Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / input / misc / ims-pcu.c
diff --git a/kernel/drivers/input/misc/ims-pcu.c b/kernel/drivers/input/misc/ims-pcu.c
new file mode 100644 (file)
index 0000000..ac1fa5f
--- /dev/null
@@ -0,0 +1,2144 @@
+/*
+ * 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_PCU_B_DEVICE_ID                5
+
+#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;
+       u8 device_id;
+
+       u8 ofn_reg_addr;
+
+       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,
+};
+
+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),
+};
+
+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");
+               error = -ENOMEM;
+               goto err_free_mem;
+       }
+
+       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 */
+#define IMS_PCU_CMD_OFN_SET_CONFIG     0xb3
+#define IMS_PCU_CMD_OFN_GET_CONFIG     0xb4
+
+/* 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_OFN_SET_CONFIG     0xd2
+#define IMS_PCU_RSP_OFN_GET_CONFIG     0xd3
+
+
+#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 = NULL;
+       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,
+};
+
+/* Support for a separate OFN attribute group */
+
+#define OFN_REG_RESULT_OFFSET  2
+
+static int ims_pcu_read_ofn_config(struct ims_pcu *pcu, u8 addr, u8 *data)
+{
+       int error;
+       s16 result;
+
+       error = ims_pcu_execute_command(pcu, OFN_GET_CONFIG,
+                                       &addr, sizeof(addr));
+       if (error)
+               return error;
+
+       result = (s16)get_unaligned_le16(pcu->cmd_buf + OFN_REG_RESULT_OFFSET);
+       if (result < 0)
+               return -EIO;
+
+       /* We only need LSB */
+       *data = pcu->cmd_buf[OFN_REG_RESULT_OFFSET];
+       return 0;
+}
+
+static int ims_pcu_write_ofn_config(struct ims_pcu *pcu, u8 addr, u8 data)
+{
+       u8 buffer[] = { addr, data };
+       int error;
+       s16 result;
+
+       error = ims_pcu_execute_command(pcu, OFN_SET_CONFIG,
+                                       &buffer, sizeof(buffer));
+       if (error)
+               return error;
+
+       result = (s16)get_unaligned_le16(pcu->cmd_buf + OFN_REG_RESULT_OFFSET);
+       if (result < 0)
+               return -EIO;
+
+       return 0;
+}
+
+static ssize_t ims_pcu_ofn_reg_data_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);
+       int error;
+       u8 data;
+
+       mutex_lock(&pcu->cmd_mutex);
+       error = ims_pcu_read_ofn_config(pcu, pcu->ofn_reg_addr, &data);
+       mutex_unlock(&pcu->cmd_mutex);
+
+       if (error)
+               return error;
+
+       return scnprintf(buf, PAGE_SIZE, "%x\n", data);
+}
+
+static ssize_t ims_pcu_ofn_reg_data_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);
+       int error;
+       u8 value;
+
+       error = kstrtou8(buf, 0, &value);
+       if (error)
+               return error;
+
+       mutex_lock(&pcu->cmd_mutex);
+       error = ims_pcu_write_ofn_config(pcu, pcu->ofn_reg_addr, value);
+       mutex_unlock(&pcu->cmd_mutex);
+
+       return error ?: count;
+}
+
+static DEVICE_ATTR(reg_data, S_IRUGO | S_IWUSR,
+                  ims_pcu_ofn_reg_data_show, ims_pcu_ofn_reg_data_store);
+
+static ssize_t ims_pcu_ofn_reg_addr_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);
+       int error;
+
+       mutex_lock(&pcu->cmd_mutex);
+       error = scnprintf(buf, PAGE_SIZE, "%x\n", pcu->ofn_reg_addr);
+       mutex_unlock(&pcu->cmd_mutex);
+
+       return error;
+}
+
+static ssize_t ims_pcu_ofn_reg_addr_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);
+       int error;
+       u8 value;
+
+       error = kstrtou8(buf, 0, &value);
+       if (error)
+               return error;
+
+       mutex_lock(&pcu->cmd_mutex);
+       pcu->ofn_reg_addr = value;
+       mutex_unlock(&pcu->cmd_mutex);
+
+       return count;
+}
+
+static DEVICE_ATTR(reg_addr, S_IRUGO | S_IWUSR,
+                  ims_pcu_ofn_reg_addr_show, ims_pcu_ofn_reg_addr_store);
+
+struct ims_pcu_ofn_bit_attribute {
+       struct device_attribute dattr;
+       u8 addr;
+       u8 nr;
+};
+
+static ssize_t ims_pcu_ofn_bit_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_ofn_bit_attribute *attr =
+               container_of(dattr, struct ims_pcu_ofn_bit_attribute, dattr);
+       int error;
+       u8 data;
+
+       mutex_lock(&pcu->cmd_mutex);
