error) {
+			/* Continue initializing if it's the last try */
+			if (retry_cnt < MAX_RETRIES - 1)
+				continue;
+		}
+
+		/* Wait for Hello packet */
+		msleep(BOOT_TIME_DELAY_MS);
+
+		error = elants_i2c_read(client, buf, sizeof(buf));
+		if (error) {
+			dev_err(&client->dev,
+				"failed to read 'hello' packet: %d\n", error);
+		} else if (!memcmp(buf, hello_packet, sizeof(hello_packet))) {
+			ts->iap_mode = ELAN_IAP_OPERATIONAL;
+			break;
+		} else if (!memcmp(buf, recov_packet, sizeof(recov_packet))) {
+			/*
+			 * Setting error code will mark device
+			 * in recovery mode below.
+			 */
+			error = -EIO;
+			break;
+		} else {
+			error = -EINVAL;
+			dev_err(&client->dev,
+				"invalid 'hello' packet: %*ph\n",
+				(int)sizeof(buf), buf);
+		}
+	}
+
+	/* hw version is available even if device in recovery state */
+	error2 = elants_i2c_query_hw_version(ts);
+	if (!error2)
+		error2 = elants_i2c_query_bc_version(ts);
+	if (!error)
+		error = error2;
+
+	if (!error)
+		error = elants_i2c_query_fw_version(ts);
+	if (!error)
+		error = elants_i2c_query_test_version(ts);
+
+	switch (ts->chip_id) {
+	case EKTH3500:
+		if (!error)
+			error = elants_i2c_query_ts_info_ekth(ts);
+		break;
+	case EKTF3624:
+		if (!error)
+			error = elants_i2c_query_ts_info_ektf(ts);
+		break;
+	default:
+		BUG();
+	}
+
+	if (error)
+		ts->iap_mode = ELAN_IAP_RECOVERY;
+
+	return 0;
+}
+
+/*
+ * Firmware update interface.
+ */
+
+static int elants_i2c_fw_write_page(struct i2c_client *client,
+				    const void *page)
+{
+	const u8 ack_ok[] = { 0xaa, 0xaa };
+	u8 buf[2];
+	int retry;
+	int error;
+
+	for (retry = 0; retry < MAX_FW_UPDATE_RETRIES; retry++) {
+		error = elants_i2c_send(client, page, ELAN_FW_PAGESIZE);
+		if (error) {
+			dev_err(&client->dev,
+				"IAP Write Page failed: %d\n", error);
+			continue;
+		}
+
+		error = elants_i2c_read(client, buf, 2);
+		if (error) {
+			dev_err(&client->dev,
+				"IAP Ack read failed: %d\n", error);
+			return error;
+		}
+
+		if (!memcmp(buf, ack_ok, sizeof(ack_ok)))
+			return 0;
+
+		error = -EIO;
+		dev_err(&client->dev,
+			"IAP Get Ack Error [%02x:%02x]\n",
+			buf[0], buf[1]);
+	}
+
+	return error;
+}
+
+static int elants_i2c_validate_remark_id(struct elants_data *ts,
+					 const struct firmware *fw)
+{
+	struct i2c_client *client = ts->client;
+	int error;
+	const u8 cmd[] = { CMD_HEADER_ROM_READ, 0x80, 0x1F, 0x00, 0x00, 0x21 };
+	u8 resp[6] = { 0 };
+	u16 ts_remark_id = 0;
+	u16 fw_remark_id = 0;
+
+	/* Compare TS Remark ID and FW Remark ID */
+	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+					   resp, sizeof(resp),
+					   1, "read Remark ID");
+	if (error)
+		return error;
+
+	ts_remark_id = get_unaligned_be16(&resp[3]);
+
+	fw_remark_id = get_unaligned_le16(&fw->data[fw->size - 4]);
+
+	if (fw_remark_id != ts_remark_id) {
+		dev_err(&client->dev,
+			"Remark ID Mismatched: ts_remark_id=0x%04x, fw_remark_id=0x%04x.\n",
+			ts_remark_id, fw_remark_id);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static bool elants_i2c_should_check_remark_id(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	const u8 bootcode_version = ts->iap_version;
+	bool check;
+
+	/* I2C eKTH3900 and eKTH5312 are NOT support Remark ID */
