Sven Van Asbroeck contributed this driver in 2019.

The following reasons lead to the removal:
- This driver generates maintenance workload
- only 11 patches during the last 3 years. Part of the patches seem to be
  motivated because of maintenance (for example - remove deprecated
  function)
- Maintainer lost interest, last "Reviewed-by:" is May 2021
- no blog about usage of this driver

The staging subsystem is the way for drivers into the kernel - at current
speed and interest this is never going to happen. I think that fieldbus
is an interesting topic. But when almost nobody cares about this driver,
it does not make sense to keep it. Please consider that support will
remain for years in the longterm kernels.

Link: https://lore.kernel.org/linux-staging/96ae2b42-c0ce-4d9a-8933-eb874dc5589b@gmail.com/T/#u
Signed-off-by: Philipp Hortmann <philipp.g.hortmann@gmail.com>
---
Artifacts of fieldbus in MAINTAINERS are removed with this patch.
Removed artifacts in Makefile and Kconfig.
---
 MAINTAINERS                                   |   11 -
 drivers/staging/Kconfig                       |    2 -
 drivers/staging/Makefile                      |    1 -
 .../Documentation/ABI/fieldbus-dev-cdev       |   31 -
 .../ABI/sysfs-class-fieldbus-dev              |   62 -
 .../fieldbus/arcx,anybus-controller.txt       |   71 -
 .../fieldbus/Documentation/fieldbus_dev.txt   |   66 -
 drivers/staging/fieldbus/Kconfig              |   19 -
 drivers/staging/fieldbus/Makefile             |    7 -
 drivers/staging/fieldbus/TODO                 |    5 -
 drivers/staging/fieldbus/anybuss/Kconfig      |   41 -
 drivers/staging/fieldbus/anybuss/Makefile     |   10 -
 .../staging/fieldbus/anybuss/anybuss-client.h |   95 --
 .../fieldbus/anybuss/anybuss-controller.h     |   47 -
 .../staging/fieldbus/anybuss/arcx-anybus.c    |  379 -----
 .../staging/fieldbus/anybuss/hms-profinet.c   |  224 ---
 drivers/staging/fieldbus/anybuss/host.c       | 1452 -----------------
 drivers/staging/fieldbus/dev_core.c           |  344 ----
 drivers/staging/fieldbus/fieldbus_dev.h       |  114 --
 19 files changed, 2981 deletions(-)
 delete mode 100644 drivers/staging/fieldbus/Documentation/ABI/fieldbus-dev-cdev
 delete mode 100644 drivers/staging/fieldbus/Documentation/ABI/sysfs-class-fieldbus-dev
 delete mode 100644 drivers/staging/fieldbus/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt
 delete mode 100644 drivers/staging/fieldbus/Documentation/fieldbus_dev.txt
 delete mode 100644 drivers/staging/fieldbus/Kconfig
 delete mode 100644 drivers/staging/fieldbus/Makefile
 delete mode 100644 drivers/staging/fieldbus/TODO
 delete mode 100644 drivers/staging/fieldbus/anybuss/Kconfig
 delete mode 100644 drivers/staging/fieldbus/anybuss/Makefile
 delete mode 100644 drivers/staging/fieldbus/anybuss/anybuss-client.h
 delete mode 100644 drivers/staging/fieldbus/anybuss/anybuss-controller.h
 delete mode 100644 drivers/staging/fieldbus/anybuss/arcx-anybus.c
 delete mode 100644 drivers/staging/fieldbus/anybuss/hms-profinet.c
 delete mode 100644 drivers/staging/fieldbus/anybuss/host.c
 delete mode 100644 drivers/staging/fieldbus/dev_core.c
 delete mode 100644 drivers/staging/fieldbus/fieldbus_dev.h

diff --git a/MAINTAINERS b/MAINTAINERS
index b609f40e1420..e4c51d40d42b 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -21930,17 +21930,6 @@ L:	linux-media@vger.kernel.org
 S:	Maintained
 F:	drivers/staging/media/atomisp/
 
-STAGING - FIELDBUS SUBSYSTEM
-M:	Sven Van Asbroeck <TheSven73@gmail.com>
-S:	Maintained
-F:	drivers/staging/fieldbus/*
-F:	drivers/staging/fieldbus/Documentation/
-
-STAGING - HMS ANYBUS-S BUS
-M:	Sven Van Asbroeck <TheSven73@gmail.com>
-S:	Maintained
-F:	drivers/staging/fieldbus/anybuss/
-
 STAGING - INDUSTRIAL IO
 M:	Jonathan Cameron <jic23@kernel.org>
 L:	linux-iio@vger.kernel.org
diff --git a/drivers/staging/Kconfig b/drivers/staging/Kconfig
index 4018f95a31bc..075e775d3868 100644
--- a/drivers/staging/Kconfig
+++ b/drivers/staging/Kconfig
@@ -46,8 +46,6 @@ source "drivers/staging/vc04_services/Kconfig"
 
 source "drivers/staging/axis-fifo/Kconfig"
 
-source "drivers/staging/fieldbus/Kconfig"
-
 source "drivers/staging/vme_user/Kconfig"
 
 source "drivers/staging/gpib/Kconfig"
diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index f29d66da02eb..e681e403509c 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -13,5 +13,4 @@ obj-$(CONFIG_MOST)		+= most/
 obj-$(CONFIG_GREYBUS)		+= greybus/
 obj-$(CONFIG_BCM2835_VCHIQ)	+= vc04_services/
 obj-$(CONFIG_XIL_AXIS_FIFO)	+= axis-fifo/
-obj-$(CONFIG_FIELDBUS_DEV)	+= fieldbus/
 obj-$(CONFIG_GPIB)	 	+= gpib/
diff --git a/drivers/staging/fieldbus/Documentation/ABI/fieldbus-dev-cdev b/drivers/staging/fieldbus/Documentation/ABI/fieldbus-dev-cdev
deleted file mode 100644
index 45f631ea32a6..000000000000
--- a/drivers/staging/fieldbus/Documentation/ABI/fieldbus-dev-cdev
+++ /dev/null
@@ -1,31 +0,0 @@
-What:		/dev/fieldbus_devX
-Date:		December 2018
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		The cdev interface to drivers for Fieldbus Device Memory
-			(aka. Process Memory).
-
-		The following file operations are supported:
-
-		open(2)
-		Create an I/O context associated with the file descriptor.
-
-		read(2)
-		Read from Process Memory's "read area".
-		Clears POLLERR | POLLPRI from the file descriptor.
-
-		write(2)
-		Write to Process Memory's "write area".
-
-		poll(2), select(2), epoll_wait(2) etc.
-		When a "Process Memory Read Area Changed" event occurs,
-		POLLERR | POLLPRI will be set on the file descriptor.
-		Note that POLLIN | POLLOUT events are always set, because the
-		process memory area is always readable and writable.
-
-		close(2)
-		Free up the I/O context that was associated
-		with the file descriptor.
-
-Users:		TBD
diff --git a/drivers/staging/fieldbus/Documentation/ABI/sysfs-class-fieldbus-dev b/drivers/staging/fieldbus/Documentation/ABI/sysfs-class-fieldbus-dev
deleted file mode 100644
index 439f14d33c3b..000000000000
--- a/drivers/staging/fieldbus/Documentation/ABI/sysfs-class-fieldbus-dev
+++ /dev/null
@@ -1,62 +0,0 @@
-What:		/sys/class/fieldbus_dev/fieldbus_devX/card_name
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		Human-readable name of the Fieldbus Device.
-
-What:		/sys/class/fieldbus_dev/fieldbus_devX/fieldbus_type
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		The type of fieldbus implemented by this device.
-		Possible values:
-			'unknown'
-			'profinet'
-
-What:		/sys/class/fieldbus_dev/fieldbus_devX/fieldbus_id
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		The unique fieldbus id associated with this device.
-		The exact format of this id is fieldbus type dependent, e.g.
-		a mac address for profinet.
-
-What:		/sys/class/fieldbus_dev/fieldbus_devX/read_area_size
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		The size, in bytes, of the Process Memory read area.
-		Note: this area is accessible by reading from the associated
-			character device (/dev/fieldbus_devX).
-
-What:		/sys/class/fieldbus_dev/fieldbus_devX/write_area_size
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		The size, in bytes, of the Process Memory write area.
-		Note: this area is accessible by writing to the associated
-			character device (/dev/fieldbus_devX)
-
-What:		/sys/class/fieldbus_dev/fieldbus_devX/online
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		Whether the fieldbus is online or offline.
-		Possible values:
-			'1' meaning 'online'
-			'0' meaning 'offline'
-		Note: an uevent is generated when this property changes.
-
-What:		/sys/class/fieldbus_dev/fieldbus_devX/enabled
-KernelVersion:	5.1 (staging)
-Contact:	Sven Van Asbroeck <TheSven73@gmail.com>
-Description:
-		Whether the device is enabled (power on) or
-			disabled (power off).
-		Possible values:
-			'1' meaning enabled
-			'0' meaning disabled
-		Normally a r/o property, but optionally r/w:
-		Writing '1' enables the device (power on) with default
-			settings.
-		Writing '0' disables the card (power off).
diff --git a/drivers/staging/fieldbus/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt b/drivers/staging/fieldbus/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt
deleted file mode 100644
index f34a95611645..000000000000
--- a/drivers/staging/fieldbus/Documentation/devicetree/bindings/fieldbus/arcx,anybus-controller.txt
+++ /dev/null
@@ -1,71 +0,0 @@
-* Arcx Anybus-S controller
-
-This chip communicates with the SoC over a parallel bus. It is
-expected that its Device Tree node is specified as the child of a node
-corresponding to the parallel bus used for communication.
-
-Required properties:
---------------------
-
-  - compatible : The following chip-specific string:
-        "arcx,anybus-controller"
-
-  - reg : three areas:
-	index 0: bus memory area where the cpld registers are located.
-	index 1: bus memory area of the first  host's dual-port ram.
-	index 2: bus memory area of the second host's dual-port ram.
-
-  - reset-gpios : the GPIO pin connected to the reset line of the controller.
-
-  - interrupts : two interrupts:
-		index 0: interrupt connected to the first  host
-		index 1: interrupt connected to the second host
-	Generic interrupt client node bindings are described in
-	interrupt-controller/interrupts.txt
-
-Optional: use of subnodes
--------------------------
-
-The card connected to a host may need additional properties. These can be
-specified in subnodes to the controller node.
-
-The subnodes are identified by the standard 'reg' property. Which information
-exactly can be specified depends on the bindings for the function driver
-for the subnode.
-
-Required controller node properties when using subnodes:
-- #address-cells: should be one.
-- #size-cells: should be zero.
-
-Required subnode properties:
-- reg: Must contain the host index of the card this subnode describes:
-		<0>	for the first  host on the controller
-		<1>	for the second host on the controller
-	Note that only a single card can be plugged into a host, so the host
-	index uniquely describes the card location.
-
-Example of usage:
------------------
-
-This example places the bridge on top of the i.MX WEIM parallel bus, see:
-Documentation/devicetree/bindings/memory-controllers/fsl/fsl,imx-weim.yaml
-
-&weim {
-	controller@0,0 {
-		compatible = "arcx,anybus-controller";
-		reg = <0 0 0x100>, <0 0x400000 0x800>, <1 0x400000 0x800>;
-		reset-gpios = <&gpio5 2 GPIO_ACTIVE_HIGH>;
-		interrupt-parent = <&gpio1>;
-		interrupts = <1 IRQ_TYPE_LEVEL_LOW>, <5 IRQ_TYPE_LEVEL_LOW>;
-		/* fsl,weim-cs-timing is a i.MX WEIM bus specific property */
-		fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
-				0x00000000 0xa0000240 0x00000000>;
-		/* optional subnode for a card plugged into the first host */
-		#address-cells = <1>;
-		#size-cells = <0>;
-		card@0 {
-			reg = <0>;
-			/* card specific properties go here */
-		};
-	};
-};
diff --git a/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt b/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt
deleted file mode 100644
index 89fb8e14676f..000000000000
--- a/drivers/staging/fieldbus/Documentation/fieldbus_dev.txt
+++ /dev/null
@@ -1,66 +0,0 @@
-                       Fieldbus-Device Subsystem
-               ============================================
-
-Part 0 - What is a Fieldbus Device ?
-------------------------------------
-
-Fieldbus is the name of a family of industrial computer network protocols used
-for real-time distributed control, standardized as IEC 61158.
-
-A complex automated industrial system -- such as manufacturing assembly line --
-usually needs a distributed control system -- an organized hierarchy of
-controller systems -- to function. In this hierarchy, there is usually a
-Human Machine Interface (HMI) at the top, where an operator can monitor or
-operate the system. This is typically linked to a middle layer of programmable
-logic controllers (PLC) via a non-time-critical communications system
-(e.g. Ethernet). At the bottom of the control chain is the fieldbus that links
-the PLCs to the components that actually do the work, such as sensors,
-actuators, electric motors, console lights, switches, valves and contactors.
-
-(Source: Wikipedia)
-
-A "Fieldbus Device" is such an actuator, motor, console light, switch, ...
-controlled via the Fieldbus by a PLC aka "Fieldbus Controller".
-
-Communication between PLC and device typically happens via process data memory,
-separated into input and output areas. The Fieldbus then cyclically transfers
-the PLC's output area to the device's input area, and vice versa.
-
-Part I - Why do we need this subsystem?
----------------------------------------
-
-Fieldbus device (client) adapters are commercially available. They allow data
-exchange with a PLC aka "Fieldbus Controller" via process data memory.
-
-They are typically used when a Linux device wants to expose itself as an
-actuator, motor, console light, switch, etc. over the fieldbus.
-
-The purpose of this subsystem is:
-a) present a general, standardized, extensible API/ABI to userspace; and
-b) present a convenient interface to drivers.
