diff --git a/drivers/input/misc/Kconfig b/drivers/input/misc/Kconfig
index 798ba29..9d32716 100644
--- a/drivers/input/misc/Kconfig
+++ b/drivers/input/misc/Kconfig
@@ -606,6 +606,16 @@ config INPUT_ADXL34X_SPI
 	  To compile this driver as a module, choose M here: the
 	  module will be called adxl34x-spi.
 
+config INPUT_IMS_PCU
+	tristate "IMS Passenger Control Unit driver"
+	depends on USB
+	depends on LEDS_CLASS
+	help
+	  Say Y here if you have system with IMS Rave Passenger Control Unit.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ims_pcu.
+
 config INPUT_CMA3000
 	tristate "VTI CMA3000 Tri-axis accelerometer"
 	help
diff --git a/drivers/input/misc/Makefile b/drivers/input/misc/Makefile
index ae5d9fd..33085784 100644
--- a/drivers/input/misc/Makefile
+++ b/drivers/input/misc/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_INPUT_GP2A)		+= gp2ap002a00f.o
 obj-$(CONFIG_INPUT_GPIO_BEEPER)		+= gpio-beeper.o
 obj-$(CONFIG_INPUT_GPIO_TILT_POLLED)	+= gpio_tilt_polled.o
 obj-$(CONFIG_HP_SDC_RTC)		+= hp_sdc_rtc.o
+obj-$(CONFIG_INPUT_IMS_PCU)		+= ims-pcu.o
 obj-$(CONFIG_INPUT_IXP4XX_BEEPER)	+= ixp4xx-beeper.o
 obj-$(CONFIG_INPUT_KEYSPAN_REMOTE)	+= keyspan_remote.o
 obj-$(CONFIG_INPUT_KXTJ9)		+= kxtj9.o
diff --git a/drivers/input/misc/ims-pcu.c b/drivers/input/misc/ims-pcu.c
new file mode 100644
index 0000000..10bd73c
--- /dev/null
+++ b/drivers/input/misc/ims-pcu.c
@@ -0,0 +1,1907 @@
+/*
+ * Driver for IMS Passenger Control Unit Devices
+ *
+ * Copyright (C) 2013 The IMS Company
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ */
+
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/firmware.h>
+#include <linux/ihex.h>
+#include <linux/input.h>
+#include <linux/kernel.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/usb/input.h>
+#include <linux/usb/cdc.h>
+#include <asm/unaligned.h>
+
+#define IMS_PCU_KEYMAP_LEN		32
+
+struct ims_pcu_buttons {
+	struct input_dev *input;
+	char name[32];
+	char phys[32];
+	unsigned short keymap[IMS_PCU_KEYMAP_LEN];
+};
+
+struct ims_pcu_gamepad {
+	struct input_dev *input;
+	char name[32];
+	char phys[32];
+};
+
+struct ims_pcu_backlight {
+	struct led_classdev cdev;
+	struct work_struct work;
+	enum led_brightness desired_brightness;
+	char name[32];
+};
+
+#define IMS_PCU_PART_NUMBER_LEN		15
+#define IMS_PCU_SERIAL_NUMBER_LEN	8
+#define IMS_PCU_DOM_LEN			8
+#define IMS_PCU_FW_VERSION_LEN		(9 + 1)
+#define IMS_PCU_BL_VERSION_LEN		(9 + 1)
+#define IMS_PCU_BL_RESET_REASON_LEN	(2 + 1)
+
+#define IMS_PCU_BUF_SIZE		128
+
+struct ims_pcu {
+	struct usb_device *udev;
+	struct device *dev; /* control interface's device, used for logging */
+
+	unsigned int device_no;
+
+	bool bootloader_mode;
+
+	char part_number[IMS_PCU_PART_NUMBER_LEN];
+	char serial_number[IMS_PCU_SERIAL_NUMBER_LEN];
+	char date_of_manufacturing[IMS_PCU_DOM_LEN];
+	char fw_version[IMS_PCU_FW_VERSION_LEN];
+	char bl_version[IMS_PCU_BL_VERSION_LEN];
+	char reset_reason[IMS_PCU_BL_RESET_REASON_LEN];
+	int update_firmware_status;
+
+	struct usb_interface *ctrl_intf;
+
+	struct usb_endpoint_descriptor *ep_ctrl;
+	struct urb *urb_ctrl;
+	u8 *urb_ctrl_buf;
+	dma_addr_t ctrl_dma;
+	size_t max_ctrl_size;
+
+	struct usb_interface *data_intf;
+
+	struct usb_endpoint_descriptor *ep_in;
+	struct urb *urb_in;
+	u8 *urb_in_buf;
+	dma_addr_t read_dma;
+	size_t max_in_size;
+
+	struct usb_endpoint_descriptor *ep_out;
+	u8 *urb_out_buf;
+	size_t max_out_size;
+
+	u8 read_buf[IMS_PCU_BUF_SIZE];
+	u8 read_pos;
+	u8 check_sum;
+	bool have_stx;
+	bool have_dle;
+
+	u8 cmd_buf[IMS_PCU_BUF_SIZE];
+	u8 ack_id;
+	u8 expected_response;
+	u8 cmd_buf_len;
+	struct completion cmd_done;
+	struct mutex cmd_mutex;
+
+	u32 fw_start_addr;
+	u32 fw_end_addr;
+	struct completion async_firmware_done;
+
+	struct ims_pcu_buttons buttons;
+	struct ims_pcu_gamepad *gamepad;
+	struct ims_pcu_backlight backlight;
+
+	bool setup_complete; /* Input and LED devices have been created */
+};
+
+
+/*********************************************************************
+ *             Buttons Input device support                          *
+ *********************************************************************/
+
+static const unsigned short ims_pcu_keymap_1[] = {
+	[1] = KEY_ATTENDANT_OFF,
+	[2] = KEY_ATTENDANT_ON,
+	[3] = KEY_LIGHTS_TOGGLE,
+	[4] = KEY_VOLUMEUP,
+	[5] = KEY_VOLUMEDOWN,
+	[6] = KEY_INFO,
+};
+
+static const unsigned short ims_pcu_keymap_2[] = {
+	[4] = KEY_VOLUMEUP,
+	[5] = KEY_VOLUMEDOWN,
+	[6] = KEY_INFO,
+};
+
+static const unsigned short ims_pcu_keymap_3[] = {
+	[1] = KEY_HOMEPAGE,
+	[2] = KEY_ATTENDANT_TOGGLE,
+	[3] = KEY_LIGHTS_TOGGLE,
+	[4] = KEY_VOLUMEUP,
+	[5] = KEY_VOLUMEDOWN,
+	[6] = KEY_DISPLAYTOGGLE,
+	[18] = KEY_PLAYPAUSE,
+};
+
+static const unsigned short ims_pcu_keymap_4[] = {
+	[1] = KEY_ATTENDANT_OFF,
+	[2] = KEY_ATTENDANT_ON,
+	[3] = KEY_LIGHTS_TOGGLE,
+	[4] = KEY_VOLUMEUP,
+	[5] = KEY_VOLUMEDOWN,
+	[6] = KEY_INFO,
+	[18] = KEY_PLAYPAUSE,
+};
+
+static const unsigned short ims_pcu_keymap_5[] = {
+	[1] = KEY_ATTENDANT_OFF,
+	[2] = KEY_ATTENDANT_ON,
+	[3] = KEY_LIGHTS_TOGGLE,
+};
+
+static const unsigned short ims_pcu_keymap_6[] = {
+	[1] = KEY_LIGHTS_TOGGLE,
+	[2] = KEY_ATTENDANT_OFF,
+	[3] = KEY_ATTENDANT_ON,
+};
+
+struct ims_pcu_device_info {
+	const unsigned short *keymap;
+	size_t keymap_len;
+	bool has_gamepad;
+};
+
+#define IMS_PCU_DEVINFO(_n, _gamepad)				\
+	[_n] = {						\
+		.keymap = ims_pcu_keymap_##_n,			\
+		.keymap_len = ARRAY_SIZE(ims_pcu_keymap_##_n),	\
+		.has_gamepad = _gamepad,			\
+	}
+
+static const struct ims_pcu_device_info ims_pcu_device_info[] = {
+	IMS_PCU_DEVINFO(1, true),
+	IMS_PCU_DEVINFO(2, true),
+	IMS_PCU_DEVINFO(3, true),
+	IMS_PCU_DEVINFO(4, true),
+	IMS_PCU_DEVINFO(5, false),
+	IMS_PCU_DEVINFO(6, false),
+};
+
+static void ims_pcu_buttons_report(struct ims_pcu *pcu, u32 data)
+{
+	struct ims_pcu_buttons *buttons = &pcu->buttons;
+	struct input_dev *input = buttons->input;
+	int i;
+
+	for (i = 0; i < 32; i++) {
+		unsigned short keycode = buttons->keymap[i];
+
+		if (keycode != KEY_RESERVED)
+			input_report_key(input, keycode, data & (1UL << i));
+	}
+
+	input_sync(input);
+}
+
+static int ims_pcu_setup_buttons(struct ims_pcu *pcu,
+				 const unsigned short *keymap,
+				 size_t keymap_len)
+{
+	struct ims_pcu_buttons *buttons = &pcu->buttons;
+	struct input_dev *input;