+	if ((bootcode_version == BC_VER_H_BYTE_FOR_EKTH3900x1_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH3900x2_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH3900x3_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312x1_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312x2_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312cx1_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312cx2_I2C) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312x1_I2C_USB) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312x2_I2C_USB) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312cx1_I2C_USB) ||
+	    (bootcode_version == BC_VER_H_BYTE_FOR_EKTH5312cx2_I2C_USB)) {
+		dev_dbg(&client->dev,
+			"eKTH3900/eKTH5312(0x%02x) are not support remark id\n",
+			bootcode_version);
+		check = false;
+	} else if (bootcode_version >= 0x60) {
+		check = true;
+	} else {
+		check = false;
+	}
+
+	return check;
+}
+
+static int elants_i2c_do_update_firmware(struct i2c_client *client,
+					 const struct firmware *fw,
+					 bool force)
+{
+	struct elants_data *ts = i2c_get_clientdata(client);
+	const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
+	const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
+	const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
+	const u8 close_idle[] = { 0x54, 0x2c, 0x01, 0x01 };
+	u8 buf[HEADER_SIZE];
+	u16 send_id;
+	int page, n_fw_pages;
+	int error;
+	bool check_remark_id = elants_i2c_should_check_remark_id(ts);
+
+	/* Recovery mode detection! */
+	if (force) {
+		dev_dbg(&client->dev, "Recovery mode procedure\n");
+
+		if (check_remark_id) {
+			error = elants_i2c_validate_remark_id(ts, fw);
+			if (error)
+				return error;
+		}
+
+		error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
+		if (error) {
+			dev_err(&client->dev, "failed to enter IAP mode: %d\n",
+				error);
+			return error;
+		}
+	} else {
+		/* Start IAP Procedure */
+		dev_dbg(&client->dev, "Normal IAP procedure\n");
+
+		/* Close idle mode */
+		error = elants_i2c_send(client, close_idle, sizeof(close_idle));
+		if (error)
+			dev_err(&client->dev, "Failed close idle: %d\n", error);
+		msleep(60);
+
+		elants_i2c_sw_reset(client);
+		msleep(20);
+
+		if (check_remark_id) {
+			error = elants_i2c_validate_remark_id(ts, fw);
+			if (error)
+				return error;
+		}
+
+		error = elants_i2c_send(client, enter_iap, sizeof(enter_iap));
+		if (error) {
+			dev_err(&client->dev, "failed to enter IAP mode: %d\n",
+				error);
+			return error;
+		}
+	}
+
+	msleep(20);
+
+	/* check IAP state */
+	error = elants_i2c_read(client, buf, 4);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to read IAP acknowledgement: %d\n",
+			error);
+		return error;
+	}
+
+	if (memcmp(buf, iap_ack, sizeof(iap_ack))) {
+		dev_err(&client->dev,
+			"failed to enter IAP: %*ph (expected %*ph)\n",
+			(int)sizeof(buf), buf, (int)sizeof(iap_ack), iap_ack);
+		return -EIO;
+	}
+
+	dev_info(&client->dev, "successfully entered IAP mode");
+
+	send_id = client->addr;
+	error = elants_i2c_send(client, &send_id, 1);
+	if (error) {
+		dev_err(&client->dev, "sending dummy byte failed: %d\n",
+			error);
+		return error;
+	}
+
+	/* Clear the last page of Master */
+	error = elants_i2c_send(client, fw->data, ELAN_FW_PAGESIZE);
+	if (error) {
