#include "stm32f0xx.h"
#include "hd44780_driver.h"

void SystemInit(void)
{
    RCC->CR |= RCC_CR_HSEON;
    /* Wait till HSE is ready */
    while((RCC->CR & RCC_CR_HSERDY) != (RCC_CR_HSERDY));
    RCC->CR &= ~(RCC_CR_HSION);
    // This is potentially a dangerous function as it could
    // result in a system with an invalid clock signal - result: a stuck system
    // Set the PLL up
    // First ensure PLL is disabled
    RCC->CR &= ~RCC_CR_PLLON;
    while ((RCC->CR & RCC_CR_PLLRDY));
    // wait for PLL ready to be cleared
    // set PLL multiplier to 6 (yielding 48MHz)
    // Warning here: if system clock is greater than 24MHz then wait-state(s) need to be
    // inserted into Flash memory interface
    FLASH->ACR |= FLASH_ACR_LATENCY;
    // Turn on FLASH prefetch buffer
    FLASH->ACR |= FLASH_ACR_PRFTBE;
    RCC->CFGR &= ~(RCC_CFGR_PLLMUL_3 | RCC_CFGR_PLLMUL_2 | RCC_CFGR_PLLMUL_1 | RCC_CFGR_PLLMUL_0);
    RCC->CFGR [code]|= (RCC_CFGR_SW_PLL | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMUL_2);
    // Need to limit ADC clock to below 14MHz so will change ADC prescaler to 4
    RCC->CFGR |= RCC_CFGR_ADCPRE;
    // Do the following to push HSI clock out on PA8 (MCO)
    // for measurement purposes.  Should be 8MHz or thereabouts (verified with oscilloscope)
    /*
            RCC->CFGR |= (RCC_CFGR_MCO_2 | RCC_CFGR_MCO_0);
            RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
            GPIOA->MODER |= GPIO_MODER_MODER8_1;
     */
    // and turn the PLL back on again
    RCC->CR |= RCC_CR_PLLON;
    // set PLL as system clock source
    RCC->CFGR |= RCC_CFGR_SW_1;
}

int main(void)
{
    // Power up PORTA
    RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
    GPIOA->MODER |= (GPIO_MODER_MODER0_0 |
                     GPIO_MODER_MODER1_0 |
                     GPIO_MODER_MODER2_0 |
                     GPIO_MODER_MODER3_0 |
                     GPIO_MODER_MODER4_0 |
                     GPIO_MODER_MODER6_0
                    );    // make bits  an output
    lcd_init(); //Инициализируем дисплей
    lcd_out("Hello"); //Выводм надпись в нулевую строку
    lcd_set_xy(0,1); //переводим курсор в первую строку
    lcd_out("Radiokot");
    for (;;)
    {
    }
}

#include "stm32f0xx.h"
#include "hd44780_driver.h"

void SystemInit(void)
{
    RCC->CR |= RCC_CR_HSEON;
    /* Wait till HSE is ready */
    while((RCC->CR & RCC_CR_HSERDY) != (RCC_CR_HSERDY));
    RCC->CR &= ~(RCC_CR_HSION);
    // This is potentially a dangerous function as it could
    // result in a system with an invalid clock signal - result: a stuck system
    // Set the PLL up
    // First ensure PLL is disabled
    RCC->CR &= ~RCC_CR_PLLON;
    while ((RCC->CR & RCC_CR_PLLRDY));
    // wait for PLL ready to be cleared
    // set PLL multiplier to 6 (yielding 48MHz)
    // Warning here: if system clock is greater than 24MHz then wait-state(s) need to be
    // inserted into Flash memory interface
    FLASH->ACR |= FLASH_ACR_LATENCY;
    // Turn on FLASH prefetch buffer
    FLASH->ACR |= FLASH_ACR_PRFTBE;
    RCC->CFGR &= ~(RCC_CFGR_PLLMUL_3 | RCC_CFGR_PLLMUL_2 | RCC_CFGR_PLLMUL_1 | RCC_CFGR_PLLMUL_0);
    RCC->CFGR |= (RCC_CFGR_SW_PLL | RCC_CFGR_PLLSRC | RCC_CFGR_PLLMUL_2);
    // Need to limit ADC clock to below 14MHz so will change ADC prescaler to 4
    RCC->CFGR |= RCC_CFGR_ADCPRE;
    // and turn the PLL back on again
    RCC->CR |= RCC_CR_PLLON;
    // set PLL as system clock source
    RCC->CFGR |= RCC_CFGR_SW_1;
}

