Added capture of SWO, passed to host over a vendor specific USB interface.

src/command.c

@@ -37,6 +37,8 @@
 
 #include "adiv5.h"
 
+#include <libopencm3/usb/usbd.h>
+
 static void cmd_version(void);
 static void cmd_help(void);
 
@@ -45,6 +47,8 @@ static void cmd_swdp_scan(void);
 static void cmd_targets(void);
 static void cmd_morse(void);
 
+static void cmd_traceswo(void);
+
 const struct command_s cmd_list[] = {
 	{"version", (cmd_handler)cmd_version, "Display firmware version info"},
 	{"help", (cmd_handler)cmd_help, "Display help for monitor commands"},
@@ -52,6 +56,7 @@ const struct command_s cmd_list[] = {
 	{"swdp_scan", (cmd_handler)cmd_swdp_scan, "Scan SW-DP for devices" },
 	{"targets", (cmd_handler)cmd_targets, "Display list of available targets" },
 	{"morse", (cmd_handler)cmd_morse, "Display morse error message" },
+	{"traceswo", (cmd_handler)cmd_traceswo, "Start trace capture" },
 
 	{NULL, NULL, NULL}
 };
@@ -159,4 +164,8 @@ void cmd_morse(void)
 		gdb_outf("%s\n", morse_msg);
 }
 
+static void cmd_traceswo(void)
+{
+	traceswo_init();
+}
 

src/stm32/Makefile.inc

@@ -11,6 +11,7 @@ LDFLAGS = $(LDFLAGS_BOOT) -Wl,-Ttext=0x8002000
 
 SRC += 	cdcacm.c	\
 	platform.c	\
+	traceswo.c	\
 
 all:	blackmagic.bin blackmagic_dfu.bin
 

src/stm32/cdcacm.c

@@ -38,12 +38,9 @@
 #include <stdlib.h>
 
 #include "platform.h"
+#include "traceswo.h"
 
-#ifdef INCLUDE_UART_INTERFACE
+#define DFU_IF_NO 4
-#	define DFU_IF_NO 4
-#else
-#	define DFU_IF_NO 2
-#endif
 
 static char *get_dev_unique_id(char *serial_no);
 
@@ -172,7 +169,6 @@ static const struct usb_iface_assoc_descriptor gdb_assoc = {
 	.iFunction = 0,
 };
 
-#ifdef INCLUDE_UART_INTERFACE
 /* Serial ACM interface */
 static const struct usb_endpoint_descriptor uart_comm_endp[] = {{
 	.bLength = USB_DT_ENDPOINT_SIZE,
@@ -275,7 +271,6 @@ static const struct usb_iface_assoc_descriptor uart_assoc = {
 	.bFunctionProtocol = USB_CDC_PROTOCOL_AT,
 	.iFunction = 0,
 };
-#endif
 
 const struct usb_dfu_descriptor dfu_function = {
 	.bLength = sizeof(struct usb_dfu_descriptor),
@@ -312,6 +307,40 @@ static const struct usb_iface_assoc_descriptor dfu_assoc = {
 	.iFunction = 6,
 };
 
