[PATCH anybus v2 0/5] Support HMS Profinet Card over Anybus

[PATCH anybus v2 0/5] Support HMS Profinet Card over Anybus

[thesven73]

From: Sven Van Asbroeck <svendev@arcx.com>

This patch set adds support for the HMS Industrial Networks AB Profinet card.

Profinet is an industry technical standard for data communication over
Industrial Ethernet, designed for collecting data from, and controlling,
equipment in industrial systems, with a particular strength in delivering data
under tight time constraints (on the order of 1ms or less).

The profinet card itself is connected to the system via an industrial bus
called 'anybus'.

I have followed the bus driver/client driver pattern, and created an anybus
bus driver, plus a client driver for the profinet card.

In case this patch set gets (eventually) accepted, drivers for other anybus
client cards may follow: flnet, cc-link, ...

The anybus slot on the host is located on an 'anybus bridge', which is
custom h/w designed by Arcx. Its driver is modeled as a misc device, which
exposes a dual reset controller, plus a power readout unrelated to the anybus.

v2:
	added architecture overview comments to host driver
	completely reworked anybus-bridge driver, it becomes a reset controller
	anybuss-host driver now needs devicetree entry, link to reset controller
	I will hold off on kernel-doc until the overall architecture gets
		more validation / approval
	fixed Kconfig, comment-style, document ioctl magic numbers
	removed redundant pwm dependency
	renamed enable-gpios to reset-gpios
	stop driving reset-gpio after unloading driver
	use interrupt-parent / interrupts method to describe interrupts
		in the devicetree
	convert references 'i.MX WEIM parallel bus' to 'parallel bus'
	replace devicetree functions with more generic platform_get_resource()
							platform_get_irq()
	added device unique data to add_device_randomness()

v1:
	first shot

Sven Van Asbroeck (5):
  misc: support the Arcx anybus bridge.
  dt-bindings: anybus-bridge: document devicetree binding.
  bus: support HMS Anybus-S bus.
  dt-bindings: anybuss-host: document devicetree binding.
  misc: support HMS Profinet IRT industrial controller.

 .../bindings/bus/arcx,anybuss-host.txt        |   36 +
 .../bindings/misc/arcx,anybus-bridge.txt      |   34 +
 .../devicetree/bindings/vendor-prefixes.txt   |    1 +
 Documentation/ioctl/ioctl-number.txt          |    1 +
 drivers/bus/Kconfig                           |   10 +
 drivers/bus/Makefile                          |    1 +
 drivers/bus/anybuss-host.c                    | 1498 +++++++++++++++++
 drivers/misc/Kconfig                          |   19 +
 drivers/misc/Makefile                         |    2 +
 drivers/misc/anybus-bridge.c                  |  301 ++++
 drivers/misc/hms-profinet.c                   |  753 +++++++++
 include/linux/anybuss-client.h                |  100 ++
 include/uapi/linux/hms-common.h               |   14 +
 include/uapi/linux/hms-profinet.h             |  102 ++
 14 files changed, 2872 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/arcx,anybuss-host.txt
 create mode 100644 Documentation/devicetree/bindings/misc/arcx,anybus-bridge.txt
 create mode 100644 drivers/bus/anybuss-host.c
 create mode 100644 drivers/misc/anybus-bridge.c
 create mode 100644 drivers/misc/hms-profinet.c
 create mode 100644 include/linux/anybuss-client.h
 create mode 100644 include/uapi/linux/hms-common.h
 create mode 100644 include/uapi/linux/hms-profinet.h

-- 
2.17.1

[PATCH anybus v2 1/5] misc: support the Arcx anybus bridge.

[thesven73]

From: Sven Van Asbroeck <svendev@arcx.com>

Add a driver for the Arcx anybus bridge.

This chip embeds up to two Anybus-S application connectors
(slots), and connects to the SoC via a parallel memory bus.
There is also a CAN power readout, unrelated to the Anybus.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 drivers/misc/Kconfig         |   9 ++
 drivers/misc/Makefile        |   1 +
 drivers/misc/anybus-bridge.c | 301 +++++++++++++++++++++++++++++++++++
 3 files changed, 311 insertions(+)
 create mode 100644 drivers/misc/anybus-bridge.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 3726eacdf65d..dd7fdbf659b7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -509,6 +509,15 @@ config PCI_ENDPOINT_TEST
            Enable this configuration option to enable the host side test driver
            for PCI Endpoint.
 
+config ARCX_ANYBUS_BRIDGE
+	tristate "Arcx Anybus-S Bridge"
+	depends on OF
+	help
+	  Select this to get support for the Arcx Anybus bridge.
+	  It connects to the SoC via a parallel memory bus, and
+	  embeds up to two Anybus-S application connectors (slots).
+	  There is also a CAN power readout, unrelated to the Anybus.
+
 config MISC_RTSX
 	tristate
 	default MISC_RTSX_PCI || MISC_RTSX_USB
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index af22bbc3d00c..20c9fbfb100b 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -56,5 +56,6 @@ obj-$(CONFIG_CXL_BASE)		+= cxl/
 obj-$(CONFIG_ASPEED_LPC_CTRL)	+= aspeed-lpc-ctrl.o
 obj-$(CONFIG_ASPEED_LPC_SNOOP)	+= aspeed-lpc-snoop.o
 obj-$(CONFIG_PCI_ENDPOINT_TEST)	+= pci_endpoint_test.o
+obj-$(CONFIG_ARCX_ANYBUS_BRIDGE)	+= anybus-bridge.o
 obj-$(CONFIG_OCXL)		+= ocxl/
 obj-$(CONFIG_MISC_RTSX)		+= cardreader/
diff --git a/drivers/misc/anybus-bridge.c b/drivers/misc/anybus-bridge.c
new file mode 100644
index 000000000000..6eb7b47dd5ee
--- /dev/null
+++ b/drivers/misc/anybus-bridge.c
@@ -0,0 +1,301 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Arcx Anybus Bridge 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.h>
+#include <linux/of_gpio.h>
+#include <linux/delay.h>
+#include <linux/regmap.h>
+#include <linux/idr.h>
+#include <linux/spinlock.h>
+#include <linux/reset-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 bridge_priv {
+	struct device *class_dev;
+	struct reset_controller_dev rcdev;
+	bool common_reset;
+	int reset_gpio;
+	void __iomem *cpld_base;
+	spinlock_t regs_lock;
+	u8 control_reg;
+	char version[3];
+	u16 design_no;
+};
+
+static void do_reset(struct bridge_priv *cd, u8 rst_bit, bool reset)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cd->regs_lock, flags);
+	/*
+	 * 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)
+		udelay(100);
+	spin_unlock_irqrestore(&cd->regs_lock, flags);
+}
+
+static int anybuss_reset(struct bridge_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 int anybuss_reset_assert(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	struct bridge_priv *cd = container_of(rcdev, struct bridge_priv, rcdev);
+
+	return anybuss_reset(cd, id, true);
+}
+
+static int anybuss_reset_deassert(struct reset_controller_dev *rcdev,
+			     unsigned long id)
+{
+	struct bridge_priv *cd = container_of(rcdev, struct bridge_priv, rcdev);
+
+	return anybuss_reset(cd, id, false);
+}
+
+static const struct reset_control_ops anybuss_reset_ops = {
+	.assert		= anybuss_reset_assert,
+	.deassert	= anybuss_reset_deassert,
+};
+
+static ssize_t version_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct bridge_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 bridge_priv *cd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n", cd->design_no);
+}
+static DEVICE_ATTR_RO(design_number);
+
+static ssize_t can_power_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct bridge_priv *cd = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%d\n",
+		!(readb(cd->cpld_base + CPLD_STATUS1) &
+					CPLD_STATUS1_CAN_POWER));
+}
+static DEVICE_ATTR_RO(can_power);
+
+static struct attribute *bridge_attributes[] = {
+	&dev_attr_version.attr,
+	&dev_attr_design_number.attr,
+	&dev_attr_can_power.attr,
+	NULL,
+};
+
+static struct attribute_group bridge_attribute_group = {
+	.attrs = bridge_attributes,
+};
+
+static const struct attribute_group *bridge_attribute_groups[] = {
+	&bridge_attribute_group,
+	NULL,
+};
+
+static void bridge_device_release(struct device *dev)
+{
+	kfree(dev);
+}
+
+static struct class *bridge_class;
+static DEFINE_IDA(bridge_index_ida);
+
+static int bridge_probe(struct platform_device *pdev)
+{
+	struct bridge_priv *cd;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	int err, id;
+	struct resource *res;
+	u8 status1, cap;
+
+	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
+	if (!cd)
+		return -ENOMEM;
+	dev_set_drvdata(dev, cd);
+	spin_lock_init(&cd->regs_lock);
+	cd->reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
+	if (!gpio_is_valid(cd->reset_gpio)) {
+		dev_err(dev, "reset-gpios not found\n");
+		return -EINVAL;
+	}
+	devm_gpio_request(dev, cd->reset_gpio, NULL);
+	gpio_direction_output(cd->reset_gpio, 0);
+
+	/* 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");
+		return PTR_ERR(cd->cpld_base);
+	}
+
+	/* 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, "Bridge is 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 bridge [cap=0x%02X]", cap);
+		return -ENODEV;
+	}
+
+	if (status1 & CPLD_STATUS1_AB) {
+		dev_info(dev, "Bridge has anybus-S slot(s)");
+		cd->common_reset = !(cap & CPLD_CAP_SEP_RESETS);
+		dev_info(dev, "Bridge supports %s", cd->common_reset ?
+			"a common reset" : "separate resets");
+		cd->rcdev.owner	= THIS_MODULE;
+		cd->rcdev.nr_resets = 2;
+		cd->rcdev.ops = &anybuss_reset_ops;
+		cd->rcdev.of_node = dev->of_node;
+		err = devm_reset_controller_register(dev, &cd->rcdev);
+		if (err)
+			return err;
+	}
+
+	id = ida_simple_get(&bridge_index_ida, 0, 0, GFP_KERNEL);
+	if (id < 0)
+		return id;
+	/* make bridge 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 = bridge_class;
+	cd->class_dev->groups = bridge_attribute_groups;
+	cd->class_dev->parent = dev;
+	cd->class_dev->id = id;
+	cd->class_dev->release = bridge_device_release;
+	dev_set_name(cd->class_dev, "bridge%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(&bridge_index_ida, id);
+	return err;
+}
+
+static int bridge_remove(struct platform_device *pdev)
+{
+	struct bridge_priv *cd = platform_get_drvdata(pdev);
+	int id = cd->class_dev->id;
+
+	device_unregister(cd->class_dev);
+	ida_simple_remove(&bridge_index_ida, id);
+	gpio_direction_input(cd->reset_gpio);
+	return 0;
+}
+
+static const struct of_device_id bridge_of_match[] = {
+	{ .compatible = "arcx,anybus-bridge" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, bridge_of_match);
+
+static struct platform_driver bridge_driver = {
+	.probe = bridge_probe,
+	.remove = bridge_remove,
+	.driver		= {
+		.name   = "arcx-anybus-bridge",
+		.owner	= THIS_MODULE,
+		.of_match_table	= of_match_ptr(bridge_of_match),
+	},
+};
+
+static int __init bridge_init(void)
+{
+	int err;
+
+	bridge_class = class_create(THIS_MODULE, "arcx_anybus_bridge");
+	if (!IS_ERR(bridge_class)) {
+		err = platform_driver_register(&bridge_driver);
+		if (err)
+			class_destroy(bridge_class);
+	} else
+		err = PTR_ERR(bridge_class);
+	return err;
+}
+
+static void __exit bridge_exit(void)
+{
+	platform_driver_unregister(&bridge_driver);
+	class_destroy(bridge_class);
+}
+
+module_init(bridge_init);
+module_exit(bridge_exit);
+
+MODULE_DESCRIPTION("Arcx Anybus Bridge driver");
+MODULE_AUTHOR("Sven Van Asbroeck <svendev@arcx.com>");
+MODULE_LICENSE("GPL v2");
-- 
2.17.1

