diff --git a/MAINTAINERS b/MAINTAINERS
index 3a761e680296..2be31b13d295 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6679,9 +6679,7 @@ M:	Paul Bolle <pebolle@tiscali.nl>
 L:	gigaset307x-common@lists.sourceforge.net
 W:	http://gigaset307x.sourceforge.net/
 S:	Odd Fixes
-F:	Documentation/isdn/README.gigaset
-F:	drivers/isdn/gigaset/
-F:	include/uapi/linux/gigaset_dev.h
+F:	drivers/staging/isdn/gigaset/
 
 GNSS SUBSYSTEM
 M:	Johan Hovold <johan@kernel.org>
@@ -8362,15 +8360,25 @@ S:	Supported
 W:	http://www.linux-iscsi.org
 F:	drivers/infiniband/ulp/isert
 
-ISDN SUBSYSTEM
+ISDN/mISDN SUBSYSTEM
 M:	Karsten Keil <isdn@linux-pingi.de>
 L:	isdn4linux@listserv.isdn4linux.de (subscribers-only)
 L:	netdev@vger.kernel.org
 W:	http://www.isdn4linux.de
-T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kkeil/isdn-2.6.git
 S:	Maintained
+F:	drivers/isdn/mISDN
+F:	drivers/isdn/hardware
+
+ISDN/CAPI SUBSYSTEM
+M:	Karsten Keil <isdn@linux-pingi.de>
+L:	isdn4linux@listserv.isdn4linux.de (subscribers-only)
+L:	netdev@vger.kernel.org
+W:	http://www.isdn4linux.de
+S:	Odd Fixes
 F:	Documentation/isdn/
-F:	drivers/isdn/
+F:	drivers/isdn/capi/
+F:	drivers/staging/isdn/
+F:	net/bluetooth/cmtp/
 F:	include/linux/isdn/
 F:	include/uapi/linux/isdn/
 
diff --git a/drivers/isdn/Kconfig b/drivers/isdn/Kconfig
index 6e3bf833c67e..be8387c0eeef 100644
--- a/drivers/isdn/Kconfig
+++ b/drivers/isdn/Kconfig
@@ -21,33 +21,8 @@ menuconfig ISDN
 
 if ISDN
 
-menuconfig ISDN_CAPI
-	tristate "CAPI 2.0 subsystem"
-	help
-	  This provides CAPI (the Common ISDN Application Programming
-	  Interface) Version 2.0, a standard making it easy for programs to
-	  access ISDN hardware in a device independent way. (For details see
-	  <http://www.capi.org/>.)  CAPI supports making and accepting voice
-	  and data connections, controlling call options and protocols,
-	  as well as ISDN supplementary services like call forwarding or
-	  three-party conferences (if supported by the specific hardware
-	  driver).
-
-	  Select this option and the appropriate hardware driver below if
-	  you have an ISDN adapter supported by the CAPI subsystem.
-
-if ISDN_CAPI
-
 source "drivers/isdn/capi/Kconfig"
 
-source "drivers/isdn/hardware/Kconfig"
-
-endif # ISDN_CAPI
-
-source "drivers/isdn/gigaset/Kconfig"
-
-source "drivers/isdn/hysdn/Kconfig"
-
 source "drivers/isdn/mISDN/Kconfig"
 
