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Diffstat (limited to 'src/platforms/stm32/usbuart.c')
-rw-r--r--src/platforms/stm32/usbuart.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/src/platforms/stm32/usbuart.c b/src/platforms/stm32/usbuart.c
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+++ b/src/platforms/stm32/usbuart.c
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+/*
+ * This file is part of the Black Magic Debug project.
+ *
+ * Copyright (C) 2012 Black Sphere Technologies Ltd.
+ * Written by Gareth McMullin <gareth@blacksphere.co.nz>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. 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/cm3/nvic.h>
+#include <libopencm3/cm3/scs.h>
+#include <libopencm3/usb/usbd.h>
+#include <libopencm3/usb/cdc.h>
+
+#include <platform.h>
+
+void usbuart_init(void)
+{
+#if defined(BLACKMAGIC)
+ /* On mini hardware, UART and SWD share connector pins.
+ * Don't enable UART if we're being debugged. */
+ if ((platform_hwversion() == 1) && (SCS_DEMCR & SCS_DEMCR_TRCENA))
+ return;
+#endif
+
+ rcc_peripheral_enable_clock(&USBUSART_APB_ENR, USBUSART_CLK_ENABLE);
+
+ /* UART TX to 'alternate function output push-pull' */
+ gpio_set_mode(USBUSART_PORT, GPIO_MODE_OUTPUT_2_MHZ,
+ GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, USBUSART_TX_PIN);
+
+ /* Setup UART parameters. */
+ usart_set_baudrate(USBUSART, 38400);
+ usart_set_databits(USBUSART, 8);
+ usart_set_stopbits(USBUSART, USART_STOPBITS_1);
+ usart_set_mode(USBUSART, USART_MODE_TX_RX);
+ usart_set_parity(USBUSART, USART_PARITY_NONE);
+ usart_set_flow_control(USBUSART, USART_FLOWCONTROL_NONE);
+
+ /* Finally enable the USART. */
+ usart_enable(USBUSART);
+
+ /* Enable interrupts */
+ USBUSART_CR1 |= USART_CR1_RXNEIE;
+ nvic_set_priority(USBUSART_IRQ, IRQ_PRI_USBUSART);
+ nvic_enable_irq(USBUSART_IRQ);
+}
+
+void usbuart_set_line_coding(struct usb_cdc_line_coding *coding)
+{
+ usart_set_baudrate(USBUSART, coding->dwDTERate);
+ usart_set_databits(USBUSART, coding->bDataBits);
+ switch(coding->bCharFormat) {
+ case 0:
+ usart_set_stopbits(USBUSART, USART_STOPBITS_1);
+ break;
+ case 1:
+ usart_set_stopbits(USBUSART, USART_STOPBITS_1_5);
+ break;
+ case 2:
+ usart_set_stopbits(USBUSART, USART_STOPBITS_2);
+ break;
+ }
+ switch(coding->bParityType) {
+ case 0:
+ usart_set_parity(USBUSART, USART_PARITY_NONE);
+ break;
+ case 1:
+ usart_set_parity(USBUSART, USART_PARITY_ODD);
+ break;
+ case 2:
+ usart_set_parity(USBUSART, USART_PARITY_EVEN);
+ break;
+ }
+}
+
+void usbuart_usb_out_cb(usbd_device *dev, uint8_t ep)
+{
+ (void)ep;
+
+ char buf[CDCACM_PACKET_SIZE];
+ int len = usbd_ep_read_packet(dev, CDCACM_UART_ENDPOINT,
+ buf, CDCACM_PACKET_SIZE);
+
+#if defined(BLACKMAGIC)
+ /* Don't bother if uart is disabled.
+ * This will be the case on mini while we're being debugged.
+ */
+ if(!(RCC_APB2ENR & RCC_APB2ENR_USART1EN))
+ return;
+#endif
+
+ gpio_set(LED_PORT_UART, LED_UART);
+ for(int i = 0; i < len; i++)
+ usart_send_blocking(USBUSART, buf[i]);
+ gpio_clear(LED_PORT_UART, LED_UART);
+}
+
+static uint8_t uart_usb_buf[CDCACM_PACKET_SIZE];
+static uint8_t uart_usb_buf_size;
+
+void usbuart_usb_in_cb(usbd_device *dev, uint8_t ep)
+{
+ if (!uart_usb_buf_size) {
+ gpio_clear(LED_PORT_UART, LED_UART);
+ return;
+ }
+
+ usbd_ep_write_packet(dev, ep, uart_usb_buf, uart_usb_buf_size);
+ uart_usb_buf_size = 0;
+}
+
+void USBUSART_ISR(void)
+{
+ char c = usart_recv(USBUSART);
+
+ gpio_set(LED_PORT_UART, LED_UART);
+
+ /* Try to send now */
+ if (usbd_ep_write_packet(usbdev, CDCACM_UART_ENDPOINT, &c, 1) == 1)
+ return;
+
+ /* We failed, so queue for later */
+ if (uart_usb_buf_size == CDCACM_PACKET_SIZE) {
+ /* Drop if the buffer's full: we have no flow control */
+ return;
+ }
+
+ uart_usb_buf[uart_usb_buf_size++] = c;
+}