-
-Part II - How can drivers use the subsystem?
---------------------------------------------
-
-Any driver that wants to register as a Fieldbus Device should allocate and
-populate a 'struct fieldbus_dev' (from include/linux/fieldbus_dev.h).
-Registration then happens by calling fieldbus_dev_register().
-
-Part III - How can userspace use the subsystem?
------------------------------------------------
-
-Fieldbus protocols and adapters are diverse and varied. However, they share
-a limited few common behaviours and properties. This allows us to define
-a simple interface consisting of a character device and a set of sysfs files:
-
-See:
-drivers/staging/fieldbus/Documentation/ABI/sysfs-class-fieldbus-dev
-drivers/staging/fieldbus/Documentation/ABI/fieldbus-dev-cdev
-
-Note that this simple interface does not provide a way to modify adapter
-configuration settings. It is therefore useful only for adapters that get their
-configuration settings some other way, e.g. non-volatile memory on the adapter,
-through the network, ...
-
-At a later phase, this simple interface can easily co-exist with a future
-(netlink-based ?) configuration settings interface.
diff --git a/drivers/staging/fieldbus/Kconfig b/drivers/staging/fieldbus/Kconfig
deleted file mode 100644
index b0b865acccfb..000000000000
--- a/drivers/staging/fieldbus/Kconfig
+++ /dev/null
@@ -1,19 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0-only
-menuconfig FIELDBUS_DEV
-	tristate "Fieldbus Device Support"
-	help
-	  Support for Fieldbus Device Adapters.
-
-	  Fieldbus device (client) adapters allow data exchange with a PLC aka.
-	  "Fieldbus Controller" over a fieldbus (Profinet, FLNet, etc.)
-
-	  They are typically used when a Linux device wants to expose itself
-	  as an actuator, motor, console light, switch, etc. over the fieldbus.
-
-	  This framework is designed to provide a generic interface to Fieldbus
-	  Devices from both the Linux Kernel and the userspace.
-
-	  If unsure, say no.
-
-source "drivers/staging/fieldbus/anybuss/Kconfig"
-
diff --git a/drivers/staging/fieldbus/Makefile b/drivers/staging/fieldbus/Makefile
deleted file mode 100644
index bdf645d41344..000000000000
--- a/drivers/staging/fieldbus/Makefile
+++ /dev/null
@@ -1,7 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0
-#
-# Makefile for fieldbus_dev drivers.
-#
-
-obj-$(CONFIG_FIELDBUS_DEV)	+= fieldbus_dev.o anybuss/
-fieldbus_dev-y			:= dev_core.o
diff --git a/drivers/staging/fieldbus/TODO b/drivers/staging/fieldbus/TODO
deleted file mode 100644
index 6d6626af4ec7..000000000000
--- a/drivers/staging/fieldbus/TODO
+++ /dev/null
@@ -1,5 +0,0 @@
-TODO:
--Get more people/drivers to use the Fieldbus userspace ABI. It requires
- verification/sign-off by multiple users.
-
-Contact: Sven Van Asbroeck <TheSven73@gmail.com>
diff --git a/drivers/staging/fieldbus/anybuss/Kconfig b/drivers/staging/fieldbus/anybuss/Kconfig
deleted file mode 100644
index 635a0a7b7dd2..000000000000
--- a/drivers/staging/fieldbus/anybuss/Kconfig
+++ /dev/null
@@ -1,41 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0-only
-config HMS_ANYBUSS_BUS
-	tristate "HMS Anybus-S Bus Support"
-	select REGMAP
-	depends on OF && FIELDBUS_DEV
-	help
-	  Driver for the HMS Industrial Networks Anybus-S bus.
-	  You can attach a single Anybus-S compatible card to it, which
-	  typically provides fieldbus and industrial ethernet
-	  functionality.
-
-if HMS_ANYBUSS_BUS
-
-config ARCX_ANYBUS_CONTROLLER
-	tristate "Arcx Anybus-S Controller"
-	depends on OF && GPIOLIB && HAS_IOMEM && REGULATOR
-	select REGMAP_MMIO
-	help
-	  Select this to get support for the Arcx Anybus controller.
-	  It connects to the SoC via a parallel memory bus, and
-	  embeds up to two Anybus-S buses (slots).
-	  There is also a CAN power readout, unrelated to the Anybus,
-	  modelled as a regulator.
-
-config HMS_PROFINET
-	tristate "HMS Profinet IRT Controller (Anybus-S)"
-	depends on FIELDBUS_DEV && HMS_ANYBUSS_BUS
-	help
-	  If you say yes here you get support for the HMS Industrial
-	  Networks Profinet IRT Controller.
-
-	  It will be registered with the kernel as a fieldbus_dev,
-	  so userspace can interact with it via the fieldbus_dev userspace
-	  interface(s).
-
-	  This driver can also be built as a module. If so, the module
-	  will be called hms-profinet.
-
-	  If unsure, say N.
-
-endif
diff --git a/drivers/staging/fieldbus/anybuss/Makefile b/drivers/staging/fieldbus/anybuss/Makefile
deleted file mode 100644
index 3ad3dcc6be56..000000000000
--- a/drivers/staging/fieldbus/anybuss/Makefile
+++ /dev/null
@@ -1,10 +0,0 @@
-# SPDX-License-Identifier: GPL-2.0
-#
-# Makefile for anybuss drivers.
-#
-
-obj-$(CONFIG_HMS_ANYBUSS_BUS)	+= anybuss_core.o
-anybuss_core-y			+= host.o
-
-obj-$(CONFIG_ARCX_ANYBUS_CONTROLLER) += arcx-anybus.o
-obj-$(CONFIG_HMS_PROFINET)	+= hms-profinet.o
diff --git a/drivers/staging/fieldbus/anybuss/anybuss-client.h b/drivers/staging/fieldbus/anybuss/anybuss-client.h
deleted file mode 100644
index c21c4bebfb84..000000000000
--- a/drivers/staging/fieldbus/anybuss/anybuss-client.h
+++ /dev/null
@@ -1,95 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Anybus-S client adapter definitions
- *
- * Copyright 2018 Arcx Inc
- */
-
-#ifndef __LINUX_ANYBUSS_CLIENT_H__
-#define __LINUX_ANYBUSS_CLIENT_H__
-
-#include <linux/device.h>
-#include <linux/types.h>
-#include <linux/poll.h>
-
-/* move to <linux/fieldbus_dev.h> when taking this out of staging */
-#include "../fieldbus_dev.h"
-
-struct anybuss_host;
-
-struct anybuss_client {
-	struct device dev;
-	struct anybuss_host *host;
-	__be16 anybus_id;
-	/*
-	 * these can be optionally set by the client to receive event
-	 * notifications from the host.
-	 */
-	void (*on_area_updated)(struct anybuss_client *client);
-	void (*on_online_changed)(struct anybuss_client *client, bool online);
-};
-
-struct anybuss_client_driver {
-	struct device_driver driver;
-	int (*probe)(struct anybuss_client *adev);
-	void (*remove)(struct anybuss_client *adev);
-	u16 anybus_id;
-};
-
-int anybuss_client_driver_register(struct anybuss_client_driver *drv);
-void anybuss_client_driver_unregister(struct anybuss_client_driver *drv);
-
-static inline struct anybuss_client *to_anybuss_client(struct device *dev)
-{
-	return container_of(dev, struct anybuss_client, dev);
-}
-
-#define to_anybuss_client_driver(__drv) container_of_const(__drv, struct anybuss_client_driver, driver)
-
-static inline void *
-anybuss_get_drvdata(const struct anybuss_client *client)
-{
-	return dev_get_drvdata(&client->dev);
-}
-
-static inline void
-anybuss_set_drvdata(struct anybuss_client *client, void *data)
-{
-	dev_set_drvdata(&client->dev, data);
-}
-
-int anybuss_set_power(struct anybuss_client *client, bool power_on);
-
-struct anybuss_memcfg {
-	u16 input_io;
-	u16 input_dpram;
-	u16 input_total;
-
-	u16 output_io;
-	u16 output_dpram;
-	u16 output_total;
-
-	enum fieldbus_dev_offl_mode offl_mode;
-};
-
-int anybuss_start_init(struct anybuss_client *client,
-		       const struct anybuss_memcfg *cfg);
-int anybuss_finish_init(struct anybuss_client *client);
-int anybuss_read_fbctrl(struct anybuss_client *client, u16 addr,
-			void *buf, size_t count);
-int anybuss_send_msg(struct anybuss_client *client, u16 cmd_num,
-		     const void *buf, size_t count);
-int anybuss_send_ext(struct anybuss_client *client, u16 cmd_num,
-		     const void *buf, size_t count);
-int anybuss_recv_msg(struct anybuss_client *client, u16 cmd_num,
-		     void *buf, size_t count);
-
-/* these help clients make a struct file_operations */
-int anybuss_write_input(struct anybuss_client *client,
-			const char __user *buf, size_t size,
-				loff_t *offset);
-int anybuss_read_output(struct anybuss_client *client,
-			char __user *buf, size_t size,
-				loff_t *offset);
-
-#endif /* __LINUX_ANYBUSS_CLIENT_H__ */
diff --git a/drivers/staging/fieldbus/anybuss/anybuss-controller.h b/drivers/staging/fieldbus/anybuss/anybuss-controller.h
deleted file mode 100644
index 02fa0749043b..000000000000
--- a/drivers/staging/fieldbus/anybuss/anybuss-controller.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Anybus-S controller definitions
- *
- * Copyright 2018 Arcx Inc
- */
-
-#ifndef __LINUX_ANYBUSS_CONTROLLER_H__
-#define __LINUX_ANYBUSS_CONTROLLER_H__
-
-#include <linux/device.h>
-#include <linux/regmap.h>
-
-/*
- * To instantiate an Anybus-S host, a controller should provide the following:
- * - a reset function which resets the attached card;
- * - a regmap which provides access to the attached card's dpram;
- * - the irq of the attached card
- */
-/**
- * struct anybuss_ops - Controller resources to instantiate an Anybus-S host
- *
- * @reset:	asserts/deasserts the anybus card's reset line.
- * @regmap:	provides access to the card's dual-port RAM area.
- * @irq:	number of the interrupt connected to the card's interrupt line.
- * @host_idx:	for multi-host controllers, the host index:
- *		0 for the first host on the controller, 1 for the second, etc.
- */
-struct anybuss_ops {
-	void (*reset)(struct device *dev, bool assert);
-	struct regmap *regmap;
-	int irq;
-	int host_idx;
-};
-
-struct anybuss_host;
-
-struct anybuss_host * __must_check
-anybuss_host_common_probe(struct device *dev,
-			  const struct anybuss_ops *ops);
-void anybuss_host_common_remove(struct anybuss_host *host);
-
-struct anybuss_host * __must_check
-devm_anybuss_host_common_probe(struct device *dev,
-			       const struct anybuss_ops *ops);
-
-#endif /* __LINUX_ANYBUSS_CONTROLLER_H__ */
diff --git a/drivers/staging/fieldbus/anybuss/arcx-anybus.c b/drivers/staging/fieldbus/anybuss/arcx-anybus.c
deleted file mode 100644
index cda0d2cf84c5..000000000000
--- a/drivers/staging/fieldbus/anybuss/arcx-anybus.c
+++ /dev/null
@@ -1,379 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Arcx Anybus-S Controller driver
- *
- * Copyright (C) 2018 Arcx Inc
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/platform_device.h>
-#include <linux/gpio/consumer.h>
-#include <linux/io.h>
-#include <linux/of.h>
-#include <linux/delay.h>
-#include <linux/idr.h>
-#include <linux/mutex.h>
-#include <linux/regulator/driver.h>
-#include <linux/regulator/machine.h>
-#include <linux/regmap.h>
-
-/* move to <linux/anybuss-controller.h> when taking this out of staging */
-#include "anybuss-controller.h"
-
-#define CPLD_STATUS1		0x80
-#define CPLD_CONTROL		0x80
-#define CPLD_CONTROL_CRST	0x40
-#define CPLD_CONTROL_RST1	0x04
-#define CPLD_CONTROL_RST2	0x80
-#define CPLD_STATUS1_AB		0x02
-#define CPLD_STATUS1_CAN_POWER	0x01
-#define CPLD_DESIGN_LO		0x81
-#define CPLD_DESIGN_HI		0x82
-#define CPLD_CAP		0x83
-#define CPLD_CAP_COMPAT		0x01
-#define CPLD_CAP_SEP_RESETS	0x02
-
-struct controller_priv {
-	struct device *class_dev;
-	bool common_reset;
-	struct gpio_desc *reset_gpiod;
-	void __iomem *cpld_base;
-	struct mutex ctrl_lock; /* protects CONTROL register */
-	u8 control_reg;
-	char version[3];
-	u16 design_no;
-};
-
-static void do_reset(struct controller_priv *cd, u8 rst_bit, bool reset)
-{
-	mutex_lock(&cd->ctrl_lock);
-	/*
-	 * CPLD_CONTROL is write-only, so cache its value in
-	 * cd->control_reg
-	 */
-	if (reset)
-		cd->control_reg &= ~rst_bit;
-	else
-		cd->control_reg |= rst_bit;
-	writeb(cd->control_reg, cd->cpld_base + CPLD_CONTROL);
-	/*
-	 * h/w work-around:
-	 * the hardware is 'too fast', so a reset followed by an immediate
-	 * not-reset will _not_ change the anybus reset line in any way,
-	 * losing the reset. to prevent this from happening, introduce
-	 * a minimum reset duration.
-	 * Verified minimum safe duration required using a scope
-	 * on 14-June-2018: 100 us.