+		dev_err(&client->dev, "clearing of the last page failed: %d\n",
+			error);
+		return error;
+	}
+
+	error = elants_i2c_read(client, buf, 2);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to read ACK for clearing the last page: %d\n",
+			error);
+		return error;
+	}
+
+	n_fw_pages = fw->size / ELAN_FW_PAGESIZE;
+	dev_dbg(&client->dev, "IAP Pages = %d\n", n_fw_pages);
+
+	for (page = 0; page < n_fw_pages; page++) {
+		error = elants_i2c_fw_write_page(client,
+					fw->data + page * ELAN_FW_PAGESIZE);
+		if (error) {
+			dev_err(&client->dev,
+				"failed to write FW page %d: %d\n",
+				page, error);
+			return error;
+		}
+	}
+
+	/* Old iap needs to wait 200ms for WDT and rest is for hello packets */
+	msleep(300);
+
+	dev_info(&client->dev, "firmware update completed\n");
+	return 0;
+}
+
+static int elants_i2c_fw_update(struct elants_data *ts)
+{
+	struct i2c_client *client = ts->client;
+	const struct firmware *fw;
+	char *fw_name;
+	int error;
+
+	fw_name = kasprintf(GFP_KERNEL, "elants_i2c_%04x.bin", ts->hw_version);
+	if (!fw_name)
+		return -ENOMEM;
+
+	dev_info(&client->dev, "requesting fw name = %s\n", fw_name);
+	error = request_firmware(&fw, fw_name, &client->dev);
+	kfree(fw_name);
+	if (error) {
+		dev_err(&client->dev, "failed to request firmware: %d\n",
+			error);
+		return error;
+	}
+
+	if (fw->size % ELAN_FW_PAGESIZE) {
+		dev_err(&client->dev, "invalid firmware length: %zu\n",
+			fw->size);
+		error = -EINVAL;
+		goto out;
+	}
+
+	disable_irq(client->irq);
+
+	error = elants_i2c_do_update_firmware(client, fw,
+					ts->iap_mode == ELAN_IAP_RECOVERY);
+	if (error) {
+		dev_err(&client->dev, "firmware update failed: %d\n", error);
+		ts->iap_mode = ELAN_IAP_RECOVERY;
+		goto out_enable_irq;
+	}
+
+	error = elants_i2c_initialize(ts);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to initialize device after firmware update: %d\n",
+			error);
+		ts->iap_mode = ELAN_IAP_RECOVERY;
+		goto out_enable_irq;
+	}
+
+	ts->iap_mode = ELAN_IAP_OPERATIONAL;
+
+out_enable_irq:
+	ts->state = ELAN_STATE_NORMAL;
+	enable_irq(client->irq);
+	msleep(100);
+
+	if (!error)
+		elants_i2c_calibrate(ts);
+out:
+	release_firmware(fw);
+	return error;
+}
+
+/*
+ * Event reporting.
+ */
+
+static void elants_i2c_mt_event(struct elants_data *ts, u8 *buf,
+				size_t packet_size)
+{
+	struct input_dev *input = ts->input;
+	unsigned int n_fingers;
+	unsigned int tool_type;
+	u16 finger_state;
+	int i;
+
+	n_fingers = buf[FW_POS_STATE + 1] & 0x0f;
+	finger_state = ((buf[FW_POS_STATE + 1] & 0x30) << 4) |
+			buf[FW_POS_STATE];
+
+	dev_dbg(&ts->client->dev,
+		"n_fingers: %u, state: %04x\n",  n_fingers, finger_state);
+
+	/* Note: all fingers have the same tool type */
+	tool_type = buf[FW_POS_TOOL_TYPE] & BIT(0) ?
+			MT_TOOL_FINGER : MT_TOOL_PALM;
+
+	for (i = 0; i < MAX_CONTACT_NUM && n_fingers; i++) {
+		if (finger_state & 1) {
+			unsigned int x, y, p, w;
+			u8 *pos;
+
+			pos = &buf[FW_POS_XY + i * 3];
+			x = (((u16)pos[0] & 0xf0) << 4) | pos[1];
+			y = (((u16)pos[0] & 0x0f) << 8) | pos[2];
+
+			/*
+			 * eKTF3624 may have use "old" touch-report format,
+			 * depending on a device and TS firmware version.
+			 * For example, ASUS Transformer devices use the "old"
+			 * format, while ASUS Nexus 7 uses the "new" formant.