[PATCH anybus v2 2/5] dt-bindings: anybus-bridge: document devicetree binding.

[thesven73]

From: Sven Van Asbroeck <svendev@arcx.com>

This patch adds devicetree binding documentation for the
Arcx anybus bridge.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 .../bindings/misc/arcx,anybus-bridge.txt      | 34 +++++++++++++++++++
 .../devicetree/bindings/vendor-prefixes.txt   |  1 +
 2 files changed, 35 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/misc/arcx,anybus-bridge.txt

diff --git a/Documentation/devicetree/bindings/misc/arcx,anybus-bridge.txt b/Documentation/devicetree/bindings/misc/arcx,anybus-bridge.txt
new file mode 100644
index 000000000000..cb801b7568b0
--- /dev/null
+++ b/Documentation/devicetree/bindings/misc/arcx,anybus-bridge.txt
@@ -0,0 +1,34 @@
+* Arcx anybus bridge
+
+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-bridge"
+
+  - reg : bus memory area where the cpld registers are located.
+
+  - reset-gpios : the GPIO pin connected to the reset line of the bridge.
+
+  - #reset-cells : Must be 1.
+	this bridge is a reset provider to its two embedded Anybus-S slots.
+
+Example of usage:
+
+This example places the bridge on top of the i.MX WEIM parallel bus, see:
+Documentation/devicetree/bindings/bus/imx-weim.txt
+
+&weim {
+	anybus_bridge: bridge@0,0 {
+		compatible = "arcx,anybus-bridge";
+		reg = <0 0 0x100>;
+		reset-gpios = <&gpio5 2 GPIO_ACTIVE_HIGH>;
+		#reset-cells = <1>;
+		/* fsl,weim-cs-timing is a i.MX WEIM bus specific property */
+		fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
+				0x00000000 0xa0000240 0x00000000>;
+	};
+};
diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 2c3fc512e746..1bf07b20a8af 100644
--- a/Documentation/devicetree/bindings/vendor-prefixes.txt
+++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
@@ -35,6 +35,7 @@ aptina	Aptina Imaging
 arasan	Arasan Chip Systems
 archermind ArcherMind Technology (Nanjing) Co., Ltd.
 arctic	Arctic Sand
+arcx	Arcx/Archronix Inc.
 aries	Aries Embedded GmbH
 arm	ARM Ltd.
 armadeus	ARMadeus Systems SARL
-- 
2.17.1

[PATCH anybus v2 3/5] bus: support HMS Anybus-S bus.

[thesven73]

From: Sven Van Asbroeck <svendev@arcx.com>

The Anybus-S/Anybus-M is a series of interchangeable fieldbus communication
modules featuring on board memory and processing power. All software and
hardware functionality required to communicate on the fieldbus is
incorporated in the module itself, allowing the application to focus on
other tasks.

Typical applications are frequency inverters, HMI and visualization
devices, instruments, scales, robotics, PLC’s and intelligent measuring
devices.

Official documentation:
https://www.anybus.com/docs/librariesprovider7/default-document-library/
manuals-design-guides/hms-hmsi-27-275.pdf

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 drivers/bus/Kconfig            |   10 +
 drivers/bus/Makefile           |    1 +
 drivers/bus/anybuss-host.c     | 1498 ++++++++++++++++++++++++++++++++
 include/linux/anybuss-client.h |  100 +++
 4 files changed, 1609 insertions(+)
 create mode 100644 drivers/bus/anybuss-host.c
 create mode 100644 include/linux/anybuss-client.h

diff --git a/drivers/bus/Kconfig b/drivers/bus/Kconfig
index 1851112ccc29..196c603f516e 100644
--- a/drivers/bus/Kconfig
+++ b/drivers/bus/Kconfig
@@ -45,6 +45,16 @@ config IMX_WEIM
 	  The WEIM(Wireless External Interface Module) works like a bus.
 	  You can attach many different devices on it, such as NOR, onenand.
 
+config HMS_ANYBUSS_HOST
+	tristate "HMS Anybus-S Host/Bus Driver"
+	select REGMAP
+	depends on OF
+	help
+	  Driver for the HMS Industrial Networks Anybus-S bus.
+	  You can attach Anybus-S compatible cards to it, which
+	  typically provide fieldbus and industrial ethernet
+	  functionality.
+
 config MIPS_CDMM
 	bool "MIPS Common Device Memory Map (CDMM) Driver"
 	depends on CPU_MIPSR2
diff --git a/drivers/bus/Makefile b/drivers/bus/Makefile
index ca300b1914ce..f67c6468126b 100644
--- a/drivers/bus/Makefile
+++ b/drivers/bus/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_BRCMSTB_GISB_ARB)	+= brcmstb_gisb.o
 obj-$(CONFIG_FSL_MC_BUS)	+= fsl-mc/
 
 obj-$(CONFIG_IMX_WEIM)		+= imx-weim.o
+obj-$(CONFIG_HMS_ANYBUSS_HOST)	+= anybuss-host.o
 obj-$(CONFIG_MIPS_CDMM)		+= mips_cdmm.o
 obj-$(CONFIG_MVEBU_MBUS) 	+= mvebu-mbus.o
 
