DISCO_L053C8: enable HSI48 clock for USB

Author: bcostm

targets/TARGET_STM/TARGET_STM32L0/TARGET_DISCO_L053C8/device/system_stm32l0xx.c

@@ -377,10 +377,8 @@ uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
     RCC_OscInitStruct.HSEState          = RCC_HSE_BYPASS; /* External 8 MHz clock on OSC_IN */
   }
   RCC_OscInitStruct.HSIState            = RCC_HSI_OFF;
-#if !defined (STM32L031xx) && !defined (STM32L041xx) && !defined(STM32L051xx) && !defined(STM32L061xx) && !defined(STM32L071xx)  && !defined(STM32L081xx) && \
-  !defined (STM32L011xx) && !defined (STM32L021xx)
   RCC_OscInitStruct.HSI48State          = RCC_HSI48_ON; /* For USB and RNG clock */
-#endif
+
   // PLLCLK = (8 MHz * 8)/2 = 32 MHz
   RCC_OscInitStruct.PLL.PLLState        = RCC_PLL_ON;
   RCC_OscInitStruct.PLL.PLLSource       = RCC_PLLSOURCE_HSE;
@@ -391,6 +389,12 @@ uint8_t SetSysClock_PLL_HSE(uint8_t bypass)
     return 0; // FAIL
   }
 
+  /* Select HSI48 as USB clock source */
+  RCC_PeriphCLKInitTypeDef  PeriphClkInitStruct;
+  PeriphClkInitStruct.PeriphClockSelection = RCC_PERIPHCLK_USB;
+  PeriphClkInitStruct.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;
+  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInitStruct);
+
   /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
   RCC_ClkInitStruct.ClockType      = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
   RCC_ClkInitStruct.SYSCLKSource   = RCC_SYSCLKSOURCE_PLLCLK; // 32 MHz