* HID driver for Valve Steam Controller
  *
  * Copyright (c) 2018 Rodrigo Rivas Costa <rodrigorivascosta@gmail.com>
+ * Copyright (c) 2022 Valve Software
  *
  * Supports both the wired and wireless interfaces.
  *
 static LIST_HEAD(steam_devices);
 
 #define STEAM_QUIRK_WIRELESS           BIT(0)
+#define STEAM_QUIRK_DECK               BIT(1)
 
 /* Touch pads are 40 mm in diameter and 65535 units */
 #define STEAM_PAD_RESOLUTION 1638
 #define STEAM_TRIGGER_RESOLUTION 51
 /* Joystick runs are about 5 mm and 256 units */
 #define STEAM_JOYSTICK_RESOLUTION 51
+/* Trigger runs are about 6 mm and 32768 units */
+#define STEAM_DECK_TRIGGER_RESOLUTION 5461
+/* Joystick runs are about 5 mm and 32768 units */
+#define STEAM_DECK_JOYSTICK_RESOLUTION 6553
 
 #define STEAM_PAD_FUZZ 256
 
 #define STEAM_REG_RPAD_MARGIN          0x18
 #define STEAM_REG_LED                  0x2d
 #define STEAM_REG_GYRO_MODE            0x30
+#define STEAM_REG_LPAD_CLICK_PRESSURE  0x34
+#define STEAM_REG_RPAD_CLICK_PRESSURE  0x35
 
 /* Raw event identifiers */
 #define STEAM_EV_INPUT_DATA            0x01
 #define STEAM_EV_CONNECT               0x03
 #define STEAM_EV_BATTERY               0x04
+#define STEAM_EV_DECK_INPUT_DATA       0x09
 
 /* Values for GYRO_MODE (bitmask) */
 #define STEAM_GYRO_MODE_OFF            0x0000
        struct power_supply __rcu *battery;
        u8 battery_charge;
        u16 voltage;
+       struct delayed_work heartbeat;
 };
 
 static int steam_recv_report(struct steam_device *steam,
         */
        do {
                ret = hid_hw_raw_request(steam->hdev, 0,
-                               buf, size + 1,
+                               buf, max(size, 64) + 1,
                                HID_FEATURE_REPORT, HID_REQ_SET_REPORT);
                if (ret != -EPIPE)
                        break;
        u8 reg;
        u16 val;
        u8 cmd[64] = {STEAM_CMD_WRITE_REGISTER, 0x00};
+       int ret;
        va_list args;
 
        va_start(args, steam);
        }
        va_end(args);
 
-       return steam_send_report(steam, cmd, 2 + cmd[1]);
+       ret = steam_send_report(steam, cmd, 2 + cmd[1]);
+       if (ret < 0)
+               return ret;
+
+       /*
+        * Sometimes a lingering report for this command can
+        * get read back instead of the last set report if
+        * this isn't explicitly queried
+        */
+       return steam_recv_report(steam, cmd, 2 + cmd[1]);
 }
 
 static int steam_get_serial(struct steam_device *steam)
                steam_write_registers(steam,
                        STEAM_REG_RPAD_MARGIN, 0x01, /* enable margin */
                        0);
+
+               cancel_delayed_work_sync(&steam->heartbeat);
        } else {
                /* disable esc, enter, cursor */
                steam_send_report_byte(steam, STEAM_CMD_CLEAR_MAPPINGS);
-               steam_write_registers(steam,
-                       STEAM_REG_RPAD_MODE, 0x07, /* disable mouse */
-                       STEAM_REG_RPAD_MARGIN, 0x00, /* disable margin */
-                       0);
+
+               if (steam->quirks & STEAM_QUIRK_DECK) {
+                       steam_write_registers(steam,
+                               STEAM_REG_RPAD_MARGIN, 0x00, /* disable margin */
+                               STEAM_REG_LPAD_MODE, 0x07, /* disable mouse */
+                               STEAM_REG_RPAD_MODE, 0x07, /* disable mouse */
+                               STEAM_REG_LPAD_CLICK_PRESSURE, 0xFFFF, /* disable clicky pad */
+                               STEAM_REG_RPAD_CLICK_PRESSURE, 0xFFFF, /* disable clicky pad */
+                               0);
+                       /*
+                        * The Steam Deck has a watchdog that automatically enables
+                        * lizard mode if it doesn't see any traffic for too long
+                        */
+                       if (!work_busy(&steam->heartbeat.work))
+                               schedule_delayed_work(&steam->heartbeat, 5 * HZ);
+               } else {
+                       steam_write_registers(steam,
+                               STEAM_REG_RPAD_MARGIN, 0x00, /* disable margin */
+                               STEAM_REG_LPAD_MODE, 0x07, /* disable mouse */
+                               STEAM_REG_RPAD_MODE, 0x07, /* disable mouse */
+                               0);
+               }
        }
 }
 