 endif # ISDN
diff --git a/drivers/isdn/Makefile b/drivers/isdn/Makefile
index f2a529c5a511..63baf27a2c79 100644
--- a/drivers/isdn/Makefile
+++ b/drivers/isdn/Makefile
@@ -6,5 +6,3 @@
 obj-$(CONFIG_ISDN_CAPI)			+= capi/
 obj-$(CONFIG_MISDN)			+= mISDN/
 obj-$(CONFIG_ISDN)			+= hardware/
-obj-$(CONFIG_HYSDN)			+= hysdn/
-obj-$(CONFIG_ISDN_DRV_GIGASET)		+= gigaset/
diff --git a/drivers/isdn/capi/Kconfig b/drivers/isdn/capi/Kconfig
index 089dbee18f36..573fea5500ce 100644
--- a/drivers/isdn/capi/Kconfig
+++ b/drivers/isdn/capi/Kconfig
@@ -1,4 +1,22 @@
 # SPDX-License-Identifier: GPL-2.0-only
+menuconfig ISDN_CAPI
+	tristate "CAPI 2.0 subsystem"
+	help
+	  This provides CAPI (the Common ISDN Application Programming
+	  Interface) Version 2.0, a standard making it easy for programs to
+	  access ISDN hardware in a device independent way. (For details see
+	  <http://www.capi.org/>.)  CAPI supports making and accepting voice
+	  and data connections, controlling call options and protocols,
+	  as well as ISDN supplementary services like call forwarding or
+	  three-party conferences (if supported by the specific hardware
+	  driver).
+
+	  This subsystem requires a hardware specific driver.
+	  See CONFIG_BT_CMTP for the last remaining regular driver
+	  in the kernel that uses the CAPI subsystem.
+
+if ISDN_CAPI
+
 config CAPI_TRACE
 	bool "CAPI trace support"
 	default y
@@ -34,3 +52,5 @@ config ISDN_CAPI_CAPIDRV_VERBOSE
 	  If you say Y here, the capidrv interface will give verbose reasons
 	  for disconnecting. This will increase the size of the kernel by 7 KB.
 	  If unsure, say N.
+
+endif
diff --git a/drivers/isdn/capi/Makefile b/drivers/isdn/capi/Makefile
index 06da3ed2c40a..d299f3e75f89 100644
--- a/drivers/isdn/capi/Makefile
+++ b/drivers/isdn/capi/Makefile
@@ -13,3 +13,5 @@ obj-$(CONFIG_ISDN_CAPI_CAPIDRV)		+= capidrv.o
 
 kernelcapi-y				:= kcapi.o capiutil.o capilib.o
 kernelcapi-$(CONFIG_PROC_FS)		+= kcapi_proc.o
+
+ccflags-y += -I$(srctree)/$(src)/../include -I$(srctree)/$(src)/../include/uapi
diff --git a/drivers/isdn/hardware/Kconfig b/drivers/isdn/hardware/Kconfig
deleted file mode 100644
index 0d609b5fcf01..000000000000
--- a/drivers/isdn/hardware/Kconfig
+++ /dev/null
@@ -1,8 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0-only
-#
-# ISDN hardware drivers
-#
-comment "CAPI hardware drivers"
-
-source "drivers/isdn/hardware/avm/Kconfig"
-
diff --git a/drivers/isdn/hardware/Makefile b/drivers/isdn/hardware/Makefile
index a43760a0a4f5..96f9eb2e46ba 100644
--- a/drivers/isdn/hardware/Makefile
+++ b/drivers/isdn/hardware/Makefile
@@ -3,5 +3,4 @@
 
 # Object files in subdirectories
 
-obj-$(CONFIG_CAPI_AVM)		+= avm/
 obj-$(CONFIG_MISDN)		+= mISDN/
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index d5f771fafc21..7c96a01eef6c 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -118,4 +118,6 @@ source "drivers/staging/fieldbus/Kconfig"
 
 source "drivers/staging/kpc2000/Kconfig"
 