+			 */
+			if (packet_size == PACKET_SIZE_OLD &&
+			    ts->chip_id == EKTF3624) {
+				w = buf[FW_POS_WIDTH + i / 2];
+				w >>= 4 * (~i & 1);
+				w |= w << 4;
+				w |= !w;
+				p = w;
+			} else {
+				p = buf[FW_POS_PRESSURE + i];
+				w = buf[FW_POS_WIDTH + i];
+			}
+
+			dev_dbg(&ts->client->dev, "i=%d x=%d y=%d p=%d w=%d\n",
+				i, x, y, p, w);
+
+			input_mt_slot(input, i);
+			input_mt_report_slot_state(input, tool_type, true);
+			touchscreen_report_pos(input, &ts->prop, x, y, true);
+			input_event(input, EV_ABS, ABS_MT_PRESSURE, p);
+			input_event(input, EV_ABS, ABS_MT_TOUCH_MAJOR, w);
+
+			n_fingers--;
+		}
+
+		finger_state >>= 1;
+	}
+
+	input_mt_sync_frame(input);
+	input_sync(input);
+}
+
+static u8 elants_i2c_calculate_checksum(u8 *buf)
+{
+	u8 checksum = 0;
+	u8 i;
+
+	for (i = 0; i < FW_POS_CHECKSUM; i++)
+		checksum += buf[i];
+
+	return checksum;
+}
+
+static void elants_i2c_event(struct elants_data *ts, u8 *buf,
+			     size_t packet_size)
+{
+	u8 checksum = elants_i2c_calculate_checksum(buf);
+
+	if (unlikely(buf[FW_POS_CHECKSUM] != checksum))
+		dev_warn(&ts->client->dev,
+			 "%s: invalid checksum for packet %02x: %02x vs. %02x\n",
+			 __func__, buf[FW_POS_HEADER],
+			 checksum, buf[FW_POS_CHECKSUM]);
+	else if (unlikely(buf[FW_POS_HEADER] != HEADER_REPORT_10_FINGER))
+		dev_warn(&ts->client->dev,
+			 "%s: unknown packet type: %02x\n",
+			 __func__, buf[FW_POS_HEADER]);
+	else
+		elants_i2c_mt_event(ts, buf, packet_size);
+}
+
+static irqreturn_t elants_i2c_irq(int irq, void *_dev)
+{
+	const u8 wait_packet[] = { 0x64, 0x64, 0x64, 0x64 };
+	struct elants_data *ts = _dev;
+	struct i2c_client *client = ts->client;
+	int report_count, report_len;
+	int i;
+	int len;
+
+	len = i2c_master_recv_dmasafe(client, ts->buf, sizeof(ts->buf));
+	if (len < 0) {
+		dev_err(&client->dev, "%s: failed to read data: %d\n",
+			__func__, len);
+		goto out;
+	}
+
+	dev_dbg(&client->dev, "%s: packet %*ph\n",
+		__func__, HEADER_SIZE, ts->buf);
+
+	switch (ts->state) {
+	case ELAN_WAIT_RECALIBRATION:
+		if (ts->buf[FW_HDR_TYPE] == CMD_HEADER_REK) {
+			memcpy(ts->cmd_resp, ts->buf, sizeof(ts->cmd_resp));
+			complete(&ts->cmd_done);
+			ts->state = ELAN_STATE_NORMAL;
+		}
+		break;
+
+	case ELAN_WAIT_QUEUE_HEADER:
+		if (ts->buf[FW_HDR_TYPE] != QUEUE_HEADER_NORMAL)
+			break;
+
+		ts->state = ELAN_STATE_NORMAL;
+		fallthrough;
+
+	case ELAN_STATE_NORMAL:
+
+		switch (ts->buf[FW_HDR_TYPE]) {
+		case CMD_HEADER_HELLO:
+		case CMD_HEADER_RESP:
+			break;
+
+		case QUEUE_HEADER_WAIT:
+			if (memcmp(ts->buf, wait_packet, sizeof(wait_packet))) {
+				dev_err(&client->dev,
+					"invalid wait packet %*ph\n",
+					HEADER_SIZE, ts->buf);
+			} else {
+				ts->state = ELAN_WAIT_QUEUE_HEADER;
+				udelay(30);
+			}
+			break;
+
+		case QUEUE_HEADER_SINGLE:
+			elants_i2c_event(ts, &ts->buf[HEADER_SIZE],
+					 ts->buf[FW_HDR_LENGTH]);
+			break;
+
+		case QUEUE_HEADER_NORMAL2: /* CMD_HEADER_REK */
+			/*
+			 * Depending on firmware version, eKTF3624 touchscreens
+			 * may utilize one of these opcodes for the touch events:
+			 * 0x63 (NORMAL) and 0x66 (NORMAL2).  The 0x63 is used by
+			 * older firmware version and differs from 0x66 such that
+			 * touch pressure value needs to be adjusted.  The 0x66
+			 * opcode of newer firmware is equal to 0x63 of eKTH3500.
