Input: add support for Elan eKTH I2C touchscreens
authorScott Liu <scott.liu@emc.com.tw>
Thu, 20 Nov 2014 01:26:44 +0000 (17:26 -0800)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Mon, 8 Dec 2014 07:09:23 +0000 (23:09 -0800)
This driver supports Elan eKTH I2C touchscreen controllers. Note that these
are using custom protocol, as opposed to other Elan parts that use
HID-over-I2C and are supported by the standard HID-multitouch driver.

Signed-off-by: Scott Liu <scott.liu@emc.com.tw>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Documentation/devicetree/bindings/input/elants_i2c.txt [new file with mode: 0644]
drivers/input/touchscreen/Kconfig
drivers/input/touchscreen/Makefile
drivers/input/touchscreen/elants_i2c.c [new file with mode: 0644]

diff --git a/Documentation/devicetree/bindings/input/elants_i2c.txt b/Documentation/devicetree/bindings/input/elants_i2c.txt
new file mode 100644 (file)
index 0000000..a765232
--- /dev/null
@@ -0,0 +1,33 @@
+Elantech I2C Touchscreen
+
+Required properties:
+- compatible: must be "elan,ekth3500".
+- reg: I2C address of the chip.
+- interrupt-parent: a phandle for the interrupt controller (see interrupt
+  binding[0]).
+- interrupts: interrupt to which the chip is connected (see interrupt
+  binding[0]).
+
+Optional properties:
+- wakeup-source: touchscreen can be used as a wakeup source.
+- pinctrl-names: should be "default" (see pinctrl binding [1]).
+- pinctrl-0: a phandle pointing to the pin settings for the device (see
+  pinctrl binding [1]).
+
+[0]: Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
+[1]: Documentation/devicetree/bindings/pinctrl/pinctrl-bindings.txt
+
+Example:
+       &i2c1 {
+               /* ... */
+
+               touchscreen@10 {
+                       compatible = "elan,ekth3500";
+                       reg = <0x10>;
+                       interrupt-parent = <&gpio4>;
+                       interrupts = <0x0 IRQ_TYPE_EDGE_FALLING>;
+                       wakeup-source;
+               };
+
+               /* ... */
+       };
index 568a0200fbc2f1fab6f3f854c7c900eefc04dda1..58917525126e86fd06cb632b2cbb3f558b0a2f83 100644 (file)
@@ -347,6 +347,18 @@ config TOUCHSCREEN_GUNZE
          To compile this driver as a module, choose M here: the
          module will be called gunze.
 
+config TOUCHSCREEN_ELAN
+       tristate "Elan eKTH I2C touchscreen"
+       depends on I2C
+       help
+         Say Y here if you have an Elan eKTH I2C touchscreen
+         connected to your system.
+
+         If unsure, say N.
+
+         To compile this driver as a module, choose M here: the
+         module will be called elants_i2c.
+
 config TOUCHSCREEN_ELO
        tristate "Elo serial touchscreens"
        select SERIO
index dab4a56ac98e68f3849f6de166195b02efc7a628..0242fea2102ac7cc5782224cb4a6705499c9431d 100644 (file)
@@ -31,6 +31,7 @@ obj-$(CONFIG_TOUCHSCREEN_EDT_FT5X06)  += edt-ft5x06.o
 obj-$(CONFIG_TOUCHSCREEN_HAMPSHIRE)    += hampshire.o
 obj-$(CONFIG_TOUCHSCREEN_GUNZE)                += gunze.o
 obj-$(CONFIG_TOUCHSCREEN_EETI)         += eeti_ts.o
+obj-$(CONFIG_TOUCHSCREEN_ELAN)         += elants_i2c.o
 obj-$(CONFIG_TOUCHSCREEN_ELO)          += elo.o
 obj-$(CONFIG_TOUCHSCREEN_EGALAX)       += egalax_ts.o
 obj-$(CONFIG_TOUCHSCREEN_FUJITSU)      += fujitsu_ts.o
diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c
new file mode 100644 (file)
index 0000000..a510f7e
--- /dev/null
@@ -0,0 +1,1271 @@
+/*
+ * 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
+ */
+
+/*
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ */
+
+#include <linux/module.h>
+#include <linux/input.h>
+#include <linux/interrupt.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/version.h>
+#include <linux/slab.h>
+#include <linux/firmware.h>
+#include <linux/version.h>
+#include <linux/input/mt.h>
+#include <linux/acpi.h>
+#include <linux/of.h>
+#include <asm/unaligned.h>
+
+/* Device, Driver information */
+#define DEVICE_NAME    "elants_i2c"
+#define DRV_VERSION    "1.0.9"
+
+/* 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
+
+/* Command header definition */
+#define CMD_HEADER_WRITE       0x54
+#define CMD_HEADER_READ                0x53
+#define CMD_HEADER_6B_READ     0x5B
+#define CMD_HEADER_RESP                0x52
+#define CMD_HEADER_6B_RESP     0x9B
+#define CMD_HEADER_HELLO       0x55
+#define CMD_HEADER_REK         0x66
+
+/* FW position data */
+#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_CHECKSUM                34
+#define FW_POS_WIDTH           35
+#define FW_POS_PRESSURE                45
+
+#define HEADER_REPORT_10_FINGER        0x62
+
+/* Header (4 bytes) plus 3 fill 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_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
+
+#define MAX_RETRIES            3
+#define MAX_FW_UPDATE_RETRIES  30
+
+#define ELAN_FW_PAGESIZE       132
