mspbsldump/nmigen/main.c

#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include <string.h>

#include <RP2040.h>
#include <system_RP2040.h>
#include <core_cm0plus.h>

#include <hardware/structs/iobank0.h>
#include <hardware/clocks.h>
#include <hardware/dma.h>
#include <hardware/gpio.h>
#include <hardware/irq.h>
#include <hardware/pio.h>
#include <hardware/pwm.h>
#include <pico/stdlib.h>
#include <pico/stdio_usb.h>

#include "trigctl.pio.h"
#include "uart_rx.pio.h"

#define PIN_TRIGGER 14
#define PIN_TRIGGER_POL glitch_positive

#define PIN_NMI 15
#define PIN_NMI_POL glitch_negative

#define PIN_ACK  16
#define PIN_UART 17

#define PIO_UNIT pio0
#define PIOSM_UART 0
#define PIOSM_TRIG 1

#define UART_BAUD 9600

static void init_gpio(void) {
	const int func = GPIO_FUNC_PIO0;

	// init trigger pin
	sio_hw->gpio_oe_clr = 1u << PIN_TRIGGER;
	hw_write_masked(&padsbank0_hw->io[PIN_TRIGGER]
		, (PADS_BANK0_GPIO0_IE_BITS)
		, (PADS_BANK0_GPIO0_IE_BITS | PADS_BANK0_GPIO0_OD_BITS)
		| (PADS_BANK0_GPIO0_SCHMITT_BITS)
	);
	hw_write_masked(&iobank0_hw->io[PIN_TRIGGER].ctrl
		, (func << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB)
		| ((uint)(PIN_TRIGGER_POL ? GPIO_OVERRIDE_INVERT
				: GPIO_OVERRIDE_NORMAL) << IO_BANK0_GPIO0_CTRL_INOVER_LSB)
		, (IO_BANK0_GPIO0_CTRL_FUNCSEL_BITS)
		| (IO_BANK0_GPIO0_CTRL_INOVER_BITS)
	);

	sio_hw->gpio_clr = 1u << PIN_NMI;
	sio_hw->gpio_oe_set = 1u << PIN_NMI;
	hw_write_masked(&padsbank0_hw->io[PIN_NMI]
		, PADS_BANK0_GPIO0_IE_BITS
		| ((uint)GPIO_SLEW_RATE_FAST << PADS_BANK0_GPIO0_SLEWFAST_LSB)
		| (PADS_BANK0_GPIO0_DRIVE_VALUE_12MA << PADS_BANK0_GPIO0_DRIVE_LSB)
		, PADS_BANK0_GPIO0_IE_BITS | PADS_BANK0_GPIO0_OD_BITS
		| PADS_BANK0_GPIO0_SLEWFAST_BITS | PADS_BANK0_GPIO0_DRIVE_BITS
	);
	hw_write_masked(&iobank0_hw->io[PIN_NMI].ctrl
		, (func << IO_BANK0_GPIO0_CTRL_FUNCSEL_LSB)
		| ((uint)(PIN_NMI_POL ? GPIO_OVERRIDE_INVERT
				: GPIO_OVERRIDE_NORMAL) << IO_BANK0_GPIO0_CTRL_OUTOVER_LSB)
		, IO_BANK0_GPIO0_CTRL_FUNCSEL_BITS | IO_BANK0_GPIO0_CTRL_OUTOVER_BITS
	);

	sio_hw->gpio_clr = 1u << PIN_ACK;
	sio_hw->gpio_oe_set = 1u << PIN_ACK;
	gpio_init(PIN_ACK);
	gpio_set_dir(PIN_ACK, GPIO_OUT);
	gpio_set_function(PIN_ACK, GPIO_FUNC_SIO);
}

static uint off_uart, off_trig;
static void init_pio(void) {
	off_uart = pio_add_program(PIO_UNIT, &uart_rx_program);
	uart_rx_program_init(PIO_UNIT, PIOSM_UART, off_uart, PIN_UART, UART_BAUD);

	off_trig = pio_add_program(PIO_UNIT, &trigctl_program);
	trigctl_pio_init(PIO_UNIT, PIOSM_TRIG, off_trig,
		trig_source_pin, PIN_NMI, PIN_TRIGGER, PIN_TRIGGER_POL,
		PIN_NMI_POL, true, 125); // 1 MHz

	const int irq = PIO0_IRQ_1;
	irq_set_enabled(irq, false);
	trigctl_ack_glitch_irq(PIO_UNIT, PIOSM_TRIG);
	trigctl_set_glitch_irq_enabled(PIO_UNIT, PIOSM_TRIG, 1, true);
	irq_set_priority(irq, PICO_HIGHEST_IRQ_PRIORITY);
	irq_set_enabled(irq, true);
}

static bool uart_poll_ch(uint8_t* ch) {
	if (pio_sm_is_rx_fifo_empty(PIO_UNIT, PIOSM_UART)) return false;

	// 8-bit read from the uppermost byte of the FIFO, as data is left-justified
	io_rw_8 *rxfifo_shift = (io_rw_8*)&PIO_UNIT->rxf[PIOSM_UART] + 3;
	*ch = *rxfifo_shift;
	return true;
}

int main() {
	stdio_init_all();

	init_gpio();
	init_pio();

	while (!stdio_usb_connected());

	uint32_t delay = 1;
	const uint32_t len = 2;

	while (true) {
		if (pio_sm_is_tx_fifo_empty(PIO_UNIT, PIOSM_TRIG)) {
			printf("push offlen\n");
			trigctl_push_off_len(PIO_UNIT, PIOSM_TRIG, delay, len);
		}

		uint8_t ch;
		if (uart_poll_ch(&ch)) {
			printf("got cmd: %c\n", ch);
			switch (ch) {
			case '0': delay = 1; break;
			case '+': ++delay; break;
			case '-': --delay; break;
			default: goto noack;
			}

			printf("send ack\n");
			sio_hw->gpio_set = 1u << PIN_ACK;
			busy_wait_us_32(50);
			sio_hw->gpio_clr = 1u << PIN_ACK;
			printf("sent ack\n");

		noack:;
		}

		if (PIO_UNIT->irq & (1u << PIOSM_TRIG)) {
			printf("sent nmi\n");
			trigctl_ack_glitch_irq(PIO_UNIT, PIOSM_TRIG);
		}
	}
}