+static const struct usb_endpoint_descriptor trace_endp[] = {{
+	.bLength = USB_DT_ENDPOINT_SIZE,
+	.bDescriptorType = USB_DT_ENDPOINT,
+	.bEndpointAddress = 0x85,
+	.bmAttributes = USB_ENDPOINT_ATTR_BULK,
+	.wMaxPacketSize = 16,
+	.bInterval = 0,
+}};
+
+const struct usb_interface_descriptor trace_iface = {
+	.bLength = USB_DT_INTERFACE_SIZE,
+	.bDescriptorType = USB_DT_INTERFACE,
+	.bInterfaceNumber = 5,
+	.bAlternateSetting = 0,
+	.bNumEndpoints = 1,
+	.bInterfaceClass = 0xFF,
+	.bInterfaceSubClass = 0xFF,
+	.bInterfaceProtocol = 0xFF,
+	.iInterface = 7,
+
+	.endpoint = trace_endp,
+};
+
+static const struct usb_iface_assoc_descriptor trace_assoc = {
+	.bLength = USB_DT_INTERFACE_ASSOCIATION_SIZE,
+	.bDescriptorType = USB_DT_INTERFACE_ASSOCIATION,
+	.bFirstInterface = 5,
+	.bInterfaceCount = 1,
+	.bFunctionClass = 0xFF,
+	.bFunctionSubClass = 0xFF,
+	.bFunctionProtocol = 0xFF,
+	.iFunction = 7,
+};
+
 static const struct usb_interface ifaces[] = {{
 	.num_altsetting = 1,
 	.iface_assoc = &gdb_assoc,
@@ -320,7 +349,6 @@ static const struct usb_interface ifaces[] = {{
 	.num_altsetting = 1,
 	.altsetting = gdb_data_iface,
 }, {
-#ifdef INCLUDE_UART_INTERFACE
 	.num_altsetting = 1,
 	.iface_assoc = &uart_assoc,
 	.altsetting = uart_comm_iface,
@@ -328,21 +356,20 @@ static const struct usb_interface ifaces[] = {{
 	.num_altsetting = 1,
 	.altsetting = uart_data_iface,
 }, {
-#endif
 	.num_altsetting = 1,
 	.iface_assoc = &dfu_assoc,
 	.altsetting = &dfu_iface,
+}, {
+	.num_altsetting = 1,
+	.iface_assoc = &trace_assoc,
+	.altsetting = &trace_iface,
 }};
 
 static const struct usb_config_descriptor config = {
 	.bLength = USB_DT_CONFIGURATION_SIZE,
 	.bDescriptorType = USB_DT_CONFIGURATION,
 	.wTotalLength = 0,
-#ifdef INCLUDE_UART_INTERFACE
+	.bNumInterfaces = 6,
-	.bNumInterfaces = 5,
-#else
-	.bNumInterfaces = 3,
-#endif
 	.bConfigurationValue = 1,
 	.iConfiguration = 0,
 	.bmAttributes = 0x80,
@@ -361,6 +388,7 @@ static const char *usb_strings[] = {
 	"Black Magic GDB Server",
 	"Black Magic UART Port",
 	"Black Magic Firmware Upgrade",
+	"Black Magic Trace Capture",
 };
 
 static void dfu_detach_complete(struct usb_setup_data *req)
@@ -395,7 +423,6 @@ static int cdcacm_control_request(struct usb_setup_data *req, uint8_t **buf,
 		cdcacm_gdb_dtr = req->wValue & 1;
 
 		return 1;
-#ifdef INCLUDE_UART_INTERFACE
 	case USB_CDC_REQ_SET_LINE_CODING: {
 		if(*len < sizeof(struct usb_cdc_line_coding)) 
 			return 0;
@@ -434,7 +461,6 @@ static int cdcacm_control_request(struct usb_setup_data *req, uint8_t **buf,
 
 		return 1;
 		}
-#endif
 	case DFU_GETSTATUS: 
 		if(req->wIndex == DFU_IF_NO) {
 			(*buf)[0] = DFU_STATUS_OK;
@@ -467,7 +493,6 @@ int cdcacm_get_dtr(void)
 	return cdcacm_gdb_dtr;
 }
 
-#ifdef INCLUDE_UART_INTERFACE
 static void cdcacm_data_rx_cb(u8 ep)
 {
 	(void)ep;
@@ -477,7 +502,6 @@ static void cdcacm_data_rx_cb(u8 ep)
 	for(int i = 0; i < len; i++)
 		usart_send_blocking(USART1, buf[i]);
 }
-#endif
 
 static void cdcacm_set_config(u16 wValue)
 {
@@ -488,12 +512,13 @@ static void cdcacm_set_config(u16 wValue)
 	usbd_ep_setup(0x81, USB_ENDPOINT_ATTR_BULK, CDCACM_PACKET_SIZE, NULL);
 	usbd_ep_setup(0x82, USB_ENDPOINT_ATTR_INTERRUPT, 16, NULL);
 
