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path: root/examples/stm32/f2/jobygps/spi_test/spi_test.c
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/*
 * This file is part of the libopencm3 project.
 *
 * Copyright (C) 2011 Fergus Noble <fergusnoble@gmail.com>
 * Copyright (C) 2011 Henry Hallam <henry@pericynthion.org>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <errno.h>
#include <libopencm3/stm32/spi.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/cm3/nvic.h>
#include <libopencm3/stm32/f2/gpio.h>
#include <libopencm3/stm32/f2/rcc.h>

void clock_setup(void)
{
	/* Enable clocks on all the peripherals we are going to use. */
	rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_SPI2EN);
	rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_USART1EN);
	rcc_peripheral_enable_clock(&RCC_AHB1ENR,
		RCC_AHB1ENR_IOPCEN | RCC_AHB1ENR_IOPAEN | RCC_AHB1ENR_IOPBEN);
}

void spi_setup(void)
{
	gpio_mode_setup(GPIOB, GPIO_MODE_AF, GPIO_PUPD_NONE,
			GPIO13 | GPIO14 | GPIO15);
	gpio_set_af(GPIOB, GPIO_AF5, GPIO13 | GPIO14 | GPIO15);

	/* Setup SPI parameters. */
	spi_init_master(SPI2, SPI_CR1_BAUDRATE_FPCLK_DIV_256, SPI_CR1_CPOL,
			SPI_CR1_CPHA, SPI_CR1_DFF_8BIT, SPI_CR1_MSBFIRST);
	spi_enable_ss_output(SPI2); /* Required, see NSS, 25.3.1 section. */

	/* Finally enable the SPI. */
	spi_enable(SPI2);
}

void usart_setup(void)
{
	gpio_mode_setup(GPIOA, GPIO_MODE_AF, GPIO_PUPD_NONE, GPIO9);
	gpio_set_af(GPIOA, GPIO_AF7, GPIO9 | GPIO10);

	/* Setup UART parameters. */
	usart_set_baudrate(USART1, 9600);
	usart_set_databits(USART1, 8);
	usart_set_stopbits(USART1, USART_STOPBITS_1);
	usart_set_parity(USART1, USART_PARITY_NONE);
	usart_set_flow_control(USART1, USART_FLOWCONTROL_NONE);
	usart_set_mode(USART1, USART_MODE_TX);

	/* Finally enable the USART. */
	usart_enable(USART1);
}

void gpio_setup(void)
{
	gpio_set(GPIOC, GPIO3);

	/* Setup GPIO3 (in GPIO port C) for LED use. */
	gpio_mode_setup(GPIOC, GPIO_MODE_OUTPUT, GPIO_MODE_OUTPUT, GPIO3);
}

int _write(int file, char *ptr, int len)
{
	int i;

	if (file == 1) {
		for (i = 0; i < len; i++)
			usart_send_blocking(USART1, ptr[i]);
		return i;
	}
	errno = EIO;
	return -1;
}

int main(void)
{
	int counter = 0;
	volatile u16 dummy __attribute__((unused));

	clock_setup();
	gpio_setup();
	usart_setup();
	spi_setup();

	while (1) {
		counter++;
		printf("Hello, world! %i\r\n", counter);
		/* Stops RX buffer overflow, but probably not needed. */
		dummy = spi_read(SPI2);
		spi_send(SPI2, (u8) counter);
		gpio_toggle(GPIOC, GPIO3);
	}

	while (1);

	return 0;
}