From b7dd33b76edee78e5da8ea856f4fcac3d44e254a Mon Sep 17 00:00:00 2001
From: hathach <thach@tinyusb.org>
Date: Tue, 21 Aug 2018 15:15:44 +0700
Subject: [PATCH] add touch 1200 for dfu-flash

---
 lib/tinyusb         |  2 +-
 ports/nrf/Makefile  | 10 ++++++----
 ports/nrf/usb/usb.c | 25 +++++++++++++++++++++++++
 3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/lib/tinyusb b/lib/tinyusb
index 6d96b12e27..7b35cd0203 160000
--- a/lib/tinyusb
+++ b/lib/tinyusb
@@ -1 +1 @@
-Subproject commit 6d96b12e27ae60ca500365ee2137105145ada9dd
+Subproject commit 7b35cd0203bc409d7c1aefc075672103cb4a913e
diff --git a/ports/nrf/Makefile b/ports/nrf/Makefile
index b62eff3dad..2ab44dbd07 100755
--- a/ports/nrf/Makefile
+++ b/ports/nrf/Makefile
@@ -314,10 +314,12 @@ endif
 #####################
 .phony: dfu-gen dfu-flash dfu-bootloader
 
-ifeq ($(OS),Windows_NT)
-   NRFUTIL = ../../lib/nrfutil/binaries/win32/nrfutil.exe
+NRFUTIL = adafruit-nrfutil
+
+ifeq ($(MCU_SUB_VARIANT),nrf52840)
+	DFU_TOUCH = --touch 1200
 else
-   NRFUTIL = nrfutil
+	DFU_TOUCH =
 endif
 
 check_defined = \
@@ -332,7 +334,7 @@ dfu-gen: $(BUILD)/$(OUTPUT_FILENAME).hex
 
 dfu-flash: $(BUILD)/dfu-package.zip
 	@:$(call check_defined, SERIAL, example: SERIAL=/dev/ttyUSB0)
-	$(NRFUTIL) --verbose dfu serial --package $^ -p $(SERIAL) -b 115200 --singlebank
+	$(NRFUTIL) --verbose dfu serial --package $^ -p $(SERIAL) -b 115200 --singlebank $(DFU_TOUCH)
 
 dfu-bootloader:
 	@:$(call check_defined, SERIAL, example: SERIAL=/dev/ttyACM0)
diff --git a/ports/nrf/usb/usb.c b/ports/nrf/usb/usb.c
index 953b61e396..7168cf53d1 100644
--- a/ports/nrf/usb/usb.c
+++ b/ports/nrf/usb/usb.c
@@ -94,9 +94,12 @@ void usb_init(void) {
 //--------------------------------------------------------------------+
 // tinyusb callbacks
 //--------------------------------------------------------------------+
+
+// Invoked when device is mounted
 void tud_mount_cb(void) {
 }
 
+// Invoked when device is unmounted
 void tud_umount_cb(void) {
 }
 
@@ -107,6 +110,28 @@ uint32_t tusb_hal_millis(void) {
     return (uint32_t) ms;
 }
 
+
+// Invoked when cdc when line state changed e.g connected/disconnected
+// Use to reset to DFU when disconnect with 1200 bps
+void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
+    (void) itf; // interface ID, not used
+
+    // disconnected event
+    if ( !dtr && !rts )
+    {
+        cdc_line_coding_t coding;
+        tud_cdc_get_line_coding(&coding);
+
+        if ( coding.bit_rate == 1200 )
+        {
+            enum { DFU_MAGIC_SERIAL = 0x4e };
+
+            NRF_POWER->GPREGRET = DFU_MAGIC_SERIAL;
+            NVIC_SystemReset();
+        }
+    }
+}
+
 #if MICROPY_KBD_EXCEPTION
 
 /**