# SPDX-License-Identifier: GPL-2.0

  include ../scripts/Makefile.include

  bindir ?= /usr/bin

  ifeq ($(srctree),)

  srctree := $(patsubst %/,%,$(dir $(CURDIR)))

  srctree := $(patsubst %/,%,$(dir $(srctree)))
  endif
  
  # Do not use make's built-in rules
  # (this improves performance and avoids hard-to-debug behaviour);
  MAKEFLAGS += -r

  CFLAGS += -O2 -Wall -g -D_GNU_SOURCE -I$(OUTPUT)include
  
  ALL_TARGETS := lsgpio gpio-hammer gpio-event-mon
  ALL_PROGRAMS := $(patsubst %,$(OUTPUT)%,$(ALL_TARGETS))
  
  all: $(ALL_PROGRAMS)

  export srctree OUTPUT CC LD CFLAGS
  include $(srctree)/tools/build/Makefile.include

  #
  # We need the following to be outside of kernel tree
  #
  $(OUTPUT)include/linux/gpio.h: ../../include/uapi/linux/gpio.h
  	mkdir -p $(OUTPUT)include/linux 2>&1 || true
  	ln -sf $(CURDIR)/../../include/uapi/linux/gpio.h $@

  prepare: $(OUTPUT)include/linux/gpio.h
  
  #
  # lsgpio
  #
  LSGPIO_IN := $(OUTPUT)lsgpio-in.o
  $(LSGPIO_IN): prepare FORCE
  	$(Q)$(MAKE) $(build)=lsgpio
  $(OUTPUT)lsgpio: $(LSGPIO_IN)
  	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
  
  #
  # gpio-hammer
  #
  GPIO_HAMMER_IN := $(OUTPUT)gpio-hammer-in.o
  $(GPIO_HAMMER_IN): prepare FORCE
  	$(Q)$(MAKE) $(build)=gpio-hammer
  $(OUTPUT)gpio-hammer: $(GPIO_HAMMER_IN)
  	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@
  
  #
  # gpio-event-mon
  #
  GPIO_EVENT_MON_IN := $(OUTPUT)gpio-event-mon-in.o
  $(GPIO_EVENT_MON_IN): prepare FORCE
  	$(Q)$(MAKE) $(build)=gpio-event-mon
  $(OUTPUT)gpio-event-mon: $(GPIO_EVENT_MON_IN)
  	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) $< -o $@

  clean:

  	rm -f $(ALL_PROGRAMS)
  	rm -f $(OUTPUT)include/linux/gpio.h
  	find $(if $(OUTPUT),$(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete

  install: $(ALL_PROGRAMS)
  	install -d -m 755 $(DESTDIR)$(bindir);		\
  	for program in $(ALL_PROGRAMS); do		\
  		install $$program $(DESTDIR)$(bindir);	\
  	done

  FORCE:

  .PHONY: all install clean FORCE prepare