const char* u32ToStr(uint32_t val)
{
    static char buf[12];

    for (int i = 10; i >= 0; i--)
    {
        buf[i] = '0' + val % 10;
        val /= 10;
        if (!val) return buf + i;
    }
    return 0;
}

void TIM3_Init(void)
{
    TIM3->PSC = 48000-1; //48000000/48000 = 1000Hz
    TIM3->ARR = 1000-1; //1000/1000 = 1Hz
    /*Enable - the Counter enable signal, CNT_EN, is used as trigger output (TRGO). It is
    useful to start several timers at the same time or to control a window in which a slave timer is
    enabled. The Counter Enable signal is generated by a logic OR between CEN control bit
    and the trigger input when configured in gated mode.
    When the Counter Enable signal is controlled by the trigger input, there is a delay on TRGO,
    except if the master/slave mode is selected (see the MSM bit description in TIMx_SMCR
    register).*/
    TIM3->CR2 |= TIM_CR2_MMS_0;
    /*Counter stops counting at the next update event (clearing the bit CEN) Counter enabled*/
    TIM3->CR1 |= TIM_CR1_OPM;
}

void TIM2_Init()
{
    /*External clock mode 2 enabled. The counter is clocked by any active edge on the ETRF
    002: Internal Trigger 2 (ITR2) TIM3_TRGO*/
    TIM2->SMCR |= TIM_SMCR_ECE | TIM_SMCR_TS_1;
    /*101: Gated Mode - The counter clock is enabled when the trigger input (TRGI) is high. The
    counter stops (but is not reset) as soon as the trigger becomes low. Both start and stop of
    the counter are controlled.*/
    TIM2->SMCR |= TIM_SMCR_SMS_0 | TIM_SMCR_SMS_2;
    /*010: Update - The update event is selected as trigger output (TRGO). For instance a master
    timer can then be used as a prescaler for a slave timer.*/
    TIM2->CR2 |= TIM_CR2_MMS_1;
    TIM2->CR1 |= TIM_CR1_CEN;
}

void GPIO_Init()
{
    GPIOA->MODER |= (GPIO_MODER_MODER0_0 |
                     GPIO_MODER_MODER1_0 |
                     GPIO_MODER_MODER2_0 |
                     GPIO_MODER_MODER3_0 |
                     GPIO_MODER_MODER4_0 |
                     GPIO_MODER_MODER5_1 |   /*Select alternate function mode */
                     GPIO_MODER_MODER6_0
                    );    /*make bits  an output*/
    /**TIM2 GPIO Configuration
    PA5   ------> TIM2_ETR
    */
    /*Configure gpio alternate function of a dedicated pin from 0 to 7 for a dedicated port.
    Possible values are from AF0 to AF7 depending on target.
    GPIOA->AFR[0] |= ((((Pin * Pin) * Pin) * Pin) * Alternate));*/
    /*PA5 Select alternate function 2*/
    GPIOA->AFR[0] |= (((((uint32_t)(1<<5) * (uint32_t)(1<<5)) * (uint32_t)(1<<5)) * (uint32_t)(1<<5)) * (uint32_t)2); //=0x00200000
}

int main(void)
{
    // Power up PORTA, TIM2, TIM3
    RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
    RCC->APB1ENR |= RCC_APB1ENR_TIM2EN | RCC_APB1ENR_TIM3EN;
    GPIO_Init();
    lcd_init(); //Инициализируем дисплей
    lcd_out("Frequency"); //Выводм надпись в нулевую строку
    TIM2_Init();
    TIM3_Init();
    for (;;)
    {
        TIM2->CNT = 0;
        TIM3->CR1 |= TIM_CR1_CEN;
        while((TIM3->CR1 & TIM_CR1_CEN) == TIM_CR1_CEN) {}
        lcd_set_xy(0,1); //переводим курсор в первую строку
        lcd_out("                "); //clear
        lcd_set_xy(0,1); //переводим курсор в первую строку
        lcd_out(u32ToStr(TIM2->CNT));
        lcd_out("Hz");
    }
}