[PATCH anybus v4 0/7] Add Fieldbus subsystem + support HMS Profinet card

[PATCH anybus v4 0/7] Add Fieldbus subsystem + support HMS Profinet card

[thesven73]

This patch:
  1. adds a Fieldbus subsystem
  2. adds support for the HMS Industrial Networks AB Profinet card.

1. Fieldbus subsystem
---------------------

Fieldbus device (client) adapters allow data exchange with a PLC aka.
"Fieldbus Controller" over a fieldbus (Profinet, FLNet, etc.)
They are typically used when a Linux device wants to expose itself
as an actuator, motor, console light, switch, etc. over the fieldbus.
The framework is designed to provide a generic interface to Fieldbus
Devices from both the Linux Kernel and the userspace.

2. Add support for HMS 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.

v4:
	general
		create fieldbus_dev subsystem, with standardized 'simple'
			userspace interface (sysfs + cdev)
		remove redundant __packed keywords
		use __be16/32 types wherever values are explicitly big-endian
	hms-profinet:
		remove configuration code, and uapi headers: not supported (yet)
			when registering as a fieldbus_dev.
	anybuss-host:
		use struct kref to reference-count tasks
		replace busy loops with usleep_range() loop after 10 tries
		use threaded irq so time_before_eq(jiffies, timeout) will
			continue to work
		allow client devices to be assigned a devicetree node,
			in the same way as pci/mmc/...

v3:
	devicetree-bindings
		adding the vendor prefix is now a separate commit
	anybus-bridge:
		moved misc driver to drivers/bus/
		converted of_gpio_* to gpiod_* abstractions
		can power readout is now a fixed-voltage regulator
	anybuss-host:
		converted refcounts from atomic_t to refcount_t
		fixed potential use-after-free
	hms-profinet:
		applied minor kernel build robot suggestion

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 (7):
  fieldbus_dev: add Fieldbus Device subsystem.
  fieldbus: support the Arcx anybus bridge
  dt-bindings: Add vendor prefix for arcx / Archronix
  dt-bindings: anybus-bridge: document devicetree binding
  fieldbus: support HMS Anybus-S bus
  dt-bindings: anybuss-host: document devicetree binding
  fieldbus_dev: support HMS Profinet IRT industrial controller

 Documentation/ABI/testing/fieldbus-dev-cdev   |   31 +
 .../ABI/testing/sysfs-class-fieldbus-dev      |   63 +
 .../bindings/fieldbus/arcx,anybus-bridge.txt  |   34 +
 .../bindings/fieldbus/arcx,anybuss-host.txt   |   66 +
 .../devicetree/bindings/vendor-prefixes.txt   |    1 +
 Documentation/fieldbus_dev/fieldbus_dev.txt   |   66 +
 drivers/Kconfig                               |    2 +
 drivers/Makefile                              |    1 +
 drivers/fieldbus/Kconfig                      |   56 +
 drivers/fieldbus/Makefile                     |   12 +
 drivers/fieldbus/anybus-bridge.c              |  321 ++++
 drivers/fieldbus/anybuss-host.c               | 1497 +++++++++++++++++
 drivers/fieldbus/dev_core.c                   |  355 ++++
 drivers/fieldbus/hms-profinet.c               |  223 +++
 include/linux/anybuss-client.h                |  104 ++
 include/linux/fieldbus_dev.h                  |  106 ++
 16 files changed, 2938 insertions(+)
 create mode 100644 Documentation/ABI/testing/fieldbus-dev-cdev
 create mode 100644 Documentation/ABI/testing/sysfs-class-fieldbus-dev
 create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybus-bridge.txt
 create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
 create mode 100644 Documentation/fieldbus_dev/fieldbus_dev.txt
 create mode 100644 drivers/fieldbus/Kconfig
 create mode 100644 drivers/fieldbus/Makefile
 create mode 100644 drivers/fieldbus/anybus-bridge.c
 create mode 100644 drivers/fieldbus/anybuss-host.c
 create mode 100644 drivers/fieldbus/dev_core.c
 create mode 100644 drivers/fieldbus/hms-profinet.c
 create mode 100644 include/linux/anybuss-client.h
 create mode 100644 include/linux/fieldbus_dev.h

-- 
2.17.1

[PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[thesven73]

Fieldbus device (client) adapters allow data exchange with a PLC aka.
"Fieldbus Controller" over a fieldbus (Profinet, FLNet, etc.)