-	 */
-	if (reset)
-		usleep_range(100, 200);
-	mutex_unlock(&cd->ctrl_lock);
-}
-
-static int anybuss_reset(struct controller_priv *cd,
-			 unsigned long id, bool reset)
-{
-	if (id >= 2)
-		return -EINVAL;
-	if (cd->common_reset)
-		do_reset(cd, CPLD_CONTROL_CRST, reset);
-	else
-		do_reset(cd, id ? CPLD_CONTROL_RST2 : CPLD_CONTROL_RST1, reset);
-	return 0;
-}
-
-static void export_reset_0(struct device *dev, bool assert)
-{
-	struct controller_priv *cd = dev_get_drvdata(dev);
-
-	anybuss_reset(cd, 0, assert);
-}
-
-static void export_reset_1(struct device *dev, bool assert)
-{
-	struct controller_priv *cd = dev_get_drvdata(dev);
-
-	anybuss_reset(cd, 1, assert);
-}
-
-/*
- * parallel bus limitation:
- *
- * the anybus is 8-bit wide. we can't assume that the hardware will translate
- * word accesses on the parallel bus to multiple byte-accesses on the anybus.
- *
- * the imx WEIM bus does not provide this type of translation.
- *
- * to be safe, we will limit parallel bus accesses to a single byte
- * at a time for now.
- */
-
-static const struct regmap_config arcx_regmap_cfg = {
-	.reg_bits = 16,
-	.val_bits = 8,
-	.max_register = 0x7ff,
-	.use_single_read = true,
-	.use_single_write = true,
-	/*
-	 * single-byte parallel bus accesses are atomic, so don't
-	 * require any synchronization.
-	 */
-	.disable_locking = true,
-};
-
-static struct regmap *create_parallel_regmap(struct platform_device *pdev,
-					     int idx)
-{
-	void __iomem *base;
-	struct device *dev = &pdev->dev;
-
-	base = devm_platform_ioremap_resource(pdev, idx + 1);
-	if (IS_ERR(base))
-		return ERR_CAST(base);
-	return devm_regmap_init_mmio(dev, base, &arcx_regmap_cfg);
-}
-
-static struct anybuss_host *
-create_anybus_host(struct platform_device *pdev, int idx)
-{
-	struct anybuss_ops ops = {};
-
-	switch (idx) {
-	case 0:
-		ops.reset = export_reset_0;
-		break;
-	case 1:
-		ops.reset = export_reset_1;
-		break;
-	default:
-		return ERR_PTR(-EINVAL);
-	}
-	ops.host_idx = idx;
-	ops.regmap = create_parallel_regmap(pdev, idx);
-	if (IS_ERR(ops.regmap))
-		return ERR_CAST(ops.regmap);
-	ops.irq = platform_get_irq(pdev, idx);
-	if (ops.irq < 0)
-		return ERR_PTR(ops.irq);
-	return devm_anybuss_host_common_probe(&pdev->dev, &ops);
-}
-
-static ssize_t version_show(struct device *dev,
-			    struct device_attribute *attr, char *buf)
-{
-	struct controller_priv *cd = dev_get_drvdata(dev);
-
-	return sprintf(buf, "%s\n", cd->version);
-}
-static DEVICE_ATTR_RO(version);
-
-static ssize_t design_number_show(struct device *dev,
-				  struct device_attribute *attr, char *buf)
-{
-	struct controller_priv *cd = dev_get_drvdata(dev);
-
-	return sprintf(buf, "%d\n", cd->design_no);
-}
-static DEVICE_ATTR_RO(design_number);
-
-static struct attribute *controller_attributes[] = {
-	&dev_attr_version.attr,
-	&dev_attr_design_number.attr,
-	NULL,
-};
-
-static const struct attribute_group controller_attribute_group = {
-	.attrs = controller_attributes,
-};
-
-static const struct attribute_group *controller_attribute_groups[] = {
-	&controller_attribute_group,
-	NULL,
-};
-
-static void controller_device_release(struct device *dev)
-{
-	kfree(dev);
-}
-
-static int can_power_is_enabled(struct regulator_dev *rdev)
-{
-	struct controller_priv *cd = rdev_get_drvdata(rdev);
-
-	return !(readb(cd->cpld_base + CPLD_STATUS1) & CPLD_STATUS1_CAN_POWER);
-}
-
-static const struct regulator_ops can_power_ops = {
-	.is_enabled = can_power_is_enabled,
-};
-
-static const struct regulator_desc can_power_desc = {
-	.name = "regulator-can-power",
-	.id = -1,
-	.type = REGULATOR_VOLTAGE,
-	.owner = THIS_MODULE,
-	.ops = &can_power_ops,
-};
-
-static const struct class controller_class = {
-	.name = "arcx_anybus_controller",
-};
-
-static DEFINE_IDA(controller_index_ida);
-
-static int controller_probe(struct platform_device *pdev)
-{
-	struct controller_priv *cd;
-	struct device *dev = &pdev->dev;
-	struct regulator_config config = { };
-	struct regulator_dev *regulator;
-	int err, id;
-	struct anybuss_host *host;
-	u8 status1, cap;
-
-	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
-	if (!cd)
-		return -ENOMEM;
-	dev_set_drvdata(dev, cd);
-	mutex_init(&cd->ctrl_lock);
-	cd->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
-	if (IS_ERR(cd->reset_gpiod))
-		return PTR_ERR(cd->reset_gpiod);
-
-	/* CPLD control memory, sits at index 0 */
-	cd->cpld_base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(cd->cpld_base)) {
-		dev_err(dev,
-			"failed to map cpld base address\n");
-		err = PTR_ERR(cd->cpld_base);
-		goto out_reset;
-	}
-
-	/* identify cpld */
-	status1 = readb(cd->cpld_base + CPLD_STATUS1);
-	cd->design_no = (readb(cd->cpld_base + CPLD_DESIGN_HI) << 8) |
-				readb(cd->cpld_base + CPLD_DESIGN_LO);
-	snprintf(cd->version, sizeof(cd->version), "%c%d",
-		 'A' + ((status1 >> 5) & 0x7),
-		 (status1 >> 2) & 0x7);
-	dev_info(dev, "design number %d, revision %s\n",
-		 cd->design_no,
-		cd->version);
-	cap = readb(cd->cpld_base + CPLD_CAP);
-	if (!(cap & CPLD_CAP_COMPAT)) {
-		dev_err(dev, "unsupported controller [cap=0x%02X]", cap);
-		err = -ENODEV;
-		goto out_reset;
-	}
-
-	if (status1 & CPLD_STATUS1_AB) {
-		dev_info(dev, "has anybus-S slot(s)");
-		cd->common_reset = !(cap & CPLD_CAP_SEP_RESETS);
-		dev_info(dev, "supports %s", cd->common_reset ?
-			"a common reset" : "separate resets");
-		for (id = 0; id < 2; id++) {
-			host = create_anybus_host(pdev, id);
-			if (!IS_ERR(host))
-				continue;
-			err = PTR_ERR(host);
-			/* -ENODEV is fine, it just means no card detected */
-			if (err != -ENODEV)
-				goto out_reset;
-		}
-	}
-
-	id = ida_alloc(&controller_index_ida, GFP_KERNEL);
-	if (id < 0) {
-		err = id;
-		goto out_reset;
-	}
-	/* export can power readout as a regulator */
-	config.dev = dev;
-	config.driver_data = cd;
-	regulator = devm_regulator_register(dev, &can_power_desc, &config);
-	if (IS_ERR(regulator)) {
-		err = PTR_ERR(regulator);
-		goto out_ida;
-	}
-	/* make controller info visible to userspace */
-	cd->class_dev = kzalloc(sizeof(*cd->class_dev), GFP_KERNEL);
-	if (!cd->class_dev) {
-		err = -ENOMEM;
-		goto out_ida;
-	}
-	cd->class_dev->class = &controller_class;
-	cd->class_dev->groups = controller_attribute_groups;
-	cd->class_dev->parent = dev;
-	cd->class_dev->id = id;
-	cd->class_dev->release = controller_device_release;
-	dev_set_name(cd->class_dev, "%d", cd->class_dev->id);
-	dev_set_drvdata(cd->class_dev, cd);
-	err = device_register(cd->class_dev);
-	if (err)
-		goto out_dev;
-	return 0;
-out_dev:
-	put_device(cd->class_dev);
-out_ida:
-	ida_free(&controller_index_ida, id);
-out_reset:
-	gpiod_set_value_cansleep(cd->reset_gpiod, 1);
-	return err;
-}
-
-static void controller_remove(struct platform_device *pdev)
-{
-	struct controller_priv *cd = platform_get_drvdata(pdev);
-	int id = cd->class_dev->id;
-
-	device_unregister(cd->class_dev);
-	ida_free(&controller_index_ida, id);
-	gpiod_set_value_cansleep(cd->reset_gpiod, 1);
-}
-
-static const struct of_device_id controller_of_match[] = {
-	{ .compatible = "arcx,anybus-controller" },
-	{ }
-};
-
-MODULE_DEVICE_TABLE(of, controller_of_match);
-
-static struct platform_driver controller_driver = {
-	.probe = controller_probe,
-	.remove = controller_remove,
-	.driver		= {
-		.name   = "arcx-anybus-controller",
-		.of_match_table	= controller_of_match,
-	},
-};
-
-static int __init controller_init(void)
-{
-	int err;
-
-	err = class_register(&controller_class);
-	if (err)
-		return err;
-	err = platform_driver_register(&controller_driver);
-	if (err)
-		class_unregister(&controller_class);
-
-	return err;
-}
-
-static void __exit controller_exit(void)
-{
-	platform_driver_unregister(&controller_driver);
-	class_unregister(&controller_class);
-	ida_destroy(&controller_index_ida);
-}
-
-module_init(controller_init);
-module_exit(controller_exit);
-
-MODULE_DESCRIPTION("Arcx Anybus-S Controller driver");
-MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/fieldbus/anybuss/hms-profinet.c b/drivers/staging/fieldbus/anybuss/hms-profinet.c
deleted file mode 100644
index e691736a53f1..000000000000
--- a/drivers/staging/fieldbus/anybuss/hms-profinet.c
+++ /dev/null
@@ -1,224 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * HMS Profinet Client Driver
- *
- * Copyright (C) 2018 Arcx Inc
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-
-/* move to <linux/fieldbus_dev.h> when taking this out of staging */
-#include "../fieldbus_dev.h"
-
-/* move to <linux/anybuss-client.h> when taking this out of staging */
-#include "anybuss-client.h"
-
-#define PROFI_DPRAM_SIZE	512
-
-/*
- * ---------------------------------------------------------------
- * Anybus Profinet mailbox messages - definitions
- * ---------------------------------------------------------------
- * note that we're depending on the layout of these structures being
- * exactly as advertised.
- */
-
-struct msg_mac_addr {
-	u8 addr[6];
-};
-
-struct profi_priv {
-	struct fieldbus_dev fbdev;
-	struct anybuss_client *client;
-	struct mutex enable_lock; /* serializes card enable */
-	bool power_on;
-};
-
-static ssize_t
-profi_read_area(struct fieldbus_dev *fbdev, char __user *buf, size_t size,
-		loff_t *offset)
-{
-	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
-
-	return anybuss_read_output(priv->client, buf, size, offset);
-}
-
-static ssize_t
-profi_write_area(struct fieldbus_dev *fbdev, const char __user *buf,
-		 size_t size, loff_t *offset)
-{
-	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
-
-	return anybuss_write_input(priv->client, buf, size, offset);
-}
-
-static int profi_id_get(struct fieldbus_dev *fbdev, char *buf,
-			size_t max_size)
-{
-	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
-	struct msg_mac_addr response;
-	int ret;
-
-	ret = anybuss_recv_msg(priv->client, 0x0010, &response,
-			       sizeof(response));
-	if (ret < 0)
-		return ret;
-	return snprintf(buf, max_size, "%pM\n", response.addr);
-}
-
-static bool profi_enable_get(struct fieldbus_dev *fbdev)
-{
-	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
-	bool power_on;
-
-	mutex_lock(&priv->enable_lock);
-	power_on = priv->power_on;
-	mutex_unlock(&priv->enable_lock);
-
-	return power_on;
-}
-
-static int __profi_enable(struct profi_priv *priv)
-{
-	int ret;
-	struct anybuss_client *client = priv->client;
-	/* Initialization Sequence, Generic Anybus Mode */
-	const struct anybuss_memcfg mem_cfg = {
-		.input_io = 220,
-		.input_dpram = PROFI_DPRAM_SIZE,
-		.input_total = PROFI_DPRAM_SIZE,
-		.output_io = 220,
-		.output_dpram = PROFI_DPRAM_SIZE,
-		.output_total = PROFI_DPRAM_SIZE,
-		.offl_mode = FIELDBUS_DEV_OFFL_MODE_CLEAR,
-	};
-
-	/*
-	 * switch anybus off then on, this ensures we can do a complete
-	 * configuration cycle in case anybus was already on.