diff --git a/drivers/bus/anybuss-host.c b/drivers/bus/anybuss-host.c
new file mode 100644
index 000000000000..e8bf7d4b2a7b
--- /dev/null
+++ b/drivers/bus/anybuss-host.c
@@ -0,0 +1,1498 @@
+// 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 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 host, 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 host; and
+ * IND_AP: written exclusively by the 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 host are able to
+ *	exchange commands and responses using a shared mailbox.
+ * 3. receive software interrupts:
+ *	using an IND_AB/IND_AP protocol, the Anybus 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 hardware, 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.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/platform_device.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/reset.h>
+#include <linux/regmap.h>
+#include <linux/of.h>
+#include <linux/random.h>
+
+#include <linux/anybuss-client.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
+
+/* ------------- 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 anybus_mbox_hdr {
+	u16 id;
+	u16 info;
+	u16 cmd_num;
+	u16 data_size;
+	u16 frame_count;
+	u16 frame_num;
+	u16 offset_high;
+	u16 offset_low;
+	u16 extended[8];
+} __packed;
+
+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;
+	atomic_t		refs;
+	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;
+	atomic_set(&t->refs, 1);
+	t->task_fn = task_fn;
+	t->done_fn = NULL;
+	t->result = 0;
+	init_completion(&t->done);
+	return t;
+}
+
+static void ab_task_put(struct ab_task *t)
+{
+	struct kmem_cache *cache = t->cache;
+
+	if (atomic_dec_and_test(&t->refs))
+		kmem_cache_free(cache, t);
+}
+
+static struct ab_task *__ab_task_get(struct ab_task *t)
+{
+	atomic_inc(&t->refs);
+	return t;
+}
+
+static void
+__ab_task_finish(struct anybuss_host *cd, struct ab_task *t)
+{
+	if (t->done_fn)
+		t->done_fn(cd);
+	complete(&t->done);
+}
+
+static void
+ab_task_dequeue_finish_put(struct anybuss_host *cd, struct kfifo *q)
+{
+	int ret;
+	struct ab_task *t;
+
+	ret = kfifo_out(q, &t, sizeof(t));
+	WARN_ON(!ret);
+	__ab_task_finish(cd, t);
+	ab_task_put(t);
+}
+
+static int
+ab_task_enqueue(wait_queue_head_t *wq, struct kfifo *q,
+			struct ab_task *t, spinlock_t *slock)
+{
+	int ret;
+
+	t->start_jiffies = jiffies;
+	ret = kfifo_in_spinlocked(q, &t, sizeof(t), slock);
+	if (!ret)
+		return -ENOMEM;
+	__ab_task_get(t);
+	wake_up(wq);
+	return 0;
+}
+
+static int
+ab_task_enqueue_wait(wait_queue_head_t *wq, struct kfifo *q,
+			struct ab_task *t, spinlock_t *slock)
+{
+	int ret;
+
+	ret = ab_task_enqueue(wq, q, t, slock);
+	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;
+	struct reset_control *reset;
+	struct regmap *regmap;
+	int irq;
+	struct task_struct *qthread;
+	wait_queue_head_t wq;
+	struct completion card_boot;
+	atomic_t ind_ab;
+	spinlock_t qlock;
+	struct kmem_cache *qcache;
+	struct kfifo qs[3];
+	struct kfifo *powerq;
+	struct kfifo *mboxq;
+	struct kfifo *areaq;
+	bool power_on;
+	bool softint_pending;
+	atomic_t dc_event;
+	wait_queue_head_t dc_wq;
+	atomic_t fieldbus_online;
+	struct kernfs_node *fieldbus_online_sd;
+};
+
+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;
+
+	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;
+		cpu_relax();
+	}
+	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;
+
+	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;
+		cpu_relax();
+	}
+	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)
+{
+	if (!cd->power_on)
+		return 0;
+	disable_irq(cd->irq);
+	reset_control_assert(cd->reset);
+	atomic_set(&cd->ind_ab, IND_AB_UPDATED);
+	atomic_set(&cd->fieldbus_online, 0);
+	sysfs_notify_dirent(cd->fieldbus_online_sd);
+	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_control_assert(cd->reset);
+		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_control_deassert(cd->reset);
+	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(&cd->wq, cd->powerq, t, &cd->qlock);
+	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 ----------------------- */
+
+struct msgAnybusInit {
+	u16 input_io_len;
+	u16 input_dpram_len;
+	u16 input_total_len;
+	u16 output_io_len;
+	u16 output_dpram_len;
+	u16 output_total_len;
+	u16 op_mode;
+	u16 notif_config;
+	u16 wd_val;
+} __packed;
+
+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(&cd->wq, cd->mboxq, t, &cd->qlock);
+	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(cd, q);
+}
+
+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)
+{
+	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) {
+		atomic_set(&cd->fieldbus_online, 1);
+		sysfs_notify_dirent(cd->fieldbus_online_sd);
+		dev_dbg(cd->dev, "Fieldbus ON");
+	}
+	if (ev & EVENT_CAUSE_FBOF) {
+		atomic_set(&cd->fieldbus_online, 0);
+		sysfs_notify_dirent(cd->fieldbus_online_sd);
+		dev_dbg(cd->dev, "Fieldbus OFF");
+	}
+	if (ev & EVENT_CAUSE_DC) {
+		atomic_inc(&cd->dc_event);
+		wake_up_all(&cd->dc_wq);
+		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(&cd->wq, cd->areaq, t, &cd->qlock);
+	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 msgAnybusInit 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(&cd->wq, cd->areaq, t, &cd->qlock);
+	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(&cd->wq, cd->areaq, t, &cd->qlock);
+	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, int *dc_event,
+				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;
+	*dc_event = atomic_read(&cd->dc_event);
+	ret = ab_task_enqueue_wait(&cd->wq, cd->areaq, t, &cd->qlock);
+	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);
+
+unsigned int anybuss_poll(struct anybuss_client *client, int dc_event,
+				struct file *filp, poll_table *wait)
+{
+	struct anybuss_host *cd = client->host;
+	unsigned int mask = POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
+
+	poll_wait(filp, &cd->dc_wq, wait);
+	/* data changed ? */
+	if (atomic_read(&cd->dc_event) != dc_event)
+		mask |= POLLPRI | POLLERR;
+	return mask;
+}
+EXPORT_SYMBOL_GPL(anybuss_poll);
+
+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->fieldbus_type == adev->fieldbus_type;
+}
+
+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);
+
+/* ------------------------ attributes ------------------------ */
+
+static ssize_t state_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct anybuss_host *cd = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+		atomic_read(&cd->fieldbus_online) ?
+			"online" : "offline");
+}
+
+static DEVICE_ATTR_RO(state);
+
+static struct attribute *ctrl_attrs[] = {
+	&dev_attr_state.attr,
+	NULL
+};
+
+static struct attribute_group ctrl_group = { .attrs = ctrl_attrs };
+
+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);
+}
+
+/*
+ * 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.
+ *
+ * therefore to be safe, we will limit parallel bus accesses to a single byte
+ * at a time.
+ *
+ * we can revisit if/when hardware becomes available that provides bus width
+ * translations.
+ */
+
+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)
+{
+	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, 0);
+	if (resource_size(res) < (1<<regmap_cfg.reg_bits))
+		return ERR_PTR(-EINVAL);
+	base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(base))
+		return (struct regmap *)base;
+	return devm_regmap_init(dev, NULL, base, &regmap_cfg);
+}
+
+static int anybus_host_probe(struct platform_device *pdev)
+{
+	int ret, i;
+	u8 val[4];
+	u16 fieldbus_type;
+	struct anybuss_host *cd;
+	struct device *dev = &pdev->dev;
+
+	cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
+	if (!cd)
+		return -ENOMEM;
+	cd->dev = dev;
+	init_completion(&cd->card_boot);
+	init_waitqueue_head(&cd->wq);
+	init_waitqueue_head(&cd->dc_wq);
+	for (i = 0; i < ARRAY_SIZE(cd->qs); i++) {
+		ret = taskq_alloc(dev, &cd->qs[i]);
+		if (ret)
+			return ret;
+	}
+	if (WARN_ON(ARRAY_SIZE(cd->qs) < 3))
+		return -EINVAL;
+	cd->powerq = &cd->qs[0];
+	cd->mboxq = &cd->qs[1];
+	cd->areaq = &cd->qs[2];
+	cd->reset = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(cd->reset))
+		return PTR_ERR(cd->reset);
+	cd->regmap = create_parallel_regmap(pdev);
+	if (IS_ERR(cd->regmap))
+		return PTR_ERR(cd->regmap);
+	spin_lock_init(&cd->qlock);
+	atomic_set(&cd->dc_event, 0);
+	atomic_set(&cd->fieldbus_online, 0);
+	cd->qcache = kmem_cache_create(dev_name(dev),
+		sizeof(struct ab_task), 0, 0, NULL);
+	if (!cd->qcache)
+		return -ENOMEM;
+	cd->irq = platform_get_irq(pdev, 0);
+	if (cd->irq <= 0) {
+		ret = cd->irq;
+		goto err_qcache;
+	}
+	/*
+	 * use a dpram test to check if a card is present, this is only
+	 * possible while in reset.
+	 */
+	reset_control_assert(cd->reset);
+	if (test_dpram(cd->regmap)) {
+		dev_err(dev, "no Anybus-S card in slot");
+		ret = -ENODEV;
+		goto err_qcache;
+	}
+	ret = devm_request_irq(dev, cd->irq, irq_handler, 0, 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_control_deassert(cd->reset);
+	ret = wait_for_completion_timeout(&cd->card_boot, TIMEOUT);
+	if (ret == 0)
+		ret = -ETIMEDOUT;
+	if (ret < 0)
+		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));
+	fieldbus_type = be16_to_cpu(fieldbus_type);
+	dev_info(dev, "Fieldbus type: %04X", 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_control_assert(cd->reset);
+	atomic_set(&cd->ind_ab, IND_AB_UPDATED);
+	/* attributes */
+	ret = sysfs_create_group(&dev->kobj, &ctrl_group);
+	if (ret < 0)
+		goto err_reset;
+	cd->fieldbus_online_sd =
+		sysfs_get_dirent(dev->kobj.sd, "state");
+	if (!cd->fieldbus_online_sd) {
+		ret = -ENODEV;
+		goto err_sysfs;
+	}
+	/* 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_dirent;
+	}
+	/*
+	 * 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->fieldbus_type = fieldbus_type;
+	cd->client->host = cd;
+	cd->client->dev.bus = &anybus_bus;
+	cd->client->dev.parent = dev;
+	cd->client->dev.id = pdev->id;
+	cd->client->dev.release = client_device_release;
+	dev_set_name(&cd->client->dev, "%s.card0",
+				dev_name(&pdev->dev));
+	ret = device_register(&cd->client->dev);
+	if (ret)
+		goto err_client;
+	platform_set_drvdata(pdev, cd);
+	dev_set_drvdata(dev, cd);
+	return 0;
+err_client:
+	put_device(&cd->client->dev);
+err_kthread:
+	kthread_stop(cd->qthread);
+err_dirent:
+	sysfs_put(cd->fieldbus_online_sd);
+err_sysfs:
+	sysfs_remove_group(&dev->kobj, &ctrl_group);
+err_reset:
+	reset_control_assert(cd->reset);
+err_qcache:
+	kmem_cache_destroy(cd->qcache);
+	return ret;
+}
+
+static int anybus_host_remove(struct platform_device *pdev)
+{
+	struct anybuss_host *cd = platform_get_drvdata(pdev);
+
+	device_unregister(&cd->client->dev);
+	kthread_stop(cd->qthread);
+	sysfs_put(cd->fieldbus_online_sd);
+	sysfs_remove_group(&cd->dev->kobj, &ctrl_group);
+	reset_control_assert(cd->reset);
+	kmem_cache_destroy(cd->qcache);
+	return 0;
+}
+
+static const struct of_device_id host_of_match[] = {
+	{ .compatible = "arcx,anybuss-host" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, host_of_match);
+
+static struct platform_driver anybus_host_driver = {
+	.probe = anybus_host_probe,
+	.remove = anybus_host_remove,
+	.driver	= {
+		.name = "anybuss-host",
+		.owner	= THIS_MODULE,
+		.of_match_table	= of_match_ptr(host_of_match),
+	},
+};
+
+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;
+	}
+	return platform_driver_register(&anybus_host_driver);
+}
+module_init(anybus_init);
+
+static void __exit anybus_exit(void)
+{
+	platform_driver_unregister(&anybus_host_driver);
+	bus_unregister(&anybus_bus);
+}
+module_exit(anybus_exit);
+
+MODULE_DESCRIPTION("HMS Anybus-S Host Driver");
+MODULE_AUTHOR("Sven Van Asbroeck <svendev@arcx.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/anybuss-client.h b/include/linux/anybuss-client.h
new file mode 100644
index 000000000000..9d439d1a496f
--- /dev/null
+++ b/include/linux/anybuss-client.h
@@ -0,0 +1,100 @@
+/* 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;
+	u16 fieldbus_type;
+};
+
+struct anybuss_client_driver {
+	struct device_driver driver;
+	int (*probe)(struct anybuss_client *adev);
+	int (*remove)(struct anybuss_client *adev);
+	u16 fieldbus_type;
+};
+
+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, int *dc_event,
+				char __user *buf, size_t size,
+				loff_t *offset);
+unsigned int anybuss_poll(struct anybuss_client *client,
+		int dc_event, struct file *filp, poll_table *wait);
+
+#endif /* __LINUX_ANYBUSS_CLIENT_H__ */
-- 
2.17.1