-#ifdef INCLUDE_UART_INTERFACE
 	/* Serial interface */
 	usbd_ep_setup(0x03, USB_ENDPOINT_ATTR_BULK, CDCACM_PACKET_SIZE, cdcacm_data_rx_cb);
 	usbd_ep_setup(0x83, USB_ENDPOINT_ATTR_BULK, CDCACM_PACKET_SIZE, NULL);
 	usbd_ep_setup(0x84, USB_ENDPOINT_ATTR_INTERRUPT, 16, NULL);
-#endif
+
+	/* Trace interface */
+	usbd_ep_setup(0x85, USB_ENDPOINT_ATTR_BULK, 16, trace_buf_drain);
 
 	usbd_register_control_callback(
 			USB_REQ_TYPE_CLASS | USB_REQ_TYPE_INTERFACE, 
@@ -514,10 +539,8 @@ static void cdcacm_set_config(u16 wValue)
 	buf[8] = 3; /* DCD | DSR */
 	buf[9] = 0;
 	usbd_ep_write_packet(0x82, buf, 10);
-#ifdef INCLUDE_UART_INTERFACE
 	notif->wIndex = 2;
 	usbd_ep_write_packet(0x84, buf, 10);
-#endif
 }
 
 /* We need a special large control buffer for this device: */

src/stm32/traceswo.c

@@ -0,0 +1,171 @@
+/*
+ * 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/>.
+ */
+
+/* This file implements capture of the TRACESWO output.
+ *
+ * ARM DDI 0403D - ARMv7M Architecture Reference Manual
+ * ARM DDI 0337I - Cortex-M3 Technical Reference Manual
+ * ARM DDI 0314H - CoreSight Components Technical Reference Manual
+ */
+
+/* TDO/TRACESWO signal comes into pin PA6/TIM3_CH1
+ * Manchester coding is assumed on TRACESWO, so bit timing can be detected.
+ * The idea is to use TIM3 input capture modes to capture pulse timings.
+ * These can be capture directly to RAM by DMA.
+ * The core can then process the buffer to extract the frame.
+ */
+#include <libopencm3/stm32/nvic.h>
+#include <libopencm3/stm32/timer.h>
+#include <libopencm3/stm32/f1/rcc.h>
+
+#include <libopencm3/usb/usbd.h>
+
+#include <string.h>
+
+void traceswo_init(void)
+{
+	rcc_peripheral_enable_clock(&RCC_APB1ENR, RCC_APB1ENR_TIM3EN);
+
+	timer_reset(TIM3);
+
+	/* Refer to ST doc RM0008 - STM32F10xx Reference Manual.
+	 * Section 14.3.4 - 14.3.6 (General Purpose Timer - Input Capture)
+	 *
+	 * CCR1 captures cycle time, CCR2 captures high time
+	 */
+
+	/* Use TI1 as capture input for CH1 and CH2 */
+	timer_ic_set_input(TIM3, TIM_IC1, TIM_IC_IN_TI1);
+	timer_ic_set_input(TIM3, TIM_IC2, TIM_IC_IN_TI1);
+
+	/* Capture CH1 on rising edge, CH2 on falling edge */
+	timer_ic_set_polarity(TIM3, TIM_IC1, TIM_IC_RISING);
+	timer_ic_set_polarity(TIM3, TIM_IC2, TIM_IC_FALLING);
+
+	/* Trigger on Filtered Timer Input 1 (TI1FP1) */
+	timer_slave_set_trigger(TIM3, TIM_SMCR_TS_IT1FP1);
+
+	/* Slave reset mode: reset counter on trigger */
+	timer_slave_set_mode(TIM3, TIM_SMCR_SMS_RM);
+
+	/* Enable capture interrupt */
+	nvic_enable_irq(NVIC_TIM3_IRQ);
