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authorPiotr Esden-Tempski2012-03-12 00:01:48 -0700
committerPiotr Esden-Tempski2012-03-12 00:01:48 -0700
commit1b7cd12f20d3dd632565b3386b9d42a62aed592b (patch)
tree55aa6d4a8b726ea9c958bb4d045b3b59830e3eba /examples
parentb41987dc7ad99f56d05c694cfd2f69f1e63c3649 (diff)
Added irq usart example for lisa/m 2.0
Diffstat (limited to 'examples')
-rw-r--r--examples/stm32/f1/lisa-m-2/usart_irq_printf/Makefile25
-rw-r--r--examples/stm32/f1/lisa-m-2/usart_irq_printf/usart_irq_printf.c269
2 files changed, 294 insertions, 0 deletions
diff --git a/examples/stm32/f1/lisa-m-2/usart_irq_printf/Makefile b/examples/stm32/f1/lisa-m-2/usart_irq_printf/Makefile
new file mode 100644
index 0000000..0b6fd3e
--- /dev/null
+++ b/examples/stm32/f1/lisa-m-2/usart_irq_printf/Makefile
@@ -0,0 +1,25 @@
+##
+## 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
+
diff --git a/examples/stm32/f1/lisa-m-2/usart_irq_printf/usart_irq_printf.c b/examples/stm32/f1/lisa-m-2/usart_irq_printf/usart_irq_printf.c
new file mode 100644
index 0000000..6b1096e
--- /dev/null
+++ b/examples/stm32/f1/lisa-m-2/usart_irq_printf/usart_irq_printf.c
@@ -0,0 +1,269 @@
+/*
+ * 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;
+}