# For building for the current running version of Linux
ifndef TARGET
TARGET = $(shell uname -r)
endif
# Or specific version
#TARGET = 2.6.33.5

KERNEL_MODULES = /lib/modules/$(TARGET)

ifneq ("","$(wildcard /usr/src/linux-headers-$(TARGET)/*)")
# Ubuntu
KERNEL_BUILD = /usr/src/linux-headers-$(TARGET)
else
ifneq ("","$(wildcard /usr/src/kernels/$(TARGET)/*)")
# Fedora
KERNEL_BUILD = /usr/src/kernels/$(TARGET)
else
KERNEL_BUILD = $(KERNEL_MODULES)/build
endif
endif

# SYSTEM_MAP = $(KERNEL_BUILD)/System.map
ifneq ("","$(wildcard /boot/System.map-$(TARGET))")
SYSTEM_MAP = /boot/System.map-$(TARGET)
else
# Arch
SYSTEM_MAP = /proc/kallsyms
endif

DRIVER := it87-extras
ifneq ("","$(wildcard .git/*)")
DRIVER_VERSION := $(shell git describe --long).$(shell date -u -d "$$(git show -s --format=%ci HEAD)" +%Y%m%d)
else
ifneq ("", "$(wildcard VERSION)")
DRIVER_VERSION := $(shell cat VERSION)
else
DRIVER_VERSION := unknown
endif
endif

# DKMS
DKMS_ROOT_PATH=/usr/src/$(DRIVER)-$(DRIVER_VERSION)
MODPROBE_OUTPUT=$(shell lsmod | grep it87)

# Directory below /lib/modules/$(TARGET)/kernel into which to install
# the module:
MOD_SUBDIR = drivers/hwmon
MODDESTDIR=$(KERNEL_MODULES)/kernel/$(MOD_SUBDIR)

obj-m = $(patsubst %,%.o,$(DRIVER))
obj-ko  := $(patsubst %,%.ko,$(DRIVER))
$(patsubst %,%-objs,$(DRIVER)) := it87.o

MAKEFLAGS += --no-print-directory

ifneq ("","$(wildcard $(MODDESTDIR)/*.ko.gz)")
COMPRESS_GZIP := y
endif
ifneq ("","$(wildcard $(MODDESTDIR)/*.ko.xz)")
COMPRESS_XZ := y
endif


.PHONY: all install modules modules_install clean dkms dkms_clean

all: modules


# Targets for running make directly in the external module directory:

IT87_CFLAGS=-DIT87_DRIVER_VERSION='\"$(DRIVER_VERSION)\"'

modules:
	@$(MAKE) EXTRA_CFLAGS="$(IT87_CFLAGS)" -C $(KERNEL_BUILD) M=$(CURDIR) $@

clean:
	@$(MAKE) -C $(KERNEL_BUILD) M=$(CURDIR) $@

install: modules_install

modules_install:
	mkdir -p $(MODDESTDIR)
	cp $(DRIVER).ko $(MODDESTDIR)/
ifeq ($(COMPRESS_GZIP), y)
	@gzip -f $(MODDESTDIR)/$(DRIVER).ko
endif
ifeq ($(COMPRESS_XZ), y)
	@xz -f -C crc32 $(MODDESTDIR)/$(DRIVER).ko
endif
	depmod -a -F $(SYSTEM_MAP) $(TARGET)

dkms:
	@mkdir -p $(DKMS_ROOT_PATH)
	@cp ./dkms.conf $(DKMS_ROOT_PATH)
	@cp ./Makefile $(DKMS_ROOT_PATH)
	@cp ./compat.h $(DKMS_ROOT_PATH)
	@cp ./it87.c $(DKMS_ROOT_PATH)
	@sed -i -e '/^PACKAGE_VERSION=/ s/=.*/=\"$(DRIVER_VERSION)\"/' $(DKMS_ROOT_PATH)/dkms.conf
	@echo "$(DRIVER_VERSION)" >$(DKMS_ROOT_PATH)/VERSION
	@dkms add -m $(DRIVER) -v $(DRIVER_VERSION)
	@dkms build -m $(DRIVER) -v $(DRIVER_VERSION) -k $(TARGET)
	@dkms install --force -m $(DRIVER) -v $(DRIVER_VERSION) -k $(TARGET)
	@modprobe $(DRIVER)

dkms_clean:
	@if [ ! -z "$(MODPROBE_OUTPUT)" ]; then \
		rmmod $(DRIVER);\
	fi
	@dkms remove -m $(DRIVER) -v $(DRIVER_VERSION) --all
	@rm -rf $(DKMS_ROOT_PATH)
