From f767b82e71d69c0fa43c83545ec8b591298a0f6b Mon Sep 17 00:00:00 2001
From: nightwalker-87 <15526941+Nightwalker-87@users.noreply.github.com>
Date: Wed, 17 Jun 2020 13:29:41 +0200
Subject: [PATCH] Added 'connect under reset' option for USB.

---
 doc/dev/app-example/main.c |  2 +-
 src/st-flash/flash.c       |  2 +-
 src/st-info/info.c         |  6 +++---
 src/st-util/gdb-server.c   |  4 ++--
 src/stlink-gui/gui.c       |  4 ++--
 src/stlink-lib/usb.c       | 10 +++++++---
 src/stlink-lib/usb.h       |  2 +-
 tests/usb.c                |  2 +-
 8 files changed, 18 insertions(+), 14 deletions(-)

diff --git a/doc/dev/app-example/main.c b/doc/dev/app-example/main.c
index b8e64b259..b56a73e17 100644
--- a/doc/dev/app-example/main.c
+++ b/doc/dev/app-example/main.c
@@ -6,7 +6,7 @@ static stlink_t *stlink_open_first(void) {
     stlink_t* sl = NULL;
     sl = stlink_v1_open(0, 1);
     if (sl == NULL)
-        sl = stlink_open_usb(0, 1, NULL);
+        sl = stlink_open_usb(0, 0, 1, NULL);
 
     return sl;
 }
diff --git a/src/st-flash/flash.c b/src/st-flash/flash.c
index 43378965c..8bd0e289f 100644
--- a/src/st-flash/flash.c
+++ b/src/st-flash/flash.c
@@ -53,7 +53,7 @@ int main(int ac, char** av) {
 
     printf("st-flash %s\n", STLINK_VERSION);
 
-    sl = stlink_open_usb(o.log_level, 1, (char *)o.serial, o.freq);
+    sl = stlink_open_usb(o.log_level, 0, 1, (char *)o.serial, o.freq);
 
     if (sl == NULL) { return(-1); }
 
diff --git a/src/st-info/info.c b/src/st-info/info.c
index 1bc48a05e..286c6f61b 100644
--- a/src/st-info/info.c
+++ b/src/st-info/info.c
@@ -76,13 +76,13 @@ static void stlink_probe(void) {
 
 static stlink_t *stlink_open_first(bool under_reset) {
     stlink_t* sl = NULL;
-    sl = stlink_v1_open(0, 1);
+    sl = stlink_v1_open(0, 1); // TODO: deprecated?
 
     if (sl == NULL) {
         if (under_reset) {
-            sl = stlink_open_usb(0, 2, NULL, 0);
+            sl = stlink_open_usb(0, 1, 2, NULL, 0);
         } else {
-            sl = stlink_open_usb(0, 1, NULL, 0);
+            sl = stlink_open_usb(0, 0, 1, NULL, 0);
         }
     }
 
diff --git a/src/st-util/gdb-server.c b/src/st-util/gdb-server.c
index 94cd6fda7..c5bca3bde 100644
--- a/src/st-util/gdb-server.c
+++ b/src/st-util/gdb-server.c
@@ -89,9 +89,9 @@ static stlink_t* do_connect(st_state_t *st) {
     stlink_t *sl = NULL;
 
     if (serial_specified) {
-        sl = stlink_open_usb(st->logging_level, st->reset, serialnumber, 0);
+        sl = stlink_open_usb(st->logging_level, 0, st->reset, serialnumber, 0);
     } else {
-        sl = stlink_open_usb(st->logging_level, st->reset, NULL, 0);
+        sl = stlink_open_usb(st->logging_level, 0, st->reset, NULL, 0);
     }
 
     return(sl);
diff --git a/src/stlink-gui/gui.c b/src/stlink-gui/gui.c
index ed38fcc7c..1515750d1 100644
--- a/src/stlink-gui/gui.c
+++ b/src/stlink-gui/gui.c
@@ -496,9 +496,9 @@ static void connect_button_cb(GtkWidget *widget, gpointer data) {
 
     if (gui->sl != NULL) { return; }
 
-    gui->sl = stlink_v1_open(0, 1); // try version 1 then version 2
+    gui->sl = stlink_v1_open(0, 1); // try version 1 then version 2 // TODO: deprecated?
 
