diff options
Diffstat (limited to 'usb-serial-rs485/main-stm32f103-generic.c')
| -rw-r--r-- | usb-serial-rs485/main-stm32f103-generic.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/usb-serial-rs485/main-stm32f103-generic.c b/usb-serial-rs485/main-stm32f103-generic.c new file mode 100644 index 0000000..415a18b --- /dev/null +++ b/usb-serial-rs485/main-stm32f103-generic.c @@ -0,0 +1,204 @@ +/* + * 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); + } + +} + |