From 1b7cd12f20d3dd632565b3386b9d42a62aed592b Mon Sep 17 00:00:00 2001 From: Piotr Esden-Tempski Date: Mon, 12 Mar 2012 00:01:48 -0700 Subject: Added irq usart example for lisa/m 2.0 --- .../stm32/f1/lisa-m-2/usart_irq_printf/Makefile | 25 ++ .../lisa-m-2/usart_irq_printf/usart_irq_printf.c | 269 +++++++++++++++++++++ 2 files changed, 294 insertions(+) create mode 100644 examples/stm32/f1/lisa-m-2/usart_irq_printf/Makefile create mode 100644 examples/stm32/f1/lisa-m-2/usart_irq_printf/usart_irq_printf.c (limited to 'examples/stm32/f1') 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 +## +## 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 . +## + +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 , + * Copyright (C) 2011 Piotr Esden-Tempski + * + * 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 . + */ + +#include +#include +#include +#include +#include +#include +#include + +/****************************************************************************** + * 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; +} -- cgit v1.2.3