+			 */
+			if (ts->chip_id != EKTF3624)
+				break;
+
+			fallthrough;
+
+		case QUEUE_HEADER_NORMAL:
+			report_count = ts->buf[FW_HDR_COUNT];
+			if (report_count == 0 || report_count > 3) {
+				dev_err(&client->dev,
+					"bad report count: %*ph\n",
+					HEADER_SIZE, ts->buf);
+				break;
+			}
+
+			report_len = ts->buf[FW_HDR_LENGTH] / report_count;
+
+			if (report_len == PACKET_SIZE_OLD &&
+			    ts->chip_id == EKTF3624) {
+				dev_dbg_once(&client->dev,
+					     "using old report format\n");
+			} else if (report_len != PACKET_SIZE) {
+				dev_err(&client->dev,
+					"mismatching report length: %*ph\n",
+					HEADER_SIZE, ts->buf);
+				break;
+			}
+
+			for (i = 0; i < report_count; i++) {
+				u8 *buf = ts->buf + HEADER_SIZE +
+							i * report_len;
+				elants_i2c_event(ts, buf, report_len);
+			}
+			break;
+
+		default:
+			dev_err(&client->dev, "unknown packet %*ph\n",
+				HEADER_SIZE, ts->buf);
+			break;
+		}
+		break;
+	}
+
+out:
+	return IRQ_HANDLED;
+}
+
+/*
+ * sysfs interface
+ */
+static ssize_t calibrate_store(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct elants_data *ts = i2c_get_clientdata(client);
+	int error;
+
+	error = mutex_lock_interruptible(&ts->sysfs_mutex);
+	if (error)
+		return error;
+
+	error = elants_i2c_calibrate(ts);
+
+	mutex_unlock(&ts->sysfs_mutex);
+	return error ?: count;
+}
+
+static ssize_t write_update_fw(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct elants_data *ts = i2c_get_clientdata(client);
+	int error;
+
+	error = mutex_lock_interruptible(&ts->sysfs_mutex);
+	if (error)
+		return error;
+
+	error = elants_i2c_fw_update(ts);
+	dev_dbg(dev, "firmware update result: %d\n", error);
+
+	mutex_unlock(&ts->sysfs_mutex);
+	return error ?: count;
+}
+
+static ssize_t show_iap_mode(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct elants_data *ts = i2c_get_clientdata(client);
+
+	return sprintf(buf, "%s\n",
+		       ts->iap_mode == ELAN_IAP_OPERATIONAL ?
+				"Normal" : "Recovery");
+}
+
+static ssize_t show_calibration_count(struct device *dev,
+				      struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_REK, 0x00, 0x01 };
+	u8 resp[HEADER_SIZE];
+	u16 rek_count;
+	int error;
+
+	error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+					   resp, sizeof(resp), 1,
+					   "read ReK status");
+	if (error)
+		return sprintf(buf, "%d\n", error);
+
+	rek_count = get_unaligned_be16(&resp[2]);
+	return sprintf(buf, "0x%04x\n", rek_count);
+}
+
+static DEVICE_ATTR_WO(calibrate);
+static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, NULL);
+static DEVICE_ATTR(calibration_count, S_IRUGO, show_calibration_count, NULL);
+static DEVICE_ATTR(update_fw, S_IWUSR, NULL, write_update_fw);
+
+struct elants_version_attribute {
+	struct device_attribute dattr;
+	size_t field_offset;
+	size_t field_size;
+};
+
+#define __ELANTS_FIELD_SIZE(_field)					\
+	sizeof(((struct elants_data *)NULL)->_field)
+#define __ELANTS_VERIFY_SIZE(_field)					\
+	(BUILD_BUG_ON_ZERO(__ELANTS_FIELD_SIZE(_field) > 2) +		\
+	 __ELANTS_FIELD_SIZE(_field))
+#define ELANTS_VERSION_ATTR(_field)					\
+	struct elants_version_attribute elants_ver_attr_##_field = {	\
+		.dattr = __ATTR(_field, S_IRUGO,			\
+				elants_version_attribute_show, NULL),	\
+		.field_offset = offsetof(struct elants_data, _field),	\
+		.field_size = __ELANTS_VERIFY_SIZE(_field),		\
+	}
+
+static ssize_t elants_version_attribute_show(struct device *dev,
+					     struct device_attribute *dattr,
+					     char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct elants_data *ts = i2c_get_clientdata(client);