+	int i;
+	int error;
+
+	input = input_allocate_device();
+	if (!input) {
+		dev_err(pcu->dev,
+			"Not enough memory for input input device\n");
+		return -ENOMEM;
+	}
+
+	snprintf(buttons->name, sizeof(buttons->name),
+		 "IMS PCU#%d Button Interface", pcu->device_no);
+
+	usb_make_path(pcu->udev, buttons->phys, sizeof(buttons->phys));
+	strlcat(buttons->phys, "/input0", sizeof(buttons->phys));
+
+	memcpy(buttons->keymap, keymap, sizeof(*keymap) * keymap_len);
+
+	input->name = buttons->name;
+	input->phys = buttons->phys;
+	usb_to_input_id(pcu->udev, &input->id);
+	input->dev.parent = &pcu->ctrl_intf->dev;
+
+	input->keycode = buttons->keymap;
+	input->keycodemax = ARRAY_SIZE(buttons->keymap);
+	input->keycodesize = sizeof(buttons->keymap[0]);
+
+	__set_bit(EV_KEY, input->evbit);
+	for (i = 0; i < IMS_PCU_KEYMAP_LEN; i++)
+		__set_bit(buttons->keymap[i], input->keybit);
+	__clear_bit(KEY_RESERVED, input->keybit);
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to register buttons input device: %d\n",
+			error);
+		input_free_device(input);
+		return error;
+	}
+
+	buttons->input = input;
+	return 0;
+}
+
+static void ims_pcu_destroy_buttons(struct ims_pcu *pcu)
+{
+	struct ims_pcu_buttons *buttons = &pcu->buttons;
+
+	input_unregister_device(buttons->input);
+}
+
+
+/*********************************************************************
+ *             Gamepad Input device support                          *
+ *********************************************************************/
+
+static void ims_pcu_gamepad_report(struct ims_pcu *pcu, u32 data)
+{
+	struct ims_pcu_gamepad *gamepad = pcu->gamepad;
+	struct input_dev *input = gamepad->input;
+	int x, y;
+
+	x = !!(data & (1 << 14)) - !!(data & (1 << 13));
+	y = !!(data & (1 << 12)) - !!(data & (1 << 11));
+
+	input_report_abs(input, ABS_X, x);
+	input_report_abs(input, ABS_Y, y);
+
+	input_report_key(input, BTN_A, data & (1 << 7));
+	input_report_key(input, BTN_B, data & (1 << 8));
+	input_report_key(input, BTN_X, data & (1 << 9));
+	input_report_key(input, BTN_Y, data & (1 << 10));
+	input_report_key(input, BTN_START, data & (1 << 15));
+	input_report_key(input, BTN_SELECT, data & (1 << 16));
+
+	input_sync(input);
+}
+
+static int ims_pcu_setup_gamepad(struct ims_pcu *pcu)
+{
+	struct ims_pcu_gamepad *gamepad;
+	struct input_dev *input;
+	int error;
+
+	gamepad = kzalloc(sizeof(struct ims_pcu_gamepad), GFP_KERNEL);
+	input = input_allocate_device();
+	if (!gamepad || !input) {
+		dev_err(pcu->dev,
+			"Not enough memory for gamepad device\n");
+		return -ENOMEM;
+	}
+
+	gamepad->input = input;
+
+	snprintf(gamepad->name, sizeof(gamepad->name),
+		 "IMS PCU#%d Gamepad Interface", pcu->device_no);
+
+	usb_make_path(pcu->udev, gamepad->phys, sizeof(gamepad->phys));
+	strlcat(gamepad->phys, "/input1", sizeof(gamepad->phys));
+
+	input->name = gamepad->name;
+	input->phys = gamepad->phys;
+	usb_to_input_id(pcu->udev, &input->id);
+	input->dev.parent = &pcu->ctrl_intf->dev;
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(BTN_A, input->keybit);
+	__set_bit(BTN_B, input->keybit);
+	__set_bit(BTN_X, input->keybit);
+	__set_bit(BTN_Y, input->keybit);
+	__set_bit(BTN_START, input->keybit);
+	__set_bit(BTN_SELECT, input->keybit);
+
+	__set_bit(EV_ABS, input->evbit);
+	input_set_abs_params(input, ABS_X, -1, 1, 0, 0);
+	input_set_abs_params(input, ABS_Y, -1, 1, 0, 0);
+
+	error = input_register_device(input);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to register gamepad input device: %d\n",
+			error);
+		goto err_free_mem;
+	}
+
+	pcu->gamepad = gamepad;
+	return 0;
+
+err_free_mem:
+	input_free_device(input);
+	kfree(gamepad);
+	return -ENOMEM;
+}
+
+static void ims_pcu_destroy_gamepad(struct ims_pcu *pcu)
+{
+	struct ims_pcu_gamepad *gamepad = pcu->gamepad;
+
+	input_unregister_device(gamepad->input);
+	kfree(gamepad);
+}
+
+
+/*********************************************************************
+ *             PCU Communication protocol handling                   *
+ *********************************************************************/
+
+#define IMS_PCU_PROTOCOL_STX		0x02
+#define IMS_PCU_PROTOCOL_ETX		0x03
+#define IMS_PCU_PROTOCOL_DLE		0x10
+
+/* PCU commands */
+#define IMS_PCU_CMD_STATUS		0xa0
+#define IMS_PCU_CMD_PCU_RESET		0xa1
+#define IMS_PCU_CMD_RESET_REASON	0xa2
+#define IMS_PCU_CMD_SEND_BUTTONS	0xa3
+#define IMS_PCU_CMD_JUMP_TO_BTLDR	0xa4
+#define IMS_PCU_CMD_GET_INFO		0xa5
+#define IMS_PCU_CMD_SET_BRIGHTNESS	0xa6
+#define IMS_PCU_CMD_EEPROM		0xa7
+#define IMS_PCU_CMD_GET_FW_VERSION	0xa8
+#define IMS_PCU_CMD_GET_BL_VERSION	0xa9
+#define IMS_PCU_CMD_SET_INFO		0xab
+#define IMS_PCU_CMD_GET_BRIGHTNESS	0xac
+#define IMS_PCU_CMD_GET_DEVICE_ID	0xae
+#define IMS_PCU_CMD_SPECIAL_INFO	0xb0
+#define IMS_PCU_CMD_BOOTLOADER		0xb1	/* Pass data to bootloader */
+
+/* PCU responses */
+#define IMS_PCU_RSP_STATUS		0xc0
+#define IMS_PCU_RSP_PCU_RESET		0	/* Originally 0xc1 */
+#define IMS_PCU_RSP_RESET_REASON	0xc2
+#define IMS_PCU_RSP_SEND_BUTTONS	0xc3
+#define IMS_PCU_RSP_JUMP_TO_BTLDR	0	/* Originally 0xc4 */
+#define IMS_PCU_RSP_GET_INFO		0xc5
+#define IMS_PCU_RSP_SET_BRIGHTNESS	0xc6
+#define IMS_PCU_RSP_EEPROM		0xc7
+#define IMS_PCU_RSP_GET_FW_VERSION	0xc8
+#define IMS_PCU_RSP_GET_BL_VERSION	0xc9
+#define IMS_PCU_RSP_SET_INFO		0xcb
+#define IMS_PCU_RSP_GET_BRIGHTNESS	0xcc
+#define IMS_PCU_RSP_CMD_INVALID		0xcd
+#define IMS_PCU_RSP_GET_DEVICE_ID	0xce
+#define IMS_PCU_RSP_SPECIAL_INFO	0xd0
+#define IMS_PCU_RSP_BOOTLOADER		0xd1	/* Bootloader response */
+
+#define IMS_PCU_RSP_EVNT_BUTTONS	0xe0	/* Unsolicited, button state */
+#define IMS_PCU_GAMEPAD_MASK		0x0001ff80UL	/* Bits 7 through 16 */
+
+
+#define IMS_PCU_MIN_PACKET_LEN		3
+#define IMS_PCU_DATA_OFFSET		2
+
+#define IMS_PCU_CMD_WRITE_TIMEOUT	100 /* msec */
+#define IMS_PCU_CMD_RESPONSE_TIMEOUT	500 /* msec */
+
+static void ims_pcu_report_events(struct ims_pcu *pcu)
+{
+	u32 data = get_unaligned_be32(&pcu->read_buf[3]);
+
+	ims_pcu_buttons_report(pcu, data & ~IMS_PCU_GAMEPAD_MASK);
+	if (pcu->gamepad)
+		ims_pcu_gamepad_report(pcu, data);
+}
+
+static void ims_pcu_handle_response(struct ims_pcu *pcu)
+{
+	switch (pcu->read_buf[0]) {
+	case IMS_PCU_RSP_EVNT_BUTTONS:
+		if (likely(pcu->setup_complete))
+			ims_pcu_report_events(pcu);
+		break;
+
+	default:
+		/*
+		 * See if we got command completion.
