bsp.stm32f407g_disc1: Initialize USB clock and pins.

hw/bsp/stm32f407g_disc1/board_stm32f407g_disc1.c

@@ -58,11 +58,24 @@ void board_init(void)
 
   // Init the LED on PD14
   RCC->AHB1ENR |= RCC_AHB1ENR_GPIODEN;
-  GPIOD->MODER = GPIO_MODER_MODE14_0;
+  GPIOD->MODER |= GPIO_MODER_MODE14_0;
 
   // USB Clock init
+  // PLL input- 16 MHz (HSI clock)
+  // VCO input- 1 to 2 MHz (2 MHz, M = 8)
+  // VCO output- 100 to 432 MHz (144 MHz, N = 72)
+  // Main PLL out- <= 180 MHz (18 MHz, P = 8, not used; HSI used as system clk.)
+  // USB PLL out- 48 MHz (Q = 3)
+  RCC->PLLCFGR = (3 << RCC_PLLCFGR_PLLQ_Pos) | (8 << RCC_PLLCFGR_PLLP_Pos) \
+    | (72 << RCC_PLLCFGR_PLLN_Pos) |  (8 << RCC_PLLCFGR_PLLM_Pos);
+  RCC->CR |= RCC_CR_PLLON;
+  RCC->AHB2ENR |= RCC_AHB2ENR_OTGFSEN;
 
   // USB Pin Init
+  // PA10- ID, PA11- DM, PA12- DP
+  // PC0- Power on
+  GPIOD->MODER |= GPIO_MODER_MODE10_1 | GPIO_MODER_MODE11_1 | GPIO_MODER_MODE12_1;
+  GPIOA->AFR[1] |= (10 << GPIO_AFRH_AFSEL10_Pos) | (10 << GPIO_AFRH_AFSEL11_Pos) | (10 << GPIO_AFRH_AFSEL12_Pos);
 }