-	 */
-	anybuss_set_power(client, false);
-	ret = anybuss_set_power(client, true);
-	if (ret)
-		goto err;
-	ret = anybuss_start_init(client, &mem_cfg);
-	if (ret)
-		goto err;
-	ret = anybuss_finish_init(client);
-	if (ret)
-		goto err;
-	priv->power_on = true;
-	return 0;
-
-err:
-	anybuss_set_power(client, false);
-	priv->power_on = false;
-	return ret;
-}
-
-static int __profi_disable(struct profi_priv *priv)
-{
-	struct anybuss_client *client = priv->client;
-
-	anybuss_set_power(client, false);
-	priv->power_on = false;
-	return 0;
-}
-
-static int profi_simple_enable(struct fieldbus_dev *fbdev, bool enable)
-{
-	int ret;
-	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
-
-	mutex_lock(&priv->enable_lock);
-	if (enable)
-		ret = __profi_enable(priv);
-	else
-		ret = __profi_disable(priv);
-	mutex_unlock(&priv->enable_lock);
-
-	return ret;
-}
-
-static void profi_on_area_updated(struct anybuss_client *client)
-{
-	struct profi_priv *priv = anybuss_get_drvdata(client);
-
-	fieldbus_dev_area_updated(&priv->fbdev);
-}
-
-static void profi_on_online_changed(struct anybuss_client *client, bool online)
-{
-	struct profi_priv *priv = anybuss_get_drvdata(client);
-
-	fieldbus_dev_online_changed(&priv->fbdev, online);
-}
-
-static int profinet_probe(struct anybuss_client *client)
-{
-	struct profi_priv *priv;
-	struct device *dev = &client->dev;
-	int err;
-
-	client->on_area_updated = profi_on_area_updated;
-	client->on_online_changed = profi_on_online_changed;
-	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
-		return -ENOMEM;
-	mutex_init(&priv->enable_lock);
-	priv->client = client;
-	priv->fbdev.read_area_sz = PROFI_DPRAM_SIZE;
-	priv->fbdev.write_area_sz = PROFI_DPRAM_SIZE;
-	priv->fbdev.card_name = "HMS Profinet IRT (Anybus-S)";
-	priv->fbdev.fieldbus_type = FIELDBUS_DEV_TYPE_PROFINET;
-	priv->fbdev.read_area = profi_read_area;
-	priv->fbdev.write_area = profi_write_area;
-	priv->fbdev.fieldbus_id_get = profi_id_get;
-	priv->fbdev.enable_get = profi_enable_get;
-	priv->fbdev.simple_enable_set = profi_simple_enable;
-	priv->fbdev.parent = dev;
-	err = fieldbus_dev_register(&priv->fbdev);
-	if (err < 0)
-		return err;
-	dev_info(dev, "card detected, registered as %s",
-		 dev_name(priv->fbdev.dev));
-	anybuss_set_drvdata(client, priv);
-
-	return 0;
-}
-
-static void profinet_remove(struct anybuss_client *client)
-{
-	struct profi_priv *priv = anybuss_get_drvdata(client);
-
-	fieldbus_dev_unregister(&priv->fbdev);
-}
-
-static struct anybuss_client_driver profinet_driver = {
-	.probe = profinet_probe,
-	.remove = profinet_remove,
-	.driver		= {
-		.name   = "hms-profinet",
-		.owner	= THIS_MODULE,
-	},
-	.anybus_id = 0x0089,
-};
-
-static int __init profinet_init(void)
-{
-	return anybuss_client_driver_register(&profinet_driver);
-}
-module_init(profinet_init);
-
-static void __exit profinet_exit(void)
-{
-	return anybuss_client_driver_unregister(&profinet_driver);
-}
-module_exit(profinet_exit);
-
-MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
-MODULE_DESCRIPTION("HMS Profinet IRT Driver (Anybus-S)");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/fieldbus/anybuss/host.c b/drivers/staging/fieldbus/anybuss/host.c
deleted file mode 100644
index 4f2b2fce92ee..000000000000
--- a/drivers/staging/fieldbus/anybuss/host.c
+++ /dev/null
@@ -1,1452 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * HMS Anybus-S Host Driver
- *
- * Copyright (C) 2018 Arcx Inc
- */
-
-/*
- * Architecture Overview
- * =====================
- * This driver (running on the CPU/SoC) and the Anybus-S card communicate
- * by reading and writing data to/from the Anybus-S Dual-Port RAM (dpram).
- * This is memory connected to both the SoC and Anybus-S card, which both sides
- * can access freely and concurrently.
- *
- * Synchronization happens by means of two registers located in the dpram:
- * IND_AB: written exclusively by the Anybus card; and
- * IND_AP: written exclusively by this driver.
- *
- * Communication happens using one of the following mechanisms:
- * 1. reserve, read/write, release dpram memory areas:
- *	using an IND_AB/IND_AP protocol, the driver is able to reserve certain
- *	memory areas. no dpram memory can be read or written except if reserved.
- *	(with a few limited exceptions)
- * 2. send and receive data structures via a shared mailbox:
- *	using an IND_AB/IND_AP protocol, the driver and Anybus card are able to
- *	exchange commands and responses using a shared mailbox.
- * 3. receive software interrupts:
- *	using an IND_AB/IND_AP protocol, the Anybus card is able to notify the
- *	driver of certain events such as: bus online/offline, data available.
- *	note that software interrupt event bits are located in a memory area
- *	which must be reserved before it can be accessed.
- *
- * The manual[1] is silent on whether these mechanisms can happen concurrently,
- * or how they should be synchronized. However, section 13 (Driver Example)
- * provides the following suggestion for developing a driver:
- * a) an interrupt handler which updates global variables;
- * b) a continuously-running task handling area requests (1 above)
- * c) a continuously-running task handling mailbox requests (2 above)
- * The example conspicuously leaves out software interrupts (3 above), which
- * is the thorniest issue to get right (see below).
- *
- * The naive, straightforward way to implement this would be:
- * - create an isr which updates shared variables;
- * - create a work_struct which handles software interrupts on a queue;
- * - create a function which does reserve/update/unlock in a loop;
- * - create a function which does mailbox send/receive in a loop;
- * - call the above functions from the driver's read/write/ioctl;
- * - synchronize using mutexes/spinlocks:
- *	+ only one area request at a time
- *	+ only one mailbox request at a time
- *	+ protect AB_IND, AB_IND against data hazards (e.g. read-after-write)
- *
- * Unfortunately, the presence of the software interrupt causes subtle yet
- * considerable synchronization issues; especially problematic is the
- * requirement to reserve/release the area which contains the status bits.
- *
- * The driver architecture presented here sidesteps these synchronization issues
- * by accessing the dpram from a single kernel thread only. User-space throws
- * "tasks" (i.e. 1, 2 above) into a task queue, waits for their completion,
- * and the kernel thread runs them to completion.
- *
- * Each task has a task_function, which is called/run by the queue thread.
- * That function communicates with the Anybus card, and returns either
- * 0 (OK), a negative error code (error), or -EINPROGRESS (waiting).
- * On OK or error, the queue thread completes and dequeues the task,
- * which also releases the user space thread which may still be waiting for it.
- * On -EINPROGRESS (waiting), the queue thread will leave the task on the queue,
- * and revisit (call again) whenever an interrupt event comes in.
- *
- * Each task has a state machine, which is run by calling its task_function.
- * It ensures that the task will go through its various stages over time,
- * returning -EINPROGRESS if it wants to wait for an event to happen.
- *
- * Note that according to the manual's driver example, the following operations
- * may run independent of each other:
- * - area reserve/read/write/release	(point 1 above)
- * - mailbox operations			(point 2 above)
- * - switching power on/off
- *
- * To allow them to run independently, each operation class gets its own queue.
- *
- * Userspace processes A, B, C, D post tasks to the appropriate queue,
- * and wait for task completion:
- *
- *	process A	B	C	D
- *		|	|	|	|
- *		v	v	v	v
- *	|<-----	========================================
- *	|		|	   |		|
- *	|		v	   v		v-------<-------+
- *	|	+--------------------------------------+	|
- *	|	| power q     | mbox q    | area q     |	|
- *	|	|------------|------------|------------|	|
- *	|	| task       | task       | task       |	|
- *	|	| task       | task       | task       |	|
- *	|	| task wait  | task wait  | task wait  |	|
- *	|	+--------------------------------------+	|
- *	|		^	   ^		^		|
- *	|		|	   |		|		^
- *	|	+--------------------------------------+	|
- *	|	|	     queue thread	       |	|
- *	|	|--------------------------------------|	|
- *	|	| single-threaded:		       |	|
- *	|	| loop:				       |	|
- *	v	|   for each queue:		       |	|
- *	|	|     run task state machine	       |	|
- *	|	|     if task waiting:		       |	|
- *	|	|       leave on queue		       |	|
- *	|	|     if task done:		       |	|
- *	|	|       complete task, remove from q   |	|
- *	|	|   if software irq event bits set:    |	|
- *	|	|     notify userspace		       |	|
- *	|	|     post clear event bits task------>|>-------+
- *	|	|   wait for IND_AB changed event OR   |
- *	|	|            task added event	  OR   |
- *	|	|	     timeout		       |
- *	|	| end loop			       |
- *	|	+--------------------------------------+
- *	|	+		wake up		       +
- *	|	+--------------------------------------+
- *	|		^			^
- *	|		|			|
- *	+-------->-------			|
- *						|
- *		+--------------------------------------+
- *		|	interrupt service routine      |
- *		|--------------------------------------|
- *		| wake up queue thread on IND_AB change|
- *		+--------------------------------------+
- *
- * Note that the Anybus interrupt is dual-purpose:
- * - after a reset, triggered when the card becomes ready;
- * - during normal operation, triggered when AB_IND changes.
- * This is why the interrupt service routine doesn't just wake up the
- * queue thread, but also completes the card_boot completion.
- *
- * [1] https://www.anybus.com/docs/librariesprovider7/default-document-library/
- *	manuals-design-guides/hms-hmsi-27-275.pdf
- */
-
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/interrupt.h>
-#include <linux/atomic.h>
-#include <linux/kthread.h>
-#include <linux/kfifo.h>
-#include <linux/spinlock.h>
-#include <linux/uaccess.h>
-#include <linux/regmap.h>
-#include <linux/of.h>
-#include <linux/random.h>
-#include <linux/kref.h>
-#include <linux/of_address.h>
-
-/* move to <linux/anybuss-*.h> when taking this out of staging */
-#include "anybuss-client.h"
-#include "anybuss-controller.h"
-
-#define DPRAM_SIZE		0x800
-#define MAX_MBOX_MSG_SZ		0x0FF
-#define TIMEOUT			(HZ * 2)
-#define MAX_DATA_AREA_SZ	0x200
-#define MAX_FBCTRL_AREA_SZ	0x1BE
-
-#define REG_BOOTLOADER_V	0x7C0
-#define REG_API_V		0x7C2
-#define REG_FIELDBUS_V		0x7C4
-#define REG_SERIAL_NO		0x7C6
-#define REG_FIELDBUS_TYPE	0x7CC
-#define REG_MODULE_SW_V		0x7CE
-#define REG_IND_AB		0x7FF
-#define REG_IND_AP		0x7FE
-#define REG_EVENT_CAUSE		0x7ED
-#define MBOX_IN_AREA		0x400
-#define MBOX_OUT_AREA		0x520
-#define DATA_IN_AREA		0x000
-#define DATA_OUT_AREA		0x200
-#define FBCTRL_AREA		0x640
-
-#define EVENT_CAUSE_DC          0x01
-#define EVENT_CAUSE_FBOF        0x02
-#define EVENT_CAUSE_FBON        0x04
-
-#define IND_AB_UPDATED		0x08
-#define IND_AX_MIN		0x80
-#define IND_AX_MOUT		0x40
-#define IND_AX_IN		0x04
-#define IND_AX_OUT		0x02
-#define IND_AX_FBCTRL		0x01
-#define IND_AP_LOCK		0x08
-#define IND_AP_ACTION		0x10
-#define IND_AX_EVNT		0x20
-#define IND_AP_ABITS		(IND_AX_IN | IND_AX_OUT | \
-					IND_AX_FBCTRL | \
-					IND_AP_ACTION | IND_AP_LOCK)
-
-#define INFO_TYPE_FB		0x0002
-#define INFO_TYPE_APP		0x0001
-#define INFO_COMMAND		0x4000
-
-#define OP_MODE_FBFC		0x0002
-#define OP_MODE_FBS		0x0004
-#define OP_MODE_CD		0x0200
-
-#define CMD_START_INIT		0x0001
-#define CMD_ANYBUS_INIT		0x0002
-#define CMD_END_INIT		0x0003
-
-/*
- * ---------------------------------------------------------------
- * Anybus mailbox messages - definitions
- * ---------------------------------------------------------------
- * note that we're depending on the layout of these structures being
- * exactly as advertised.
