#![no_main]
#![no_std]

use panic_semihosting as _;

use stm32h7xx_hal::hal::digital::v2::{
	InputPin,
	OutputPin,
};
use stm32h7xx_hal::{pac, prelude::*, spi};

use cortex_m;
use cortex_m::asm::nop;
use cortex_m_rt::entry;
use cortex_m_semihosting::hprintln;

use core::ptr;
use nb::block;


#[entry]
fn main() -> ! {

	let cp = cortex_m::Peripherals::take().unwrap();
	let dp = pac::Peripherals::take().unwrap();

	let pwr = dp.PWR.constrain();
	let vos = pwr.freeze();

	let rcc = dp.RCC.constrain();
	let ccdr = rcc
		.sys_ck(400.mhz())
		.pll1_q_ck(48.mhz())
		.freeze(vos, &dp.SYSCFG);
	
	let mut delay = cp.SYST.delay(ccdr.clocks);

	let gpioa = dp.GPIOA.split(ccdr.peripheral.GPIOA);
	let gpiob = dp.GPIOB.split(ccdr.peripheral.GPIOB);
	let gpiod = dp.GPIOD.split(ccdr.peripheral.GPIOD);
	let gpiof = dp.GPIOF.split(ccdr.peripheral.GPIOF);

	// Setup CDONE for checking
	let fpga_cdone = gpiod.pd15.into_pull_up_input();

	match fpga_cdone.is_high() {
		Ok(true)	=> hprintln!("FPGA is ready."),
		Ok(_)		=> hprintln!("FPGA is in reset state."),
		Err(_)		=> hprintln!("Error: Cannot read C_DONE"),
	}.unwrap();

	hprintln!("Start reading pin output...").unwrap();
	delay.delay_ms(200_u16);


	let pin = gpioa.pa0.into_pull_up_input();
	let mut state = pin.is_high().unwrap();

	hprintln!("Initial reading...");

	match state {
		true 	=> hprintln!("High."),
		false 	=> hprintln!("Low."),
	}.unwrap();

	hprintln!("Polling...");

	loop {
		if pin.is_high().unwrap() != state {
			match !state {
				true 	=> hprintln!("High."),
				false 	=> hprintln!("Low."),
			}.unwrap();
			state = !state;
		}

		if fpga_cdone.is_low().unwrap() {
			hprintln!("FPGA is in reset state.");
		}
	}

}