+		 * If both the sequence and response code match save
+		 * the data and signal completion.
+		 */
+		if (pcu->read_buf[0] == pcu->expected_response &&
+		    pcu->read_buf[1] == pcu->ack_id - 1) {
+
+			memcpy(pcu->cmd_buf, pcu->read_buf, pcu->read_pos);
+			pcu->cmd_buf_len = pcu->read_pos;
+			complete(&pcu->cmd_done);
+		}
+		break;
+	}
+}
+
+static void ims_pcu_process_data(struct ims_pcu *pcu, struct urb *urb)
+{
+	int i;
+
+	for (i = 0; i < urb->actual_length; i++) {
+		u8 data = pcu->urb_in_buf[i];
+
+		/* Skip everything until we get Start Xmit */
+		if (!pcu->have_stx && data != IMS_PCU_PROTOCOL_STX)
+			continue;
+
+		if (pcu->have_dle) {
+			pcu->have_dle = false;
+			pcu->read_buf[pcu->read_pos++] = data;
+			pcu->check_sum += data;
+			continue;
+		}
+
+		switch (data) {
+		case IMS_PCU_PROTOCOL_STX:
+			if (pcu->have_stx)
+				dev_warn(pcu->dev,
+					 "Unexpected STX at byte %d, discarding old data\n",
+					 pcu->read_pos);
+			pcu->have_stx = true;
+			pcu->have_dle = false;
+			pcu->read_pos = 0;
+			pcu->check_sum = 0;
+			break;
+
+		case IMS_PCU_PROTOCOL_DLE:
+			pcu->have_dle = true;
+			break;
+
+		case IMS_PCU_PROTOCOL_ETX:
+			if (pcu->read_pos < IMS_PCU_MIN_PACKET_LEN) {
+				dev_warn(pcu->dev,
+					 "Short packet received (%d bytes), ignoring\n",
+					 pcu->read_pos);
+			} else if (pcu->check_sum != 0) {
+				dev_warn(pcu->dev,
+					 "Invalid checksum in packet (%d bytes), ignoring\n",
+					 pcu->read_pos);
+			} else {
+				ims_pcu_handle_response(pcu);
+			}
+
+			pcu->have_stx = false;
+			pcu->have_dle = false;
+			pcu->read_pos = 0;
+			break;
+
+		default:
+			pcu->read_buf[pcu->read_pos++] = data;
+			pcu->check_sum += data;
+			break;
+		}
+	}
+}
+
+static bool ims_pcu_byte_needs_escape(u8 byte)
+{
+	return byte == IMS_PCU_PROTOCOL_STX ||
+	       byte == IMS_PCU_PROTOCOL_ETX ||
+	       byte == IMS_PCU_PROTOCOL_DLE;
+}
+
+static int ims_pcu_send_cmd_chunk(struct ims_pcu *pcu,
+				  u8 command, int chunk, int len)
+{
+	int error;
+
+	error = usb_bulk_msg(pcu->udev,
+			     usb_sndbulkpipe(pcu->udev,
+					     pcu->ep_out->bEndpointAddress),
+			     pcu->urb_out_buf, len,
+			     NULL, IMS_PCU_CMD_WRITE_TIMEOUT);
+	if (error < 0) {
+		dev_dbg(pcu->dev,
+			"Sending 0x%02x command failed at chunk %d: %d\n",
+			command, chunk, error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int ims_pcu_send_command(struct ims_pcu *pcu,
+				u8 command, const u8 *data, int len)
+{
+	int count = 0;
+	int chunk = 0;
+	int delta;
+	int i;
+	int error;
+	u8 csum = 0;
+	u8 ack_id;
+
+	pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_STX;
+
+	/* We know the command need not be escaped */
+	pcu->urb_out_buf[count++] = command;
+	csum += command;
+
+	ack_id = pcu->ack_id++;
+	if (ack_id == 0xff)
+		ack_id = pcu->ack_id++;
+
+	if (ims_pcu_byte_needs_escape(ack_id))
+		pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
+
+	pcu->urb_out_buf[count++] = ack_id;
+	csum += ack_id;
+
+	for (i = 0; i < len; i++) {
+
+		delta = ims_pcu_byte_needs_escape(data[i]) ? 2 : 1;
+		if (count + delta >= pcu->max_out_size) {
+			error = ims_pcu_send_cmd_chunk(pcu, command,
+						       ++chunk, count);
+			if (error)
+				return error;
+
+			count = 0;
+		}
+
+		if (delta == 2)
+			pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
+
+		pcu->urb_out_buf[count++] = data[i];
+		csum += data[i];
+	}
+
+	csum = 1 + ~csum;
+
+	delta = ims_pcu_byte_needs_escape(csum) ? 3 : 2;
+	if (count + delta >= pcu->max_out_size) {
+		error = ims_pcu_send_cmd_chunk(pcu, command, ++chunk, count);
+		if (error)
+			return error;
+
+		count = 0;
+	}
+
+	if (delta == 3)
+		pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_DLE;
+
+	pcu->urb_out_buf[count++] = csum;
+	pcu->urb_out_buf[count++] = IMS_PCU_PROTOCOL_ETX;
+
+	return ims_pcu_send_cmd_chunk(pcu, command, ++chunk, count);
+}
+
+static int __ims_pcu_execute_command(struct ims_pcu *pcu,
+				     u8 command, const void *data, size_t len,
+				     u8 expected_response, int response_time)
+{
+	int error;
+
+	pcu->expected_response = expected_response;
+	init_completion(&pcu->cmd_done);
+
+	error = ims_pcu_send_command(pcu, command, data, len);
+	if (error)
+		return error;
+
+	if (expected_response &&
+	    !wait_for_completion_timeout(&pcu->cmd_done,
+					 msecs_to_jiffies(response_time))) {
+		dev_dbg(pcu->dev, "Command 0x%02x timed out\n", command);
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+#define ims_pcu_execute_command(pcu, code, data, len)			\
+	__ims_pcu_execute_command(pcu,					\
+				  IMS_PCU_CMD_##code, data, len,	\
+				  IMS_PCU_RSP_##code,			\
+				  IMS_PCU_CMD_RESPONSE_TIMEOUT)
+
+#define ims_pcu_execute_query(pcu, code)				\
+	ims_pcu_execute_command(pcu, code, NULL, 0)
+
+/* Bootloader commands */
+#define IMS_PCU_BL_CMD_QUERY_DEVICE	0xa1
+#define IMS_PCU_BL_CMD_UNLOCK_CONFIG	0xa2
+#define IMS_PCU_BL_CMD_ERASE_APP	0xa3
+#define IMS_PCU_BL_CMD_PROGRAM_DEVICE	0xa4
+#define IMS_PCU_BL_CMD_PROGRAM_COMPLETE	0xa5
+#define IMS_PCU_BL_CMD_READ_APP		0xa6
+#define IMS_PCU_BL_CMD_RESET_DEVICE	0xa7
+#define IMS_PCU_BL_CMD_LAUNCH_APP	0xa8
+
+/* Bootloader commands */
+#define IMS_PCU_BL_RSP_QUERY_DEVICE	0xc1
+#define IMS_PCU_BL_RSP_UNLOCK_CONFIG	0xc2
+#define IMS_PCU_BL_RSP_ERASE_APP	0xc3
+#define IMS_PCU_BL_RSP_PROGRAM_DEVICE	0xc4
+#define IMS_PCU_BL_RSP_PROGRAM_COMPLETE	0xc5