[PATCH anybus v2 4/5] dt-bindings: anybuss-host: document devicetree binding.

[thesven73]

From: Sven Van Asbroeck <svendev@arcx.com>

This patch adds devicetree binding documentation for the
Arcx Anybus-S host.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 .../bindings/bus/arcx,anybuss-host.txt        | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/bus/arcx,anybuss-host.txt

diff --git a/Documentation/devicetree/bindings/bus/arcx,anybuss-host.txt b/Documentation/devicetree/bindings/bus/arcx,anybuss-host.txt
new file mode 100644
index 000000000000..5c28e4e09bb2
--- /dev/null
+++ b/Documentation/devicetree/bindings/bus/arcx,anybuss-host.txt
@@ -0,0 +1,36 @@
+* Arcx Anybus-S host
+
+This host 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 string:
+        "arcx,anybuss-host"
+
+  - reg : bus memory area where the Anybus-S host dpram is located.
+
+  - interrupts : interrupt connected to the Anybus-S host interrupt line.
+	Generic interrupt client node bindings are described in
+		interrupt-controller/interrupts.txt
+
+  - resets : the reset line associated with the Anybus-S host.
+
+Example of usage:
+
+This example places the Anybus-S host on top of the i.MX WEIM parallel bus, see:
+Documentation/devicetree/bindings/bus/imx-weim.txt
+
+&weim {
+	anybus-host@0 {
+		compatible = "arcx,anybuss-host";
+		reg = <0 0x400000 0x800>;
+		interrupt-parent = <&gpio1>;
+		interrupts = <1 IRQ_TYPE_LEVEL_LOW>;
+		resets = <&anybus_bridge 0>;
+		/* fsl,weim-cs-timing is a i.MX WEIM bus specific property */
+		fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
+				0x00000000 0xa0000240 0x00000000>;
+	};
+};
-- 
2.17.1

[PATCH anybus v2 5/5] misc: support HMS Profinet IRT industrial controller.

[thesven73]

From: Sven Van Asbroeck <svendev@arcx.com>

The Anybus-S PROFINET IRT communication module provides instant integration
to any Ethernet based LAN via SMTP, FTP, HTTP as well as PROFINET and
Modbus-TCP. Additional protocols can be implemented on top of TCP/IP
or UDP using the transparent socket interface.

Official documentation:
https://www.anybus.com/docs/librariesprovider7/default-document-library
/manuals-design-guides/hms-hmsi-168-52.pdf

This implementation is an Anybus-S client driver, designed to be
instantiated by the Anybus-S bus driver when it discovers the Profinet
card.

If loaded successfully, the driver creates a /dev/profinet%d devnode,
and a /sys/class/misc/profinet%d sysfs subdir:
- the card can be configured with a single, atomic ioctl on the devnode;
- the card's internal dpram is accessed by calling read/write/seek
    on the devnode.
- the card's "fieldbus specific area" properties can be accessed via
    the sysfs dir.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 Documentation/ioctl/ioctl-number.txt |   1 +
 drivers/misc/Kconfig                 |  10 +
 drivers/misc/Makefile                |   1 +
 drivers/misc/hms-profinet.c          | 753 +++++++++++++++++++++++++++
 include/uapi/linux/hms-common.h      |  14 +
 include/uapi/linux/hms-profinet.h    | 102 ++++
 6 files changed, 881 insertions(+)
 create mode 100644 drivers/misc/hms-profinet.c
 create mode 100644 include/uapi/linux/hms-common.h
 create mode 100644 include/uapi/linux/hms-profinet.h

diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index 13a7c999c04a..a389a4ec1429 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -241,6 +241,7 @@ Code  Seq#(hex)	Include File		Comments
 					<http://web.archive.org/web/*/http://mikonos.dia.unisa.it/tcfs>
 'l'	40-7F	linux/udf_fs_i.h	in development:
 					<http://sourceforge.net/projects/linux-udf/>
+'l'	80-9F	linux/hms-profinet.h	Anybus-S
 'm'	00-09	linux/mmtimer.h		conflict!
 'm'	all	linux/mtio.h		conflict!
 'm'	all	linux/soundcard.h	conflict!
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index dd7fdbf659b7..d17b581c06f7 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -406,6 +406,16 @@ config SPEAR13XX_PCIE_GADGET
 	 entry will be created for that controller. User can use these
 	 sysfs node to configure PCIe EP as per his requirements.
 
