Removed the HAL_RCCEx_PeriphCLKConfig statement that was selecting the HSI48 CLK for USB. Assumption is that the STM32G4 reset value (defaults to HSI48 selected for USB) is preserved throughout Mbed initialization.

Author: Tauno Magnusson

targets/TARGET_STM/TARGET_STM32G4/TARGET_STM32G431xB/system_clock.c

@@ -121,15 +121,6 @@ MBED_WEAK uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
         return 0; // FAIL
     }
 
-#if defined(DEVICE_TRNG) || defined(DEVICE_USBDEVICE)
-    // Connect the HSI48 Clock to drive the USB & RNG Clocks @ 48 MHz (CK48 Clock Mux)
-    RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
-    RCC_PeriphCLKInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
-    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphCLKInitStruct) != HAL_OK) {
-        return 0; // FAIL
-    }
-#endif
-
     RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                                   | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
     RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
@@ -184,15 +175,6 @@ uint8_t SetSysClock_PLL_HSI(void)
         return 0; // FAIL
     }
 
-#if defined(DEVICE_TRNG) || defined(DEVICE_USBDEVICE)
-    // Connect the HSI48 Clock to drive the USB & RNG Clocks @ 48 MHz (CK48 Clock Mux)
-    RCC_PeriphCLKInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
-    RCC_PeriphCLKInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
-    if (HAL_RCCEx_PeriphCLKConfig(&RCC_PeriphCLKInitStruct) != HAL_OK) {
-        return 0; // FAIL
-    }
-#endif    
-
     RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_SYSCLK
                                   | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2;
     RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;