+#define IMS_PCU_BL_RSP_READ_APP		0xc6
+#define IMS_PCU_BL_RSP_RESET_DEVICE	0	/* originally 0xa7 */
+#define IMS_PCU_BL_RSP_LAUNCH_APP	0	/* originally 0xa8 */
+
+#define IMS_PCU_BL_DATA_OFFSET		3
+
+static int __ims_pcu_execute_bl_command(struct ims_pcu *pcu,
+				        u8 command, const void *data, size_t len,
+				        u8 expected_response, int response_time)
+{
+	int error;
+
+	pcu->cmd_buf[0] = command;
+	if (data)
+		memcpy(&pcu->cmd_buf[1], data, len);
+
+	error = __ims_pcu_execute_command(pcu,
+				IMS_PCU_CMD_BOOTLOADER, pcu->cmd_buf, len + 1,
+				expected_response ? IMS_PCU_RSP_BOOTLOADER : 0,
+				response_time);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failure when sending 0x%02x command to bootloader, error: %d\n",
+			pcu->cmd_buf[0], error);
+		return error;
+	}
+
+	if (expected_response && pcu->cmd_buf[2] != expected_response) {
+		dev_err(pcu->dev,
+			"Unexpected response from bootloader: 0x%02x, wanted 0x%02x\n",
+			pcu->cmd_buf[2], expected_response);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+#define ims_pcu_execute_bl_command(pcu, code, data, len, timeout)	\
+	__ims_pcu_execute_bl_command(pcu,				\
+				     IMS_PCU_BL_CMD_##code, data, len,	\
+				     IMS_PCU_BL_RSP_##code, timeout)	\
+
+#define IMS_PCU_INFO_PART_OFFSET	2
+#define IMS_PCU_INFO_DOM_OFFSET		17
+#define IMS_PCU_INFO_SERIAL_OFFSET	25
+
+#define IMS_PCU_SET_INFO_SIZE		31
+
+static int ims_pcu_get_info(struct ims_pcu *pcu)
+{
+	int error;
+
+	error = ims_pcu_execute_query(pcu, GET_INFO);
+	if (error) {
+		dev_err(pcu->dev,
+			"GET_INFO command failed, error: %d\n", error);
+		return error;
+	}
+
+	memcpy(pcu->part_number,
+	       &pcu->cmd_buf[IMS_PCU_INFO_PART_OFFSET],
+	       sizeof(pcu->part_number));
+	memcpy(pcu->date_of_manufacturing,
+	       &pcu->cmd_buf[IMS_PCU_INFO_DOM_OFFSET],
+	       sizeof(pcu->date_of_manufacturing));
+	memcpy(pcu->serial_number,
+	       &pcu->cmd_buf[IMS_PCU_INFO_SERIAL_OFFSET],
+	       sizeof(pcu->serial_number));
+
+	return 0;
+}
+
+static int ims_pcu_set_info(struct ims_pcu *pcu)
+{
+	int error;
+
+	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_PART_OFFSET],
+	       pcu->part_number, sizeof(pcu->part_number));
+	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_DOM_OFFSET],
+	       pcu->date_of_manufacturing, sizeof(pcu->date_of_manufacturing));
+	memcpy(&pcu->cmd_buf[IMS_PCU_INFO_SERIAL_OFFSET],
+	       pcu->serial_number, sizeof(pcu->serial_number));
+
+	error = ims_pcu_execute_command(pcu, SET_INFO,
+					&pcu->cmd_buf[IMS_PCU_DATA_OFFSET],
+					IMS_PCU_SET_INFO_SIZE);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to update device information, error: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int ims_pcu_switch_to_bootloader(struct ims_pcu *pcu)
+{
+	int error;
+
+	/* Execute jump to the bootoloader */
+	error = ims_pcu_execute_command(pcu, JUMP_TO_BTLDR, NULL, 0);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failure when sending JUMP TO BOOLTLOADER command, error: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+/*********************************************************************
+ *             Firmware Update handling                              *
+ *********************************************************************/
+
+#define IMS_PCU_FIRMWARE_NAME	"imspcu.fw"
+
+struct ims_pcu_flash_fmt {
+	__le32 addr;
+	u8 len;
+	u8 data[];
+};
+
+static unsigned int ims_pcu_count_fw_records(const struct firmware *fw)
+{
+	const struct ihex_binrec *rec = (const struct ihex_binrec *)fw->data;
+	unsigned int count = 0;
+
+	while (rec) {
+		count++;
+		rec = ihex_next_binrec(rec);
+	}
+
+	return count;
+}
+
+static int ims_pcu_verify_block(struct ims_pcu *pcu,
+				u32 addr, u8 len, const u8 *data)
+{
+	struct ims_pcu_flash_fmt *fragment;
+	int error;
+
+	fragment = (void *)&pcu->cmd_buf[1];
+	put_unaligned_le32(addr, &fragment->addr);
+	fragment->len = len;
+
+	error = ims_pcu_execute_bl_command(pcu, READ_APP, NULL, 5,
+					IMS_PCU_CMD_RESPONSE_TIMEOUT);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to retrieve block at 0x%08x, len %d, error: %d\n",
+			addr, len, error);
+		return error;
+	}
+
+	fragment = (void *)&pcu->cmd_buf[IMS_PCU_BL_DATA_OFFSET];
+	if (get_unaligned_le32(&fragment->addr) != addr ||
+	    fragment->len != len) {
+		dev_err(pcu->dev,
+			"Wrong block when retrieving 0x%08x (0x%08x), len %d (%d)\n",
+			addr, get_unaligned_le32(&fragment->addr),
+			len, fragment->len);
+		return -EINVAL;
+	}
+
+	if (memcmp(fragment->data, data, len)) {
+		dev_err(pcu->dev,
+			"Mismatch in block at 0x%08x, len %d\n",
+			addr, len);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ims_pcu_flash_firmware(struct ims_pcu *pcu,
+				  const struct firmware *fw,
+				  unsigned int n_fw_records)
+{
+	const struct ihex_binrec *rec = (const struct ihex_binrec *)fw->data;
+	struct ims_pcu_flash_fmt *fragment;
+	unsigned int count = 0;
+	u32 addr;
+	u8 len;
+	int error;
+
+	error = ims_pcu_execute_bl_command(pcu, ERASE_APP, NULL, 0, 2000);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to erase application image, error: %d\n",
+			error);
+		return error;
+	}
+
+	while (rec) {
+		/*
+		 * The firmware format is messed up for some reason.
+		 * The address twice that of what is needed for some
+		 * reason and we end up overwriting half of the data
+		 * with the next record.