-    if (gui->sl == NULL) { gui->sl = stlink_open_usb(0, 1, NULL, 0); }
+    if (gui->sl == NULL) { gui->sl = stlink_open_usb(0, 0, 1, NULL, 0); }
 
     if (gui->sl == NULL) {
         stlink_gui_set_info_error_message(gui, "Failed to connect to STLink.");
diff --git a/src/stlink-lib/usb.c b/src/stlink-lib/usb.c
index f9b4775f3..089bb906f 100644
--- a/src/stlink-lib/usb.c
+++ b/src/stlink-lib/usb.c
@@ -1002,7 +1002,7 @@ static stlink_backend_t _stlink_usb_backend = {
     _stlink_usb_set_swdclk
 };
 
-stlink_t *stlink_open_usb(enum ugly_loglevel verbose, int reset, char serial[STLINK_SERIAL_MAX_SIZE], int freq) {
+stlink_t *stlink_open_usb(enum ugly_loglevel verbose, bool connect_under_reset, int reset, char serial[STLINK_SERIAL_MAX_SIZE], int freq) {
     stlink_t* sl = NULL;
     struct stlink_libusb* slu = NULL;
     int ret = -1;
@@ -1226,7 +1226,11 @@ stlink_t *stlink_open_usb(enum ugly_loglevel verbose, int reset, char serial[STL
     if (reset == 2) {
         stlink_jtag_reset(sl, 0);
 
-        if (stlink_current_mode(sl) != STLINK_DEV_DEBUG_MODE) { stlink_enter_swd_mode(sl); }
+        if (stlink_current_mode(sl) != STLINK_DEV_DEBUG_MODE) {
+            if (connect_under_reset) { stlink_jtag_reset(sl, 0); }
+            stlink_enter_swd_mode(sl);
+            if (connect_under_reset) { stlink_jtag_reset(sl, 1); }
+        }
 
         stlink_force_debug(sl);
         stlink_jtag_reset(sl, 1);
@@ -1332,7 +1336,7 @@ static size_t stlink_probe_usb_devs(libusb_device **devs, stlink_t **sldevs[]) {
 
         if (ret < 0) { continue; }
 
-        stlink_t *sl = stlink_open_usb(0, 1, serial, 0);
+        stlink_t *sl = stlink_open_usb(0, 0, 1, serial, 0);
 
         if (!sl) {
             ELOG("Failed to open USB device %#06x:%#06x\n", desc.idVendor, desc.idProduct);
diff --git a/src/stlink-lib/usb.h b/src/stlink-lib/usb.h
index d11f17381..8a678fa91 100644
--- a/src/stlink-lib/usb.h
+++ b/src/stlink-lib/usb.h
@@ -66,7 +66,7 @@ struct stlink_libusb {
  * @retval NULL   Error while opening the stlink
  * @retval !NULL  Stlink found and ready to use
  */
-stlink_t *stlink_open_usb(enum ugly_loglevel verbose, int reset, char serial[STLINK_SERIAL_MAX_SIZE], int freq);
+stlink_t *stlink_open_usb(enum ugly_loglevel verbose, bool connect_under_reset, int reset, char serial[STLINK_SERIAL_MAX_SIZE], int freq);
 size_t stlink_probe_usb(stlink_t **stdevs[]);
 void stlink_probe_usb_free(stlink_t **stdevs[], size_t size);
 
diff --git a/tests/usb.c b/tests/usb.c
index 03c135f00..9e6e0d0c4 100644
--- a/tests/usb.c
+++ b/tests/usb.c
@@ -26,7 +26,7 @@ int main(int ac, char** av) {
         return(0);
     }
 
-    sl = stlink_open_usb(10, reset, NULL, 0);
+    sl = stlink_open_usb(10, 0, reset, NULL, 0);
 
     if (sl != NULL) {
         printf("-- version\n");