+#define ELAN_FW_FILENAME       "elants_i2c.bin"
+
+/* calibration timeout definition */
+#define ELAN_CALI_TIMEOUT_MSEC 10000
+
+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;
+
+       u16 fw_version;
+       u8 test_version;
+       u8 solution_version;
+       u8 bc_version;
+       u8 iap_version;
+       u16 hw_version;
+       unsigned int x_res;     /* resolution in units/mm */
+       unsigned int y_res;
+       unsigned int x_max;
+       unsigned int y_max;
+
+       enum elants_state state;
+       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;
+
+       u8 buf[MAX_PACKET_SIZE];
+
+       bool wake_irq_enabled;
+};
+
+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)
+{
+       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;
+
+       default:
+               dev_err(&client->dev, "%s: invalid command %*ph\n",
+                       __func__, (int)cmd_size, cmd);
+               return -EINVAL;
+       }
+
+       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;
+       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)
+               return ret;
+
+       if (ret != ARRAY_SIZE(msgs) || resp[FW_HDR_TYPE] != expected_response)
+               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[] = { 0x54, 0xC0, 0xE1, 0x5A };
+       static const u8 rek[] = { 0x54, 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_fw_id(struct elants_data *ts)
+{
+       struct i2c_client *client = ts->client;
+       int error, retry_cnt;
+       const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_ID, 0x00, 0x01 };
+       u8 resp[HEADER_SIZE];
+
+       for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
+               error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+                                                  resp, sizeof(resp));
+               if (!error) {
+                       ts->hw_version = elants_i2c_parse_version(resp);
+                       if (ts->hw_version != 0xffff)
+                               return 0;
+               }
+
+               dev_dbg(&client->dev, "read fw id error=%d, buf=%*phC\n",
+                       error, (int)sizeof(resp), resp);
+       }
+
+       dev_err(&client->dev,
+               "Failed to read fw id or fw id is invalid\n");
+
+       return -EINVAL;
+}
+
+static int elants_i2c_query_fw_version(struct elants_data *ts)
+{
+       struct i2c_client *client = ts->client;
+       int error, retry_cnt;
+       const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_FW_VER, 0x00, 0x01 };
+       u8 resp[HEADER_SIZE];
+
+       for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
+               error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+                                                  resp, sizeof(resp));
+               if (!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 error=%d, buf=%*phC\n",
+                       error, (int)sizeof(resp), resp);
+       }
+
+       dev_err(&client->dev,
+               "Failed to read fw version or fw version is invalid\n");
+
+       return -EINVAL;
+}
+
+static int elants_i2c_query_test_version(struct elants_data *ts)
+{
+       struct i2c_client *client = ts->client;
+       int error, retry_cnt;
+       u16 version;
+       const u8 cmd[] = { CMD_HEADER_READ, E_ELAN_INFO_TEST_VER, 0x00, 0x01 };
+       u8 resp[HEADER_SIZE];
+
+       for (retry_cnt = 0; retry_cnt < MAX_RETRIES; retry_cnt++) {
+               error = elants_i2c_execute_command(client, cmd, sizeof(cmd),
+                                                  resp, sizeof(resp));
+               if (!error) {
+                       version = elants_i2c_parse_version(resp);
+                       ts->test_version = version >> 8;
+                       ts->solution_version = version & 0xff;
+
+                       return 0;
+               }
+
+               dev_dbg(&client->dev,
+                       "read test version error rc=%d, buf=%*phC\n",
+                       error, (int)sizeof(resp), resp);
+       }
+
+       dev_err(&client->dev, "Failed to read test version\n");
+
+       return -EINVAL;
+}
+
+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));
+       if (error) {
+               dev_err(&client->dev,
+                       "read BC version error=%d, buf=%*phC\n",
+                       error, (int)sizeof(resp), resp);
+               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(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));
+       if (error) {
+               dev_err(&client->dev, "get resolution command failed: %d\n",
+                       error);
+               return error;
+       }
+
+       rows = resp[2] + resp[6] + resp[10];
+       cols = resp[3] + resp[7] + resp[11];
+
+       /* Process mm_to_pixel information */
