First test code for SK6812 LEDs

firmware/setup/system_init.c

@@ -61,10 +61,34 @@ static void __init_default_clocks(void)
   RCC->CIR = 0x00000000;
 }
 
+void __setup_clocks(void)
+{
+	uint32_t tmp;
+
+	/* TODO: Switch HSE on for better accuracy */
+	
+	/* Switch PLL source to HSI OSC */
+	RCC->CFGR &= ~RCC_CFGR_PLLSRC;
+
+	/* Set PLL multiplication to 12 (4 MHz * 12 = 48 MHz SysClk) */
+	RCC->CFGR |= RCC_CFGR_PLLMUL_3 | RCC_CFGR_PLLMUL_1;
+		
+	/* HSI Already running. Switch on PLL */
+	RCC->CR |= RCC_CR_PLLON;
+	
+	/* Wait for PLL to be ready */
+	while (!(RCC->CR & RCC_CR_PLLRDY));
+	
+	/* Switch System Clock to PLL */
+	tmp = RCC->CFGR;
+	tmp &= ~0x3;
+	tmp |= RCC_CFGR_SW_1;
+	RCC->CFGR = tmp;
+}
 
 void __system_init(void)
 {
 
- __init_default_clocks();
- 
+	__init_default_clocks();
+	__setup_clocks(); 
 }