makefiles/tools/serial.inc.mk: Allow detection of debug adapter

Boards with an integrated debugger/programmer that also provides the
serial as UART <--> USB adapter, the TTY serial matches the serial of
the programmer.

This adapts the `serial.inc.mk` to set the `DEBUG_ADAPTER_ID` to the
TTY serial if (and only if) `MOST_RECENT_PORT` *and*
`DEBUG_ADAPTER_ID_IS_TTY_SERIAL` both have a value of `1`. Boards with
an integrated programmer are expected to set
`DEBUG_ADAPTER_ID_IS_TTY_SERIAL` to `1` in their `Makefile.include`.

boards/arduino-mega2560/Makefile.include

@@ -25,11 +25,11 @@ ARDUINO_MEGA2560_COMPAT_WITH_CLONES ?= 1
 ifeq (1,$(ARDUINO_MEGA2560_COMPAT_WITH_CLONES))
   TTY_SELECT_CMD := $(RIOTTOOLS)/usb-serial/ttys.py \
                     --most-recent \
-                    --format path \
+                    --format path serial \
                     $(TTY_BOARD_FILTER) || \
                     $(RIOTTOOLS)/usb-serial/ttys.py \
                     --most-recent \
-                    --format path \
+                    --format path serial \
                     $(TTY_BOARD_FILTER_CLONE)
 endif
 

doc/doxygen/src/flashing.md

@@ -478,20 +478,20 @@ In most cases, just adding a simple `TTY_BOARD_FILTER` is sufficient. If we
 however have wildly different flavors of the same board (e.g. genuine Arduino
 Mega 2560 with an ATmega16U2 and clones with a cheap USB to UART bridge) that we
 all want to support, we have to instead provide a `TTY_SELECT_CMD` that prints
-the path to the TTY and exists with `0` if a TTY was found, or that exists with
-`1` and prints nothing when no TTY was found. We can still use the `ttys.py`
-script to detect all Arduino Mega 2560 versions: We first try to detect a
-genuine Arduino Mega and fall back to selecting cheap USB UART bridges when that
-fails using the `||` shell operator:
+the path to and the serial of the TTY (separated by a space) and exists with
+`0` if a TTY was found, or that exists with `1` and prints nothing when no TTY
+was found. We can still use the `ttys.py` script to detect all Arduino Mega
+2560 versions: We first try to detect a genuine Arduino Mega and fall back to
+selecting cheap USB UART bridges when that fails using the `||` shell operator:
 
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   TTY_SELECT_CMD := $(RIOTTOOLS)/usb-serial/ttys.py \
                     --most-recent \
-                    --format path \
+                    --format path serial \
                     --vendor 'Arduino' \
                     --model-db 'Mega 2560|Mega ADK' || \
                     $(RIOTTOOLS)/usb-serial/ttys.py \
                     --most-recent \
-                    --format path \
+                    --format path serial \
                     --driver 'cp210x'
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

makefiles/tools/serial.inc.mk

@@ -5,10 +5,15 @@ ifeq (1,$(MOST_RECENT_PORT))
   endif
   TTY_SELECT_CMD ?= $(RIOTTOOLS)/usb-serial/ttys.py \
                     --most-recent \
-                    --format path \
+                    --format path serial \
                     $(TTY_BOARD_FILTER)
-  PORT_DETECTED := $(shell $(TTY_SELECT_CMD) || echo 'no-tty-detected')
-  PORT ?= $(PORT_DETECTED)
+  TTY_DETECTED := $(shell $(TTY_SELECT_CMD) || echo 'no-tty-detected no-serial-detected')
+  PORT_DETECTED := $(firstword $(TTY_DETECTED))
+  PORT_SERIAL_DETECTED := $(lastword $(TTY_DETECTED))
+  PORT ?= $(firstword $(TTY_DETECTED))
+  ifeq (1,$(DEBUG_ADAPTER_ID_IS_TTY_SERIAL))
+    DEBUG_ADAPTER_ID ?= $(PORT_SERIAL_DETECTED)
+  endif
 endif
 # Otherwise, use as default the most commonly used ports on Linux and OSX
 PORT_LINUX ?= /dev/ttyACM0