- */
-
-struct anybus_mbox_hdr {
-	__be16 id;
-	__be16 info;
-	__be16 cmd_num;
-	__be16 data_size;
-	__be16 frame_count;
-	__be16 frame_num;
-	__be16 offset_high;
-	__be16 offset_low;
-	__be16 extended[8];
-};
-
-struct msg_anybus_init {
-	__be16 input_io_len;
-	__be16 input_dpram_len;
-	__be16 input_total_len;
-	__be16 output_io_len;
-	__be16 output_dpram_len;
-	__be16 output_total_len;
-	__be16 op_mode;
-	__be16 notif_config;
-	__be16 wd_val;
-};
-
-/* ------------- ref counted tasks ------------- */
-
-struct ab_task;
-typedef int (*ab_task_fn_t)(struct anybuss_host *cd,
-					struct ab_task *t);
-typedef void (*ab_done_fn_t)(struct anybuss_host *cd);
-
-struct area_priv {
-	bool is_write;
-	u16 flags;
-	u16 addr;
-	size_t count;
-	u8 buf[MAX_DATA_AREA_SZ];
-};
-
-struct mbox_priv {
-	struct anybus_mbox_hdr hdr;
-	size_t msg_out_sz;
-	size_t msg_in_sz;
-	u8 msg[MAX_MBOX_MSG_SZ];
-};
-
-struct ab_task {
-	struct kmem_cache	*cache;
-	struct kref		refcount;
-	ab_task_fn_t		task_fn;
-	ab_done_fn_t		done_fn;
-	int			result;
-	struct completion	done;
-	unsigned long		start_jiffies;
-	union {
-		struct area_priv area_pd;
-		struct mbox_priv mbox_pd;
-	};
-};
-
-static struct ab_task *ab_task_create_get(struct kmem_cache *cache,
-					  ab_task_fn_t task_fn)
-{
-	struct ab_task *t;
-
-	t = kmem_cache_alloc(cache, GFP_KERNEL);
-	if (!t)
-		return NULL;
-	t->cache = cache;
-	kref_init(&t->refcount);
-	t->task_fn = task_fn;
-	t->done_fn = NULL;
-	t->result = 0;
-	init_completion(&t->done);
-	return t;
-}
-
-static void __ab_task_destroy(struct kref *refcount)
-{
-	struct ab_task *t = container_of(refcount, struct ab_task, refcount);
-	struct kmem_cache *cache = t->cache;
-
-	kmem_cache_free(cache, t);
-}
-
-static void ab_task_put(struct ab_task *t)
-{
-	kref_put(&t->refcount, __ab_task_destroy);
-}
-
-static struct ab_task *__ab_task_get(struct ab_task *t)
-{
-	kref_get(&t->refcount);
-	return t;
-}
-
-static void __ab_task_finish(struct ab_task *t, struct anybuss_host *cd)
-{
-	if (t->done_fn)
-		t->done_fn(cd);
-	complete(&t->done);
-}
-
-static void
-ab_task_dequeue_finish_put(struct kfifo *q, struct anybuss_host *cd)
-{
-	int ret;
-	struct ab_task *t;
-
-	ret = kfifo_out(q, &t, sizeof(t));
-	WARN_ON(!ret);
-	__ab_task_finish(t, cd);
-	ab_task_put(t);
-}
-
-static int
-ab_task_enqueue(struct ab_task *t, struct kfifo *q, spinlock_t *slock,
-		wait_queue_head_t *wq)
-{
-	int ret;
-
-	t->start_jiffies = jiffies;
-	__ab_task_get(t);
-	ret = kfifo_in_spinlocked(q, &t, sizeof(t), slock);
-	if (!ret) {
-		ab_task_put(t);
-		return -ENOMEM;
-	}
-	wake_up(wq);
-	return 0;
-}
-
-static int
-ab_task_enqueue_wait(struct ab_task *t, struct kfifo *q, spinlock_t *slock,
-		     wait_queue_head_t *wq)
-{
-	int ret;
-
-	ret = ab_task_enqueue(t, q, slock, wq);
-	if (ret)
-		return ret;
-	ret = wait_for_completion_interruptible(&t->done);
-	if (ret)
-		return ret;
-	return t->result;
-}
-
-/* ------------------------ anybus hardware ------------------------ */
-
-struct anybuss_host {
-	struct device *dev;
-	struct anybuss_client *client;
-	void (*reset)(struct device *dev, bool assert);
-	struct regmap *regmap;
-	int irq;
-	int host_idx;
-	struct task_struct *qthread;
-	wait_queue_head_t wq;
-	struct completion card_boot;
-	atomic_t ind_ab;
-	spinlock_t qlock; /* protects IN side of powerq, mboxq, areaq */
-	struct kmem_cache *qcache;
-	struct kfifo qs[3];
-	struct kfifo *powerq;
-	struct kfifo *mboxq;
-	struct kfifo *areaq;
-	bool power_on;
-	bool softint_pending;
-};
-
-static void reset_assert(struct anybuss_host *cd)
-{
-	cd->reset(cd->dev, true);
-}
-
-static void reset_deassert(struct anybuss_host *cd)
-{
-	cd->reset(cd->dev, false);
-}
-
-static int test_dpram(struct regmap *regmap)
-{
-	int i;
-	unsigned int val;
-
-	for (i = 0; i < DPRAM_SIZE; i++)
-		regmap_write(regmap, i, (u8)i);
-	for (i = 0; i < DPRAM_SIZE; i++) {
-		regmap_read(regmap, i, &val);
-		if ((u8)val != (u8)i)
-			return -EIO;
-	}
-	return 0;
-}
-
-static int read_ind_ab(struct regmap *regmap)
-{
-	unsigned long timeout = jiffies + HZ / 2;
-	unsigned int a, b, i = 0;
-
-	while (time_before_eq(jiffies, timeout)) {
-		regmap_read(regmap, REG_IND_AB, &a);
-		regmap_read(regmap, REG_IND_AB, &b);
-		if (likely(a == b))
-			return (int)a;
-		if (i < 10) {
-			cpu_relax();
-			i++;
-		} else {
-			usleep_range(500, 1000);
-		}
-	}
-	WARN(1, "IND_AB register not stable");
-	return -ETIMEDOUT;
-}
-
-static int write_ind_ap(struct regmap *regmap, unsigned int ind_ap)
-{
-	unsigned long timeout = jiffies + HZ / 2;
-	unsigned int v, i = 0;
-
-	while (time_before_eq(jiffies, timeout)) {
-		regmap_write(regmap, REG_IND_AP, ind_ap);
-		regmap_read(regmap, REG_IND_AP, &v);
-		if (likely(ind_ap == v))
-			return 0;
-		if (i < 10) {
-			cpu_relax();
-			i++;
-		} else {
-			usleep_range(500, 1000);
-		}
-	}
-	WARN(1, "IND_AP register not stable");
-	return -ETIMEDOUT;
-}
-
-static irqreturn_t irq_handler(int irq, void *data)
-{
-	struct anybuss_host *cd = data;
-	int ind_ab;
-
-	/*
-	 * irq handler needs exclusive access to the IND_AB register,
-	 * because the act of reading the register acks the interrupt.
-	 *
-	 * store the register value in cd->ind_ab (an atomic_t), so that the
-	 * queue thread is able to read it without causing an interrupt ack
-	 * side-effect (and without spuriously acking an interrupt).
-	 */
-	ind_ab = read_ind_ab(cd->regmap);
-	if (ind_ab < 0)
-		return IRQ_NONE;
-	atomic_set(&cd->ind_ab, ind_ab);
-	complete(&cd->card_boot);
-	wake_up(&cd->wq);
-	return IRQ_HANDLED;
-}
-
-/* ------------------------ power on/off tasks --------------------- */
-
-static int task_fn_power_off(struct anybuss_host *cd,
-			     struct ab_task *t)
-{
-	struct anybuss_client *client = cd->client;
-
-	if (!cd->power_on)
-		return 0;
-	disable_irq(cd->irq);
-	reset_assert(cd);
-	atomic_set(&cd->ind_ab, IND_AB_UPDATED);
-	if (client->on_online_changed)
-		client->on_online_changed(client, false);
-	cd->power_on = false;
-	return 0;
-}
-
-static int task_fn_power_on_2(struct anybuss_host *cd,
-			      struct ab_task *t)
-{
-	if (completion_done(&cd->card_boot)) {
-		cd->power_on = true;
-		return 0;
-	}
-	if (time_after(jiffies, t->start_jiffies + TIMEOUT)) {
-		disable_irq(cd->irq);
-		reset_assert(cd);
-		dev_err(cd->dev, "power on timed out");
-		return -ETIMEDOUT;
-	}
-	return -EINPROGRESS;
-}
-
-static int task_fn_power_on(struct anybuss_host *cd,
-			    struct ab_task *t)
-{
-	unsigned int dummy;
-
-	if (cd->power_on)
-		return 0;
-	/*
-	 * anybus docs: prevent false 'init done' interrupt by
-	 * doing a dummy read of IND_AB register while in reset.
-	 */
-	regmap_read(cd->regmap, REG_IND_AB, &dummy);
-	reinit_completion(&cd->card_boot);
-	enable_irq(cd->irq);
-	reset_deassert(cd);
-	t->task_fn = task_fn_power_on_2;
-	return -EINPROGRESS;
-}
-
-int anybuss_set_power(struct anybuss_client *client, bool power_on)
-{
-	struct anybuss_host *cd = client->host;
-	struct ab_task *t;
-	int err;
-
-	t = ab_task_create_get(cd->qcache, power_on ?
-				task_fn_power_on : task_fn_power_off);
-	if (!t)
-		return -ENOMEM;
-	err = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
-	ab_task_put(t);
-	return err;
-}
-EXPORT_SYMBOL_GPL(anybuss_set_power);
-
-/* ---------------------------- area tasks ------------------------ */
-
-static int task_fn_area_3(struct anybuss_host *cd, struct ab_task *t)
-{
-	struct area_priv *pd = &t->area_pd;
-
-	if (!cd->power_on)
-		return -EIO;
-	if (atomic_read(&cd->ind_ab) & pd->flags) {
-		/* area not released yet */
-		if (time_after(jiffies, t->start_jiffies + TIMEOUT))
-			return -ETIMEDOUT;
-		return -EINPROGRESS;
-	}
-	return 0;
-}
-
-static int task_fn_area_2(struct anybuss_host *cd, struct ab_task *t)
-{
-	struct area_priv *pd = &t->area_pd;
-	unsigned int ind_ap;
-	int ret;
-
-	if (!cd->power_on)
-		return -EIO;
-	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
-	if (!(atomic_read(&cd->ind_ab) & pd->flags)) {
-		/* we don't own the area yet */
-		if (time_after(jiffies, t->start_jiffies + TIMEOUT)) {
-			dev_warn(cd->dev, "timeout waiting for area");
-			dump_stack();
-			return -ETIMEDOUT;
-		}
-		return -EINPROGRESS;
-	}
-	/* we own the area, do what we're here to do */
-	if (pd->is_write)
-		regmap_bulk_write(cd->regmap, pd->addr, pd->buf,
-				  pd->count);
-	else
-		regmap_bulk_read(cd->regmap, pd->addr, pd->buf,
-				 pd->count);
-	/* ask to release the area, must use unlocked release */
-	ind_ap &= ~IND_AP_ABITS;
-	ind_ap |= pd->flags;
-	ret = write_ind_ap(cd->regmap, ind_ap);
-	if (ret)
-		return ret;
-	t->task_fn = task_fn_area_3;
-	return -EINPROGRESS;
-}
-
-static int task_fn_area(struct anybuss_host *cd, struct ab_task *t)
-{
-	struct area_priv *pd = &t->area_pd;
-	unsigned int ind_ap;
-	int ret;
-
-	if (!cd->power_on)
-		return -EIO;
-	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
-	/* ask to take the area */
-	ind_ap &= ~IND_AP_ABITS;
-	ind_ap |= pd->flags | IND_AP_ACTION | IND_AP_LOCK;
-	ret = write_ind_ap(cd->regmap, ind_ap);
-	if (ret)
-		return ret;
-	t->task_fn = task_fn_area_2;
-	return -EINPROGRESS;
-}
-
-static struct ab_task *
-create_area_reader(struct kmem_cache *qcache, u16 flags, u16 addr,
-		   size_t count)
-{
-	struct ab_task *t;
-	struct area_priv *ap;
-
-	t = ab_task_create_get(qcache, task_fn_area);
-	if (!t)
-		return NULL;
-	ap = &t->area_pd;
-	ap->flags = flags;
-	ap->addr = addr;
-	ap->is_write = false;
-	ap->count = count;
-	return t;
-}
-
-static struct ab_task *
-create_area_writer(struct kmem_cache *qcache, u16 flags, u16 addr,
-		   const void *buf, size_t count)