+		 */
+		addr = be32_to_cpu(rec->addr) / 2;
+		len = be16_to_cpu(rec->len);
+
+		fragment = (void *)&pcu->cmd_buf[1];
+		put_unaligned_le32(addr, &fragment->addr);
+		fragment->len = len;
+		memcpy(fragment->data, rec->data, len);
+
+		error = ims_pcu_execute_bl_command(pcu, PROGRAM_DEVICE,
+						NULL, len + 5,
+						IMS_PCU_CMD_RESPONSE_TIMEOUT);
+		if (error) {
+			dev_err(pcu->dev,
+				"Failed to write block at 0x%08x, len %d, error: %d\n",
+				addr, len, error);
+			return error;
+		}
+
+		if (addr >= pcu->fw_start_addr && addr < pcu->fw_end_addr) {
+			error = ims_pcu_verify_block(pcu, addr, len, rec->data);
+			if (error)
+				return error;
+		}
+
+		count++;
+		pcu->update_firmware_status = (count * 100) / n_fw_records;
+
+		rec = ihex_next_binrec(rec);
+	}
+
+	error = ims_pcu_execute_bl_command(pcu, PROGRAM_COMPLETE,
+					    NULL, 0, 2000);
+	if (error)
+		dev_err(pcu->dev,
+			"Failed to send PROGRAM_COMPLETE, error: %d\n",
+			error);
+
+	return 0;
+}
+
+static int ims_pcu_handle_firmware_update(struct ims_pcu *pcu,
+					  const struct firmware *fw)
+{
+	unsigned int n_fw_records;
+	int retval;
+
+	dev_info(pcu->dev, "Updating firmware %s, size: %zu\n",
+		 IMS_PCU_FIRMWARE_NAME, fw->size);
+
+	n_fw_records = ims_pcu_count_fw_records(fw);
+
+	retval = ims_pcu_flash_firmware(pcu, fw, n_fw_records);
+	if (retval)
+		goto out;
+
+	retval = ims_pcu_execute_bl_command(pcu, LAUNCH_APP, NULL, 0, 0);
+	if (retval)
+		dev_err(pcu->dev,
+			"Failed to start application image, error: %d\n",
+			retval);
+
+out:
+	pcu->update_firmware_status = retval;
+	sysfs_notify(&pcu->dev->kobj, NULL, "update_firmware_status");
+	return retval;
+}
+
+static void ims_pcu_process_async_firmware(const struct firmware *fw,
+					   void *context)
+{
+	struct ims_pcu *pcu = context;
+	int error;
+
+	if (!fw) {
+		dev_err(pcu->dev, "Failed to get firmware %s\n",
+			IMS_PCU_FIRMWARE_NAME);
+		goto out;
+	}
+
+	error = ihex_validate_fw(fw);
+	if (error) {
+		dev_err(pcu->dev, "Firmware %s is invalid\n",
+			IMS_PCU_FIRMWARE_NAME);
+		goto out;
+	}
+
+	mutex_lock(&pcu->cmd_mutex);
+	ims_pcu_handle_firmware_update(pcu, fw);
+	mutex_unlock(&pcu->cmd_mutex);
+
+	release_firmware(fw);
+
+out:
+	complete(&pcu->async_firmware_done);
+}
+
+/*********************************************************************
+ *             Backlight LED device support                          *
+ *********************************************************************/
+
+#define IMS_PCU_MAX_BRIGHTNESS		31998
+
+static void ims_pcu_backlight_work(struct work_struct *work)
+{
+	struct ims_pcu_backlight *backlight =
+			container_of(work, struct ims_pcu_backlight, work);
+	struct ims_pcu *pcu =
+			container_of(backlight, struct ims_pcu, backlight);
+	int desired_brightness = backlight->desired_brightness;
+	__le16 br_val = cpu_to_le16(desired_brightness);
+	int error;
+
+	mutex_lock(&pcu->cmd_mutex);
+
+	error = ims_pcu_execute_command(pcu, SET_BRIGHTNESS,
+					&br_val, sizeof(br_val));
+	if (error && error != -ENODEV)
+		dev_warn(pcu->dev,
+			 "Failed to set desired brightness %u, error: %d\n",
+			 desired_brightness, error);
+
+	mutex_unlock(&pcu->cmd_mutex);
+}
+
+static void ims_pcu_backlight_set_brightness(struct led_classdev *cdev,
+					     enum led_brightness value)
+{
+	struct ims_pcu_backlight *backlight =
+			container_of(cdev, struct ims_pcu_backlight, cdev);
+
+	backlight->desired_brightness = value;
+	schedule_work(&backlight->work);
+}
+
+static enum led_brightness
+ims_pcu_backlight_get_brightness(struct led_classdev *cdev)
+{
+	struct ims_pcu_backlight *backlight =
+			container_of(cdev, struct ims_pcu_backlight, cdev);
+	struct ims_pcu *pcu =
+			container_of(backlight, struct ims_pcu, backlight);
+	int brightness;
+	int error;
+
+	mutex_lock(&pcu->cmd_mutex);
+
+	error = ims_pcu_execute_query(pcu, GET_BRIGHTNESS);
+	if (error) {
+		dev_warn(pcu->dev,
+			 "Failed to get current brightness, error: %d\n",
+			 error);
+		/* Assume the LED is OFF */
+		brightness = LED_OFF;
+	} else {
+		brightness =
+			get_unaligned_le16(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET]);
+	}
+
+	mutex_unlock(&pcu->cmd_mutex);
+
+	return brightness;
+}
+
+static int ims_pcu_setup_backlight(struct ims_pcu *pcu)
+{
+	struct ims_pcu_backlight *backlight = &pcu->backlight;
+	int error;
+
+	INIT_WORK(&backlight->work, ims_pcu_backlight_work);
+	snprintf(backlight->name, sizeof(backlight->name),
+		 "pcu%d::kbd_backlight", pcu->device_no);
+
+	backlight->cdev.name = backlight->name;
+	backlight->cdev.max_brightness = IMS_PCU_MAX_BRIGHTNESS;
+	backlight->cdev.brightness_get = ims_pcu_backlight_get_brightness;
+	backlight->cdev.brightness_set = ims_pcu_backlight_set_brightness;
+
+	error = led_classdev_register(pcu->dev, &backlight->cdev);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to register backlight LED device, error: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static void ims_pcu_destroy_backlight(struct ims_pcu *pcu)
+{
+	struct ims_pcu_backlight *backlight = &pcu->backlight;
+
+	led_classdev_unregister(&backlight->cdev);
+	cancel_work_sync(&backlight->work);
+}
+
+
+/*********************************************************************
+ *             Sysfs attributes handling                             *
+ *********************************************************************/
+
+struct ims_pcu_attribute {
+	struct device_attribute dattr;
+	size_t field_offset;
+	int field_length;
+};
+
+static ssize_t ims_pcu_attribute_show(struct device *dev,
+				      struct device_attribute *dattr,
+				      char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	struct ims_pcu_attribute *attr =
+			container_of(dattr, struct ims_pcu_attribute, dattr);
+	char *field = (char *)pcu + attr->field_offset;
+
+	return scnprintf(buf, PAGE_SIZE, "%.*s\n", attr->field_length, field);
+}
+
+static ssize_t ims_pcu_attribute_store(struct device *dev,
+				       struct device_attribute *dattr,
+				       const char *buf, size_t count)
+{
+
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	struct ims_pcu_attribute *attr =
+			container_of(dattr, struct ims_pcu_attribute, dattr);
+	char *field = (char *)pcu + attr->field_offset;
+	size_t data_len;
+	int error;
+
+	if (count > attr->field_length)
+		return -EINVAL;
+
+	data_len = strnlen(buf, attr->field_length);
+	if (data_len > attr->field_length)
+		return -EINVAL;
+
+	error = mutex_lock_interruptible(&pcu->cmd_mutex);
+	if (error)
+		return error;
+
+	memset(field, 0, attr->field_length);
+	memcpy(field, buf, data_len);
+
+	error = ims_pcu_set_info(pcu);
+
+	/*
+	 * Even if update failed, let's fetch the info again as we just
+	 * clobbered one of the fields.
+	 */
+	ims_pcu_get_info(pcu);
+
+	mutex_unlock(&pcu->cmd_mutex);
+
+	return error < 0 ? error : count;
+}
+
+#define IMS_PCU_ATTR(_field, _mode)					\
+struct ims_pcu_attribute ims_pcu_attr_##_field = {			\
+	.dattr = __ATTR(_field, _mode,					\
+			ims_pcu_attribute_show,				\
+			ims_pcu_attribute_store),			\
+	.field_offset = offsetof(struct ims_pcu, _field),		\
+	.field_length = sizeof(((struct ims_pcu *)NULL)->_field),	\
+}
+
+#define IMS_PCU_RO_ATTR(_field)						\
+		IMS_PCU_ATTR(_field, S_IRUGO)
+#define IMS_PCU_RW_ATTR(_field)						\
+		IMS_PCU_ATTR(_field, S_IRUGO | S_IWUSR)
+
+static IMS_PCU_RW_ATTR(part_number);
+static IMS_PCU_RW_ATTR(serial_number);
+static IMS_PCU_RW_ATTR(date_of_manufacturing);
+
+static IMS_PCU_RO_ATTR(fw_version);
+static IMS_PCU_RO_ATTR(bl_version);
+static IMS_PCU_RO_ATTR(reset_reason);
+
+static ssize_t ims_pcu_reset_device(struct device *dev,
+				    struct device_attribute *dattr,
+				    const char *buf, size_t count)
+{
+	static const u8 reset_byte = 1;
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	int value;
+	int error;
+
+	error = kstrtoint(buf, 0, &value);
+	if (error)
+		return error;
+
+	if (value != 1)
+		return -EINVAL;
+
+	dev_info(pcu->dev, "Attempting to reset device\n");
+
+	error = ims_pcu_execute_command(pcu, PCU_RESET, &reset_byte, 1);
+	if (error) {
+		dev_info(pcu->dev,
+			 "Failed to reset device, error: %d\n",
+			 error);
+		return error;
+	}
+
+	return count;
+}
+
+static DEVICE_ATTR(reset_device, S_IWUSR, NULL, ims_pcu_reset_device);
+
+static ssize_t ims_pcu_update_firmware_store(struct device *dev,
+					     struct device_attribute *dattr,
+					     const char *buf, size_t count)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	const struct firmware *fw;
+	int value;
+	int error;
+
+	error = kstrtoint(buf, 0, &value);
+	if (error)
+		return error;
+
+	if (value != 1)
+		return -EINVAL;
+
+	error = mutex_lock_interruptible(&pcu->cmd_mutex);
+	if (error)
+		return error;
+
+	error = request_ihex_firmware(&fw, IMS_PCU_FIRMWARE_NAME, pcu->dev);
+	if (error) {
+		dev_err(pcu->dev, "Failed to request firmware %s, error: %d\n",
+			IMS_PCU_FIRMWARE_NAME, error);
+		goto out;
+	}
+
+	/*
+	 * If we are already in bootloader mode we can proceed with
+	 * flashing the firmware.