+source "drivers/staging/isdn/Kconfig"
+
 endif # STAGING
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 0da0d3f0b5e4..fcaac9693b83 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -49,3 +49,4 @@ obj-$(CONFIG_XIL_AXIS_FIFO)	+= axis-fifo/
 obj-$(CONFIG_EROFS_FS)		+= erofs/
 obj-$(CONFIG_FIELDBUS_DEV)     += fieldbus/
 obj-$(CONFIG_KPC2000)		+= kpc2000/
+obj-$(CONFIG_ISDN_CAPI)		+= isdn/
diff --git a/drivers/staging/isdn/Kconfig b/drivers/staging/isdn/Kconfig
new file mode 100644
index 000000000000..faaf63887094
--- /dev/null
+++ b/drivers/staging/isdn/Kconfig
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "ISDN CAPI drivers"
+	depends on ISDN_CAPI
+
+source "drivers/staging/isdn/avm/Kconfig"
+
+source "drivers/staging/isdn/gigaset/Kconfig"
+
+source "drivers/staging/isdn/hysdn/Kconfig"
+
+endmenu
+
diff --git a/drivers/staging/isdn/Makefile b/drivers/staging/isdn/Makefile
new file mode 100644
index 000000000000..025504bae5df
--- /dev/null
+++ b/drivers/staging/isdn/Makefile
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-2.0
+# Makefile for the kernel ISDN subsystem and device drivers.
+
+# Object files in subdirectories
+
+obj-$(CONFIG_CAPI_AVM)			+= avm/
+obj-$(CONFIG_HYSDN)			+= hysdn/
+obj-$(CONFIG_ISDN_DRV_GIGASET)		+= gigaset/
diff --git a/drivers/staging/isdn/TODO b/drivers/staging/isdn/TODO
new file mode 100644
index 000000000000..9210d11eb68b
--- /dev/null
+++ b/drivers/staging/isdn/TODO
@@ -0,0 +1,22 @@
+TODO: Remove in late 2019 unless there are users
+
+
+I tried to find any indication of whether the capi drivers are
+still in use, and have not found anything  from a long time ago.
+
+With public ISDN networks almost completely shut down over the past 12
+months, there is very little you can actually do with this hardware. The
+main remaining use case would be to connect ISDN voice phones to an
+in-house installation with Asterisk or LCR, but anyone trying this in
+turn seems to be using either the mISDN driver stack, or out-of-tree
+drivers from the hardware vendors.
+
+I may of course have missed something, so I would suggest moving
+these into drivers/staging/ just in case someone still uses one
+of the three remaining in-kernel drivers (avm, hysdn, gigaset).
+
+If nobody complains, we can remove them entirely in six months,
+or otherwise move the core code and any drivers that are still
+needed back into drivers/isdn.
+
+  Arnd Bergmann <arnd@arndb.de>
diff --git a/drivers/isdn/hardware/avm/Kconfig b/drivers/staging/isdn/avm/Kconfig
similarity index 100%
rename from drivers/isdn/hardware/avm/Kconfig
rename to drivers/staging/isdn/avm/Kconfig
diff --git a/drivers/isdn/hardware/avm/Makefile b/drivers/staging/isdn/avm/Makefile
similarity index 100%
rename from drivers/isdn/hardware/avm/Makefile
rename to drivers/staging/isdn/avm/Makefile
diff --git a/drivers/isdn/hardware/avm/avm_cs.c b/drivers/staging/isdn/avm/avm_cs.c
similarity index 100%
rename from drivers/isdn/hardware/avm/avm_cs.c
rename to drivers/staging/isdn/avm/avm_cs.c
diff --git a/drivers/isdn/hardware/avm/avmcard.h b/drivers/staging/isdn/avm/avmcard.h
similarity index 100%
rename from drivers/isdn/hardware/avm/avmcard.h
rename to drivers/staging/isdn/avm/avmcard.h
diff --git a/drivers/isdn/hardware/avm/b1.c b/drivers/staging/isdn/avm/b1.c
similarity index 100%
rename from drivers/isdn/hardware/avm/b1.c
rename to drivers/staging/isdn/avm/b1.c
