From db5e22a5b36e71619ee4492d8d9edbe9d73afb85 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Wed, 10 Mar 2021 14:15:04 +0100
Subject: [PATCH] application: include SWD utilities

---
 application.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 4 deletions(-)

diff --git a/application.c b/application.c
index 33982be..957dabd 100644
--- a/application.c
+++ b/application.c
@@ -1,8 +1,8 @@
-/** STM32F4 application example
+/** SWJ (SWD + JTAG) finder
  *  @file
  *  @author King Kévin <kingkevin@cuvoodoo.info>
  *  @copyright SPDX-License-Identifier: GPL-3.0-or-later
- *  @date 2016-2020
+ *  @date 2016-2021
  */
 
 /* standard libraries */
@@ -32,6 +32,7 @@
 #include "usb_cdcacm.h" // USB CDC ACM utilities
 #include "terminal.h" // handle the terminal interface
 #include "menu.h" // menu utilities
+#include "swd.h" // SWD utilities
 
 /** watchdog period in ms */
 #define WATCHDOG_PERIOD 10000
@@ -69,6 +70,36 @@ size_t putc(char c)
 
 // menu commands
 
+static void command_swd_scan(void* argument)
+{
+	(void)argument; // we won't use the argument
+	printf("SWD target DPIDR: ");
+	uint32_t data; // data to read/write over SWD
+	enum swd_ack_e ack; // SWD acknowledge response
+	swd_line_reset(); // put target in reset state
+	swd_jtag_to_swd(); // put target SWJ in SWD mode
+	swd_line_reset(); // put target in reset state
+	swd_idle_cycles(2); // idle before packer request
+	swd_packet_request(false, SWD_A_DP_DPIDR, true); // request DPIDR
+	swd_turnaround(1); // switch from writing to reading
+	ack = swd_acknowledge_response(); // get ack
+	if (SWD_ACK_OK != ack) {
+		printf("ack error\n");
+		return;
+	}
+	if (!swd_read(&data)) {
+		printf("parity error\n");
+		return;
+	}
+	swd_turnaround(1); // switch from reading to writing
+	printf("0x%08x ", data);
+	if (data & 0x1) {
+		printf("(designer: %03x/%s, version: %u, part number: 0x%02x/%s, revision %u)\n", (data >> 1) & 0x3ff, swd_jep106_manufacturer((data >> 8) & 0x0f, (data >> 1) & 0x7f), (data >> 12) & 0x0f, (data >> 20) & 0xff, swd_dpidr_partno((data >> 1) & 0x3ff, (data >> 20) & 0xff), (data >> 28) & 0x0f);
+	} else {
+		printf("(invalid: RAO != 1)\n");
+	}
+}
+
 /** display available commands
  *  @param[in] argument no argument required
  */
@@ -305,7 +336,7 @@ static const struct menu_command_t menu_commands[] = {
 		.command_handler = &command_reset,
 	},
 	{
-		.shortcut = 's',
+		.shortcut = 'S',
 		.name = "system",
 		.command_description = "reboot into system memory",
 		.argument = MENU_ARGUMENT_NONE,
@@ -320,6 +351,14 @@ static const struct menu_command_t menu_commands[] = {
 		.argument_description = NULL,
 		.command_handler = &command_bootloader,
 	},
+	{
+		.shortcut = 's',
+		.name = "scan",
+		.command_description = "scan SWD device",
+		.argument = MENU_ARGUMENT_NONE,
+		.argument_description = NULL,
+		.command_handler = &command_swd_scan,
+	},
 };
 
 static void command_help(void* argument)
@@ -374,7 +413,7 @@ void main(void)
 	board_setup(); // setup board
 	uart_setup(); // setup USART (for printing)
 	usb_cdcacm_setup(); // setup USB CDC ACM (for printing)
-	puts("\nwelcome to the CuVoodoo STM32F4 example firmware\n"); // print welcome message
+	puts("\nwelcome to the CuVoodoo SWJ finder\n"); // print welcome message
 
 #if DEBUG
 	// show reset cause
@@ -454,6 +493,10 @@ void main(void)
 	// important: do not re-enable backup_domain_write_protect, since this will prevent clearing flags (but RTC registers do not need to be unlocked)
 	puts("OK\n");
 
+	puts("setup SWD: ");
+	swd_setup(100000); // setup SWD clock to 100 KHz, slow enough for any target and loose connection
+	puts("OK\n");
+
 	// setup terminal
 	terminal_prefix = ""; // set default prefix
 	terminal_process = &process_command; // set central function to process commands