[core] Add restartDownloadMode() method

arduino/beken-72xx/cores/arduino/LibreTuyaAPI.cpp

@@ -32,6 +32,10 @@ void LibreTuya::restart() {
 	bk_reboot();
 }
 
+void LibreTuya::restartDownloadMode() {
+	bk_reboot();
+}
+
 ResetReason LibreTuya::getResetReason() {
 	switch (bk_misc_get_start_type()) {
 		case RESET_SOURCE_POWERON:

arduino/libretuya/core/LibreTuyaClass.h

@@ -63,6 +63,10 @@ class LibreTuya {
 	 * @brief Reboot the CPU.
 	 */
 	void restart();
+	/**
+	 * @brief Reboot the CPU and stay in download mode (if possible).
+	 */
+	void restartDownloadMode();
 	/**
 	 * @brief Get the reason of last chip reset.
 	 */

arduino/realtek-ambz/cores/arduino/LibreTuyaAPI.cpp

@@ -15,6 +15,14 @@ void LibreTuya::restart() {
 	while (1) {}
 }
 
+void LibreTuya::restartDownloadMode() {
+	// mww 0x40000138 0x8
+	HAL_WRITE32(SYSTEM_CTRL_BASE, REG_SYS_NORESET_FF, 0x08);
+	// reboot it the ugly way
+	sys_reset();
+	while (1) {}
+}
+
 ResetReason LibreTuya::getResetReason() {
 	return RESET_REASON_UNKNOWN;
 }