+	 *
+	 * If we are in application mode, then we need to switch into
+	 * bootloader mode, which will cause the device to disconnect
+	 * and reconnect as different device.
+	 */
+	if (pcu->bootloader_mode)
+		error = ims_pcu_handle_firmware_update(pcu, fw);
+	else
+		error = ims_pcu_switch_to_bootloader(pcu);
+
+	release_firmware(fw);
+
+out:
+	mutex_unlock(&pcu->cmd_mutex);
+	return error ?: count;
+}
+
+static DEVICE_ATTR(update_firmware, S_IWUSR,
+		   NULL, ims_pcu_update_firmware_store);
+
+static ssize_t
+ims_pcu_update_firmware_status_show(struct device *dev,
+				    struct device_attribute *dattr,
+				    char *buf)
+{
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", pcu->update_firmware_status);
+}
+
+static DEVICE_ATTR(update_firmware_status, S_IRUGO,
+		   ims_pcu_update_firmware_status_show, NULL);
+
+static struct attribute *ims_pcu_attrs[] = {
+	&ims_pcu_attr_part_number.dattr.attr,
+	&ims_pcu_attr_serial_number.dattr.attr,
+	&ims_pcu_attr_date_of_manufacturing.dattr.attr,
+	&ims_pcu_attr_fw_version.dattr.attr,
+	&ims_pcu_attr_bl_version.dattr.attr,
+	&ims_pcu_attr_reset_reason.dattr.attr,
+	&dev_attr_reset_device.attr,
+	&dev_attr_update_firmware.attr,
+	&dev_attr_update_firmware_status.attr,
+	NULL
+};
+
+static umode_t ims_pcu_is_attr_visible(struct kobject *kobj,
+				       struct attribute *attr, int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct usb_interface *intf = to_usb_interface(dev);
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	umode_t mode = attr->mode;
+
+	if (pcu->bootloader_mode) {
+		if (attr != &dev_attr_update_firmware_status.attr &&
+		    attr != &dev_attr_update_firmware.attr &&
+		    attr != &dev_attr_reset_device.attr) {
+			mode = 0;
+		}
+	} else {
+		if (attr == &dev_attr_update_firmware_status.attr)
+			mode = 0;
+	}
+
+	return mode;
+}
+
+static struct attribute_group ims_pcu_attr_group = {
+	.is_visible	= ims_pcu_is_attr_visible,
+	.attrs		= ims_pcu_attrs,
+};
+
+static void ims_pcu_irq(struct urb *urb)
+{
+	struct ims_pcu *pcu = urb->context;
+	int retval, status;
+
+	status = urb->status;
+
+	switch (status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		/* this urb is terminated, clean up */
+		dev_dbg(pcu->dev, "%s - urb shutting down with status: %d\n",
+			__func__, status);
+		return;
+	default:
+		dev_dbg(pcu->dev, "%s - nonzero urb status received: %d\n",
+			__func__, status);
+		goto exit;
+	}
+
+	dev_dbg(pcu->dev, "%s: received %d: %*ph\n", __func__,
+		urb->actual_length, urb->actual_length, pcu->urb_in_buf);
+
+	if (urb == pcu->urb_in)
+		ims_pcu_process_data(pcu, urb);
+
+exit:
+	retval = usb_submit_urb(urb, GFP_ATOMIC);
+	if (retval && retval != -ENODEV)
+		dev_err(pcu->dev, "%s - usb_submit_urb failed with result %d\n",
+			__func__, retval);
+}
+
+static int ims_pcu_buffers_alloc(struct ims_pcu *pcu)
+{
+	int error;
+
+	pcu->urb_in_buf = usb_alloc_coherent(pcu->udev, pcu->max_in_size,
+					     GFP_KERNEL, &pcu->read_dma);
+	if (!pcu->urb_in_buf) {
+		dev_err(pcu->dev,
+			"Failed to allocate memory for read buffer\n");
+		return -ENOMEM;
+	}
+
+	pcu->urb_in = usb_alloc_urb(0, GFP_KERNEL);
+	if (!pcu->urb_in) {
+		dev_err(pcu->dev, "Failed to allocate input URB\n");
+		error = -ENOMEM;
+		goto err_free_urb_in_buf;
+	}
+
+	pcu->urb_in->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	pcu->urb_in->transfer_dma = pcu->read_dma;
+
+	usb_fill_bulk_urb(pcu->urb_in, pcu->udev,
+			  usb_rcvbulkpipe(pcu->udev,
+					  pcu->ep_in->bEndpointAddress),
+			  pcu->urb_in_buf, pcu->max_in_size,
+			  ims_pcu_irq, pcu);
+
+	/*
+	 * We are using usb_bulk_msg() for sending so there is no point
+	 * in allocating memory with usb_alloc_coherent().
+	 */
+	pcu->urb_out_buf = kmalloc(pcu->max_out_size, GFP_KERNEL);
+	if (!pcu->urb_out_buf) {
+		dev_err(pcu->dev, "Failed to allocate memory for write buffer\n");
+		error = -ENOMEM;
+		goto err_free_in_urb;
+	}
+
+	pcu->urb_ctrl_buf = usb_alloc_coherent(pcu->udev, pcu->max_ctrl_size,
+					       GFP_KERNEL, &pcu->ctrl_dma);
+	if (!pcu->urb_ctrl_buf) {
+		dev_err(pcu->dev,
+			"Failed to allocate memory for read buffer\n");
+		goto err_free_urb_out_buf;
+	}
+
+	pcu->urb_ctrl = usb_alloc_urb(0, GFP_KERNEL);
+	if (!pcu->urb_ctrl) {
+		dev_err(pcu->dev, "Failed to allocate input URB\n");
+		error = -ENOMEM;
+		goto err_free_urb_ctrl_buf;
+	}
+
+	pcu->urb_ctrl->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	pcu->urb_ctrl->transfer_dma = pcu->ctrl_dma;
+
+	usb_fill_int_urb(pcu->urb_ctrl, pcu->udev,
+			  usb_rcvintpipe(pcu->udev,
+					 pcu->ep_ctrl->bEndpointAddress),
+			  pcu->urb_ctrl_buf, pcu->max_ctrl_size,
+			  ims_pcu_irq, pcu, pcu->ep_ctrl->bInterval);
+
+	return 0;
+
+err_free_urb_ctrl_buf:
+	usb_free_coherent(pcu->udev, pcu->max_ctrl_size,
+			  pcu->urb_ctrl_buf, pcu->ctrl_dma);
+err_free_urb_out_buf:
+	kfree(pcu->urb_out_buf);
+err_free_in_urb:
+	usb_free_urb(pcu->urb_in);
+err_free_urb_in_buf:
+	usb_free_coherent(pcu->udev, pcu->max_in_size,
+			  pcu->urb_in_buf, pcu->read_dma);
+	return error;
+}
+
+static void ims_pcu_buffers_free(struct ims_pcu *pcu)
+{
+	usb_kill_urb(pcu->urb_in);
+	usb_free_urb(pcu->urb_in);
+
+	usb_free_coherent(pcu->udev, pcu->max_out_size,
+			  pcu->urb_in_buf, pcu->read_dma);
+
+	kfree(pcu->urb_out_buf);
+
+	usb_kill_urb(pcu->urb_ctrl);
+	usb_free_urb(pcu->urb_ctrl);
+
+	usb_free_coherent(pcu->udev, pcu->max_ctrl_size,
+			  pcu->urb_ctrl_buf, pcu->ctrl_dma);
+}
+
+static const struct usb_cdc_union_desc *
+ims_pcu_get_cdc_union_desc(struct usb_interface *intf)
+{
+	const void *buf = intf->altsetting->extra;
+	size_t buflen = intf->altsetting->extralen;
+	struct usb_cdc_union_desc *union_desc;
+
+	if (!buf) {
+		dev_err(&intf->dev, "Missing descriptor data\n");
+		return NULL;
+	}
+
+	if (!buflen) {
+		dev_err(&intf->dev, "Zero length descriptor\n");
+		return NULL;
+	}
+
+	while (buflen > 0) {
+		union_desc = (struct usb_cdc_union_desc *)buf;
+
