USB FD via native USB Host + MSC (#20571)

Marlin/src/HAL/STM32/usb_host.h

@@ -0,0 +1,60 @@
+/**
+ * Marlin 3D Printer Firmware
+ * Copyright (c) 2020 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
+ *
+ * Based on Sprinter and grbl.
+ * Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+#pragma once
+
+#include <stdint.h>
+
+typedef enum {
+  USB_STATE_INIT,
+  USB_STATE_ERROR,
+  USB_STATE_RUNNING,
+} usb_state_t;
+
+class USBHost {
+public:
+  bool start();
+  void Task();
+  uint8_t getUsbTaskState();
+  void setUsbTaskState(uint8_t state);
+  uint8_t regRd(uint8_t reg) { return 0x0; };
+  uint8_t usb_task_state = USB_STATE_INIT;
+  uint8_t lun = 0;
+  uint32_t capacity = 0;
+  uint16_t block_size = 0;
+  uint32_t block_count = 0;
+};
+
+class BulkStorage {
+public:
+  BulkStorage(USBHost *usb) : usb(usb) {};
+
+  bool LUNIsGood(uint8_t t);
+  uint32_t GetCapacity(uint8_t lun);
+  uint16_t GetSectorSize(uint8_t lun);
+  uint8_t Read(uint8_t lun, uint32_t addr, uint16_t bsize, uint8_t blocks, uint8_t *buf);
+  uint8_t Write(uint8_t lun, uint32_t addr, uint16_t bsize, uint8_t blocks, const uint8_t * buf);
+
+  USBHost *usb;
+};
+
+extern USBHost usb;
+extern BulkStorage bulk;