7 files changed, 2283 insertions, 0 deletions

diff --git a/drivers/staging/fieldbus/anybuss/Kconfig b/drivers/staging/fieldbus/anybuss/Kconfig
new file mode 100644
index 000000000000..41f241c73826
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/Kconfig
@@ -0,0 +1,39 @@
+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
+	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
new file mode 100644
index 000000000000..3ad3dcc6be56
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/Makefile
@@ -0,0 +1,10 @@
+# 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
new file mode 100644
index 000000000000..0c4b6a1ffe10
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/anybuss-client.h
@@ -0,0 +1,102 @@
+/* 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>
+
+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);
+	int (*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);
+}
+
+static inline struct anybuss_client_driver *
+to_anybuss_client_driver(struct device_driver *drv)
+{
+	return container_of(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);
+
+enum anybuss_offl_mode {
+	AB_OFFL_MODE_CLEAR = 0,
+	AB_OFFL_MODE_FREEZE,
+	AB_OFFL_MODE_SET
+};
+
+struct anybuss_memcfg {
+	u16 input_io;
+	u16 input_dpram;
+	u16 input_total;
+
+	u16 output_io;
+	u16 output_dpram;
+	u16 output_total;
+
+	enum anybuss_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
new file mode 100644
index 000000000000..02fa0749043b
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/anybuss-controller.h
@@ -0,0 +1,47 @@
+/* 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
new file mode 100644
index 000000000000..a167fb68e355
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/arcx-anybus.c
@@ -0,0 +1,399 @@
+// 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 int read_reg_bus(void *context, unsigned int reg,
+			unsigned int *val)
+{
+	void __iomem *base = context;
+
+	*val = readb(base + reg);
+	return 0;
+}
+
+static int write_reg_bus(void *context, unsigned int reg,
+			 unsigned int val)
+{
+	void __iomem *base = context;
+
+	writeb(val, base + reg);
+	return 0;
+}
+
+static struct regmap *create_parallel_regmap(struct platform_device *pdev,
+					     int idx)
+{
+	struct regmap_config regmap_cfg = {
+		.reg_bits = 11,
+		.val_bits = 8,
+		/*
+		 * single-byte parallel bus accesses are atomic, so don't
+		 * require any synchronization.
+		 */
+		.disable_locking = true,
+		.reg_read = read_reg_bus,
+		.reg_write = write_reg_bus,
+	};
+	struct resource *res;
+	void __iomem *base;
+	struct device *dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, idx + 1);
+	if (resource_size(res) < (1 << regmap_cfg.reg_bits))
+		return ERR_PTR(-EINVAL);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return ERR_CAST(base);
+	return devm_regmap_init(dev, NULL, base, &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(-EINVAL);
+	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 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 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 struct class *controller_class;
+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 resource *res;
+	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 */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cd->cpld_base = devm_ioremap_resource(dev, res);
+	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_simple_get(&controller_index_ida, 0, 0, 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_reset;
+	}
+	/* 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_simple_remove(&controller_index_ida, id);
+out_reset:
+	gpiod_set_value_cansleep(cd->reset_gpiod, 1);
+	return err;
+}
+
+static int 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_simple_remove(&controller_index_ida, id);
+	gpiod_set_value_cansleep(cd->reset_gpiod, 1);
+	return 0;
+}
+
+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	= of_match_ptr(controller_of_match),
+	},
+};
+
+static int __init controller_init(void)
+{
+	int err;
+
+	controller_class = class_create(THIS_MODULE, "arcx_anybus_controller");
+	if (IS_ERR(controller_class))
+		return PTR_ERR(controller_class);
+	err = platform_driver_register(&controller_driver);
+	if (err)
+		class_destroy(controller_class);
+
+	return err;
+}
+
+static void __exit controller_exit(void)
+{
+	platform_driver_unregister(&controller_driver);
+	class_destroy(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
new file mode 100644
index 000000000000..5446843e35f4
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/hms-profinet.c
@@ -0,0 +1,228 @@
+// 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, "%02X:%02X:%02X:%02X:%02X:%02X\n",
+		response.addr[0], response.addr[1],
+		response.addr[2], response.addr[3],
+		response.addr[4], response.addr[5]);
+}
+
+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 = AB_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 int profinet_remove(struct anybuss_client *client)
+{
+	struct profi_priv *priv = anybuss_get_drvdata(client);
+
+	fieldbus_dev_unregister(&priv->fbdev);
+	return 0;
+}
+
+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
new file mode 100644
index 000000000000..f69dc4930457
--- /dev/null
+++ b/drivers/staging/fieldbus/anybuss/host.c
@@ -0,0 +1,1458 @@
+// 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 AB_OFFL_MODE_CLEAR:
+		op_mode = 0;
+		break;
+	case AB_OFFL_MODE_FREEZE:
+		op_mode = OP_MODE_FBFC;
+		break;
+	case AB_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,
+			    struct device_driver *drv)
+{
+	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);
+
+	if (!adrv->probe)
+		return -ENODEV;
+	return adrv->probe(adev);
+}
+
+static int anybus_bus_remove(struct device *dev)
+{
+	struct anybuss_client_driver *adrv =
+		to_anybuss_client_driver(dev->driver);
+
+	if (adrv->remove)
+		return adrv->remove(to_anybuss_client(dev));
+	return 0;
+}
+
+static 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)
+{
+	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:
+	 *   perform dummy IND_AB read to prevent false 'init done' irq
+	 *     (already done by test_dpram() above)
+	 *   release reset
+	 *   wait for first interrupt
+	 *   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:
+	device_unregister(&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(struct device *dev, void *res)
+{
+	struct anybuss_host **dr = res;
+
+	anybuss_host_common_remove(*dr);
+}
+
+struct anybuss_host * __must_check
+devm_anybuss_host_common_probe(struct device *dev,
+			       const struct anybuss_ops *ops)
+{
+	struct anybuss_host **dr;
+	struct anybuss_host *host;
+
+	dr = devres_alloc(host_release, sizeof(struct anybuss_host *),
+			  GFP_KERNEL);
+	if (!dr)
+		return ERR_PTR(-ENOMEM);
+
+	host = anybuss_host_common_probe(dev, ops);
+	if (IS_ERR(host)) {
+		devres_free(dr);
+		return host;
+	}
+	*dr = host;
+	devres_add(dev, dr);
+	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");