        input->open = steam_input_open;
        input->close = steam_input_close;
 
-       input->name = (steam->quirks & STEAM_QUIRK_WIRELESS) ?
-               "Wireless Steam Controller" :
+       input->name = (steam->quirks & STEAM_QUIRK_WIRELESS) ? "Wireless Steam Controller" :
+               (steam->quirks & STEAM_QUIRK_DECK) ? "Steam Deck" :
                "Steam Controller";
        input->phys = hdev->phys;
        input->uniq = steam->serial_no;
        input_set_capability(input, EV_KEY, BTN_SELECT);
        input_set_capability(input, EV_KEY, BTN_MODE);
        input_set_capability(input, EV_KEY, BTN_START);
-       input_set_capability(input, EV_KEY, BTN_GEAR_DOWN);
-       input_set_capability(input, EV_KEY, BTN_GEAR_UP);
        input_set_capability(input, EV_KEY, BTN_THUMBR);
        input_set_capability(input, EV_KEY, BTN_THUMBL);
        input_set_capability(input, EV_KEY, BTN_THUMB);
        input_set_capability(input, EV_KEY, BTN_THUMB2);
+       if (steam->quirks & STEAM_QUIRK_DECK) {
+               input_set_capability(input, EV_KEY, BTN_BASE);
+               input_set_capability(input, EV_KEY, BTN_TRIGGER_HAPPY1);
+               input_set_capability(input, EV_KEY, BTN_TRIGGER_HAPPY2);
+               input_set_capability(input, EV_KEY, BTN_TRIGGER_HAPPY3);
+               input_set_capability(input, EV_KEY, BTN_TRIGGER_HAPPY4);
+       } else {
+               input_set_capability(input, EV_KEY, BTN_GEAR_DOWN);
+               input_set_capability(input, EV_KEY, BTN_GEAR_UP);
+       }
 