diff --git a/drivers/isdn/hardware/avm/b1dma.c b/drivers/staging/isdn/avm/b1dma.c
similarity index 100%
rename from drivers/isdn/hardware/avm/b1dma.c
rename to drivers/staging/isdn/avm/b1dma.c
diff --git a/drivers/isdn/hardware/avm/b1isa.c b/drivers/staging/isdn/avm/b1isa.c
similarity index 100%
rename from drivers/isdn/hardware/avm/b1isa.c
rename to drivers/staging/isdn/avm/b1isa.c
diff --git a/drivers/isdn/hardware/avm/b1pci.c b/drivers/staging/isdn/avm/b1pci.c
similarity index 100%
rename from drivers/isdn/hardware/avm/b1pci.c
rename to drivers/staging/isdn/avm/b1pci.c
diff --git a/drivers/isdn/hardware/avm/b1pcmcia.c b/drivers/staging/isdn/avm/b1pcmcia.c
similarity index 100%
rename from drivers/isdn/hardware/avm/b1pcmcia.c
rename to drivers/staging/isdn/avm/b1pcmcia.c
diff --git a/drivers/isdn/hardware/avm/c4.c b/drivers/staging/isdn/avm/c4.c
similarity index 100%
rename from drivers/isdn/hardware/avm/c4.c
rename to drivers/staging/isdn/avm/c4.c
diff --git a/drivers/isdn/hardware/avm/t1isa.c b/drivers/staging/isdn/avm/t1isa.c
similarity index 100%
rename from drivers/isdn/hardware/avm/t1isa.c
rename to drivers/staging/isdn/avm/t1isa.c
diff --git a/drivers/isdn/hardware/avm/t1pci.c b/drivers/staging/isdn/avm/t1pci.c
similarity index 100%
rename from drivers/isdn/hardware/avm/t1pci.c
rename to drivers/staging/isdn/avm/t1pci.c
diff --git a/drivers/isdn/gigaset/Kconfig b/drivers/staging/isdn/gigaset/Kconfig
similarity index 100%
rename from drivers/isdn/gigaset/Kconfig
rename to drivers/staging/isdn/gigaset/Kconfig
diff --git a/drivers/isdn/gigaset/Makefile b/drivers/staging/isdn/gigaset/Makefile
similarity index 100%
rename from drivers/isdn/gigaset/Makefile
rename to drivers/staging/isdn/gigaset/Makefile
diff --git a/drivers/isdn/gigaset/asyncdata.c b/drivers/staging/isdn/gigaset/asyncdata.c
similarity index 100%
rename from drivers/isdn/gigaset/asyncdata.c
rename to drivers/staging/isdn/gigaset/asyncdata.c
diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/staging/isdn/gigaset/bas-gigaset.c
similarity index 100%
rename from drivers/isdn/gigaset/bas-gigaset.c
rename to drivers/staging/isdn/gigaset/bas-gigaset.c
diff --git a/drivers/isdn/gigaset/capi.c b/drivers/staging/isdn/gigaset/capi.c
similarity index 100%
rename from drivers/isdn/gigaset/capi.c
rename to drivers/staging/isdn/gigaset/capi.c
diff --git a/drivers/isdn/gigaset/common.c b/drivers/staging/isdn/gigaset/common.c
similarity index 100%
rename from drivers/isdn/gigaset/common.c
rename to drivers/staging/isdn/gigaset/common.c
diff --git a/drivers/isdn/gigaset/dummyll.c b/drivers/staging/isdn/gigaset/dummyll.c
similarity index 100%
rename from drivers/isdn/gigaset/dummyll.c
rename to drivers/staging/isdn/gigaset/dummyll.c
diff --git a/drivers/isdn/gigaset/ev-layer.c b/drivers/staging/isdn/gigaset/ev-layer.c
similarity index 100%
rename from drivers/isdn/gigaset/ev-layer.c
rename to drivers/staging/isdn/gigaset/ev-layer.c
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/staging/isdn/gigaset/gigaset.h
similarity index 100%
rename from drivers/isdn/gigaset/gigaset.h
rename to drivers/staging/isdn/gigaset/gigaset.h
diff --git a/drivers/isdn/gigaset/interface.c b/drivers/staging/isdn/gigaset/interface.c
similarity index 100%
rename from drivers/isdn/gigaset/interface.c
rename to drivers/staging/isdn/gigaset/interface.c
diff --git a/drivers/isdn/gigaset/isocdata.c b/drivers/staging/isdn/gigaset/isocdata.c
similarity index 100%
rename from drivers/isdn/gigaset/isocdata.c