+	timer_enable_irq(TIM3, TIM_DIER_CC1IE); 
+
+	/* Enable the capture channels */
+	timer_ic_enable(TIM3, TIM_IC1);
+	timer_ic_enable(TIM3, TIM_IC2);
+
+	timer_enable_counter(TIM3);
+}
+
+static uint8_t trace_usb_buf[16];
+static uint8_t trace_usb_buf_size;
+
+void trace_buf_push(uint8_t *buf, int len)
+{
+	if (usbd_ep_write_packet(0x85, buf, len) != len) {
+		memcpy(trace_usb_buf, buf, len);
+		trace_usb_buf_size = len;
+	}
+}
+
+void trace_buf_drain(uint8_t ep)
+{
+	if (!trace_usb_buf_size) 
+		return;
+
+	usbd_ep_write_packet(ep, trace_usb_buf, trace_usb_buf_size);
+	trace_usb_buf_size = 0;
+}
+
+void tim3_isr(void)
+{
+	uint16_t sr = TIM_SR(TIM3) & TIM_DIER(TIM3);
+	uint16_t duty, cycle;
+	static uint16_t bt;
+	static uint8_t lastbit;
+	static uint8_t decbuf[17];
+	static uint8_t decbuf_pos;
+
+	/* Reset decoder state if capture overflowed */
+	if (sr & (TIM_SR_CC1OF | TIM_SR_UIF)) {
+		timer_clear_flag(TIM3, TIM_SR_CC1OF | TIM_SR_UIF);
+		if (!(sr & TIM_SR_CC1IF)) {
+			trace_buf_push(decbuf, decbuf_pos >> 3);
+			memset(decbuf, 0, sizeof(decbuf));
+			decbuf_pos = 0;
+			bt = 0;
+			timer_set_period(TIM3, -1);
+			timer_disable_irq(TIM3, TIM_DIER_UIE); 
+			return;
+		}
+	}
+
+	if (!(sr & TIM_SR_CC1IF))
+		return;
+
+	cycle = TIM_CCR1(TIM3);
+	duty = TIM_CCR2(TIM3);
+
+	/* Reset decoder state if crazy shit happened */
+	if ((bt && (((duty / bt) > 2) || ((cycle / bt) > 4))) ||
+	    (duty == 0)) {
+		bt = 0;
+		trace_buf_push(decbuf, decbuf_pos >> 3);
+		decbuf_pos = 0;
+		memset(decbuf, 0, sizeof(decbuf));
+		return;
+	}
+
+	if (!bt) {
+		/* First bit, sync decoder */
+		if ((cycle / (duty - 5)) != 2)
+			return;
+		bt = duty - 5;
+		lastbit = 1;
+		timer_set_period(TIM3, duty * 5);
+		timer_clear_flag(TIM3, TIM_SR_UIF);
+		timer_enable_irq(TIM3, TIM_DIER_UIE); 
+	} else {
+		/* If high time is extended we need to flip the bit */
+		if ((duty / bt) > 1)
+			lastbit ^= 1;
+		decbuf[decbuf_pos >> 3] |= lastbit << (decbuf_pos & 7);
+		decbuf_pos++;
+	}
+
+	if (((cycle - duty) / bt) > 1) {
+		/* If low time extended we need to pack another bit. */
+		lastbit ^= 1;
+		decbuf[decbuf_pos >> 3] |= lastbit << (decbuf_pos & 7);
+		decbuf_pos++;
+	}
+
+	if (decbuf_pos >= 128) {
+		trace_buf_push(decbuf, 16);
+		/* bt = 0; */
+		decbuf_pos = 0;
+		memset(decbuf, 0, sizeof(decbuf));
+	}
+
+}
+
+

src/stm32/traceswo.h

@@ -0,0 +1,27 @@
+/*
+ * 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/>.
+ */
+#ifndef __TRACESWO_H
+#define __TRACESWO_H
+
+void traceswo_init(void);
+void trace_buf_drain(uint8_t ep);
+
+#endif
+