+config HMS_PROFINET
+	tristate "HMS Profinet IRT Controller (Anybus-S)"
+	select HMS_ANYBUSS_HOST
+	help
+	 If you say yes here you get support for the HMS Industrial
+	 Networks Profinet IRT Controller.
+	 This driver can also be built as a module. If so, the module
+	 will be called hms-profinet.
+	 If unsure, say N.
+
 config VMWARE_BALLOON
 	tristate "VMware Balloon Driver"
 	depends on VMWARE_VMCI && X86 && HYPERVISOR_GUEST
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 20c9fbfb100b..087c48273179 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -34,6 +34,7 @@ obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o
 obj-$(CONFIG_DS1682)		+= ds1682.o
 obj-$(CONFIG_C2PORT)		+= c2port/
 obj-$(CONFIG_HMC6352)		+= hmc6352.o
+obj-$(CONFIG_HMS_PROFINET)	+= hms-profinet.o
 obj-y				+= eeprom/
 obj-y				+= cb710/
 obj-$(CONFIG_SPEAR13XX_PCIE_GADGET)	+= spear13xx_pcie_gadget.o
diff --git a/drivers/misc/hms-profinet.c b/drivers/misc/hms-profinet.c
new file mode 100644
index 000000000000..dd6c0f715bf1
--- /dev/null
+++ b/drivers/misc/hms-profinet.c
@@ -0,0 +1,753 @@
+// 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>
+#include <linux/idr.h>
+#include <linux/miscdevice.h>
+
+#include <linux/anybuss-client.h>
+#include <uapi/linux/hms-profinet.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 - which means they need to be packed.
+ */
+
+struct msgEthConfig {
+	u32 ip_addr, subnet_msk, gateway_addr;
+} __packed;
+
+struct msgMacAddr {
+	u8 addr[6];
+} __packed;
+
+struct msgStr {
+	char	s[128];
+} __packed;
+
+struct msgShortStr {
+	char	s[64];
+} __packed;
+
+struct msgHicp {
+	char	enable;
+} __packed;
+
+/*
+ * --------------------------------------------------------------
+ * Fieldbus Specific Area - memory locations
+ * --------------------------------------------------------------
+ */
+#define FSA_NETWORK_STATUS	0x700
+#define FSA_LAYER_STATUS	0x7B2
+#define FSA_IO_CTRL_STATUS	0x7B0
+#define FSA_LAYER_FAULT_CODE	0x7B4
+
+struct profi_priv {
+	struct anybuss_client *client;
+	int id;
+	atomic_t refcount;
+	char node_name[16];
+	struct miscdevice misc;
+	struct device *dev;	/* just a link to the misc device */
+	struct mutex enable_lock;
+};
+
+static int profinet_configure(struct anybuss_client *ab,
+				struct ProfinetConfig *cfg)
+{
+	int ret;
+
+	if (cfg->eth.is_valid) {
+		struct msgEthConfig msg = {
+			.ip_addr = cfg->eth.ip_addr,
+			.subnet_msk = cfg->eth.subnet_msk,
+			.gateway_addr = cfg->eth.gateway_addr,
+		};
+		ret = anybuss_send_msg(ab, 0x0001, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->dev_id.is_valid) {
+		u16 ext[2] = {
+			cpu_to_be16(cfg->dev_id.vendorid),
+			cpu_to_be16(cfg->dev_id.deviceid)
+		};
+		ret = anybuss_send_ext(ab, 0x0102, ext, sizeof(ext));
+		if (ret)
+			return ret;
+	}
+	if (cfg->station_name.is_valid) {
+		struct msgStr msg = { 0 };
+
+		strncpy(msg.s, cfg->station_name.name, sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0103, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->station_type.is_valid) {
+		struct msgShortStr msg = { 0 };
+
+		strncpy(msg.s, cfg->station_type.name, sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0104, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->mac_addr.is_valid) {
+		struct msgMacAddr msg = { 0 };
+
+		memcpy(msg.addr, cfg->mac_addr.addr, sizeof(msg.addr));
+		ret = anybuss_send_msg(ab, 0x0019, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->host_domain.is_valid) {
+		size_t len;
+		struct msgStr msg = { 0 };
+		/*
+		 * check if host and domain names fit in msg structure
+		 */
+		len =	strnlen(cfg->host_domain.hostname,
+				sizeof(cfg->host_domain.hostname))
+					+ 1 +
+			strnlen(cfg->host_domain.domainname,
+				sizeof(cfg->host_domain.domainname))
+					+ 1;
+		if (len > sizeof(msg.s))
+			return -ENAMETOOLONG;
+		strncpy(msg.s, cfg->host_domain.hostname,
+			sizeof(msg.s));
+		len = strnlen(msg.s, sizeof(msg.s)) + 1; /* NULL term */
+		strncpy(msg.s + len, cfg->host_domain.domainname,
+				sizeof(msg.s) - len);
+		ret = anybuss_send_msg(ab, 0x0032, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->hicp.is_valid) {
+		struct msgHicp msg = {
+			.enable = cfg->hicp.enable ? 1 : 0,
+		};
+		ret = anybuss_send_msg(ab, 0x0013, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->web_server.is_valid) {
+		ret = anybuss_send_msg(ab,
+			cfg->web_server.enable ? 0x0005 : 0x0004,
+			NULL, 0);
+		if (ret)
+			return ret;
+	}
+	if (cfg->ftp_server.disable) {
+		ret = anybuss_send_msg(ab, 0x0006, NULL, 0);
+		if (ret)
+			return ret;
+	}
+	if (cfg->global_admin_mode.enable) {
+		ret = anybuss_send_msg(ab, 0x000B, NULL, 0);
+		if (ret)
+			return ret;
+	}
+	if (cfg->vfs.disable) {
+		ret = anybuss_send_msg(ab, 0x0011, NULL, 0);
+		if (ret)
+			return ret;
+	}
+	if (cfg->stop_mode.is_valid) {
+		u16 action;
+
+		switch (cfg->stop_mode.action) {
+		case HMS_SMA_CLEAR:
+			action = 0;
+			break;
+		case HMS_SMA_FREEZE:
+			action = 1;
+			break;
+		case HMS_SMA_SET:
+			action = 2;
+			break;
+		default:
+			return -EINVAL;
+		}
+		action = cpu_to_be16(action);
+		ret = anybuss_send_ext(ab, 0x0101, &action,
+						sizeof(action));
+		if (ret)
+			return ret;
+	}
+	if (cfg->snmp_system_descr.is_valid) {
+		struct msgStr msg = { 0 };
+
+		strncpy(msg.s, cfg->snmp_system_descr.description,
+					sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0120, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->snmp_iface_descr.is_valid) {
+		struct msgStr msg = { 0 };
+
+		strncpy(msg.s, cfg->snmp_iface_descr.description,
+					sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0121, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->mib2_system_descr.is_valid) {
+		struct msgStr msg = { 0 };
+
+		strncpy(msg.s, cfg->mib2_system_descr.description,
+					sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0124, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->mib2_system_contact.is_valid) {
+		struct msgStr msg = { 0 };
+
+		strncpy(msg.s, cfg->mib2_system_contact.contact,
+					sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0125, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	if (cfg->mib2_system_location.is_valid) {
+		struct msgStr msg = { 0 };
+
+		strncpy(msg.s, cfg->mib2_system_location.location,
+					sizeof(msg.s));
+		ret = anybuss_send_msg(ab, 0x0126, &msg, sizeof(msg));
+		if (ret)
+			return ret;
+	}
+	return 0;
+}
+
+static int profinet_enable(struct profi_priv *priv,
+				struct ProfinetConfig *cfg)
+{
+	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,
+	};
+	if (mutex_lock_interruptible(&priv->enable_lock))
+		return -ERESTARTSYS;
+	/*
+	 * 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_init;
+	ret = anybuss_start_init(client, &mem_cfg);
+	if (ret)
+		goto err_init;
+	if (cfg)
+		ret = profinet_configure(client, cfg);
+	if (ret)
+		goto err_init;
+	ret = anybuss_finish_init(client);
+	if (ret)
+		goto err_init;
+	mutex_unlock(&priv->enable_lock);
+	return 0;
+err_init:
+	anybuss_set_power(client, false);
+	mutex_unlock(&priv->enable_lock);
+	return ret;
+}
+
+static int profinet_disable(struct profi_priv *priv)
+{
+	int ret;
+
+	if (mutex_lock_interruptible(&priv->enable_lock))
+		return -ERESTARTSYS;
+	ret = anybuss_set_power(priv->client, false);
+	mutex_unlock(&priv->enable_lock);
+	return ret;
+}
+
+static int fbctrl_readw(struct anybuss_client *client, u16 addr)
+{
+	int ret;
+	u16 val;
+
+	ret = anybuss_read_fbctrl(client, addr, &val, sizeof(val));
+	if (ret < 0)
+		return ret;
+	return (int)be16_to_cpu(val);
+}
+
+static ssize_t mac_addr_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	struct msgMacAddr response;
+	int ret;
+
+	ret = anybuss_recv_msg(priv->client, 0x0010, &response,
+						sizeof(response));
+	if (ret)
+		return ret;
+	return snprintf(buf, PAGE_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 DEVICE_ATTR_RO(mac_addr);
+
+static ssize_t start_defaults_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	unsigned long num;
+
+	if (kstrtoul(buf, 0, &num))
+		return -EINVAL;
+	if (num)
+		profinet_enable(priv, NULL);
+	return count;
+}
+
+static DEVICE_ATTR_WO(start_defaults);
+
+static ssize_t ip_addr_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	struct msgEthConfig response;
+	int ret;
+
+	ret = anybuss_recv_msg(priv->client, 0x0002, &response,
+						sizeof(response));
+	if (ret)
+		return ret;
+	return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
+		response.ip_addr & 0xFF,
+		(response.ip_addr >>  8) & 0xFF,
+		(response.ip_addr >> 16) & 0xFF,
+		(response.ip_addr >> 24) & 0xFF);
+}
+
+static DEVICE_ATTR_RO(ip_addr);
+
+static ssize_t subnet_mask_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	struct msgEthConfig response;
+	int ret;
+
+	ret = anybuss_recv_msg(priv->client, 0x0002, &response,
+						sizeof(response));
+	if (ret)
+		return ret;
+	return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
+		response.subnet_msk & 0xFF,
+		(response.subnet_msk >>  8) & 0xFF,
+		(response.subnet_msk >> 16) & 0xFF,
+		(response.subnet_msk >> 24) & 0xFF);
+}
+
+static DEVICE_ATTR_RO(subnet_mask);
+
+static ssize_t gateway_addr_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	struct msgEthConfig response;
+	int ret;
+
+	ret = anybuss_recv_msg(priv->client, 0x0002, &response,
+						sizeof(response));
+	if (ret)
+		return ret;
+	return snprintf(buf, PAGE_SIZE, "%d.%d.%d.%d\n",
+		response.gateway_addr & 0xFF,
+		(response.gateway_addr >>  8) & 0xFF,
+		(response.gateway_addr >> 16) & 0xFF,
+		(response.gateway_addr >> 24) & 0xFF);
+}
+
+static DEVICE_ATTR_RO(gateway_addr);
+
+static ssize_t hostname_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	struct msgStr response;
+	int ret;
+
+	ret = anybuss_recv_msg(priv->client, 0x0034, &response,
+						sizeof(response));
+	if (ret)
+		return ret;
+	return snprintf(buf, PAGE_SIZE, "%s\n", response.s);
+}
+
+static DEVICE_ATTR_RO(hostname);
+
+static ssize_t domainname_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	struct msgStr response;
+	int ret, pos;
+
+	ret = anybuss_recv_msg(priv->client, 0x0034, &response,