rename to drivers/staging/isdn/gigaset/isocdata.c
diff --git a/drivers/isdn/gigaset/proc.c b/drivers/staging/isdn/gigaset/proc.c
similarity index 100%
rename from drivers/isdn/gigaset/proc.c
rename to drivers/staging/isdn/gigaset/proc.c
diff --git a/drivers/isdn/gigaset/ser-gigaset.c b/drivers/staging/isdn/gigaset/ser-gigaset.c
similarity index 100%
rename from drivers/isdn/gigaset/ser-gigaset.c
rename to drivers/staging/isdn/gigaset/ser-gigaset.c
diff --git a/drivers/isdn/gigaset/usb-gigaset.c b/drivers/staging/isdn/gigaset/usb-gigaset.c
similarity index 100%
rename from drivers/isdn/gigaset/usb-gigaset.c
rename to drivers/staging/isdn/gigaset/usb-gigaset.c
diff --git a/drivers/isdn/hysdn/Kconfig b/drivers/staging/isdn/hysdn/Kconfig
similarity index 100%
rename from drivers/isdn/hysdn/Kconfig
rename to drivers/staging/isdn/hysdn/Kconfig
diff --git a/drivers/isdn/hysdn/Makefile b/drivers/staging/isdn/hysdn/Makefile
similarity index 100%
rename from drivers/isdn/hysdn/Makefile
rename to drivers/staging/isdn/hysdn/Makefile
diff --git a/drivers/isdn/hysdn/boardergo.c b/drivers/staging/isdn/hysdn/boardergo.c
similarity index 100%
rename from drivers/isdn/hysdn/boardergo.c
rename to drivers/staging/isdn/hysdn/boardergo.c
diff --git a/drivers/isdn/hysdn/boardergo.h b/drivers/staging/isdn/hysdn/boardergo.h
similarity index 100%
rename from drivers/isdn/hysdn/boardergo.h
rename to drivers/staging/isdn/hysdn/boardergo.h
diff --git a/drivers/isdn/hysdn/hycapi.c b/drivers/staging/isdn/hysdn/hycapi.c
similarity index 100%
rename from drivers/isdn/hysdn/hycapi.c
rename to drivers/staging/isdn/hysdn/hycapi.c
diff --git a/drivers/isdn/hysdn/hysdn_boot.c b/drivers/staging/isdn/hysdn/hysdn_boot.c
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_boot.c
rename to drivers/staging/isdn/hysdn/hysdn_boot.c
diff --git a/drivers/isdn/hysdn/hysdn_defs.h b/drivers/staging/isdn/hysdn/hysdn_defs.h
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_defs.h
rename to drivers/staging/isdn/hysdn/hysdn_defs.h
diff --git a/drivers/isdn/hysdn/hysdn_init.c b/drivers/staging/isdn/hysdn/hysdn_init.c
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_init.c
rename to drivers/staging/isdn/hysdn/hysdn_init.c
diff --git a/drivers/isdn/hysdn/hysdn_net.c b/drivers/staging/isdn/hysdn/hysdn_net.c
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_net.c
rename to drivers/staging/isdn/hysdn/hysdn_net.c
diff --git a/drivers/isdn/hysdn/hysdn_pof.h b/drivers/staging/isdn/hysdn/hysdn_pof.h
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_pof.h
rename to drivers/staging/isdn/hysdn/hysdn_pof.h
diff --git a/drivers/isdn/hysdn/hysdn_procconf.c b/drivers/staging/isdn/hysdn/hysdn_procconf.c
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_procconf.c
rename to drivers/staging/isdn/hysdn/hysdn_procconf.c
diff --git a/drivers/isdn/hysdn/hysdn_proclog.c b/drivers/staging/isdn/hysdn/hysdn_proclog.c
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_proclog.c
rename to drivers/staging/isdn/hysdn/hysdn_proclog.c
diff --git a/drivers/isdn/hysdn/hysdn_sched.c b/drivers/staging/isdn/hysdn/hysdn_sched.c
similarity index 100%
rename from drivers/isdn/hysdn/hysdn_sched.c
rename to drivers/staging/isdn/hysdn/hysdn_sched.c
diff --git a/drivers/isdn/hysdn/ince1pc.h b/drivers/staging/isdn/hysdn/ince1pc.h
similarity index 100%
rename from drivers/isdn/hysdn/ince1pc.h
rename to drivers/staging/isdn/hysdn/ince1pc.h