+       error = elants_i2c_execute_command(client,
+                                          get_osr_cmd, sizeof(get_osr_cmd),
+                                          resp, sizeof(resp));
+       if (error) {
+               dev_err(&client->dev, "get osr command failed: %d\n",
+                       error);
+               return error;
+       }
+
+       osr = resp[3];
+
+       error = elants_i2c_execute_command(client,
+                                          get_physical_scan_cmd,
+                                          sizeof(get_physical_scan_cmd),
+                                          resp, sizeof(resp));
+       if (error) {
+               dev_err(&client->dev, "get physical scan command failed: %d\n",
+                       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));
+       if (error) {
+               dev_err(&client->dev, "get physical drive command failed: %d\n",
+                       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);
+       }
+
+       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, 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);
+               }
+       }
+
+       if (!error)
+               error = elants_i2c_query_fw_id(ts);
+       if (!error)
+               error = elants_i2c_query_fw_version(ts);
+
+       if (error) {
+               ts->iap_mode = ELAN_IAP_RECOVERY;
+       } else {
+               elants_i2c_query_test_version(ts);
+               elants_i2c_query_bc_version(ts);
+               elants_i2c_query_ts_info(ts);
+       }
+
+       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_do_update_firmware(struct i2c_client *client,
+                                        const struct firmware *fw,
+                                        bool force)
+{
+       const u8 enter_iap[] = { 0x45, 0x49, 0x41, 0x50 };
+       const u8 enter_iap2[] = { 0x54, 0x00, 0x12, 0x34 };
+       const u8 iap_ack[] = { 0x55, 0xaa, 0x33, 0xcc };
+       u8 buf[HEADER_SIZE];
+       u16 send_id;
+       int page, n_fw_pages;
+       int error;
+
+       /* Recovery mode detection! */
+       if (force) {
+               dev_dbg(&client->dev, "Recovery mode procedure\n");
+               error = elants_i2c_send(client, enter_iap2, sizeof(enter_iap2));
+       } else {
+               /* Start IAP Procedure */
+               dev_dbg(&client->dev, "Normal IAP procedure\n");
+               elants_i2c_sw_reset(client);
+
+               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;
+       int error;
+
+       error = request_firmware(&fw, ELAN_FW_FILENAME, &client->dev);
+       if (error) {
+               dev_err(&client->dev, "failed to request firmware %s: %d\n",
+                       ELAN_FW_FILENAME, 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)
+{
+       struct input_dev *input = ts->input;
+       unsigned int n_fingers;
+       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);
+
+       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];
+                       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, MT_TOOL_FINGER, true);
+                       input_event(input, EV_ABS, ABS_MT_POSITION_X, x);
+                       input_event(input, EV_ABS, ABS_MT_POSITION_Y, y);
+                       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)
+{
+       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);
+}
+
+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(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;
+               /* fall through */
+
+       case ELAN_STATE_NORMAL:
+
+               switch (ts->buf[FW_HDR_TYPE]) {
+               case CMD_HEADER_HELLO:
+               case CMD_HEADER_RESP:
+               case CMD_HEADER_REK:
+                       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]);
+                       break;
+
+               case QUEUE_HEADER_NORMAL:
+                       report_count = ts->buf[FW_HDR_COUNT];
+                       if (report_count > 3) {
+                               dev_err(&client->dev,
+                                       "too large report count: %*ph\n",
+                                       HEADER_SIZE, ts->buf);
+                               break;
+                       }
+
+                       report_len = ts->buf[FW_HDR_LENGTH] / report_count;
+                       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 * PACKET_SIZE;
+                               elants_i2c_event(ts, buf);
+                       }
+                       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 DEVICE_ATTR(calibrate, S_IWUSR, NULL, calibrate_store);
+static DEVICE_ATTR(iap_mode, S_IRUGO, show_iap_mode, 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,
+
+       &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 struct attribute_group elants_attribute_group = {