-       input_set_abs_params(input, ABS_HAT2Y, 0, 255, 0, 0);
-       input_set_abs_params(input, ABS_HAT2X, 0, 255, 0, 0);
        input_set_abs_params(input, ABS_X, -32767, 32767, 0, 0);
        input_set_abs_params(input, ABS_Y, -32767, 32767, 0, 0);
-       input_set_abs_params(input, ABS_RX, -32767, 32767,
-                       STEAM_PAD_FUZZ, 0);
-       input_set_abs_params(input, ABS_RY, -32767, 32767,
-                       STEAM_PAD_FUZZ, 0);
+
        input_set_abs_params(input, ABS_HAT0X, -32767, 32767,
                        STEAM_PAD_FUZZ, 0);
        input_set_abs_params(input, ABS_HAT0Y, -32767, 32767,
                        STEAM_PAD_FUZZ, 0);
-       input_abs_set_res(input, ABS_X, STEAM_JOYSTICK_RESOLUTION);
-       input_abs_set_res(input, ABS_Y, STEAM_JOYSTICK_RESOLUTION);
-       input_abs_set_res(input, ABS_RX, STEAM_PAD_RESOLUTION);
-       input_abs_set_res(input, ABS_RY, STEAM_PAD_RESOLUTION);
+
+       if (steam->quirks & STEAM_QUIRK_DECK) {
+               input_set_abs_params(input, ABS_HAT2Y, 0, 32767, 0, 0);
+               input_set_abs_params(input, ABS_HAT2X, 0, 32767, 0, 0);
+
+               input_set_abs_params(input, ABS_RX, -32767, 32767, 0, 0);
+               input_set_abs_params(input, ABS_RY, -32767, 32767, 0, 0);
+
+               input_set_abs_params(input, ABS_HAT1X, -32767, 32767,
+                               STEAM_PAD_FUZZ, 0);
+               input_set_abs_params(input, ABS_HAT1Y, -32767, 32767,
+                               STEAM_PAD_FUZZ, 0);
+
+               input_abs_set_res(input, ABS_X, STEAM_DECK_JOYSTICK_RESOLUTION);
+               input_abs_set_res(input, ABS_Y, STEAM_DECK_JOYSTICK_RESOLUTION);
+               input_abs_set_res(input, ABS_RX, STEAM_DECK_JOYSTICK_RESOLUTION);
+               input_abs_set_res(input, ABS_RY, STEAM_DECK_JOYSTICK_RESOLUTION);
+               input_abs_set_res(input, ABS_HAT1X, STEAM_PAD_RESOLUTION);
+               input_abs_set_res(input, ABS_HAT1Y, STEAM_PAD_RESOLUTION);
+               input_abs_set_res(input, ABS_HAT2Y, STEAM_DECK_TRIGGER_RESOLUTION);
+               input_abs_set_res(input, ABS_HAT2X, STEAM_DECK_TRIGGER_RESOLUTION);
+       } else {
+               input_set_abs_params(input, ABS_HAT2Y, 0, 255, 0, 0);
+               input_set_abs_params(input, ABS_HAT2X, 0, 255, 0, 0);
+
+               input_set_abs_params(input, ABS_RX, -32767, 32767,
+                               STEAM_PAD_FUZZ, 0);
+               input_set_abs_params(input, ABS_RY, -32767, 32767,
+                               STEAM_PAD_FUZZ, 0);
+
+               input_abs_set_res(input, ABS_X, STEAM_JOYSTICK_RESOLUTION);
+               input_abs_set_res(input, ABS_Y, STEAM_JOYSTICK_RESOLUTION);
+               input_abs_set_res(input, ABS_RX, STEAM_PAD_RESOLUTION);
+               input_abs_set_res(input, ABS_RY, STEAM_PAD_RESOLUTION);
+               input_abs_set_res(input, ABS_HAT2Y, STEAM_TRIGGER_RESOLUTION);
+               input_abs_set_res(input, ABS_HAT2X, STEAM_TRIGGER_RESOLUTION);
+       }
        input_abs_set_res(input, ABS_HAT0X, STEAM_PAD_RESOLUTION);
        input_abs_set_res(input, ABS_HAT0Y, STEAM_PAD_RESOLUTION);
-       input_abs_set_res(input, ABS_HAT2Y, STEAM_TRIGGER_RESOLUTION);
-       input_abs_set_res(input, ABS_HAT2X, STEAM_TRIGGER_RESOLUTION);
 
        ret = input_register_device(input);
        if (ret)
        return !list_empty(&rep_enum->report_list);
 }
 
+static void steam_lizard_mode_heartbeat(struct work_struct *work)
+{
+       struct steam_device *steam = container_of(work, struct steam_device,
+                                                       heartbeat.work);
+
+       mutex_lock(&steam->mutex);
+       if (!steam->client_opened && steam->client_hdev) {
+               steam_send_report_byte(steam, STEAM_CMD_CLEAR_MAPPINGS);
+               steam_write_registers(steam,
+                       STEAM_REG_RPAD_MODE, 0x07, /* disable mouse */
+                       0);
+               schedule_delayed_work(&steam->heartbeat, 5 * HZ);
+       }
+       mutex_unlock(&steam->mutex);
+}
+
 static int steam_client_ll_parse(struct hid_device *hdev)
 {
        struct steam_device *steam = hdev->driver_data;
        steam->quirks = id->driver_data;
        INIT_WORK(&steam->work_connect, steam_work_connect_cb);
        INIT_LIST_HEAD(&steam->list);
+       INIT_DEFERRABLE_WORK(&steam->heartbeat, steam_lizard_mode_heartbeat);
 
