/* Baremetal Risc-V USB <=> Amiga Joystick/Mouse HID converter. 
 * March 2026 - Anders Holck
 * This software has no license. If you choose to use, please include my name :)
*/

#ifndef USB_DESCRIPTORS_H
#define USB_DESCRIPTORS_H

#include <stdint.h>

// USB Standard Request Codes
#define USB_REQ_GET_STATUS        0x00
#define USB_REQ_CLEAR_FEATURE     0x01
#define USB_REQ_SET_FEATURE       0x03
#define USB_REQ_SET_ADDRESS       0x05
#define USB_REQ_GET_DESCRIPTOR    0x06
#define USB_REQ_SET_DESCRIPTOR    0x07
#define USB_REQ_GET_CONFIGURATION 0x08
#define USB_REQ_SET_CONFIGURATION 0x09

// Descriptor Types
#define USB_DESC_DEVICE           0x01
#define USB_DESC_CONFIGURATION    0x02
#define USB_DESC_STRING           0x03
#define USB_DESC_INTERFACE        0x04
#define USB_DESC_ENDPOINT         0x05
#define USB_DESC_HID              0x21
#define USB_DESC_REPORT           0x22

// Device Descriptor
const uint8_t device_desc[] = {
    18,                 // bLength
    USB_DESC_DEVICE,    // bDescriptorType
    0x00, 0x02,         // bcdUSB (2.0)
    0x00,               // bDeviceClass
    0x00,               // bDeviceSubClass
    0x00,               // bDeviceProtocol
    64,                 // bMaxPacketSize0
    0x6B, 0x1D,         // idVendor (0x1D6B - Linux Foundation)
    0x04, 0x01,         // idProduct (0x0104)
    0x00, 0x01,         // bcdDevice
    1,                  // iManufacturer
    2,                  // iProduct
    3,                  // iSerialNumber
    1                   // bNumConfigurations
};

// HID Report Descriptor (Combined Gamepad and Mouse)
const uint8_t hid_report_desc[] = {
    0x05, 0x01,        // Usage Page (Generic Desktop)
    0x09, 0x04,        // Usage (Joystick)
    0xA1, 0x01,        // Collection (Application)
    
    // Joystick 1 & 2 Buttons (10 buttons total)
    0x05, 0x09,        //   Usage Page (Button)
    0x19, 0x01,        //   Usage Minimum (Button 1)
    0x29, 0x0A,        //   Usage Maximum (Button 10)
    0x15, 0x00,        //   Logical Minimum (0)
    0x25, 0x01,        //   Logical Maximum (1)
    0x75, 0x01,        //   Report Size (1)
    0x95, 0x0A,        //   Report Count (10)
    0x81, 0x02,        //   Input (Data, Var, Abs)
    
    // Padding for buttons (6 bits)
    0x75, 0x01,        //   Report Size (1)
    0x95, 0x06,        //   Report Count (6)
    0x81, 0x03,        //   Input (Cnst, Var, Abs)

    // Mouse X/Y (Relative)
    0x05, 0x01,        //   Usage Page (Generic Desktop)
    0x09, 0x01,        //   Usage (Pointer)
    0xA1, 0x00,        //   Collection (Physical)
    0x09, 0x30,        //     Usage (X)
    0x09, 0x31,        //     Usage (Y)
    0x15, 0x81,        //     Logical Minimum (-127)
    0x25, 0x7F,        //     Logical Maximum (127)
    0x75, 0x08,        //     Report Size (8)
    0x95, 0x02,        //     Report Count (2)
    0x81, 0x06,        //     Input (Data, Var, Rel)
    0xC0,              //   End Collection

    0xC0               // End Collection
};

// Configuration Descriptor
const uint8_t config_desc[] = {
    9,                  // bLength
    USB_DESC_CONFIGURATION,
    34, 0,              // wTotalLength (9+9+9+7)
    1,                  // bNumInterfaces
    1,                  // bConfigurationValue
    0,                  // iConfiguration
    0x80,               // bmAttributes (Bus Powered)
    250,                // bMaxPower (500mA)

    // Interface Descriptor
    9,                  // bLength
    USB_DESC_INTERFACE,
    0,                  // bInterfaceNumber
    0,                  // bAlternateSetting
    1,                  // bNumEndpoints
    0x03,               // bInterfaceClass (HID)
    0x00,               // bInterfaceSubClass
    0x00,               // bInterfaceProtocol
    0,                  // iInterface

    // HID Descriptor
    9,                  // bLength
    USB_DESC_HID,
    0x11, 0x01,         // bcdHID (1.11)
    0x00,               // bCountryCode
    1,                  // bNumDescriptors
    USB_DESC_REPORT,    // bDescriptorType
    sizeof(hid_report_desc), 0, // wItemLength

    // Endpoint Descriptor (IN 1)
    7,                  // bLength
    USB_DESC_ENDPOINT,
    0x81,               // bEndpointAddress (IN 1)
    0x03,               // bmAttributes (Interrupt)
    8, 0,               // wMaxPacketSize (8 bytes)
    10                  // bInterval (10ms)
};

#endif /* USB_DESCRIPTORS_H */