+	struct elants_version_attribute *attr =
+		container_of(dattr, struct elants_version_attribute, dattr);
+	u8 *field = (u8 *)((char *)ts + attr->field_offset);
+	unsigned int fmt_size;
+	unsigned int val;
+
+	if (attr->field_size == 1) {
+		val = *field;
+		fmt_size = 2; /* 2 HEX digits */
+	} else {
+		val = *(u16 *)field;
+		fmt_size = 4; /* 4 HEX digits */
+	}
+
+	return sprintf(buf, "%0*x\n", fmt_size, val);
+}
+
+static ELANTS_VERSION_ATTR(fw_version);
+static ELANTS_VERSION_ATTR(hw_version);
+static ELANTS_VERSION_ATTR(test_version);
+static ELANTS_VERSION_ATTR(solution_version);
+static ELANTS_VERSION_ATTR(bc_version);
+static ELANTS_VERSION_ATTR(iap_version);
+
+static struct attribute *elants_attributes[] = {
+	&dev_attr_calibrate.attr,
+	&dev_attr_update_fw.attr,
+	&dev_attr_iap_mode.attr,
+	&dev_attr_calibration_count.attr,
+
+	&elants_ver_attr_fw_version.dattr.attr,
+	&elants_ver_attr_hw_version.dattr.attr,
+	&elants_ver_attr_test_version.dattr.attr,
+	&elants_ver_attr_solution_version.dattr.attr,
+	&elants_ver_attr_bc_version.dattr.attr,
+	&elants_ver_attr_iap_version.dattr.attr,
+	NULL
+};
+
+static const struct attribute_group elants_attribute_group = {
+	.attrs = elants_attributes,
+};
+
+static int elants_i2c_power_on(struct elants_data *ts)
+{
+	int error;
+
+	/*
+	 * If we do not have reset gpio assume platform firmware
+	 * controls regulators and does power them on for us.
+	 */
+	if (IS_ERR_OR_NULL(ts->reset_gpio))
+		return 0;
+
+	error = regulator_enable(ts->vcc33);
+	if (error) {
+		dev_err(&ts->client->dev,
+			"failed to enable vcc33 regulator: %d\n",
+			error);
+		return error;
+	}
+
+	error = regulator_enable(ts->vccio);
+	if (error) {
+		dev_err(&ts->client->dev,
+			"failed to enable vccio regulator: %d\n",
+			error);
+		regulator_disable(ts->vcc33);
+		return error;
+	}
+
+	/*
+	 * We need to wait a bit after powering on controller before
+	 * we are allowed to release reset GPIO.
+	 */
+	usleep_range(ELAN_POWERON_DELAY_USEC, ELAN_POWERON_DELAY_USEC + 100);
+
+	gpiod_set_value_cansleep(ts->reset_gpio, 0);
+
+	msleep(ELAN_RESET_DELAY_MSEC);
+
+	return 0;
+}
+
+static void elants_i2c_power_off(void *_data)
+{
+	struct elants_data *ts = _data;
+
+	if (!IS_ERR_OR_NULL(ts->reset_gpio)) {
+		/*
+		 * Activate reset gpio to prevent leakage through the
+		 * pin once we shut off power to the controller.
+		 */
+		gpiod_set_value_cansleep(ts->reset_gpio, 1);
+		regulator_disable(ts->vccio);
+		regulator_disable(ts->vcc33);
+	}
+}
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id i2c_hid_ids[] = {
+	{"ACPI0C50", 0 },
+	{"PNP0C50", 0 },
+	{ },
+};
+
+static const guid_t i2c_hid_guid =
+	GUID_INIT(0x3CDFF6F7, 0x4267, 0x4555,
+		  0xAD, 0x05, 0xB3, 0x0A, 0x3D, 0x89, 0x38, 0xDE);
+
+static bool elants_acpi_is_hid_device(struct device *dev)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object *obj;
+
+	if (acpi_match_device_ids(ACPI_COMPANION(dev), i2c_hid_ids))
+		return false;
+
+	obj = acpi_evaluate_dsm_typed(handle, &i2c_hid_guid, 1, 1, NULL, ACPI_TYPE_INTEGER);
+	if (obj) {
+		ACPI_FREE(obj);
+		return true;
+	}
+
+	return false;
+}
+#else
+static bool elants_acpi_is_hid_device(struct device *dev)
+{
+	return false;
+}
+#endif
+
+static int elants_i2c_probe(struct i2c_client *client)
+{
+	union i2c_smbus_data dummy;
+	struct elants_data *ts;
+	unsigned long irqflags;
+	int error;
+
+	/* Don't bind to i2c-hid compatible devices, these are handled by the i2c-hid drv. */
+	if (elants_acpi_is_hid_device(&client->dev)) {
+		dev_warn(&client->dev, "This device appears to be an I2C-HID device, not binding\n");
