/*
 * More info here:
 * https://stm32-base.org/boards/STM32F103C8T6-Blue-Pill.html
 *
 * And resistor fix:
 * https://amitesh-singh.github.io/stm32/2017/05/27/Overcoming-wrong-pullup-in-blue-pill.html
 *
 * Note: I didn't have to do this fix, and things seem to work fine.
 */

#include <stm32f1xx_hal_flash.h>
#include <stm32f1xx_hal_rcc.h>

#include <sysinit.h>

/*
 * Referenced from:
 * Projects/STM32F103RB-Nucleo/Applications/USB_Device/HID_Standalone/Src/main.c
 */
static void
oscconfig(const void *none)
{
	RCC_ClkInitTypeDef clkinitstruct;
	RCC_OscInitTypeDef oscinitstruct;
	RCC_PeriphCLKInitTypeDef rccperiphclkinit;

	__HAL_RCC_PWR_CLK_ENABLE();

	oscinitstruct = (RCC_OscInitTypeDef){
		.OscillatorType	= RCC_OSCILLATORTYPE_HSE,
		.HSEState	= RCC_HSE_ON,
		.HSEPredivValue	= RCC_HSE_PREDIV_DIV1,
		.PLL.PLLMUL	= RCC_PLL_MUL9,

		.PLL.PLLState	= RCC_PLL_ON,
		.PLL.PLLSource	= RCC_PLLSOURCE_HSE,
	};

	HAL_RCC_OscConfig(&oscinitstruct);

	/* USB clock selection */
	rccperiphclkinit = (RCC_PeriphCLKInitTypeDef){
		.PeriphClockSelection = RCC_PERIPHCLK_USB,
		.UsbClockSelection = RCC_USBCLKSOURCE_PLL_DIV1_5,
	};
	HAL_RCCEx_PeriphCLKConfig(&rccperiphclkinit);

	/*
	 * Select PLL as system clock source and configure the HCLK,
	 * PCLK1 and PCLK2 clocks dividers
	 */
	clkinitstruct = (RCC_ClkInitTypeDef){
		.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK |
		    RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2),
		.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK,
		.AHBCLKDivider = RCC_SYSCLK_DIV1,
		.APB1CLKDivider = RCC_HCLK_DIV2,
		.APB2CLKDivider = RCC_HCLK_DIV1,
	};
	HAL_RCC_ClockConfig(&clkinitstruct, FLASH_LATENCY_2);
}
SYSINIT(oscconfig, SI_SUB_HAL, SI_ORDER_THIRD, oscconfig, NULL);