-{
-	struct ab_task *t;
-	struct area_priv *ap;
-
-	t = ab_task_create_get(qcache, task_fn_area);
-	if (!t)
-		return NULL;
-	ap = &t->area_pd;
-	ap->flags = flags;
-	ap->addr = addr;
-	ap->is_write = true;
-	ap->count = count;
-	memcpy(ap->buf, buf, count);
-	return t;
-}
-
-static struct ab_task *
-create_area_user_writer(struct kmem_cache *qcache, u16 flags, u16 addr,
-			const void __user *buf, size_t count)
-{
-	struct ab_task *t;
-	struct area_priv *ap;
-
-	t = ab_task_create_get(qcache, task_fn_area);
-	if (!t)
-		return ERR_PTR(-ENOMEM);
-	ap = &t->area_pd;
-	ap->flags = flags;
-	ap->addr = addr;
-	ap->is_write = true;
-	ap->count = count;
-	if (copy_from_user(ap->buf, buf, count)) {
-		ab_task_put(t);
-		return ERR_PTR(-EFAULT);
-	}
-	return t;
-}
-
-static bool area_range_ok(u16 addr, size_t count, u16 area_start,
-			  size_t area_sz)
-{
-	u16 area_end_ex = area_start + area_sz;
-	u16 addr_end_ex;
-
-	if (addr < area_start)
-		return false;
-	if (addr >= area_end_ex)
-		return false;
-	addr_end_ex = addr + count;
-	if (addr_end_ex > area_end_ex)
-		return false;
-	return true;
-}
-
-/* -------------------------- mailbox tasks ----------------------- */
-
-static int task_fn_mbox_2(struct anybuss_host *cd, struct ab_task *t)
-{
-	struct mbox_priv *pd = &t->mbox_pd;
-	unsigned int ind_ap;
-
-	if (!cd->power_on)
-		return -EIO;
-	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
-	if (((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_MOUT) == 0) {
-		/* output message not here */
-		if (time_after(jiffies, t->start_jiffies + TIMEOUT))
-			return -ETIMEDOUT;
-		return -EINPROGRESS;
-	}
-	/* grab the returned header and msg */
-	regmap_bulk_read(cd->regmap, MBOX_OUT_AREA, &pd->hdr,
-			 sizeof(pd->hdr));
-	regmap_bulk_read(cd->regmap, MBOX_OUT_AREA + sizeof(pd->hdr),
-			 pd->msg, pd->msg_in_sz);
-	/* tell anybus we've consumed the message */
-	ind_ap ^= IND_AX_MOUT;
-	return write_ind_ap(cd->regmap, ind_ap);
-}
-
-static int task_fn_mbox(struct anybuss_host *cd, struct ab_task *t)
-{
-	struct mbox_priv *pd = &t->mbox_pd;
-	unsigned int ind_ap;
-	int ret;
-
-	if (!cd->power_on)
-		return -EIO;
-	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
-	if ((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_MIN) {
-		/* mbox input area busy */
-		if (time_after(jiffies, t->start_jiffies + TIMEOUT))
-			return -ETIMEDOUT;
-		return -EINPROGRESS;
-	}
-	/* write the header and msg to input area */
-	regmap_bulk_write(cd->regmap, MBOX_IN_AREA, &pd->hdr,
-			  sizeof(pd->hdr));
-	regmap_bulk_write(cd->regmap, MBOX_IN_AREA + sizeof(pd->hdr),
-			  pd->msg, pd->msg_out_sz);
-	/* tell anybus we gave it a message */
-	ind_ap ^= IND_AX_MIN;
-	ret = write_ind_ap(cd->regmap, ind_ap);
-	if (ret)
-		return ret;
-	t->start_jiffies = jiffies;
-	t->task_fn = task_fn_mbox_2;
-	return -EINPROGRESS;
-}
-
-static void log_invalid_other(struct device *dev,
-			      struct anybus_mbox_hdr *hdr)
-{
-	size_t ext_offs = ARRAY_SIZE(hdr->extended) - 1;
-	u16 code = be16_to_cpu(hdr->extended[ext_offs]);
-
-	dev_err(dev, "   Invalid other: [0x%02X]", code);
-}
-
-static const char * const EMSGS[] = {
-	"Invalid Message ID",
-	"Invalid Message Type",
-	"Invalid Command",
-	"Invalid Data Size",
-	"Message Header Malformed (offset 008h)",
-	"Message Header Malformed (offset 00Ah)",
-	"Message Header Malformed (offset 00Ch - 00Dh)",
-	"Invalid Address",
-	"Invalid Response",
-	"Flash Config Error",
-};
-
-static int mbox_cmd_err(struct device *dev, struct mbox_priv *mpriv)
-{
-	int i;
-	u8 ecode;
-	struct anybus_mbox_hdr *hdr = &mpriv->hdr;
-	u16 info = be16_to_cpu(hdr->info);
-	u8 *phdr = (u8 *)hdr;
-	u8 *pmsg = mpriv->msg;
-
-	if (!(info & 0x8000))
-		return 0;
-	ecode = (info >> 8) & 0x0F;
-	dev_err(dev, "mailbox command failed:");
-	if (ecode == 0x0F)
-		log_invalid_other(dev, hdr);
-	else if (ecode < ARRAY_SIZE(EMSGS))
-		dev_err(dev, "   Error code: %s (0x%02X)",
-			EMSGS[ecode], ecode);
-	else
-		dev_err(dev, "   Error code: 0x%02X\n", ecode);
-	dev_err(dev, "Failed command:");
-	dev_err(dev, "Message Header:");
-	for (i = 0; i < sizeof(mpriv->hdr); i += 2)
-		dev_err(dev, "%02X%02X", phdr[i], phdr[i + 1]);
-	dev_err(dev, "Message Data:");
-	for (i = 0; i < mpriv->msg_in_sz; i += 2)
-		dev_err(dev, "%02X%02X", pmsg[i], pmsg[i + 1]);
-	dev_err(dev, "Stack dump:");
-	dump_stack();
-	return -EIO;
-}
-
-static int _anybus_mbox_cmd(struct anybuss_host *cd,
-			    u16 cmd_num, bool is_fb_cmd,
-				const void *msg_out, size_t msg_out_sz,
-				void *msg_in, size_t msg_in_sz,
-				const void *ext, size_t ext_sz)
-{
-	struct ab_task *t;
-	struct mbox_priv *pd;
-	struct anybus_mbox_hdr *h;
-	size_t msg_sz = max(msg_in_sz, msg_out_sz);
-	u16 info;
-	int err;
-
-	if (msg_sz > MAX_MBOX_MSG_SZ)
-		return -EINVAL;
-	if (ext && ext_sz > sizeof(h->extended))
-		return -EINVAL;
-	t = ab_task_create_get(cd->qcache, task_fn_mbox);
-	if (!t)
-		return -ENOMEM;
-	pd = &t->mbox_pd;
-	h = &pd->hdr;
-	info = is_fb_cmd ? INFO_TYPE_FB : INFO_TYPE_APP;
-	/*
-	 * prevent uninitialized memory in the header from being sent
-	 * across the anybus
-	 */
-	memset(h, 0, sizeof(*h));
-	h->info = cpu_to_be16(info | INFO_COMMAND);
-	h->cmd_num = cpu_to_be16(cmd_num);
-	h->data_size = cpu_to_be16(msg_out_sz);
-	h->frame_count = cpu_to_be16(1);
-	h->frame_num = cpu_to_be16(1);
-	h->offset_high = cpu_to_be16(0);
-	h->offset_low = cpu_to_be16(0);
-	if (ext)
-		memcpy(h->extended, ext, ext_sz);
-	memcpy(pd->msg, msg_out, msg_out_sz);
-	pd->msg_out_sz = msg_out_sz;
-	pd->msg_in_sz = msg_in_sz;
-	err = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
-	if (err)
-		goto out;
-	/*
-	 * mailbox mechanism worked ok, but maybe the mbox response
-	 * contains an error ?
-	 */
-	err = mbox_cmd_err(cd->dev, pd);
-	if (err)
-		goto out;
-	memcpy(msg_in, pd->msg, msg_in_sz);
-out:
-	ab_task_put(t);
-	return err;
-}
-
-/* ------------------------ anybus queues ------------------------ */
-
-static void process_q(struct anybuss_host *cd, struct kfifo *q)
-{
-	struct ab_task *t;
-	int ret;
-
-	ret = kfifo_out_peek(q, &t, sizeof(t));
-	if (!ret)
-		return;
-	t->result = t->task_fn(cd, t);
-	if (t->result != -EINPROGRESS)
-		ab_task_dequeue_finish_put(q, cd);
-}
-
-static bool qs_have_work(struct kfifo *qs, size_t num)
-{
-	size_t i;
-	struct ab_task *t;
-	int ret;
-
-	for (i = 0; i < num; i++, qs++) {
-		ret = kfifo_out_peek(qs, &t, sizeof(t));
-		if (ret && (t->result != -EINPROGRESS))
-			return true;
-	}
-	return false;
-}
-
-static void process_qs(struct anybuss_host *cd)
-{
-	size_t i;
-	struct kfifo *qs = cd->qs;
-	size_t nqs = ARRAY_SIZE(cd->qs);
-
-	for (i = 0; i < nqs; i++, qs++)
-		process_q(cd, qs);
-}
-
-static void softint_ack(struct anybuss_host *cd)
-{
-	unsigned int ind_ap;
-
-	cd->softint_pending = false;
-	if (!cd->power_on)
-		return;
-	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
-	ind_ap &= ~IND_AX_EVNT;
-	ind_ap |= atomic_read(&cd->ind_ab) & IND_AX_EVNT;
-	write_ind_ap(cd->regmap, ind_ap);
-}
-
-static void process_softint(struct anybuss_host *cd)
-{
-	struct anybuss_client *client = cd->client;
-	static const u8 zero;
-	int ret;
-	unsigned int ind_ap, ev;
-	struct ab_task *t;
-
-	if (!cd->power_on)
-		return;
-	if (cd->softint_pending)
-		return;
-	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
-	if (!((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_EVNT))
-		return;
-	/* process software interrupt */
-	regmap_read(cd->regmap, REG_EVENT_CAUSE, &ev);
-	if (ev & EVENT_CAUSE_FBON) {
-		if (client->on_online_changed)
-			client->on_online_changed(client, true);
-		dev_dbg(cd->dev, "Fieldbus ON");
-	}
-	if (ev & EVENT_CAUSE_FBOF) {
-		if (client->on_online_changed)
-			client->on_online_changed(client, false);
-		dev_dbg(cd->dev, "Fieldbus OFF");
-	}
-	if (ev & EVENT_CAUSE_DC) {
-		if (client->on_area_updated)
-			client->on_area_updated(client);
-		dev_dbg(cd->dev, "Fieldbus data changed");
-	}
-	/*
-	 * reset the event cause bits.
-	 * this must be done while owning the fbctrl area, so we'll
-	 * enqueue a task to do that.
-	 */
-	t = create_area_writer(cd->qcache, IND_AX_FBCTRL,
-			       REG_EVENT_CAUSE, &zero, sizeof(zero));
-	if (!t) {
-		ret = -ENOMEM;
-		goto out;
-	}
-	t->done_fn = softint_ack;
-	ret = ab_task_enqueue(t, cd->powerq, &cd->qlock, &cd->wq);
-	ab_task_put(t);
-	cd->softint_pending = true;
-out:
-	WARN_ON(ret);
-	if (ret)
-		softint_ack(cd);
-}
-
-static int qthread_fn(void *data)
-{
-	struct anybuss_host *cd = data;
-	struct kfifo *qs = cd->qs;
-	size_t nqs = ARRAY_SIZE(cd->qs);
-	unsigned int ind_ab;
-
-	/*
-	 * this kernel thread has exclusive access to the anybus's memory.
-	 * only exception: the IND_AB register, which is accessed exclusively
-	 * by the interrupt service routine (ISR). This thread must not touch
-	 * the IND_AB register, but it does require access to its value.
-	 *
-	 * the interrupt service routine stores the register's value in
-	 * cd->ind_ab (an atomic_t), where we may safely access it, with the
-	 * understanding that it can be modified by the ISR at any time.
-	 */
-
-	while (!kthread_should_stop()) {
-		/*
-		 * make a local copy of IND_AB, so we can go around the loop
-		 * again in case it changed while processing queues and softint.
-		 */
-		ind_ab = atomic_read(&cd->ind_ab);
-		process_qs(cd);
-		process_softint(cd);
-		wait_event_timeout(cd->wq,
-				   (atomic_read(&cd->ind_ab) != ind_ab) ||
-				qs_have_work(qs, nqs) ||
-				kthread_should_stop(),
-			HZ);
-		/*
-		 * time out so even 'stuck' tasks will run eventually,
-		 * and can time out.
