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Added irq usart example for lisa/m 2.0

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This commit is contained in:
Piotr Esden-Tempski 2012-03-12 00:01:48 -07:00
parent b41987dc7a
commit 1b7cd12f20
2 changed files with 294 additions and 0 deletions
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25
examples/stm32/f1/lisa-m-2/usart_irq_printf/Makefile Normal file
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##
## This file is part of the libopencm3 project.
##
## Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>
##
## 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/>.
##
BINARY = usart_irq_printf
LDSCRIPT = ../lisa-m.ld
include ../../Makefile.include

269
examples/stm32/f1/lisa-m-2/usart_irq_printf/usart_irq_printf.c Normal file
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/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2009 Uwe Hermann <uwe@hermann-uwe.de>,
* Copyright (C) 2011 Piotr Esden-Tempski <piotr@esden.net>
*
* 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 <libopencm3/stm32/f1/rcc.h>
#include <libopencm3/stm32/f1/gpio.h>
#include <libopencm3/stm32/usart.h>
#include <libopencm3/stm32/nvic.h>
#include <libopencm3/stm32/systick.h>
#include <stdio.h>
#include <errno.h>
/******************************************************************************
* Simple ringbuffer implementation from open-bldc's libgovernor that
* you can find at:
* https://github.com/open-bldc/open-bldc/tree/master/source/libgovernor
*****************************************************************************/
typedef s32 ring_size_t;
struct ring {
u8 *data;
ring_size_t size;
u32 begin;
u32 end;
};
#define RING_SIZE(RING) ((RING)->size - 1)
#define RING_DATA(RING) (RING)->data
#define RING_EMPTY(RING) ((RING)->begin == (RING)->end)
void ring_init(struct ring *ring, u8 *buf, ring_size_t size)
{
ring->data = buf;
ring->size = size;
ring->begin = 0;
ring->end = 0;
}
s32 ring_write_ch(struct ring *ring, u8 ch)
{
if (((ring->end + 1) % ring->size) != ring->begin) {
ring->data[ring->end++] = ch;
ring->end %= ring->size;
return (u32)ch;
}
return -1;
}
s32 ring_write(struct ring *ring, u8 *data, ring_size_t size)
{
s32 i;
for (i = 0; i < size; i++) {
if (ring_write_ch(ring, data[i]) < 0)
return -i;
}
return i;
}
s32 ring_read_ch(struct ring *ring, u8 *ch)
{
s32 ret = -1;
if (ring->begin != ring->end) {
ret = ring->data[ring->begin++];
ring->begin %= ring->size;
if (ch)
*ch = ret;
}
return ret;
}
s32 ring_read(struct ring *ring, u8 *data, ring_size_t size)
{
s32 i;
for (i = 0; i < size; i++) {
if (ring_read_ch(ring, data + i) < 0)
return i;
}
return -i;
}
/******************************************************************************
* The example implementation
*****************************************************************************/
#define BUFFER_SIZE 1024
struct ring output_ring;
u8 output_ring_buffer[BUFFER_SIZE];
void clock_setup(void)
{
rcc_clock_setup_in_hse_12mhz_out_72mhz();
/* Enable GPIOA clock (for LED GPIOs). */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN);
/* Enable clocks for GPIO port A (for GPIO_USART2_TX) and USART2. */
rcc_peripheral_enable_clock(&RCC_APB2ENR, RCC_APB2ENR_IOPAEN |
RCC_APB2ENR_AFIOEN);
rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_USART2EN);
}
void usart_setup(void)
{
/* Initialize output ring buffer. */
ring_init(&output_ring, output_ring_buffer, BUFFER_SIZE);
/* Enable the USART2 interrupt. */
nvic_enable_irq(NVIC_USART2_IRQ);
/* Setup GPIO pin GPIO_USART2_TX on GPIO port A for transmit. */
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
/* Setup GPIO pin GPIO_USART2_RX on GPIO port A for receive. */
gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
GPIO_CNF_INPUT_FLOAT, GPIO_USART2_RX);
/* Setup UART parameters. */
usart_set_baudrate(USART2, 230400);
usart_set_databits(USART2, 8);
usart_set_stopbits(USART2, USART_STOPBITS_1);
usart_set_parity(USART2, USART_PARITY_NONE);
usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
usart_set_mode(USART2, USART_MODE_TX_RX);
/* Enable USART2 Receive interrupt. */
USART_CR1(USART2) |= USART_CR1_RXNEIE;
/* Finally enable the USART. */
usart_enable(USART2);
}
void gpio_setup(void)
{
gpio_set(GPIOA, GPIO8);
/* Setup GPIO8 (in GPIO port A) for LED use. */
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_PUSHPULL, GPIO8);
}
void usart2_isr(void)
{
/* Check if we were called because of RXNE. */
if (((USART_CR1(USART2) & USART_CR1_RXNEIE) != 0) &&
((USART_SR(USART2) & USART_SR_RXNE) != 0)) {
/* Indicate that we got data. */
gpio_toggle(GPIOA, GPIO8);
/* Retrieve the data from the peripheral. */
ring_write_ch(&output_ring, usart_recv(USART2));
/* Enable transmit interrupt so it sends back the data. */
USART_CR1(USART2) |= USART_CR1_TXEIE;
}
/* Check if we were called because of TXE. */
if (((USART_CR1(USART2) & USART_CR1_TXEIE) != 0) &&
((USART_SR(USART2) & USART_SR_TXE) != 0)) {
s32 data;
data = ring_read_ch(&output_ring, NULL);
if (data == -1) {
/* Disable the TXE interrupt, it's no longer needed. */
USART_CR1(USART2) &= ~USART_CR1_TXEIE;
} else {
/* Put data into the transmit register. */
usart_send(USART2, data);
}
}
}
int _write(int file, char *ptr, int len)
{
int ret;
if (file == 1) {
ret = ring_write(&output_ring, (u8 *)ptr, len);
if (ret < 0)
ret = -ret;
USART_CR1(USART2) |= USART_CR1_TXEIE;
return ret;
}
errno = EIO;
return -1;
}
void systick_setup(void)
{
/* 72MHz / 8 => 9000000 counts per second. */
systick_set_clocksource(STK_CTRL_CLKSOURCE_AHB_DIV8);
/* 9000000/9000 = 1000 overflows per second - every 1ms one interrupt */
systick_set_reload(9000);
systick_interrupt_enable();
/* Start counting. */
systick_counter_enable();
}
void sys_tick_handler(void)
{
static int counter = 0;
static float fcounter = 0.0;
static double dcounter = 0.0;
static u32 temp32 = 0;
temp32++;
/*
* We call this handler every 1ms so we are sending hello world
* every 10ms / 100Hz.
*/
if (temp32 == 10) {
printf("Hello World! %i %f %f\r\n", counter, fcounter,
dcounter);
counter++;
fcounter += 0.01;
dcounter += 0.01;
temp32 = 0;
}
}
int main(void)
{
clock_setup();
gpio_setup();
usart_setup();
systick_setup();
while (1)
__asm__("nop");
return 0;
}