+       .attrs = elants_attributes,
+};
+
+static void elants_i2c_remove_sysfs_group(void *_data)
+{
+       struct elants_data *ts = _data;
+
+       sysfs_remove_group(&ts->client->dev.kobj, &elants_attribute_group);
+}
+
+static int elants_i2c_probe(struct i2c_client *client,
+                           const struct i2c_device_id *id)
+{
+       union i2c_smbus_data dummy;
+       struct elants_data *ts;
+       unsigned long irqflags;
+       int error;
+
+       if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+               dev_err(&client->dev,
+                       "%s: i2c check functionality error\n", DEVICE_NAME);
+               return -ENXIO;
+       }
+
+       /* 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;
+       }
+
+       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;
+       i2c_set_clientdata(client, ts);
+
+       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;
+
+       __set_bit(BTN_TOUCH, ts->input->keybit);
+       __set_bit(EV_ABS, ts->input->evbit);
+       __set_bit(EV_KEY, ts->input->evbit);
+
+       /* Single touch input params setup */
+       input_set_abs_params(ts->input, ABS_X, 0, ts->x_max, 0, 0);
+       input_set_abs_params(ts->input, ABS_Y, 0, ts->y_max, 0, 0);
+       input_set_abs_params(ts->input, ABS_PRESSURE, 0, 255, 0, 0);
+       input_abs_set_res(ts->input, ABS_X, ts->x_res);
+       input_abs_set_res(ts->input, ABS_Y, ts->y_res);
+
+       /* Multitouch input params setup */
+       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;
+       }
+
+       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_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_set_drvdata(ts->input, ts);
+
+       error = input_register_device(ts->input);
+       if (error) {
+               dev_err(&client->dev,
+                       "unable to register input device: %d\n", error);
+               return error;
+       }
+
+       /*
+        * Systems using device tree should set up interrupt via DTS,
+        * the rest will use the default falling edge interrupts.
+        */
+       irqflags = client->dev.of_node ? 0 : 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;
+       }
+
+       /*
+        * Systems using device tree should set up wakeup via DTS,
+        * the rest will configure device as wakeup source by default.
+        */
+       if (!client->dev.of_node)
+               device_init_wakeup(&client->dev, true);
+
+       error = sysfs_create_group(&client->dev.kobj, &elants_attribute_group);
+       if (error) {
+               dev_err(&client->dev, "failed to create sysfs attributes: %d\n",
+                       error);
+               return error;
+       }
+
+       error = devm_add_action(&client->dev,
+                               elants_i2c_remove_sysfs_group, ts);
+       if (error) {
+               elants_i2c_remove_sysfs_group(ts);
+               dev_err(&client->dev,
+                       "Failed to add sysfs cleanup action: %d\n",
+                       error);
+               return error;
+       }
+
+       return 0;
+}
+
+static int __maybe_unused 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[] = { 0x54, 0x50, 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);
+
+       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);
+       }
+
+       if (device_may_wakeup(dev))
+               ts->wake_irq_enabled = (enable_irq_wake(client->irq) == 0);
+
+       return 0;
+}
+
+static int __maybe_unused 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[] = { 0x54, 0x58, 0x00, 0x01 };
+       int retry_cnt;
+       int error;
+
+       if (device_may_wakeup(dev) && ts->wake_irq_enabled)
+               disable_irq_wake(client->irq);
+
+       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);
+       }
+
+       ts->state = ELAN_STATE_NORMAL;
+       enable_irq(client->irq);
+
+       return 0;
+}
+
+static 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, 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(i2c, elants_i2c_id);
+
+#ifdef CONFIG_ACPI
+static const struct acpi_device_id elants_acpi_id[] = {
+       { "ELAN0001", 0 },
+       { }
+};
+MODULE_DEVICE_TABLE(acpi, elants_acpi_id);
+#endif
+
+#ifdef CONFIG_OF
+static const struct of_device_id elants_of_match[] = {
+       { .compatible = "elan,ekth3500" },
+       { /* 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,
+               .owner = THIS_MODULE,
+               .pm = &elants_i2c_pm_ops,
+               .acpi_match_table = ACPI_PTR(elants_acpi_id),
+               .of_match_table = of_match_ptr(elants_of_match),
+       },
+};
+module_i2c_driver(elants_i2c_driver);
+
+MODULE_AUTHOR("Scott Liu <scott.liu@emc.com.tw>");
+MODULE_DESCRIPTION("Elan I2c Touchscreen driver");
+MODULE_VERSION(DRV_VERSION);
+MODULE_LICENSE("GPL");