        steam->client_hdev = steam_create_client_hid(hdev);
        if (IS_ERR(steam->client_hdev)) {
        hid_destroy_device(steam->client_hdev);
 client_hdev_fail:
        cancel_work_sync(&steam->work_connect);
+       cancel_delayed_work_sync(&steam->heartbeat);
 steam_alloc_fail:
        hid_err(hdev, "%s: failed with error %d\n",
                        __func__, ret);
        }
 
        hid_destroy_device(steam->client_hdev);
+       mutex_lock(&steam->mutex);
+       steam->client_hdev = NULL;
        steam->client_opened = false;
+       cancel_delayed_work_sync(&steam->heartbeat);
+       mutex_unlock(&steam->mutex);
        cancel_work_sync(&steam->work_connect);
        if (steam->quirks & STEAM_QUIRK_WIRELESS) {
                hid_info(hdev, "Steam wireless receiver disconnected");
  *  8.5  | BTN_B      | button B
  *  8.6  | BTN_X      | button X
  *  8.7  | BTN_A      | button A
- *  9.0  | BTN_DPAD_UP    | lef-pad up
- *  9.1  | BTN_DPAD_RIGHT | lef-pad right
- *  9.2  | BTN_DPAD_LEFT  | lef-pad left
- *  9.3  | BTN_DPAD_DOWN  | lef-pad down
+ *  9.0  | BTN_DPAD_UP    | left-pad up
+ *  9.1  | BTN_DPAD_RIGHT | left-pad right
+ *  9.2  | BTN_DPAD_LEFT  | left-pad left
+ *  9.3  | BTN_DPAD_DOWN  | left-pad down
  *  9.4  | BTN_SELECT | menu left
  *  9.5  | BTN_MODE   | steam logo
  *  9.6  | BTN_START  | menu right
        input_sync(input);
 }
 