+						sizeof(response));
+	if (ret)
+		return ret;
+	/*
+	 * domain name string located right behind null-terminated
+	 * host name string.
+	 */
+	pos = strnlen(response.s, sizeof(response.s)) + 1;
+	if (pos >= sizeof(response.s))
+		return -ENAMETOOLONG;
+	return snprintf(buf, PAGE_SIZE, "%s\n", response.s + pos);
+}
+
+static DEVICE_ATTR_RO(domainname);
+
+static ssize_t network_link_on_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	int ns;
+
+	ns = fbctrl_readw(priv->client, FSA_NETWORK_STATUS);
+	if (ns < 0)
+		return ns;
+	return snprintf(buf, PAGE_SIZE, "%d\n", ns & 1);
+}
+
+static DEVICE_ATTR_RO(network_link_on);
+
+static ssize_t network_ip_in_use_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	int ns;
+
+	ns = fbctrl_readw(priv->client, FSA_NETWORK_STATUS);
+	if (ns < 0)
+		return ns;
+	return snprintf(buf, PAGE_SIZE, "%d\n", (ns>>1) & 1);
+}
+
+static DEVICE_ATTR_RO(network_ip_in_use);
+
+static ssize_t layer_status_show(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	const char *s;
+	int ls;
+
+	ls = fbctrl_readw(priv->client, FSA_LAYER_STATUS);
+	if (ls < 0)
+		return ls;
+	switch (ls) {
+	case 0x0000:
+		s = "not yet initialized";
+		break;
+	case 0x0001:
+		s = "successfully initialized";
+		break;
+	case 0x0002:
+		s = "failed to initialize";
+		break;
+	default:
+		return -EINVAL;
+	}
+	return snprintf(buf, PAGE_SIZE, "%s\n", s);
+}
+
+static DEVICE_ATTR_RO(layer_status);
+
+static ssize_t io_controller_status_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct profi_priv *priv = dev_get_drvdata(dev);
+	const char *s;
+	int w;
+
+	w = fbctrl_readw(priv->client, FSA_IO_CTRL_STATUS);
+	if (w < 0)
+		return w;
+	switch (w) {
+	case 0x0000:
+		s = "No connection made";
+		break;
+	case 0x0001:
+		s = "STOP";
+		break;
+	case 0x0002:
+		s = "RUN";
+		break;
+	case 0x0004:
+		s = "STATION OK";
+		break;
+	case 0x0008:
+		s = "STATION PROBLEM";
+		break;
+	case 0x0010:
+		s = "PRIMARY";
+		break;
+	case 0x0020:
+		s = "BACKUP";
+		break;
+	default:
+		return -EINVAL;
+	}
+	return snprintf(buf, PAGE_SIZE, "%s\n", s);
+}
+
+static DEVICE_ATTR_RO(io_controller_status);
+
+static ssize_t layer_fault_code_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	int fc;
+	struct profi_priv *priv = dev_get_drvdata(dev);
+
+	fc = fbctrl_readw(priv->client, FSA_LAYER_FAULT_CODE);
+	if (fc < 0)
+		return fc;
+	return snprintf(buf, PAGE_SIZE, "%d\n", fc);
+}
+
+static DEVICE_ATTR_RO(layer_fault_code);
+
+static struct attribute *ctrl_attrs[] = {
+	&dev_attr_mac_addr.attr,
+	&dev_attr_start_defaults.attr,
+	&dev_attr_ip_addr.attr,
+	&dev_attr_subnet_mask.attr,
+	&dev_attr_gateway_addr.attr,
+	&dev_attr_hostname.attr,
+	&dev_attr_domainname.attr,
+	&dev_attr_network_link_on.attr,
+	&dev_attr_network_ip_in_use.attr,
+	&dev_attr_io_controller_status.attr,
+	&dev_attr_layer_status.attr,
+	&dev_attr_layer_fault_code.attr,
+	NULL
+};
+
+static struct attribute_group ctrl_group = { .attrs = ctrl_attrs };
+
+struct profi_open_file {
+	struct profi_priv *priv;
+	int event;
+};
+
+static int profi_open(struct inode *node, struct file *filp)
+{
+	struct profi_open_file *of;
+	struct profi_priv *priv = container_of(filp->private_data,
+					struct profi_priv, misc);
+
+	of = kzalloc(sizeof(*of), GFP_KERNEL);
+	if (!of)
+		return -ENOMEM;
+	of->priv = priv;
+	filp->private_data = of;
+	atomic_inc(&priv->refcount);
+	return 0;
+}
+
+static int profi_release(struct inode *node, struct file *filp)
+{
+	struct profi_open_file *of = filp->private_data;
+	struct profi_priv *priv = of->priv;
+
+	kfree(of);
+	if (!atomic_dec_and_test(&priv->refcount))
+		return 0;
+	return profinet_disable(priv);
+}
+
+static long profi_ioctl(struct file *filp, unsigned int cmd,
+						unsigned long arg)
+{
+	struct profi_open_file *of = filp->private_data;
+	struct profi_priv *priv = of->priv;
+	void __user *argp = (void __user *)arg;
+	struct ProfinetConfig config;
+
+	if (_IOC_TYPE(cmd) != PROFINET_IOC_MAGIC)
+		return -EINVAL;
+	if (!(_IOC_DIR(cmd) & _IOC_WRITE))
+		return -EINVAL;
+	switch (cmd) {
+	case PROFINET_IOCSETCONFIG:
+		if (copy_from_user(&config, argp, sizeof(config)))
+			return -EFAULT;
+		return profinet_enable(priv, &config);
+	default:
+		break;
+	}
+	return -ENOTTY;
+}
+
+static ssize_t
+profi_read(struct file *filp, char __user *buf, size_t size,
+							loff_t *offset)
+{
+	struct profi_open_file *of = filp->private_data;
+	struct profi_priv *priv = of->priv;
+
+	return anybuss_read_output(priv->client, &of->event, buf, size,
+							offset);
+}
+
+static ssize_t
+profi_write(struct file *filp, const char __user *buf, size_t size,
+							loff_t *offset)
+{
+	struct profi_open_file *of = filp->private_data;
+	struct profi_priv *priv = of->priv;
+
+	return anybuss_write_input(priv->client, buf, size, offset);
+}
+
+static unsigned int profi_poll(struct file *filp, poll_table *wait)
+{
+	struct profi_open_file *of = filp->private_data;
+	struct profi_priv *priv = of->priv;
+
+	return anybuss_poll(priv->client, of->event, filp, wait);
+}
+
+static const struct file_operations fops = {
+	.open = profi_open,
+	.release = profi_release,
+	.read = profi_read,
+	.write = profi_write,
+	.unlocked_ioctl = profi_ioctl,
+	.poll = profi_poll,
+	.llseek = generic_file_llseek,
+	.owner = THIS_MODULE,
+};
+
+static DEFINE_IDA(profi_index_ida);
+
+static int profinet_probe(struct anybuss_client *client)
+{
+	struct profi_priv *priv;
+	struct device *dev = &client->dev;
+	int err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	atomic_set(&priv->refcount, 0);
+	mutex_init(&priv->enable_lock);
+	priv->client = client;
+	priv->misc.minor = MISC_DYNAMIC_MINOR;
+	priv->id = ida_simple_get(&profi_index_ida, 0, 0, GFP_KERNEL);
+	if (priv->id < 0)
+		return priv->id;
+	snprintf(priv->node_name, sizeof(priv->node_name), "profinet%d",
+				priv->id);
+	priv->misc.name = priv->node_name;
+	priv->misc.fops = &fops;
+	priv->misc.parent = client->dev.parent;
+	err = misc_register(&priv->misc);
+	if (err < 0) {
+		dev_err(dev, "could not register device (%d)", err);
+		goto err_ida;
+	}
+	priv->dev = priv->misc.this_device;
+	dev_set_drvdata(priv->dev, priv);
+	err = sysfs_create_group(&priv->dev->kobj, &ctrl_group);
+	if (err < 0) {
+		dev_err(dev, "could not create sysfs group (%d)", err);
+		goto err_register;
+	}
+	dev_info(priv->dev, "detected on %s", dev_name(&client->dev));
+	anybuss_set_drvdata(client, priv);
+	return 0;
+err_register:
+	misc_deregister(&priv->misc);
+err_ida:
+	ida_simple_remove(&profi_index_ida, priv->id);
+	return err;
+}
+
+static int profinet_remove(struct anybuss_client *client)
+{
+	struct profi_priv *priv = anybuss_get_drvdata(client);
+
+	sysfs_remove_group(&priv->dev->kobj, &ctrl_group);
+	misc_deregister(&priv->misc);
+	ida_simple_remove(&profi_index_ida, priv->id);
+	return 0;
+}
+
+static struct anybuss_client_driver profinet_driver = {
+	.probe = profinet_probe,
+	.remove = profinet_remove,
+	.driver		= {
+		.name   = "hms-profinet",
+		.owner	= THIS_MODULE,
+	},
+	.fieldbus_type = 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 <svendev@arcx.com>");
+MODULE_DESCRIPTION("HMS Profinet IRT Driver (Anybus-S)");
+MODULE_LICENSE("GPL v2");
diff --git a/include/uapi/linux/hms-common.h b/include/uapi/linux/hms-common.h
new file mode 100644
index 000000000000..4b69963a3863
--- /dev/null
+++ b/include/uapi/linux/hms-common.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2018 Archronix Corp. All Rights Reserved.
+ *
+ */
+
+#ifndef _UAPILINUX_HMSCOMMON_H_
+#define _UAPILINUX_HMSCOMMON_H_
+
+#define HMS_SMA_CLEAR		0
+#define HMS_SMA_FREEZE		1
+#define HMS_SMA_SET		2
+
+#endif /* _UAPILINUX_HMSCOMMON_H_ */
diff --git a/include/uapi/linux/hms-profinet.h b/include/uapi/linux/hms-profinet.h
new file mode 100644
index 000000000000..beed797191f2
--- /dev/null
+++ b/include/uapi/linux/hms-profinet.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2018 Archronix Corp. All Rights Reserved.
+ *
+ */
+
+#ifndef _UAPILINUX_PROFINET_H_
+#define _UAPILINUX_PROFINET_H_
+
+#include <asm/types.h>
+#include <linux/hms-common.h>
+
+#define PROFI_CFG_STRLEN	64
+
+struct ProfinetConfig {
+	struct {
+		/* addresses IN NETWORK ORDER! */
+		__u32 ip_addr;
+		__u32 subnet_msk;
+		__u32 gateway_addr;
+		__u8  is_valid:1;
+	} eth;
+	struct {
+		__u16 vendorid, deviceid;
+		__u8  is_valid:1;
+	} dev_id;
+	struct {
+		char name[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} station_name;
+	struct {
+		char name[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} station_type;
+	struct {
+		__u8 addr[6];
+		__u8 is_valid:1;
+	} mac_addr;
+	struct {
+		char hostname[PROFI_CFG_STRLEN];
+		char domainname[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} host_domain;
+	struct {
+		__u8 enable:1;
+		__u8 is_valid:1;
+	} hicp;
+	struct {
+		__u8 enable:1;
+		__u8 is_valid:1;
+	} web_server;
+	struct {
+		__u8 disable:1;
+	} ftp_server;
+	struct {
+		__u8 enable:1;
+	} global_admin_mode;
+	struct {
+		__u8 disable:1;
+	} vfs;
+	struct {
+		/* one of HMS_SMA_CLEAR/FREEZE/SET */
+		int action;
+		__u8 is_valid:1;
+	} stop_mode;
+	struct {
+		char description[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} snmp_system_descr;
+	struct {
+		char description[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} snmp_iface_descr;
+	struct {
+		char description[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} mib2_system_descr;
+	struct {
+		char contact[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} mib2_system_contact;
+	struct {
+		char location[PROFI_CFG_STRLEN];
+		__u8 is_valid:1;
+	} mib2_system_location;
+	/*
+	 * use non-volatile defaults for any properties not specified.
+	 * when in doubt, keep this OFF.
+	 */
+	__u8 use_nv_defaults:1;
+};
+
+#define PROFINET_IOC_MAGIC 'l'
+
+/*
+ * Configures profinet according to the ProfinetConfig structure, and
+ * switches the card on if it was previously off.
+ */
+#define PROFINET_IOCSETCONFIG   _IOW(PROFINET_IOC_MAGIC, 0x80,\
+						struct ProfinetConfig)
+
+#endif /* _UAPILINUX_PROFINET_H_ */
-- 
2.17.1