+       error = ims_pcu_read_ofn_config(pcu, attr->addr, &data);
+       mutex_unlock(&pcu->cmd_mutex);
+
+       if (error)
+               return error;
+
+       return scnprintf(buf, PAGE_SIZE, "%d\n", !!(data & (1 << attr->nr)));
+}
+
+static ssize_t ims_pcu_ofn_bit_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_ofn_bit_attribute *attr =
+               container_of(dattr, struct ims_pcu_ofn_bit_attribute, dattr);
+       int error;
+       int value;
+       u8 data;
+
+       error = kstrtoint(buf, 0, &value);
+       if (error)
+               return error;
+
+       if (value > 1)
+               return -EINVAL;
+
+       mutex_lock(&pcu->cmd_mutex);
+
+       error = ims_pcu_read_ofn_config(pcu, attr->addr, &data);
+       if (!error) {
+               if (value)
+                       data |= 1U << attr->nr;
+               else
+                       data &= ~(1U << attr->nr);
+
+               error = ims_pcu_write_ofn_config(pcu, attr->addr, data);
+       }
+
+       mutex_unlock(&pcu->cmd_mutex);
+
+       return error ?: count;
+}
+
+#define IMS_PCU_OFN_BIT_ATTR(_field, _addr, _nr)                       \
+struct ims_pcu_ofn_bit_attribute ims_pcu_ofn_attr_##_field = {         \
+       .dattr = __ATTR(_field, S_IWUSR | S_IRUGO,                      \
+                       ims_pcu_ofn_bit_show, ims_pcu_ofn_bit_store),   \
+       .addr = _addr,                                                  \
+       .nr = _nr,                                                      \
+}
+
+static IMS_PCU_OFN_BIT_ATTR(engine_enable,   0x60, 7);
+static IMS_PCU_OFN_BIT_ATTR(speed_enable,    0x60, 6);
+static IMS_PCU_OFN_BIT_ATTR(assert_enable,   0x60, 5);
+static IMS_PCU_OFN_BIT_ATTR(xyquant_enable,  0x60, 4);
+static IMS_PCU_OFN_BIT_ATTR(xyscale_enable,  0x60, 1);
+
+static IMS_PCU_OFN_BIT_ATTR(scale_x2,        0x63, 6);
+static IMS_PCU_OFN_BIT_ATTR(scale_y2,        0x63, 7);
+
+static struct attribute *ims_pcu_ofn_attrs[] = {
+       &dev_attr_reg_data.attr,
+       &dev_attr_reg_addr.attr,
+       &ims_pcu_ofn_attr_engine_enable.dattr.attr,
+       &ims_pcu_ofn_attr_speed_enable.dattr.attr,
+       &ims_pcu_ofn_attr_assert_enable.dattr.attr,
+       &ims_pcu_ofn_attr_xyquant_enable.dattr.attr,
+       &ims_pcu_ofn_attr_xyscale_enable.dattr.attr,
+       &ims_pcu_ofn_attr_scale_x2.dattr.attr,
+       &ims_pcu_ofn_attr_scale_y2.dattr.attr,
+       NULL
+};
+
+static struct attribute_group ims_pcu_ofn_attr_group = {
+       .name   = "ofn",
+       .attrs  = ims_pcu_ofn_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");
+               error = -ENOMEM;
+               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),
+                "%02d%02d%02d%02d.%c%c",
+                pcu->cmd_buf[2], pcu->cmd_buf[3], 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),
+                "%02d%02d%02d%02d.%c%c",
+                pcu->cmd_buf[2], pcu->cmd_buf[3], 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(-1);
+
+       const struct ims_pcu_device_info *info;
+       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, &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 (pcu->device_id >= ARRAY_SIZE(ims_pcu_device_info) ||
+           !ims_pcu_device_info[pcu->device_id].keymap) {
+               dev_err(pcu->dev, "Device ID %d is not valid\n", pcu->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);
+
+       /*
+        * PCU-B devices, both GEN_1 and GEN_2 do not have OFN sensor
+        */
+       if (pcu->device_id != IMS_PCU_PCU_B_DEVICE_ID) {
+               error = sysfs_create_group(&pcu->dev->kobj,
+                                          &ims_pcu_ofn_attr_group);
+               if (error)
+                       return error;
+       }
+
+       error = ims_pcu_setup_backlight(pcu);
+       if (error)
+               return error;
+
+       info = &ims_pcu_device_info[pcu->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_buttons:
+       ims_pcu_destroy_buttons(pcu);
+err_destroy_backlight:
+       ims_pcu_destroy_backlight(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);
+
+               if (pcu->device_id != IMS_PCU_PCU_B_DEVICE_ID)
+                       sysfs_remove_group(&pcu->dev->kobj,
+                                          &ims_pcu_ofn_attr_group);
+       }
+}
+
+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");