pkg/nimble: conditional compilation of nRF5x code

The package uses the nRFx SDK package `nrfx`. In addition, the `mynewt-nimble` repository contains some files (`porting/nimble/src/hal_timer.c` and `porting/npl/riot/src/nrf5x_isr.c`) that are compilable only for nRF MCUs. To allow the compilation for other platforms, the use of the `nrfx` package and the compilation of these files are now dependent on the use of any nRF5x MCU.

cpu/nrf5x_common/Makefile.dep

@@ -10,3 +10,7 @@ USEMODULE += cpu_common
 FEATURES_OPTIONAL += vdd_lc_filter_reg1
 # reg0 feature denotes stage 0 two-stage regulator models
 FEATURES_OPTIONAL += vdd_lc_filter_reg0
+
+ifneq (,$(filter nimble,$(USEPKG)))
+  USEPKG += nrfx
+endif

pkg/nimble/Makefile

@@ -38,7 +38,7 @@ nimble_porting_nimble:
 	$(QQ)"$(MAKE)" -C $(PDIR)/porting/nimble/src/ -f $(RIOTPKG)/$(PKG_NAME)/nimble.porting.mk MODULE=$@
 
 nimble_npl_riot:
-	$(QQ)"$(MAKE)" -C $(PDIR)/porting/npl/riot/src/ -f $(RIOTBASE)/Makefile.base MODULE=$@
+	$(QQ)"$(MAKE)" -C $(PDIR)/porting/npl/riot/src/ -f $(RIOTPKG)/$(PKG_NAME)/nimble.npl.mk MODULE=$@
 
 # generic modules
 nimble_transport:

pkg/nimble/Makefile.dep

@@ -3,8 +3,6 @@ USEMODULE += sema
 USEMODULE += event_callback
 USEMODULE += ztimer_msec
 
-USEPKG += nrfx
-
 # Requires nimble feature
 FEATURES_REQUIRED += ble_nimble
 

pkg/nimble/nimble.npl.mk

@@ -0,0 +1,7 @@
+ifeq (,$(filter nrf51 nrf52 nrf53,$(CPU_FAM)))
+  # nrf5x_isr.c does only compile for nRF5x MCUs
+  IGNORE := nrf5x_isr.c
+  SRC := $(filter-out $(IGNORE),$(wildcard *.c))
+endif
+
+include $(RIOTBASE)/Makefile.base

pkg/nimble/nimble.porting.mk

@@ -1,5 +1,9 @@
 ifneq (,$(filter mynewt-core,$(USEMODULE)))
   SRC = nimble_port.c
+else ifeq (,$(filter nrf51 nrf52 nrf53,$(CPU_FAM)))
+  # hal_timer.c does only compile for nRF5x MCUs
+  IGNORE := hal_timer.c
+  SRC := $(filter-out $(IGNORE),$(wildcard *.c))
 endif
 
 include $(RIOTBASE)/Makefile.base