+		return -ENODEV;
+	}
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "I2C check functionality error\n");
+		return -ENXIO;
+	}
+
+	ts = devm_kzalloc(&client->dev, sizeof(struct elants_data), GFP_KERNEL);
+	if (!ts)
+		return -ENOMEM;
+
+	mutex_init(&ts->sysfs_mutex);
+	init_completion(&ts->cmd_done);
+
+	ts->client = client;
+	ts->chip_id = (enum elants_chip_id)(uintptr_t)device_get_match_data(&client->dev);
+	i2c_set_clientdata(client, ts);
+
+	ts->vcc33 = devm_regulator_get(&client->dev, "vcc33");
+	if (IS_ERR(ts->vcc33))
+		return dev_err_probe(&client->dev, PTR_ERR(ts->vcc33),
+				     "Failed to get 'vcc33' regulator\n");
+
+	ts->vccio = devm_regulator_get(&client->dev, "vccio");
+	if (IS_ERR(ts->vccio))
+		return dev_err_probe(&client->dev, PTR_ERR(ts->vccio),
+				     "Failed to get 'vccio' regulator\n");
+
+	ts->reset_gpio = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(ts->reset_gpio)) {
+		error = PTR_ERR(ts->reset_gpio);
+
+		if (error == -EPROBE_DEFER)
+			return error;
+
+		if (error != -ENOENT && error != -ENOSYS) {
+			dev_err(&client->dev,
+				"failed to get reset gpio: %d\n",
+				error);
+			return error;
+		}
+
+		ts->keep_power_in_suspend = true;
+	}
+
+	error = elants_i2c_power_on(ts);
+	if (error)
+		return error;
+
+	error = devm_add_action_or_reset(&client->dev,
+					 elants_i2c_power_off, ts);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to install power off action: %d\n", error);
+		return error;
+	}
+
+	/* Make sure there is something at this address */
+	if (i2c_smbus_xfer(client->adapter, client->addr, 0,
+			   I2C_SMBUS_READ, 0, I2C_SMBUS_BYTE, &dummy) < 0) {
+		dev_err(&client->dev, "nothing at this address\n");
+		return -ENXIO;
+	}
+
+	error = elants_i2c_initialize(ts);
+	if (error) {
+		dev_err(&client->dev, "failed to initialize: %d\n", error);
+		return error;
+	}
+
+	ts->input = devm_input_allocate_device(&client->dev);
+	if (!ts->input) {
+		dev_err(&client->dev, "Failed to allocate input device\n");
+		return -ENOMEM;
+	}
+
+	ts->input->name = "Elan Touchscreen";
+	ts->input->id.bustype = BUS_I2C;
+
+	/* Multitouch input params setup */
+
+	input_set_abs_params(ts->input, ABS_MT_POSITION_X, 0, ts->x_max, 0, 0);
+	input_set_abs_params(ts->input, ABS_MT_POSITION_Y, 0, ts->y_max, 0, 0);
+	input_set_abs_params(ts->input, ABS_MT_TOUCH_MAJOR, 0, 255, 0, 0);
+	input_set_abs_params(ts->input, ABS_MT_PRESSURE, 0, 255, 0, 0);
+	input_set_abs_params(ts->input, ABS_MT_TOOL_TYPE,
+			     0, MT_TOOL_PALM, 0, 0);
+
+	touchscreen_parse_properties(ts->input, true, &ts->prop);
+
+	if (ts->chip_id == EKTF3624 && ts->phy_x && ts->phy_y) {
+		/* calculate resolution from size */
+		ts->x_res = DIV_ROUND_CLOSEST(ts->prop.max_x, ts->phy_x);
+		ts->y_res = DIV_ROUND_CLOSEST(ts->prop.max_y, ts->phy_y);
+	}
+
+	input_abs_set_res(ts->input, ABS_MT_POSITION_X, ts->x_res);
+	input_abs_set_res(ts->input, ABS_MT_POSITION_Y, ts->y_res);
+	input_abs_set_res(ts->input, ABS_MT_TOUCH_MAJOR, ts->major_res);
+
+	error = input_mt_init_slots(ts->input, MAX_CONTACT_NUM,
+				    INPUT_MT_DIRECT | INPUT_MT_DROP_UNUSED);
+	if (error) {
+		dev_err(&client->dev,
+			"failed to initialize MT slots: %d\n", error);
+		return error;
+	}
+
+	error = input_register_device(ts->input);
+	if (error) {
+		dev_err(&client->dev,
+			"unable to register input device: %d\n", error);
+		return error;
+	}
+
+	/*
+	 * Platform code (ACPI, DTS) should normally set up interrupt
+	 * for us, but in case it did not let's fall back to using falling
+	 * edge to be compatible with older Chromebooks.