-		 */
-	}
-
-	return 0;
-}
-
-/* ------------------------ anybus exports ------------------------ */
-
-int anybuss_start_init(struct anybuss_client *client,
-		       const struct anybuss_memcfg *cfg)
-{
-	int ret;
-	u16 op_mode;
-	struct anybuss_host *cd = client->host;
-	struct msg_anybus_init msg = {
-		.input_io_len = cpu_to_be16(cfg->input_io),
-		.input_dpram_len = cpu_to_be16(cfg->input_dpram),
-		.input_total_len = cpu_to_be16(cfg->input_total),
-		.output_io_len = cpu_to_be16(cfg->output_io),
-		.output_dpram_len = cpu_to_be16(cfg->output_dpram),
-		.output_total_len = cpu_to_be16(cfg->output_total),
-		.notif_config = cpu_to_be16(0x000F),
-		.wd_val = cpu_to_be16(0),
-	};
-
-	switch (cfg->offl_mode) {
-	case FIELDBUS_DEV_OFFL_MODE_CLEAR:
-		op_mode = 0;
-		break;
-	case FIELDBUS_DEV_OFFL_MODE_FREEZE:
-		op_mode = OP_MODE_FBFC;
-		break;
-	case FIELDBUS_DEV_OFFL_MODE_SET:
-		op_mode = OP_MODE_FBS;
-		break;
-	default:
-		return -EINVAL;
-	}
-	msg.op_mode = cpu_to_be16(op_mode | OP_MODE_CD);
-	ret = _anybus_mbox_cmd(cd, CMD_START_INIT, false, NULL, 0,
-			       NULL, 0, NULL, 0);
-	if (ret)
-		return ret;
-	return _anybus_mbox_cmd(cd, CMD_ANYBUS_INIT, false,
-			&msg, sizeof(msg), NULL, 0, NULL, 0);
-}
-EXPORT_SYMBOL_GPL(anybuss_start_init);
-
-int anybuss_finish_init(struct anybuss_client *client)
-{
-	struct anybuss_host *cd = client->host;
-
-	return _anybus_mbox_cmd(cd, CMD_END_INIT, false, NULL, 0,
-					NULL, 0, NULL, 0);
-}
-EXPORT_SYMBOL_GPL(anybuss_finish_init);
-
-int anybuss_read_fbctrl(struct anybuss_client *client, u16 addr,
-			void *buf, size_t count)
-{
-	struct anybuss_host *cd = client->host;
-	struct ab_task *t;
-	int ret;
-
-	if (count == 0)
-		return 0;
-	if (!area_range_ok(addr, count, FBCTRL_AREA,
-			   MAX_FBCTRL_AREA_SZ))
-		return -EFAULT;
-	t = create_area_reader(cd->qcache, IND_AX_FBCTRL, addr, count);
-	if (!t)
-		return -ENOMEM;
-	ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
-	if (ret)
-		goto out;
-	memcpy(buf, t->area_pd.buf, count);
-out:
-	ab_task_put(t);
-	return ret;
-}
-EXPORT_SYMBOL_GPL(anybuss_read_fbctrl);
-
-int anybuss_write_input(struct anybuss_client *client,
-			const char __user *buf, size_t size,
-				loff_t *offset)
-{
-	ssize_t len = min_t(loff_t, MAX_DATA_AREA_SZ - *offset, size);
-	struct anybuss_host *cd = client->host;
-	struct ab_task *t;
-	int ret;
-
-	if (len <= 0)
-		return 0;
-	t = create_area_user_writer(cd->qcache, IND_AX_IN,
-				    DATA_IN_AREA + *offset, buf, len);
-	if (IS_ERR(t))
-		return PTR_ERR(t);
-	ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
-	ab_task_put(t);
-	if (ret)
-		return ret;
-	/* success */
-	*offset += len;
-	return len;
-}
-EXPORT_SYMBOL_GPL(anybuss_write_input);
-
-int anybuss_read_output(struct anybuss_client *client,
-			char __user *buf, size_t size,
-				loff_t *offset)
-{
-	ssize_t len = min_t(loff_t, MAX_DATA_AREA_SZ - *offset, size);
-	struct anybuss_host *cd = client->host;
-	struct ab_task *t;
-	int ret;
-
-	if (len <= 0)
-		return 0;
-	t = create_area_reader(cd->qcache, IND_AX_OUT,
-			       DATA_OUT_AREA + *offset, len);
-	if (!t)
-		return -ENOMEM;
-	ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
-	if (ret)
-		goto out;
-	if (copy_to_user(buf, t->area_pd.buf, len))
-		ret = -EFAULT;
-out:
-	ab_task_put(t);
-	if (ret)
-		return ret;
-	/* success */
-	*offset += len;
-	return len;
-}
-EXPORT_SYMBOL_GPL(anybuss_read_output);
-
-int anybuss_send_msg(struct anybuss_client *client, u16 cmd_num,
-		     const void *buf, size_t count)
-{
-	struct anybuss_host *cd = client->host;
-
-	return _anybus_mbox_cmd(cd, cmd_num, true, buf, count, NULL, 0,
-					NULL, 0);
-}
-EXPORT_SYMBOL_GPL(anybuss_send_msg);
-
-int anybuss_send_ext(struct anybuss_client *client, u16 cmd_num,
-		     const void *buf, size_t count)
-{
-	struct anybuss_host *cd = client->host;
-
-	return _anybus_mbox_cmd(cd, cmd_num, true, NULL, 0, NULL, 0,
-					buf, count);
-}
-EXPORT_SYMBOL_GPL(anybuss_send_ext);
-
-int anybuss_recv_msg(struct anybuss_client *client, u16 cmd_num,
-		     void *buf, size_t count)
-{
-	struct anybuss_host *cd = client->host;
-
-	return _anybus_mbox_cmd(cd, cmd_num, true, NULL, 0, buf, count,
-					NULL, 0);
-}
-EXPORT_SYMBOL_GPL(anybuss_recv_msg);
-
-/* ------------------------ bus functions ------------------------ */
-
-static int anybus_bus_match(struct device *dev,
-			    const struct device_driver *drv)
-{
-	const struct anybuss_client_driver *adrv =
-		to_anybuss_client_driver(drv);
-	struct anybuss_client *adev =
-		to_anybuss_client(dev);
-
-	return adrv->anybus_id == be16_to_cpu(adev->anybus_id);
-}
-
-static int anybus_bus_probe(struct device *dev)
-{
-	struct anybuss_client_driver *adrv =
-		to_anybuss_client_driver(dev->driver);
-	struct anybuss_client *adev =
-		to_anybuss_client(dev);
-
-	return adrv->probe(adev);
-}
-
-static void anybus_bus_remove(struct device *dev)
-{
-	struct anybuss_client_driver *adrv =
-		to_anybuss_client_driver(dev->driver);
-
-	if (adrv->remove)
-		adrv->remove(to_anybuss_client(dev));
-}
-
-static const struct bus_type anybus_bus = {
-	.name		= "anybuss",
-	.match		= anybus_bus_match,
-	.probe		= anybus_bus_probe,
-	.remove		= anybus_bus_remove,
-};
-
-int anybuss_client_driver_register(struct anybuss_client_driver *drv)
-{
-	if (!drv->probe)
-		return -ENODEV;
-
-	drv->driver.bus = &anybus_bus;
-	return driver_register(&drv->driver);
-}
-EXPORT_SYMBOL_GPL(anybuss_client_driver_register);
-
-void anybuss_client_driver_unregister(struct anybuss_client_driver *drv)
-{
-	return driver_unregister(&drv->driver);
-}
-EXPORT_SYMBOL_GPL(anybuss_client_driver_unregister);
-
-static void client_device_release(struct device *dev)
-{
-	kfree(to_anybuss_client(dev));
-}
-
-static int taskq_alloc(struct device *dev, struct kfifo *q)
-{
-	void *buf;
-	size_t size = 64 * sizeof(struct ab_task *);
-
-	buf = devm_kzalloc(dev, size, GFP_KERNEL);
-	if (!buf)
-		return -EIO;
-	return kfifo_init(q, buf, size);
-}
-
-static int anybus_of_get_host_idx(struct device_node *np)
-{
-	const __be32 *host_idx;
-
-	host_idx = of_get_address(np, 0, NULL, NULL);
-	if (!host_idx)
-		return -ENOENT;
-	return __be32_to_cpu(*host_idx);
-}
-
-static struct device_node *
-anybus_of_find_child_device(struct device *dev, int host_idx)
-{
-	struct device_node *node;
-
-	if (!dev || !dev->of_node)
-		return NULL;
-	for_each_child_of_node(dev->of_node, node) {
-		if (anybus_of_get_host_idx(node) == host_idx)
-			return node;
-	}
-	return NULL;
-}
-
-struct anybuss_host * __must_check
-anybuss_host_common_probe(struct device *dev,
-			  const struct anybuss_ops *ops)
-{
-	int ret, i;
-	u8 val[4];
-	__be16 fieldbus_type;
-	struct anybuss_host *cd;
-
-	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
-	if (!cd)
-		return ERR_PTR(-ENOMEM);
-	cd->dev = dev;
-	cd->host_idx = ops->host_idx;
-	init_completion(&cd->card_boot);
-	init_waitqueue_head(&cd->wq);
-	for (i = 0; i < ARRAY_SIZE(cd->qs); i++) {
-		ret = taskq_alloc(dev, &cd->qs[i]);
-		if (ret)
-			return ERR_PTR(ret);
-	}
-	if (WARN_ON(ARRAY_SIZE(cd->qs) < 3))
-		return ERR_PTR(-EINVAL);
-	cd->powerq = &cd->qs[0];
-	cd->mboxq = &cd->qs[1];
-	cd->areaq = &cd->qs[2];
-	cd->reset = ops->reset;
-	if (!cd->reset)
-		return ERR_PTR(-EINVAL);
-	cd->regmap = ops->regmap;
-	if (!cd->regmap)
-		return ERR_PTR(-EINVAL);
-	spin_lock_init(&cd->qlock);
-	cd->qcache = kmem_cache_create(dev_name(dev),
-				       sizeof(struct ab_task), 0, 0, NULL);
-	if (!cd->qcache)
-		return ERR_PTR(-ENOMEM);
-	cd->irq = ops->irq;
-	if (cd->irq <= 0) {
-		ret = -EINVAL;
-		goto err_qcache;
-	}
-	/*
-	 * use a dpram test to check if a card is present, this is only
-	 * possible while in reset.
-	 */
-	reset_assert(cd);
-	if (test_dpram(cd->regmap)) {
-		dev_err(dev, "no Anybus-S card in slot");
-		ret = -ENODEV;
-		goto err_qcache;
-	}
-	ret = devm_request_threaded_irq(dev, cd->irq, NULL, irq_handler,
-					IRQF_ONESHOT, dev_name(dev), cd);
-	if (ret) {
-		dev_err(dev, "could not request irq");
-		goto err_qcache;
-	}
-	/*
-	 * startup sequence:
-	 *   a) perform dummy IND_AB read to prevent false 'init done' irq
-	 *     (already done by test_dpram() above)
-	 *   b) release reset
-	 *   c) wait for first interrupt
-	 *   d) interrupt came in: ready to go !
-	 */
-	reset_deassert(cd);
-	if (!wait_for_completion_timeout(&cd->card_boot, TIMEOUT)) {
-		ret = -ETIMEDOUT;
-		goto err_reset;
-	}
-	/*
-	 * according to the anybus docs, we're allowed to read these
-	 * without handshaking / reserving the area
-	 */
-	dev_info(dev, "Anybus-S card detected");
-	regmap_bulk_read(cd->regmap, REG_BOOTLOADER_V, val, 2);
-	dev_info(dev, "Bootloader version: %02X%02X",
-		 val[0], val[1]);
-	regmap_bulk_read(cd->regmap, REG_API_V, val, 2);
-	dev_info(dev, "API version: %02X%02X", val[0], val[1]);
-	regmap_bulk_read(cd->regmap, REG_FIELDBUS_V, val, 2);
-	dev_info(dev, "Fieldbus version: %02X%02X", val[0], val[1]);
-	regmap_bulk_read(cd->regmap, REG_SERIAL_NO, val, 4);
-	dev_info(dev, "Serial number: %02X%02X%02X%02X",
-		 val[0], val[1], val[2], val[3]);
-	add_device_randomness(&val, 4);
-	regmap_bulk_read(cd->regmap, REG_FIELDBUS_TYPE, &fieldbus_type,
-			 sizeof(fieldbus_type));
-	dev_info(dev, "Fieldbus type: %04X", be16_to_cpu(fieldbus_type));
-	regmap_bulk_read(cd->regmap, REG_MODULE_SW_V, val, 2);
-	dev_info(dev, "Module SW version: %02X%02X",
-		 val[0], val[1]);
-	/* put card back reset until a client driver releases it */
-	disable_irq(cd->irq);
-	reset_assert(cd);
-	atomic_set(&cd->ind_ab, IND_AB_UPDATED);
-	/* fire up the queue thread */
-	cd->qthread = kthread_run(qthread_fn, cd, dev_name(dev));
-	if (IS_ERR(cd->qthread)) {
-		dev_err(dev, "could not create kthread");
-		ret = PTR_ERR(cd->qthread);
-		goto err_reset;
-	}
-	/*
-	 * now advertise that we've detected a client device (card).
-	 * the bus infrastructure will match it to a client driver.
-	 */
-	cd->client = kzalloc(sizeof(*cd->client), GFP_KERNEL);
-	if (!cd->client) {
-		ret = -ENOMEM;
-		goto err_kthread;
-	}
-	cd->client->anybus_id = fieldbus_type;
-	cd->client->host = cd;
-	cd->client->dev.bus = &anybus_bus;
-	cd->client->dev.parent = dev;
-	cd->client->dev.release = client_device_release;
-	cd->client->dev.of_node =
-		anybus_of_find_child_device(dev, cd->host_idx);
-	dev_set_name(&cd->client->dev, "anybuss.card%d", cd->host_idx);
-	ret = device_register(&cd->client->dev);
-	if (ret)
-		goto err_device;
-	return cd;
-err_device:
-	put_device(&cd->client->dev);
-err_kthread:
-	kthread_stop(cd->qthread);
-err_reset:
-	reset_assert(cd);
-err_qcache:
-	kmem_cache_destroy(cd->qcache);
-	return ERR_PTR(ret);
-}
-EXPORT_SYMBOL_GPL(anybuss_host_common_probe);
-
-void anybuss_host_common_remove(struct anybuss_host *host)
-{
-	struct anybuss_host *cd = host;
-
-	device_unregister(&cd->client->dev);
-	kthread_stop(cd->qthread);
-	reset_assert(cd);
-	kmem_cache_destroy(cd->qcache);
-}
-EXPORT_SYMBOL_GPL(anybuss_host_common_remove);
-
-static void host_release(void *res)
-{
-	anybuss_host_common_remove(res);
-}
-
-struct anybuss_host * __must_check
-devm_anybuss_host_common_probe(struct device *dev,
-			       const struct anybuss_ops *ops)
-{
-	struct anybuss_host *host;
-	int ret;
-
-	host = anybuss_host_common_probe(dev, ops);
-	if (IS_ERR(host))
-		return host;
-
-	ret = devm_add_action_or_reset(dev, host_release, host);
-	if (ret)
-		return ERR_PTR(ret);
-
-	return host;
-}
-EXPORT_SYMBOL_GPL(devm_anybuss_host_common_probe);
-
-static int __init anybus_init(void)
-{
-	int ret;
-
-	ret = bus_register(&anybus_bus);
-	if (ret)
-		pr_err("could not register Anybus-S bus: %d\n", ret);
-	return ret;
-}
-module_init(anybus_init);
-
-static void __exit anybus_exit(void)
-{
-	bus_unregister(&anybus_bus);
-}
-module_exit(anybus_exit);
-
-MODULE_DESCRIPTION("HMS Anybus-S Host Driver");
-MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/fieldbus/dev_core.c b/drivers/staging/fieldbus/dev_core.c
deleted file mode 100644
index 0053ebd91442..000000000000
--- a/drivers/staging/fieldbus/dev_core.c
+++ /dev/null
@@ -1,344 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Fieldbus Device Driver Core
- *
- */
-
-#include <linux/mutex.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/idr.h>
