cpu/atmega_common: implements pseudomodule-based pin change interrupts

boards/common/atmega/doc.txt

@@ -0,0 +1,17 @@
+/**
+@defgroup    boards_common_atmega ATmega common
+@ingroup     boards
+@brief       Shared files and configuration for ATmega-based boards
+
+### Pin Change Interrupts
+
+Pin Change Interrupts (PCINTs) can be enabled using pseudo modules. To provide
+a low-memory overhead implementation, the PCINTs are grouped into **banks**.
+Each banks corresponds to one PCINT on the ATmega (PCINT0, ..., PCINT3).
+
+To enable only a specific bank, simply add `USEMODULE += atmega_pcintN` to your
+Makefile. To enable all interrupts you can use `USEMODULE += atmega_pcint`.
+
+In case you want to add a new CPU, simply provide an `atmega_pcint.h` with your
+CPU and adapt your Makefile.dep and Makefile.featues files.
+ */

cpu/atmega_common/Makefile.dep

@@ -0,0 +1,24 @@
+# expand atmega_pcint module
+ifneq (,$(filter atmega_pcint,$(USEMODULE)))
+  USEMODULE += atmega_pcint0
+endif
+
+# feature for atmega_pcint0 module
+ifneq (,$(filter atmega_pcint0,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint0
+endif
+
+# feature for atmega_pcint1 module
+ifneq (,$(filter atmega_pcint1,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint1
+endif
+
+# feature for atmega_pcint2 module
+ifneq (,$(filter atmega_pcint2,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint2
+endif
+
+# feature for atmega_pcint3 module
+ifneq (,$(filter atmega_pcint3,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint3
+endif

cpu/atmega_common/Makefile.features

@@ -1,2 +1,4 @@
 FEATURES_PROVIDED += periph_eeprom
 FEATURES_PROVIDED += periph_pm
+
+FEATURES_PROVIDED += atmega_pcint0

cpu/atmega_common/Makefile.include

@@ -6,4 +6,34 @@ export INCLUDES += -I$(RIOTCPU)/atmega_common/include \
 # avr libc needs some RIOT-specific support code
 USEMODULE += avr_libc_extra
 
+PSEUDOMODULES += atmega_pcint
+PSEUDOMODULES += atmega_pcint%
+
+# expand atmega_pcint module
+# atmega16u4 only features atmega_pcint0, therefore additional pseudomodules
+# are activated in each CPU's Makefile.include
+ifneq (,$(filter atmega_pcint,$(USEMODULE)))
+  USEMODULE += atmega_pcint0
+endif
+
+# feature for atmega_pcint0 module
+ifneq (,$(filter atmega_pcint0,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint0
+endif
+
+# feature for atmega_pcint1 module
+ifneq (,$(filter atmega_pcint1,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint1
+endif
+
+# feature for atmega_pcint2 module
+ifneq (,$(filter atmega_pcint2,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint2
+endif
+
+# feature for atmega_pcint3 module
+ifneq (,$(filter atmega_pcint3,$(USEMODULE)))
+  FEATURES_REQUIRED += atmega_pcint3
+endif
+
 include $(RIOTMAKE)/arch/atmega.inc.mk