+/*
+ * The size for this message payload is 56.
+ * The known values are:
+ *  Offset| Type  | Mapped to |Meaning
+ * -------+-------+-----------+--------------------------
+ *  4-7   | u32   | --        | sequence number
+ *  8-15  | u64   | see below | buttons
+ *  16-17 | s16   | ABS_HAT0X | left-pad X value
+ *  18-19 | s16   | ABS_HAT0Y | left-pad Y value
+ *  20-21 | s16   | ABS_HAT1X | right-pad X value
+ *  22-23 | s16   | ABS_HAT1Y | right-pad Y value
+ *  24-25 | s16   | --        | accelerometer X value
+ *  26-27 | s16   | --        | accelerometer Y value
+ *  28-29 | s16   | --        | accelerometer Z value
+ *  30-31 | s16   | --        | gyro X value
+ *  32-33 | s16   | --        | gyro Y value
+ *  34-35 | s16   | --        | gyro Z value
+ *  36-37 | s16   | --        | quaternion W value
+ *  38-39 | s16   | --        | quaternion X value
+ *  40-41 | s16   | --        | quaternion Y value
+ *  42-43 | s16   | --        | quaternion Z value
+ *  44-45 | u16   | ABS_HAT2Y | left trigger (uncalibrated)
+ *  46-47 | u16   | ABS_HAT2X | right trigger (uncalibrated)
+ *  48-49 | s16   | ABS_X     | left joystick X
+ *  50-51 | s16   | ABS_Y     | left joystick Y
+ *  52-53 | s16   | ABS_RX    | right joystick X
+ *  54-55 | s16   | ABS_RY    | right joystick Y
+ *  56-57 | u16   | --        | left pad pressure
+ *  58-59 | u16   | --        | right pad pressure
+ *
+ * The buttons are:
+ *  Bit  | Mapped to  | Description
+ * ------+------------+--------------------------------
+ *  8.0  | BTN_TR2    | right trigger fully pressed
+ *  8.1  | BTN_TL2    | left trigger fully pressed
+ *  8.2  | BTN_TR     | right shoulder
+ *  8.3  | BTN_TL     | left shoulder
+ *  8.4  | BTN_Y      | button Y
+ *  8.5  | BTN_B      | button B
+ *  8.6  | BTN_X      | button X
+ *  8.7  | BTN_A      | button A
+ *  9.0  | BTN_DPAD_UP    | left-pad up
+ *  9.1  | BTN_DPAD_RIGHT | left-pad right
+ *  9.2  | BTN_DPAD_LEFT  | left-pad left
+ *  9.3  | BTN_DPAD_DOWN  | left-pad down
+ *  9.4  | BTN_SELECT | menu left
+ *  9.5  | BTN_MODE   | steam logo
+ *  9.6  | BTN_START  | menu right
+ *  9.7  | BTN_TRIGGER_HAPPY3 | left bottom grip button
+ *  10.0 | BTN_TRIGGER_HAPPY4 | right bottom grip button
+ *  10.1 | BTN_THUMB  | left pad pressed
+ *  10.2 | BTN_THUMB2 | right pad pressed
+ *  10.3 | --         | left pad touched
+ *  10.4 | --         | right pad touched
+ *  10.5 | --         | unknown
+ *  10.6 | BTN_THUMBL | left joystick clicked
+ *  10.7 | --         | unknown
+ *  11.0 | --         | unknown
+ *  11.1 | --         | unknown
+ *  11.2 | BTN_THUMBR | right joystick clicked
+ *  11.3 | --         | unknown
+ *  11.4 | --         | unknown
+ *  11.5 | --         | unknown
+ *  11.6 | --         | unknown
+ *  11.7 | --         | unknown
+ *  12.0 | --         | unknown
+ *  12.1 | --         | unknown
+ *  12.2 | --         | unknown
+ *  12.3 | --         | unknown
+ *  12.4 | --         | unknown
+ *  12.5 | --         | unknown
+ *  12.6 | --         | unknown
+ *  12.7 | --         | unknown
+ *  13.0 | --         | unknown
+ *  13.1 | BTN_TRIGGER_HAPPY1 | left top grip button
+ *  13.2 | BTN_TRIGGER_HAPPY2 | right top grip button
+ *  13.3 | --         | unknown
+ *  13.4 | --         | unknown
+ *  13.5 | --         | unknown
+ *  13.6 | --         | left joystick touched
+ *  13.7 | --         | right joystick touched
+ *  14.0 | --         | unknown
+ *  14.1 | --         | unknown
+ *  14.2 | BTN_BASE   | quick access button
+ *  14.3 | --         | unknown
+ *  14.4 | --         | unknown
+ *  14.5 | --         | unknown
+ *  14.6 | --         | unknown
+ *  14.7 | --         | unknown
+ *  15.0 | --         | unknown
+ *  15.1 | --         | unknown
+ *  15.2 | --         | unknown
+ *  15.3 | --         | unknown
+ *  15.4 | --         | unknown
+ *  15.5 | --         | unknown
+ *  15.6 | --         | unknown
+ *  15.7 | --         | unknown
+ */
+static void steam_do_deck_input_event(struct steam_device *steam,
+               struct input_dev *input, u8 *data)
+{
+       u8 b8, b9, b10, b11, b13, b14;
