From 591550d4daf44b8d89225f5b3690e50f46693ed3 Mon Sep 17 00:00:00 2001
From: Kirill Kotyagin <kirill.kotyagin@gmail.com>
Date: Sun, 1 Aug 2021 18:49:26 +0300
Subject: [PATCH] ADD: force USB re-enumeration on device reset

---
 usb_io.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/usb_io.c b/usb_io.c
index e0bd9cb..4862cd0 100644
--- a/usb_io.c
+++ b/usb_io.c
@@ -53,6 +53,16 @@ void usb_io_reset() {
 }
 
 void usb_io_init() {
+    /* Force USB re-enumeration */
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN;
+    GPIOA->CRH &= ~GPIO_CRH_CNF12;
+    GPIOA->CRH |= GPIO_CRH_MODE12_1;
+    for (int i=0; i<0xFFFF; i++) {
+        __NOP();
+    }
+    GPIOA->CRH &= ~GPIO_CRH_MODE12;
+    GPIOA->CRH |= GPIO_CRH_CNF12_0;
+    /* Initialize USB */
     NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
     if (SystemCoreClock != RCC_MAX_FREQUENCY) {
         RCC->CFGR |= RCC_CFGR_USBPRE;