-#include <linux/fs.h>
-#include <linux/slab.h>
-#include <linux/poll.h>
-
-/* move to <linux/fieldbus_dev.h> when taking this out of staging */
-#include "fieldbus_dev.h"
-
-/* Maximum number of fieldbus devices */
-#define MAX_FIELDBUSES		32
-
-/* the dev_t structure to store the dynamically allocated fieldbus devices */
-static dev_t fieldbus_devt;
-static DEFINE_IDA(fieldbus_ida);
-static DEFINE_MUTEX(fieldbus_mtx);
-
-static ssize_t online_show(struct device *dev, struct device_attribute *attr,
-			   char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-
-	return sysfs_emit(buf, "%d\n", !!fb->online);
-}
-static DEVICE_ATTR_RO(online);
-
-static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
-			    char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-
-	if (!fb->enable_get)
-		return -EINVAL;
-	return sysfs_emit(buf, "%d\n", !!fb->enable_get(fb));
-}
-
-static ssize_t enabled_store(struct device *dev, struct device_attribute *attr,
-			     const char *buf, size_t n)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-	bool value;
-	int ret;
-
-	if (!fb->simple_enable_set)
-		return -ENOTSUPP;
-	ret = kstrtobool(buf, &value);
-	if (ret)
-		return ret;
-	ret = fb->simple_enable_set(fb, value);
-	if (ret < 0)
-		return ret;
-	return n;
-}
-static DEVICE_ATTR_RW(enabled);
-
-static ssize_t card_name_show(struct device *dev, struct device_attribute *attr,
-			      char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-
-	/* card_name was provided by child driver. */
-	return sysfs_emit(buf, "%s\n", fb->card_name);
-}
-static DEVICE_ATTR_RO(card_name);
-
-static ssize_t read_area_size_show(struct device *dev,
-				   struct device_attribute *attr, char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-
-	return sysfs_emit(buf, "%zu\n", fb->read_area_sz);
-}
-static DEVICE_ATTR_RO(read_area_size);
-
-static ssize_t write_area_size_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-
-	return sysfs_emit(buf, "%zu\n", fb->write_area_sz);
-}
-static DEVICE_ATTR_RO(write_area_size);
-
-static ssize_t fieldbus_id_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-
-	return fb->fieldbus_id_get(fb, buf, PAGE_SIZE);
-}
-static DEVICE_ATTR_RO(fieldbus_id);
-
-static ssize_t fieldbus_type_show(struct device *dev,
-				  struct device_attribute *attr, char *buf)
-{
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-	const char *t;
-
-	switch (fb->fieldbus_type) {
-	case FIELDBUS_DEV_TYPE_PROFINET:
-		t = "profinet";
-		break;
-	default:
-		t = "unknown";
-		break;
-	}
-
-	return sysfs_emit(buf, "%s\n", t);
-}
-static DEVICE_ATTR_RO(fieldbus_type);
-
-static struct attribute *fieldbus_attrs[] = {
-	&dev_attr_enabled.attr,
-	&dev_attr_card_name.attr,
-	&dev_attr_fieldbus_id.attr,
-	&dev_attr_read_area_size.attr,
-	&dev_attr_write_area_size.attr,
-	&dev_attr_online.attr,
-	&dev_attr_fieldbus_type.attr,
-	NULL,
-};
-
-static umode_t fieldbus_is_visible(struct kobject *kobj, struct attribute *attr,
-				   int n)
-{
-	struct device *dev = kobj_to_dev(kobj);
-	struct fieldbus_dev *fb = dev_get_drvdata(dev);
-	umode_t mode = attr->mode;
-
-	if (attr == &dev_attr_enabled.attr) {
-		mode = 0;
-		if (fb->enable_get)
-			mode |= 0444;
-		if (fb->simple_enable_set)
-			mode |= 0200;
-	}
-
-	return mode;
-}
-
-static const struct attribute_group fieldbus_group = {
-	.attrs = fieldbus_attrs,
-	.is_visible = fieldbus_is_visible,
-};
-__ATTRIBUTE_GROUPS(fieldbus);
-
-static const struct class fieldbus_class = {
-	.name =		"fieldbus_dev",
-	.dev_groups =	fieldbus_groups,
-};
-
-struct fb_open_file {
-	struct fieldbus_dev *fbdev;
-	int dc_event;
-};
-
-static int fieldbus_open(struct inode *inode, struct file *filp)
-{
-	struct fb_open_file *of;
-	struct fieldbus_dev *fbdev = container_of(inode->i_cdev,
-						struct fieldbus_dev,
-						cdev);
-
-	of = kzalloc(sizeof(*of), GFP_KERNEL);
-	if (!of)
-		return -ENOMEM;
-	of->fbdev = fbdev;
-	filp->private_data = of;
-	return 0;
-}
-
-static int fieldbus_release(struct inode *node, struct file *filp)
-{
-	struct fb_open_file *of = filp->private_data;
-
-	kfree(of);
-	return 0;
-}
-
-static ssize_t fieldbus_read(struct file *filp, char __user *buf, size_t size,
-			     loff_t *offset)
-{
-	struct fb_open_file *of = filp->private_data;
-	struct fieldbus_dev *fbdev = of->fbdev;
-
-	of->dc_event = fbdev->dc_event;
-	return fbdev->read_area(fbdev, buf, size, offset);
-}
-
-static ssize_t fieldbus_write(struct file *filp, const char __user *buf,
-			      size_t size, loff_t *offset)
-{
-	struct fb_open_file *of = filp->private_data;
-	struct fieldbus_dev *fbdev = of->fbdev;
-
-	return fbdev->write_area(fbdev, buf, size, offset);
-}
-
-static __poll_t fieldbus_poll(struct file *filp, poll_table *wait)
-{
-	struct fb_open_file *of = filp->private_data;
-	struct fieldbus_dev *fbdev = of->fbdev;
-	__poll_t mask = EPOLLIN | EPOLLRDNORM | EPOLLOUT | EPOLLWRNORM;
-
-	poll_wait(filp, &fbdev->dc_wq, wait);
-	/* data changed ? */
-	if (fbdev->dc_event != of->dc_event)
-		mask |= EPOLLPRI | EPOLLERR;
-	return mask;
-}
-
-static const struct file_operations fieldbus_fops = {
-	.open		= fieldbus_open,
-	.release	= fieldbus_release,
-	.read		= fieldbus_read,
-	.write		= fieldbus_write,
-	.poll		= fieldbus_poll,
-	.llseek		= generic_file_llseek,
-	.owner		= THIS_MODULE,
-};
-
-void fieldbus_dev_area_updated(struct fieldbus_dev *fb)
-{
-	fb->dc_event++;
-	wake_up_all(&fb->dc_wq);
-}
-EXPORT_SYMBOL_GPL(fieldbus_dev_area_updated);
-
-void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online)
-{
-	fb->online = online;
-	kobject_uevent(&fb->dev->kobj, KOBJ_CHANGE);
-}
-EXPORT_SYMBOL_GPL(fieldbus_dev_online_changed);
-
-static void __fieldbus_dev_unregister(struct fieldbus_dev *fb)
-{
-	if (!fb)
-		return;
-	device_destroy(&fieldbus_class, fb->cdev.dev);
-	cdev_del(&fb->cdev);
-	ida_free(&fieldbus_ida, fb->id);
-}
-
-void fieldbus_dev_unregister(struct fieldbus_dev *fb)
-{
-	mutex_lock(&fieldbus_mtx);
-	__fieldbus_dev_unregister(fb);
-	mutex_unlock(&fieldbus_mtx);
-}
-EXPORT_SYMBOL_GPL(fieldbus_dev_unregister);
-
-static int __fieldbus_dev_register(struct fieldbus_dev *fb)
-{
-	dev_t devno;
-	int err;
-
-	if (!fb)
-		return -EINVAL;
-	if (!fb->read_area || !fb->write_area || !fb->fieldbus_id_get)
-		return -EINVAL;
-	fb->id = ida_alloc_max(&fieldbus_ida, MAX_FIELDBUSES - 1, GFP_KERNEL);
-	if (fb->id < 0)
-		return fb->id;
-	devno = MKDEV(MAJOR(fieldbus_devt), fb->id);
-	init_waitqueue_head(&fb->dc_wq);
-	cdev_init(&fb->cdev, &fieldbus_fops);
-	err = cdev_add(&fb->cdev, devno, 1);
-	if (err) {
-		pr_err("fieldbus_dev%d unable to add device %d:%d\n",
-		       fb->id, MAJOR(fieldbus_devt), fb->id);
-		goto err_cdev;
-	}
-	fb->dev = device_create(&fieldbus_class, fb->parent, devno, fb,
-				"fieldbus_dev%d", fb->id);
-	if (IS_ERR(fb->dev)) {
-		err = PTR_ERR(fb->dev);
-		goto err_dev_create;
-	}
-	return 0;
-
-err_dev_create:
-	cdev_del(&fb->cdev);
-err_cdev:
-	ida_free(&fieldbus_ida, fb->id);
-	return err;
-}
-
-int fieldbus_dev_register(struct fieldbus_dev *fb)
-{
-	int err;
-
-	mutex_lock(&fieldbus_mtx);
-	err = __fieldbus_dev_register(fb);
-	mutex_unlock(&fieldbus_mtx);
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(fieldbus_dev_register);
-
-static int __init fieldbus_init(void)
-{
-	int err;
-
-	err = class_register(&fieldbus_class);
-	if (err < 0) {
-		pr_err("fieldbus_dev: could not register class\n");
-		return err;
-	}
-	err = alloc_chrdev_region(&fieldbus_devt, 0,
-				  MAX_FIELDBUSES, "fieldbus_dev");
-	if (err < 0) {
-		pr_err("fieldbus_dev: unable to allocate char dev region\n");
-		goto err_alloc;
-	}
-	return 0;
-
-err_alloc:
-	class_unregister(&fieldbus_class);
-	return err;
-}
-
-static void __exit fieldbus_exit(void)
-{
-	unregister_chrdev_region(fieldbus_devt, MAX_FIELDBUSES);
-	class_unregister(&fieldbus_class);
-	ida_destroy(&fieldbus_ida);
-}
-
-subsys_initcall(fieldbus_init);
-module_exit(fieldbus_exit);
-
-MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>");
-MODULE_AUTHOR("Jonathan Stiles <jonathans@arcx.com>");
-MODULE_DESCRIPTION("Fieldbus Device Driver Core");
-MODULE_LICENSE("GPL v2");
diff --git a/drivers/staging/fieldbus/fieldbus_dev.h b/drivers/staging/fieldbus/fieldbus_dev.h
deleted file mode 100644
index 301dca3b8d71..000000000000
--- a/drivers/staging/fieldbus/fieldbus_dev.h
+++ /dev/null
@@ -1,114 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/*
- * Fieldbus Device Driver Core
- *
- */
-
-#ifndef __FIELDBUS_DEV_H
-#define __FIELDBUS_DEV_H
-
-#include <linux/cdev.h>
-#include <linux/wait.h>
-
-enum fieldbus_dev_type {
-	FIELDBUS_DEV_TYPE_UNKNOWN = 0,
-	FIELDBUS_DEV_TYPE_PROFINET,
-};
-
-enum fieldbus_dev_offl_mode {
-	FIELDBUS_DEV_OFFL_MODE_CLEAR = 0,
-	FIELDBUS_DEV_OFFL_MODE_FREEZE,
-	FIELDBUS_DEV_OFFL_MODE_SET
-};
-
-/**
- * struct fieldbus_dev - Fieldbus device
- * @read_area:		[DRIVER] function to read the process data area of the
- *				 device. same parameters/return values as
- *				 the read function in struct file_operations
- * @write_area:		[DRIVER] function to write to the process data area of
- *				 the device. same parameters/return values as
- *				 the write function in struct file_operations
- * @write_area_sz	[DRIVER] size of the writable process data area
- * @read_area_sz	[DRIVER] size of the readable process data area
- * @card_name		[DRIVER] name of the card, e.g. "ACME Inc. profinet"
- * @fieldbus_type	[DRIVER] fieldbus type of this device, e.g.
- *					FIELDBUS_DEV_TYPE_PROFINET
- * @enable_get		[DRIVER] function which returns true if the card
- *				 is enabled, false otherwise
- * @fieldbus_id_get	[DRIVER] function to retrieve the unique fieldbus id
- *				 by which this device can be identified;
- *				 return value follows the snprintf convention
- * @simple_enable_set	[DRIVER] (optional) function to enable the device
- *				 according to its default settings
- * @parent		[DRIVER] (optional) the device's parent device
- */
-struct fieldbus_dev {
-	ssize_t (*read_area)(struct fieldbus_dev *fbdev, char __user *buf,
-			     size_t size, loff_t *offset);
-	ssize_t (*write_area)(struct fieldbus_dev *fbdev,
-			      const char __user *buf, size_t size,
-			      loff_t *offset);
-	size_t write_area_sz, read_area_sz;
-	const char *card_name;
-	enum fieldbus_dev_type fieldbus_type;
-	bool (*enable_get)(struct fieldbus_dev *fbdev);
-	int (*fieldbus_id_get)(struct fieldbus_dev *fbdev, char *buf,
-			       size_t max_size);
-	int (*simple_enable_set)(struct fieldbus_dev *fbdev, bool enable);
-	struct device *parent;
-
-	/* private data */
-	int id;
-	struct cdev cdev;
-	struct device *dev;
-	int dc_event;
-	wait_queue_head_t dc_wq;
-	bool online;
-};
-
-#if IS_ENABLED(CONFIG_FIELDBUS_DEV)
-
-/**
- * fieldbus_dev_unregister()
- *	- unregister a previously registered fieldbus device
- * @fb:		Device structure previously registered
- **/
-void fieldbus_dev_unregister(struct fieldbus_dev *fb);
-
-/**
- * fieldbus_dev_register()
- *	- register a device with the fieldbus device subsystem
- * @fb:		Device structure filled by the device driver
- **/
-int __must_check fieldbus_dev_register(struct fieldbus_dev *fb);
-
-/**
- * fieldbus_dev_area_updated()
- *	- notify the subsystem that an external fieldbus controller updated
- *			the process data area
- * @fb:		Device structure
- **/
-void fieldbus_dev_area_updated(struct fieldbus_dev *fb);
-
-/**
- * fieldbus_dev_online_changed()
- *	- notify the subsystem that the fieldbus online status changed
- * @fb:		Device structure
- **/
-void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online);
-
-#else /* IS_ENABLED(CONFIG_FIELDBUS_DEV) */
-
-static inline void fieldbus_dev_unregister(struct fieldbus_dev *fb) {}
-static inline int __must_check fieldbus_dev_register(struct fieldbus_dev *fb)
-{
-	return -ENOTSUPP;
-}
-
-static inline void fieldbus_dev_area_updated(struct fieldbus_dev *fb) {}
-static inline void fieldbus_dev_online_changed(struct fieldbus_dev *fb,
-					       bool online) {}
-
-#endif /* IS_ENABLED(CONFIG_FIELDBUS_DEV) */
-#endif /* __FIELDBUS_DEV_H */
-- 
2.43.0

This is no longer part of any working product that I know of, so:

Acked-by: Sven Van Asbroeck <TheSven73@gmail.com>