+		if (union_desc->bDescriptorType == USB_DT_CS_INTERFACE &&
+		    union_desc->bDescriptorSubType == USB_CDC_UNION_TYPE) {
+			dev_dbg(&intf->dev, "Found union header\n");
+			return union_desc;
+		}
+
+		buflen -= union_desc->bLength;
+		buf += union_desc->bLength;
+	}
+
+	dev_err(&intf->dev, "Missing CDC union descriptor\n");
+	return NULL;
+}
+
+static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pcu)
+{
+	const struct usb_cdc_union_desc *union_desc;
+	struct usb_host_interface *alt;
+
+	union_desc = ims_pcu_get_cdc_union_desc(intf);
+	if (!union_desc)
+		return -EINVAL;
+
+	pcu->ctrl_intf = usb_ifnum_to_if(pcu->udev,
+					 union_desc->bMasterInterface0);
+
+	alt = pcu->ctrl_intf->cur_altsetting;
+	pcu->ep_ctrl = &alt->endpoint[0].desc;
+	pcu->max_ctrl_size = usb_endpoint_maxp(pcu->ep_ctrl);
+
+	pcu->data_intf = usb_ifnum_to_if(pcu->udev,
+					 union_desc->bSlaveInterface0);
+
+	alt = pcu->data_intf->cur_altsetting;
+	if (alt->desc.bNumEndpoints != 2) {
+		dev_err(pcu->dev,
+			"Incorrect number of endpoints on data interface (%d)\n",
+			alt->desc.bNumEndpoints);
+		return -EINVAL;
+	}
+
+	pcu->ep_out = &alt->endpoint[0].desc;
+	if (!usb_endpoint_is_bulk_out(pcu->ep_out)) {
+		dev_err(pcu->dev,
+			"First endpoint on data interface is not BULK OUT\n");
+		return -EINVAL;
+	}
+
+	pcu->max_out_size = usb_endpoint_maxp(pcu->ep_out);
+	if (pcu->max_out_size < 8) {
+		dev_err(pcu->dev,
+			"Max OUT packet size is too small (%zd)\n",
+			pcu->max_out_size);
+		return -EINVAL;
+	}
+
+	pcu->ep_in = &alt->endpoint[1].desc;
+	if (!usb_endpoint_is_bulk_in(pcu->ep_in)) {
+		dev_err(pcu->dev,
+			"Second endpoint on data interface is not BULK IN\n");
+		return -EINVAL;
+	}
+
+	pcu->max_in_size = usb_endpoint_maxp(pcu->ep_in);
+	if (pcu->max_in_size < 8) {
+		dev_err(pcu->dev,
+			"Max IN packet size is too small (%zd)\n",
+			pcu->max_in_size);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int ims_pcu_start_io(struct ims_pcu *pcu)
+{
+	int error;
+
+	error = usb_submit_urb(pcu->urb_ctrl, GFP_KERNEL);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to start control IO - usb_submit_urb failed with result: %d\n",
+			error);
+		return -EIO;
+	}
+
+	error = usb_submit_urb(pcu->urb_in, GFP_KERNEL);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to start IO - usb_submit_urb failed with result: %d\n",
+			error);
+		usb_kill_urb(pcu->urb_ctrl);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+static void ims_pcu_stop_io(struct ims_pcu *pcu)
+{
+	usb_kill_urb(pcu->urb_in);
+	usb_kill_urb(pcu->urb_ctrl);
+}
+
+static int ims_pcu_line_setup(struct ims_pcu *pcu)
+{
+	struct usb_host_interface *interface = pcu->ctrl_intf->cur_altsetting;
+	struct usb_cdc_line_coding *line = (void *)pcu->cmd_buf;
+	int error;
+
+	memset(line, 0, sizeof(*line));
+	line->dwDTERate = cpu_to_le32(57600);
+	line->bDataBits = 8;
+
+	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
+				USB_CDC_REQ_SET_LINE_CODING,
+				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+				0, interface->desc.bInterfaceNumber,
+				line, sizeof(struct usb_cdc_line_coding),
+				5000);
+	if (error < 0) {
+		dev_err(pcu->dev, "Failed to set line coding, error: %d\n",
+			error);
+		return error;
+	}
+
+	error = usb_control_msg(pcu->udev, usb_sndctrlpipe(pcu->udev, 0),
+				USB_CDC_REQ_SET_CONTROL_LINE_STATE,
+				USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+				0x03, interface->desc.bInterfaceNumber,
+				NULL, 0, 5000);
+	if (error < 0) {
+		dev_err(pcu->dev, "Failed to set line state, error: %d\n",
+			error);
+		return error;
+	}
+
+	return 0;
+}
+
+static int ims_pcu_get_device_info(struct ims_pcu *pcu)
+{
+	int error;
+
+	error = ims_pcu_get_info(pcu);
+	if (error)
+		return error;
+
+	error = ims_pcu_execute_query(pcu, GET_FW_VERSION);
+	if (error) {
+		dev_err(pcu->dev,
+			"GET_FW_VERSION command failed, error: %d\n", error);
+		return error;
+	}
+
+	snprintf(pcu->fw_version, sizeof(pcu->fw_version),
+		 "%02x%02x%02x.%c%c",
+		 pcu->cmd_buf[2], pcu->cmd_buf[4], pcu->cmd_buf[5],
+		 pcu->cmd_buf[6], pcu->cmd_buf[7]);
+
+	error = ims_pcu_execute_query(pcu, GET_BL_VERSION);
+	if (error) {
+		dev_err(pcu->dev,
+			"GET_BL_VERSION command failed, error: %d\n", error);
+		return error;
+	}
+
+	snprintf(pcu->bl_version, sizeof(pcu->bl_version),
+		 "%02x%02x%02x.%c%c",
+		 pcu->cmd_buf[2], pcu->cmd_buf[4], pcu->cmd_buf[5],
+		 pcu->cmd_buf[6], pcu->cmd_buf[7]);
+
+	error = ims_pcu_execute_query(pcu, RESET_REASON);
+	if (error) {
+		dev_err(pcu->dev,
+			"RESET_REASON command failed, error: %d\n", error);
+		return error;
+	}
+
+	snprintf(pcu->reset_reason, sizeof(pcu->reset_reason),
+		 "%02x", pcu->cmd_buf[IMS_PCU_DATA_OFFSET]);
+
+	dev_dbg(pcu->dev,
+		"P/N: %s, MD: %s, S/N: %s, FW: %s, BL: %s, RR: %s\n",
+		pcu->part_number,
+		pcu->date_of_manufacturing,
+		pcu->serial_number,
+		pcu->fw_version,
+		pcu->bl_version,
+		pcu->reset_reason);
+
+	return 0;
+}
+
+static int ims_pcu_identify_type(struct ims_pcu *pcu, u8 *device_id)
+{
+	int error;
+
+	error = ims_pcu_execute_query(pcu, GET_DEVICE_ID);
+	if (error) {
+		dev_err(pcu->dev,
+			"GET_DEVICE_ID command failed, error: %d\n", error);
+		return error;
+	}
+
+	*device_id = pcu->cmd_buf[IMS_PCU_DATA_OFFSET];
+	dev_dbg(pcu->dev, "Detected device ID: %d\n", *device_id);
+
+	return 0;
+}
+
+static int ims_pcu_init_application_mode(struct ims_pcu *pcu)
+{
+	static atomic_t device_no = ATOMIC_INIT(0);
+
+	const struct ims_pcu_device_info *info;
+	u8 device_id;
+	int error;
+
+	error = ims_pcu_get_device_info(pcu);
+	if (error) {
+		/* Device does not respond to basic queries, hopeless */
+		return error;
+	}
+
+	error = ims_pcu_identify_type(pcu, &device_id);
+	if (error) {
+		dev_err(pcu->dev,
+			"Failed to identify device, error: %d\n", error);
+		/*
+		 * Do not signal error, but do not create input nor
+		 * backlight devices either, let userspace figure this
+		 * out (flash a new firmware?).