+       bool lpad_touched, rpad_touched;
+
+       b8 = data[8];
+       b9 = data[9];
+       b10 = data[10];
+       b11 = data[11];
+       b13 = data[13];
+       b14 = data[14];
+
+       lpad_touched = b10 & BIT(3);
+       rpad_touched = b10 & BIT(4);
+
+       if (lpad_touched) {
+               input_report_abs(input, ABS_HAT0X, steam_le16(data + 16));
+               input_report_abs(input, ABS_HAT0Y, steam_le16(data + 18));
+       } else {
+               input_report_abs(input, ABS_HAT0X, 0);
+               input_report_abs(input, ABS_HAT0Y, 0);
+       }
+
+       if (rpad_touched) {
+               input_report_abs(input, ABS_HAT1X, steam_le16(data + 20));
+               input_report_abs(input, ABS_HAT1Y, steam_le16(data + 22));
+       } else {
+               input_report_abs(input, ABS_HAT1X, 0);
+               input_report_abs(input, ABS_HAT1Y, 0);
+       }
+
+       input_report_abs(input, ABS_X, steam_le16(data + 48));
+       input_report_abs(input, ABS_Y, -steam_le16(data + 50));
+       input_report_abs(input, ABS_RX, steam_le16(data + 52));
+       input_report_abs(input, ABS_RY, -steam_le16(data + 54));
+
+       input_report_abs(input, ABS_HAT2Y, steam_le16(data + 44));
+       input_report_abs(input, ABS_HAT2X, steam_le16(data + 46));
+
+       input_event(input, EV_KEY, BTN_TR2, !!(b8 & BIT(0)));
+       input_event(input, EV_KEY, BTN_TL2, !!(b8 & BIT(1)));
+       input_event(input, EV_KEY, BTN_TR, !!(b8 & BIT(2)));
+       input_event(input, EV_KEY, BTN_TL, !!(b8 & BIT(3)));
+       input_event(input, EV_KEY, BTN_Y, !!(b8 & BIT(4)));
+       input_event(input, EV_KEY, BTN_B, !!(b8 & BIT(5)));
+       input_event(input, EV_KEY, BTN_X, !!(b8 & BIT(6)));
+       input_event(input, EV_KEY, BTN_A, !!(b8 & BIT(7)));
+       input_event(input, EV_KEY, BTN_SELECT, !!(b9 & BIT(4)));
+       input_event(input, EV_KEY, BTN_MODE, !!(b9 & BIT(5)));
+       input_event(input, EV_KEY, BTN_START, !!(b9 & BIT(6)));
+       input_event(input, EV_KEY, BTN_TRIGGER_HAPPY3, !!(b9 & BIT(7)));
+       input_event(input, EV_KEY, BTN_TRIGGER_HAPPY4, !!(b10 & BIT(0)));
+       input_event(input, EV_KEY, BTN_THUMBL, !!(b10 & BIT(6)));
+       input_event(input, EV_KEY, BTN_THUMBR, !!(b11 & BIT(2)));
+       input_event(input, EV_KEY, BTN_DPAD_UP, !!(b9 & BIT(0)));
+       input_event(input, EV_KEY, BTN_DPAD_RIGHT, !!(b9 & BIT(1)));
+       input_event(input, EV_KEY, BTN_DPAD_LEFT, !!(b9 & BIT(2)));
+       input_event(input, EV_KEY, BTN_DPAD_DOWN, !!(b9 & BIT(3)));
+       input_event(input, EV_KEY, BTN_THUMB, !!(b10 & BIT(1)));
+       input_event(input, EV_KEY, BTN_THUMB2, !!(b10 & BIT(2)));
+       input_event(input, EV_KEY, BTN_TRIGGER_HAPPY1, !!(b13 & BIT(1)));
+       input_event(input, EV_KEY, BTN_TRIGGER_HAPPY2, !!(b13 & BIT(2)));
+       input_event(input, EV_KEY, BTN_BASE, !!(b14 & BIT(2)));
+
+       input_sync(input);
+}
+
 /*
  * The size for this message payload is 11.
  * The known values are:
         *  0x01: input data (60 bytes)
         *  0x03: wireless connect/disconnect (1 byte)
         *  0x04: battery status (11 bytes)
+        *  0x09: Steam Deck input data (56 bytes)
         */
 
        if (size != 64 || data[0] != 1 || data[1] != 0)
                        steam_do_input_event(steam, input, data);
                rcu_read_unlock();
                break;
+       case STEAM_EV_DECK_INPUT_DATA:
+               if (steam->client_opened)
+                       return 0;
+               rcu_read_lock();
+               input = rcu_dereference(steam->input);
+               if (likely(input))
+                       steam_do_deck_input_event(steam, input, data);
+               rcu_read_unlock();
+               break;
        case STEAM_EV_CONNECT:
                /*
                 * The payload of this event is a single byte:
                USB_DEVICE_ID_STEAM_CONTROLLER_WIRELESS),
          .driver_data = STEAM_QUIRK_WIRELESS
        },
+       { /* Steam Deck */
+         HID_USB_DEVICE(USB_VENDOR_ID_VALVE,
+               USB_DEVICE_ID_STEAM_DECK),
+         .driver_data = STEAM_QUIRK_DECK
+       },
        {}
 };