Re: [PATCH anybus v2 1/5] misc: support the Arcx anybus bridge.

[Linus Walleij]

Hi Sven,

On Wed, Oct 31, 2018 at 8:44 PM <thesven73@gmail.com> wrote:

> From: Sven Van Asbroeck <svendev@arcx.com>
>
> Add a driver for the Arcx anybus bridge.
>
> This chip embeds up to two Anybus-S application connectors
> (slots), and connects to the SoC via a parallel memory bus.
> There is also a CAN power readout, unrelated to the Anybus.
>
> Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>

This is fun :)

>  drivers/misc/Kconfig         |   9 ++
>  drivers/misc/Makefile        |   1 +
>  drivers/misc/anybus-bridge.c | 301 +++++++++++++++++++++++++++++++++++

I would put this also in drivers/bus, why not. Just two files
there. It's a bus bridge for sure, we keep them there.
drivers/reset if it is mostly about resetting stuff.

> +config ARCX_ANYBUS_BRIDGE
> +       tristate "Arcx Anybus-S Bridge"
> +       depends on OF

depends on GPIOLIB

> +       help
> +         Select this to get support for the Arcx Anybus bridge.
> +         It connects to the SoC via a parallel memory bus, and
> +         embeds up to two Anybus-S application connectors (slots).
> +         There is also a CAN power readout, unrelated to the Anybus.

(...)
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>

Don't use these please. Juse use
#include <linux/gpio/consumer.h>

> +struct bridge_priv {
> +       struct device *class_dev;
> +       struct reset_controller_dev rcdev;
> +       bool common_reset;
> +       int reset_gpio;

struct gpio_desc *reset_gpiod;

> +       void __iomem *cpld_base;
> +       spinlock_t regs_lock;
> +       u8 control_reg;
> +       char version[3];
> +       u16 design_no;
(...)

> +static ssize_t version_show(struct device *dev,
> +               struct device_attribute *attr, char *buf)
> +{
> +       struct bridge_priv *cd = dev_get_drvdata(dev);
> +
> +       return sprintf(buf, "%s\n", cd->version);
> +}
> +static DEVICE_ATTR_RO(version);

Do you need this in userspace really?