+		 */
+		return 0;
+	}
+
+	if (device_id >= ARRAY_SIZE(ims_pcu_device_info) ||
+	    !ims_pcu_device_info[device_id].keymap) {
+		dev_err(pcu->dev, "Device ID %d is not valid\n", device_id);
+		/* Same as above, punt to userspace */
+		return 0;
+	}
+
+	/* Device appears to be operable, complete initialization */
+	pcu->device_no = atomic_inc_return(&device_no) - 1;
+
+	error = ims_pcu_setup_backlight(pcu);
+	if (error)
+		return error;
+
+	info = &ims_pcu_device_info[device_id];
+	error = ims_pcu_setup_buttons(pcu, info->keymap, info->keymap_len);
+	if (error)
+		goto err_destroy_backlight;
+
+	if (info->has_gamepad) {
+		error = ims_pcu_setup_gamepad(pcu);
+		if (error)
+			goto err_destroy_buttons;
+	}
+
+	pcu->setup_complete = true;
+
+	return 0;
+
+err_destroy_backlight:
+	ims_pcu_destroy_backlight(pcu);
+err_destroy_buttons:
+	ims_pcu_destroy_buttons(pcu);
+	return error;
+}
+
+static void ims_pcu_destroy_application_mode(struct ims_pcu *pcu)
+{
+	if (pcu->setup_complete) {
+		pcu->setup_complete = false;
+		mb(); /* make sure flag setting is not reordered */
+
+		if (pcu->gamepad)
+			ims_pcu_destroy_gamepad(pcu);
+		ims_pcu_destroy_buttons(pcu);
+		ims_pcu_destroy_backlight(pcu);
+	}
+}
+
+static int ims_pcu_init_bootloader_mode(struct ims_pcu *pcu)
+{
+	int error;
+
+	error = ims_pcu_execute_bl_command(pcu, QUERY_DEVICE, NULL, 0,
+					   IMS_PCU_CMD_RESPONSE_TIMEOUT);
+	if (error) {
+		dev_err(pcu->dev, "Bootloader does not respond, aborting\n");
+		return error;
+	}
+
+	pcu->fw_start_addr =
+		get_unaligned_le32(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET + 11]);
+	pcu->fw_end_addr =
+		get_unaligned_le32(&pcu->cmd_buf[IMS_PCU_DATA_OFFSET + 15]);
+
+	dev_info(pcu->dev,
+		 "Device is in bootloader mode (addr 0x%08x-0x%08x), requesting firmware\n",
+		 pcu->fw_start_addr, pcu->fw_end_addr);
+
+	error = request_firmware_nowait(THIS_MODULE, true,
+					IMS_PCU_FIRMWARE_NAME,
+					pcu->dev, GFP_KERNEL, pcu,
+					ims_pcu_process_async_firmware);
+	if (error) {
+		/* This error is not fatal, let userspace have another chance */
+		complete(&pcu->async_firmware_done);
+	}
+
+	return 0;
+}
+
+static void ims_pcu_destroy_bootloader_mode(struct ims_pcu *pcu)
+{
+	/* Make sure our initial firmware request has completed */
+	wait_for_completion(&pcu->async_firmware_done);
+}
+
+#define IMS_PCU_APPLICATION_MODE	0
+#define IMS_PCU_BOOTLOADER_MODE		1
+
+static struct usb_driver ims_pcu_driver;
+
+static int ims_pcu_probe(struct usb_interface *intf,
+			 const struct usb_device_id *id)
+{
+	struct usb_device *udev = interface_to_usbdev(intf);
+	struct ims_pcu *pcu;
+	int error;
+
+	pcu = kzalloc(sizeof(struct ims_pcu), GFP_KERNEL);
+	if (!pcu)
+		return -ENOMEM;
+
+	pcu->dev = &intf->dev;
+	pcu->udev = udev;
+	pcu->bootloader_mode = id->driver_info == IMS_PCU_BOOTLOADER_MODE;
+	mutex_init(&pcu->cmd_mutex);
+	init_completion(&pcu->cmd_done);
+	init_completion(&pcu->async_firmware_done);
+
+	error = ims_pcu_parse_cdc_data(intf, pcu);
+	if (error)
+		goto err_free_mem;
+
+	error = usb_driver_claim_interface(&ims_pcu_driver,
+					   pcu->data_intf, pcu);
+	if (error) {
+		dev_err(&intf->dev,
+			"Unable to claim corresponding data interface: %d\n",
+			error);
+		goto err_free_mem;
+	}
+
+	usb_set_intfdata(pcu->ctrl_intf, pcu);
+	usb_set_intfdata(pcu->data_intf, pcu);
+
+	error = ims_pcu_buffers_alloc(pcu);
+	if (error)
+		goto err_unclaim_intf;
+
+	error = ims_pcu_start_io(pcu);
+	if (error)
+		goto err_free_buffers;
+
+	error = ims_pcu_line_setup(pcu);
+	if (error)
+		goto err_stop_io;
+
+	error = sysfs_create_group(&intf->dev.kobj, &ims_pcu_attr_group);
+	if (error)
+		goto err_stop_io;
+
+	error = pcu->bootloader_mode ?
+			ims_pcu_init_bootloader_mode(pcu) :
+			ims_pcu_init_application_mode(pcu);
+	if (error)
+		goto err_remove_sysfs;
+
+	return 0;
+
+err_remove_sysfs:
+	sysfs_remove_group(&intf->dev.kobj, &ims_pcu_attr_group);
+err_stop_io:
+	ims_pcu_stop_io(pcu);
+err_free_buffers:
+	ims_pcu_buffers_free(pcu);
+err_unclaim_intf:
+	usb_driver_release_interface(&ims_pcu_driver, pcu->data_intf);
+err_free_mem:
+	kfree(pcu);
+	return error;
+}
+
+static void ims_pcu_disconnect(struct usb_interface *intf)
+{
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	struct usb_host_interface *alt = intf->cur_altsetting;
+
+	usb_set_intfdata(intf, NULL);
+
+	/*
+	 * See if we are dealing with control or data interface. The cleanup
+	 * happens when we unbind primary (control) interface.
+	 */
+	if (alt->desc.bInterfaceClass != USB_CLASS_COMM)
+		return;
+
+	sysfs_remove_group(&intf->dev.kobj, &ims_pcu_attr_group);
+
+	ims_pcu_stop_io(pcu);
+
+	if (pcu->bootloader_mode)
+		ims_pcu_destroy_bootloader_mode(pcu);
+	else
+		ims_pcu_destroy_application_mode(pcu);
+
+	ims_pcu_buffers_free(pcu);
+	kfree(pcu);
+}
+
+#ifdef CONFIG_PM
+static int ims_pcu_suspend(struct usb_interface *intf,
+			   pm_message_t message)
+{
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	struct usb_host_interface *alt = intf->cur_altsetting;
+
+	if (alt->desc.bInterfaceClass == USB_CLASS_COMM)
+		ims_pcu_stop_io(pcu);
+
+	return 0;
+}
+
+static int ims_pcu_resume(struct usb_interface *intf)
+{
+	struct ims_pcu *pcu = usb_get_intfdata(intf);
+	struct usb_host_interface *alt = intf->cur_altsetting;
+	int retval = 0;
+
+	if (alt->desc.bInterfaceClass == USB_CLASS_COMM) {
+		retval = ims_pcu_start_io(pcu);
+		if (retval == 0)
+			retval = ims_pcu_line_setup(pcu);
+	}
+
+	return retval;
+}
+#endif
+
+static const struct usb_device_id ims_pcu_id_table[] = {
+	{
+		USB_DEVICE_AND_INTERFACE_INFO(0x04d8, 0x0082,
+					USB_CLASS_COMM,
+					USB_CDC_SUBCLASS_ACM,
+					USB_CDC_ACM_PROTO_AT_V25TER),
+		.driver_info = IMS_PCU_APPLICATION_MODE,
+	},
+	{
+		USB_DEVICE_AND_INTERFACE_INFO(0x04d8, 0x0083,
+					USB_CLASS_COMM,
+					USB_CDC_SUBCLASS_ACM,
+					USB_CDC_ACM_PROTO_AT_V25TER),
+		.driver_info = IMS_PCU_BOOTLOADER_MODE,
+	},
+	{ }
+};
+
+static struct usb_driver ims_pcu_driver = {
+	.name			= "ims_pcu",
+	.id_table		= ims_pcu_id_table,
+	.probe			= ims_pcu_probe,
+	.disconnect		= ims_pcu_disconnect,
+#ifdef CONFIG_PM
+	.suspend		= ims_pcu_suspend,
+	.resume			= ims_pcu_resume,
+	.reset_resume		= ims_pcu_resume,
+#endif
+};
+
+module_usb_driver(ims_pcu_driver);
+
+MODULE_DESCRIPTION("IMS Passenger Control Unit driver");
+MODULE_AUTHOR("Dmitry Torokhov <dmitry.torokhov@gmail.com>");
+MODULE_LICENSE("GPL");