+	 */
+	irqflags = irq_get_trigger_type(client->irq);
+	if (!irqflags)
+		irqflags = IRQF_TRIGGER_FALLING;
+
+	error = devm_request_threaded_irq(&client->dev, client->irq,
+					  NULL, elants_i2c_irq,
+					  irqflags | IRQF_ONESHOT,
+					  client->name, ts);
+	if (error) {
+		dev_err(&client->dev, "Failed to register interrupt\n");
+		return error;
+	}
+
+	error = devm_device_add_group(&client->dev, &elants_attribute_group);
+	if (error) {
+		dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int elants_i2c_suspend(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct elants_data *ts = i2c_get_clientdata(client);
+	const u8 set_sleep_cmd[] = {
+		CMD_HEADER_WRITE, E_POWER_STATE_SLEEP, 0x00, 0x01
+	};
+	int retry_cnt;
+	int error;
+
+	/* Command not support in IAP recovery mode */
+	if (ts->iap_mode != ELAN_IAP_OPERATIONAL)
+		return -EBUSY;
+
+	disable_irq(client->irq);
+
+	if (device_may_wakeup(dev)) {
+		/*
+		 * The device will automatically enter idle mode
+		 * that has reduced power consumption.
+		 */
+		return 0;
+	} else if (ts->keep_power_in_suspend) {
+		for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
+			error = elants_i2c_send(client, set_sleep_cmd,
+						sizeof(set_sleep_cmd));
+			if (!error)
+				break;
+
+			dev_err(&client->dev,
+				"suspend command failed: %d\n", error);
+		}
+	} else {
+		elants_i2c_power_off(ts);
+	}
+
+	return 0;
+}
+
+static int elants_i2c_resume(struct device *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct elants_data *ts = i2c_get_clientdata(client);
+	const u8 set_active_cmd[] = {
+		CMD_HEADER_WRITE, E_POWER_STATE_RESUME, 0x00, 0x01
+	};
+	int retry_cnt;
+	int error;
+
+	if (device_may_wakeup(dev)) {
+		elants_i2c_sw_reset(client);
+	} else if (ts->keep_power_in_suspend) {
+		for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
+			error = elants_i2c_send(client, set_active_cmd,
+						sizeof(set_active_cmd));
+			if (!error)
+				break;
+
+			dev_err(&client->dev,
+				"resume command failed: %d\n", error);
+		}
+	} else {
+		elants_i2c_power_on(ts);
+		elants_i2c_initialize(ts);
+	}
+
+	ts->state = ELAN_STATE_NORMAL;
+	enable_irq(client->irq);
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(elants_i2c_pm_ops,
+				elants_i2c_suspend, elants_i2c_resume);
+
+static const struct i2c_device_id elants_i2c_id[] = {
+	{ DEVICE_NAME, EKTH3500 },
+	{ "ekth3500", EKTH3500 },
+	{ "ektf3624", EKTF3624 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id elants_acpi_id[] = {
+	{ "ELAN0001", EKTH3500 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id elants_of_match[] = {
+	{ .compatible = "elan,ekth3500", .data = (void *)EKTH3500 },
+	{ .compatible = "elan,ektf3624", .data = (void *)EKTF3624 },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, elants_of_match);
+#endif
+
+static struct i2c_driver elants_i2c_driver = {
+	.probe = elants_i2c_probe,
+	.id_table = elants_i2c_id,
+	.driver = {
+		.name = DEVICE_NAME,
+		.pm = pm_sleep_ptr(&elants_i2c_pm_ops),
+		.acpi_match_table = ACPI_PTR(elants_acpi_id),
+		.of_match_table = of_match_ptr(elants_of_match),
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+module_i2c_driver(elants_i2c_driver);
+
+MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
+MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
+MODULE_LICENSE("GPL");