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/*
* This file is part of the libopencm3 project.
*
* Copyright (C) 2014 Karl Palsson <karlp@tweak.net.au>
*
* 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/cm3/nvic.h>
#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/rcc.h>
#include <libopencm3/stm32/usart.h>
#include <stdio.h>
#include "syscfg.h"
#include "usb_cdcacm.h"
#include "ringb.h"
#include "trace.h"
#define ER_DEBUG
#ifdef ER_DEBUG
#define ER_DPRINTF(fmt, ...) \
do { printf(fmt, ## __VA_ARGS__); } while (0)
#else
#define ER_DPRINTF(fmt, ...) \
do { } while (0)
#endif
static inline void gpio_really(uint32_t port, uint16_t pin, const bool set)
{
int shift = set ? 0 : 16;
GPIO_BSRR(port) = pin << shift;
}
extern struct ringb rx_ring, tx_ring;
static void usart_setup(void)
{
/* Enable the USART2 interrupt. */
nvic_enable_irq(NVIC_USART2_IRQ);
/* USART2 pins are on port A */
rcc_periph_clock_enable(RCC_GPIOA);
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ,
GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, GPIO_USART2_TX);
gpio_set_mode(GPIOA, GPIO_MODE_INPUT,
GPIO_CNF_INPUT_PULL_UPDOWN, GPIO_USART2_RX);
/* Enable clocks for USART2. */
rcc_periph_clock_enable(RCC_USART2);
/* Setup USART2 parameters. */
usart_set_baudrate(USART2, 115200);
usart_set_databits(USART2, 8);
usart_set_stopbits(USART2, USART_STOPBITS_1);
usart_set_mode(USART2, USART_MODE_TX_RX);
usart_set_parity(USART2, USART_PARITY_NONE);
usart_set_flow_control(USART2, USART_FLOWCONTROL_NONE);
/* Enable USART2 Receive interrupt. */
usart_enable_rx_interrupt(USART2);
/* Finally enable the USART. */
usart_enable(USART2);
}
void usart2_isr(void)
{
gpio_really(GPIOA, GPIO5, 1);
// usbser-rxne()
/* Check if we were called because of RXNE. */
if (usart_get_interrupt_source(USART2, USART_SR_RXNE)) {
gpio_set(LED_RX_PORT, LED_RX_PIN);
uint8_t c = usart_recv(USART2);
if (ringb_put(&rx_ring, c)) {
// good,
} else {
// fatal, you should always have drained by now.
// (when you've got it all ironed out, _actually_
// just drop and count drops), but not yet...
ER_DPRINTF("rx buffer full\n");
while(1);
}
trace_send8(STIMULUS_RING_PUSH, c);
gpio_clear(LED_RX_PORT, LED_RX_PIN);
}
// usbser-irq-txe()
if (usart_get_interrupt_source(USART2, USART_SR_TXE)) {
if (ringb_depth(&tx_ring) == 0) {
// turn off tx empty interrupts, nothing left to send
cdcacm_arch_txirq(0, 0);
ER_DPRINTF("OFF\n");
// Turn on tx complete interrupts, for rs485 de
USART_CR1(USART2) |= USART_CR1_TCIE;
} else {
int c = ringb_get(&tx_ring);
usart_send(USART2, c);
}
}
// usbser-irq-txc? rs485 is auto on some devices, but can be emulated anyway
if (usart_get_interrupt_source(USART2, USART_SR_TC)) {
ER_DPRINTF("TC");
// turn off the complete irqs, we're done now.
USART_CR1(USART2) &= ~USART_CR1_TCIE;
USART_SR(USART2) &= ~USART_SR_TC;
cdcacm_arch_pin(0, CDCACM_PIN_RS485DE, 0);
}
gpio_really(GPIOA, GPIO5, 0);
}
void usb_cdcacm_setup_pre_arch(void)
{
// Hack to reenumerate
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_2_MHZ,
GPIO_CNF_OUTPUT_PUSHPULL, GPIO12);
gpio_clear(GPIOA, GPIO12);
for (unsigned int i = 0; i < 800000; i++) {
__asm__("nop");
}
}
void usb_cdcacm_setup_post_arch(usbd_device *dev)
{
(void)dev;
}
void cdcacm_arch_pin(int port, enum cdcacm_pin pin, bool set)
{
(void)port; // TODO if you want to handle multiple ports
switch (pin) {
case CDCACM_PIN_LED_TX:
gpio_really(LED_TX_PORT, LED_TX_PIN, set);
break;
case CDCACM_PIN_LED_RX:
gpio_really(LED_RX_PORT, LED_RX_PIN, set);
break;
case CDCACM_PIN_RS485DE:
gpio_really(RS485DE_PORT, RS485DE_PIN, set);
break;
default:
break;
}
}
void cdcacm_arch_txirq(int port, bool set) {
(void)port; //FIXME if you make this multi port
if (set) {
usart_enable_tx_interrupt(USART2);
} else {
usart_disable_tx_interrupt(USART2);
}
}
void cdcacm_arch_set_line_state(int port, uint8_t dtr, uint8_t rts)
{
(void)port; // FIXME if you want multiple ports
(void) dtr;
(void) rts;
// LM4f has an implementation of this if you're keen
}
int main(void)
{
rcc_clock_setup_in_hse_8mhz_out_72mhz();
ER_DPRINTF("And we're alive!\n");
/* Led */
rcc_periph_clock_enable(RCC_GPIOC);
gpio_set_mode(LED_RX_PORT, GPIO_MODE_OUTPUT_2_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, LED_RX_PIN);
// IRQ timing
rcc_periph_clock_enable(RCC_GPIOA);
gpio_set_mode(GPIOA, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, GPIO5);
gpio_set_mode(RS485DE_PORT, GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_PUSHPULL, RS485DE_PIN);
usart_setup();
usb_cdcacm_setup_pre_arch();
usbd_device *usbd_dev = usb_cdcacm_init(&st_usbfs_v1_usb_driver,
"stm32f103-generic");
usb_cdcacm_setup_post_arch(usbd_dev);
ER_DPRINTF("Looping...\n");
volatile int i = 0;
while (1) {
usbd_poll(usbd_dev);
usb_cdcacm_poll(usbd_dev);
}
}
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