> +static ssize_t design_number_show(struct device *dev,
> +               struct device_attribute *attr, char *buf)
> +{
> +       struct bridge_priv *cd = dev_get_drvdata(dev);
> +
> +       return sprintf(buf, "%d\n", cd->design_no);
> +}
> +static DEVICE_ATTR_RO(design_number);

And this?

> +static ssize_t can_power_show(struct device *dev,
> +               struct device_attribute *attr, char *buf)
> +{
> +       struct bridge_priv *cd = dev_get_drvdata(dev);
> +
> +       return sprintf(buf, "%d\n",
> +               !(readb(cd->cpld_base + CPLD_STATUS1) &
> +                                       CPLD_STATUS1_CAN_POWER));
> +}
> +static DEVICE_ATTR_RO(can_power);

This should certainly be reflected as a fixed-voltage regulator
and not a random integer in sysfs.

> +static int bridge_probe(struct platform_device *pdev)
> +{
> +       struct bridge_priv *cd;
> +       struct device *dev = &pdev->dev;
> +       struct device_node *np = dev->of_node;
> +       int err, id;
> +       struct resource *res;
> +       u8 status1, cap;
> +
> +       cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL);
> +       if (!cd)
> +               return -ENOMEM;
> +       dev_set_drvdata(dev, cd);
> +       spin_lock_init(&cd->regs_lock);

This:

> +       cd->reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
> +       if (!gpio_is_valid(cd->reset_gpio)) {
> +               dev_err(dev, "reset-gpios not found\n");
> +               return -EINVAL;
> +       }
> +       devm_gpio_request(dev, cd->reset_gpio, NULL);
> +       gpio_direction_output(cd->reset_gpio, 0);

Should be:

cd->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(cd->reset_gpiod))
    return PTR_ERR(cd->reset_gpiod);

You can turn it to input as you do in the .remove() function to let
a pull-up resistor pull it high, but isn't it better to actively just drive
it high?

Yours,
Linus Walleij

Re: [PATCH anybus v2 2/5] dt-bindings: anybus-bridge: document devicetree binding.

[Andreas Färber]

Hi Sven,

Am 31.10.18 um 20:44 schrieb thesven73@gmail.com:
> From: Sven Van Asbroeck <svendev@arcx.com>
> 
> This patch adds devicetree binding documentation for the
> Arcx anybus bridge.
> 
> Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
> ---
>  .../bindings/misc/arcx,anybus-bridge.txt      | 34 +++++++++++++++++++
>  .../devicetree/bindings/vendor-prefixes.txt   |  1 +
>  2 files changed, 35 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/misc/arcx,anybus-bridge.txt
[...]
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
> index 2c3fc512e746..1bf07b20a8af 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.txt
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
> @@ -35,6 +35,7 @@ aptina	Aptina Imaging
>  arasan	Arasan Chip Systems
>  archermind ArcherMind Technology (Nanjing) Co., Ltd.
>  arctic	Arctic Sand
> +arcx	Arcx/Archronix Inc.
>  aries	Aries Embedded GmbH
>  arm	ARM Ltd.
>  armadeus	ARMadeus Systems SARL

Please move this to a separate patch, titled "dt-bindings: Add vendor
prefix for Arcx", with the commit message describing what the company does.
Also note that subject lines usually do not end with a full stop,
similar to book titles or news headlines.
And it is usually preferable to have such a long list of people in CC
rather than in To, to make it clear whom you expect to handle it and to
facilitate replies going to you without hand-editing every other To.

I notice that arcx.com spells it ARCX Inc., in upper-case without any
mention of Archronix in the name. So if that's a previous name you may
want to write it as "ARCX Inc. (formerly Archronix Inc.)"? Look for
other examples in that file.

Regards,
Andreas

-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)

Re: [PATCH anybus v2 5/5] misc: support HMS Profinet IRT industrial controller.

[kbuild test robot]

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Hi Sven,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on char-misc/char-misc-testing]
[also build test WARNING on v4.19 next-20181101]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/thesven73-gmail-com/Support-HMS-Profinet-Card-over-Anybus/20181101-225600
config: i386-tinyconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=i386 

All warnings (new ones prefixed by >>):

>> ./usr/include/linux/hms-profinet.h:10: include of <linux/types.h> is preferred over <asm/types.h>
>> ./usr/include/linux/hms-profinet.h:18: found __[us]{8,16,32,64} type without #include <linux/types.h>

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

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Re: [PATCH anybus v2 1/5] misc: support the Arcx anybus bridge.

[Sven Van Asbroeck]

Hi Linus,

> This is fun :)

It sure is ! It's fascinating to see how the kernel abstractions are designed,
and how code is reviewed here.

>> +static DEVICE_ATTR_RO(version);
>
> Do you need this in userspace really?
>
>> +static DEVICE_ATTR_RO(design_number);
>
> And this?

Unfortunately, I do :(
The application software reads these out and displays them in an UI. It's
important to be able to see these on a running device.
Perhaps there is another kernel abstraction I could use?

> This:
>>
>> +       cd->reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
>> +       if (!gpio_is_valid(cd->reset_gpio)) {
>> +               dev_err(dev, "reset-gpios not found\n");
>> +               return -EINVAL;
>> +       }
>> +       devm_gpio_request(dev, cd->reset_gpio, NULL);
>> +       gpio_direction_output(cd->reset_gpio, 0);
>
> Should be:
>
> cd->reset_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> if (IS_ERR(cd->reset_gpiod))
>     return PTR_ERR(cd->reset_gpiod);

That's actually pretty neat !
Now we have nothing that explicitly refers to the devicetree (except the
device binding, of course). I now see the point you made earlier:
resets, gpios, interrupts etc are associated with "struct device" and
not necessarily with the devicetree.

The rest of your suggestions have already gone in.

I hope you'll have some time later to look at the architecture description
in the bus driver. Looking forward to your feedback and to the next iteration !

Cheers,
Sven

Re: [PATCH anybus v2 1/5] misc: support the Arcx anybus bridge.

[Linus Walleij]

On Thu, Nov 1, 2018 at 6:17 PM Sven Van Asbroeck <thesven73@gmail.com> wrote:

> >> +static DEVICE_ATTR_RO(version);
> >
> > Do you need this in userspace really?
> >
> >> +static DEVICE_ATTR_RO(design_number);
> >
> > And this?
>
> Unfortunately, I do :(
> The application software reads these out and displays them in an UI. It's
> important to be able to see these on a running device.

OK...

> Perhaps there is another kernel abstraction I could use?

I don't think so. If you want to be pedantic, document the sysfs
files in Documentation/ABI/testing/sysfs-*

Maybe the properties should be on the bus though? I don't know :/

Yours,
Linus Walleij

Re: [PATCH anybus v2 1/5] misc: support the Arcx anybus bridge.

[Sven Van Asbroeck]

On Thu, Nov 1, 2018 at 5:53 PM Linus Walleij <linus.walleij@linaro.org> wrote:
>
> On Thu, Nov 1, 2018 at 6:17 PM Sven Van Asbroeck <thesven73@gmail.com> wrote:
> > Perhaps there is another kernel abstraction I could use?
>
> Maybe the properties should be on the bus though? I don't know :/

Let's keep the version associated with the bridge. After all, the bus
has its own version associated with it. And the app developers have
separate data structures for the bridge and the bus.

Cheers,
Sven

Re: [PATCH anybus v2 3/5] bus: support HMS Anybus-S bus.

[kbuild test robot]

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Hi Sven,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on char-misc/char-misc-testing]
[also build test ERROR on v4.20-rc2 next-20181114]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/thesven73-gmail-com/Support-HMS-Profinet-Card-over-Anybus/20181101-225600
config: um-allyesconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=um 

All errors (new ones prefixed by >>):

   arch/um/drivers/vde.o: In function `vde_open_real':
   (.text+0x951): warning: Using 'getgrnam' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   (.text+0x79c): warning: Using 'getpwuid' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   arch/um/drivers/vector_user.o: In function `user_init_socket_fds':
   vector_user.c:(.text+0x334): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   arch/um/drivers/pcap.o: In function `pcap_nametoaddr':
   (.text+0xdee5): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   arch/um/drivers/pcap.o: In function `pcap_nametonetaddr':
   (.text+0xdf85): warning: Using 'getnetbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   arch/um/drivers/pcap.o: In function `pcap_nametoproto':
   (.text+0xe1a5): warning: Using 'getprotobyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   arch/um/drivers/pcap.o: In function `pcap_nametoport':
   (.text+0xdfd7): warning: Using 'getservbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking
   drivers/bus/anybuss-host.o: In function `create_parallel_regmap':
>> anybuss-host.c:(.text+0x1afd): undefined reference to `devm_ioremap_resource'
   collect2: error: ld returned 1 exit status

---
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