They are typically used when a Linux device wants to expose itself
as an actuator, motor, console light, switch, etc. over the fieldbus.

This framework is designed to provide a generic interface to Fieldbus
Devices from both the Linux Kernel and the userspace.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 Documentation/ABI/testing/fieldbus-dev-cdev   |  31 ++
 .../ABI/testing/sysfs-class-fieldbus-dev      |  63 ++++
 Documentation/fieldbus_dev/fieldbus_dev.txt   |  66 ++++
 drivers/Kconfig                               |   2 +
 drivers/Makefile                              |   1 +
 drivers/fieldbus/Kconfig                      |  19 +
 drivers/fieldbus/Makefile                     |   9 +
 drivers/fieldbus/dev_core.c                   | 355 ++++++++++++++++++
 include/linux/fieldbus_dev.h                  | 106 ++++++
 9 files changed, 652 insertions(+)
 create mode 100644 Documentation/ABI/testing/fieldbus-dev-cdev
 create mode 100644 Documentation/ABI/testing/sysfs-class-fieldbus-dev
 create mode 100644 Documentation/fieldbus_dev/fieldbus_dev.txt
 create mode 100644 drivers/fieldbus/Kconfig
 create mode 100644 drivers/fieldbus/Makefile
 create mode 100644 drivers/fieldbus/dev_core.c
 create mode 100644 include/linux/fieldbus_dev.h

diff --git a/Documentation/ABI/testing/fieldbus-dev-cdev b/Documentation/ABI/testing/fieldbus-dev-cdev
new file mode 100644
index 000000000000..450b43cd6799
--- /dev/null
+++ b/Documentation/ABI/testing/fieldbus-dev-cdev
@@ -0,0 +1,31 @@
+What:		/dev/fieldbus_devX
+Date:		December 2018
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		The cdev interface to drivers for Fieldbus Device Memory
+			(aka. Process Memory).
+
+		The following file operations are supported:
+
+		open(2)
+		Create an I/O context associated with the file descriptor.
+
+		read(2)
+		Read from Process Memory's "read area".
+		Clears POLLERR | POLLPRI from the file descriptor.
+
+		write(2)
+		Write to Process Memory's "write area".
+
+		poll(2), select(2), epoll_wait(2) etc.
+		When a "Process Memory Read Area Changed" event occurs,
+		POLLERR | POLLPRI will be set on the file descriptor.
+		Note that POLLIN | POLLOUT events are always set, because the
+		process memory area is always readable and writable.
+
+		close(2)
+		Free up the I/O context that was associated
+		with the file descriptor.
+
+Users:		TBD
diff --git a/Documentation/ABI/testing/sysfs-class-fieldbus-dev b/Documentation/ABI/testing/sysfs-class-fieldbus-dev
new file mode 100644
index 000000000000..d126706a997e
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-fieldbus-dev
@@ -0,0 +1,63 @@
+What:		/sys/class/fieldbus_dev/fieldbus_devX/card_name
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		Human-readable name of the Fieldbus Device.
+
+What:		/sys/class/fieldbus_dev/fieldbus_devX/fieldbus_type
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		The type of fieldbus implemented by this device.
+		Possible values:
+			'unknown'
+			'profinet'
+
+What:		/sys/class/fieldbus_dev/fieldbus_devX/fieldbus_id
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		The unique fieldbus id associated with this device.
+		The exact format of this id is fieldbus type dependent, e.g.
+		a mac address for profinet.
+
+What:		/sys/class/fieldbus_dev/fieldbus_devX/read_area_size
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		The size, in bytes, of the Process Memory read area.
+		Note: this area is accessible by reading from the associated
+			character device (/dev/fieldbus_devX).
+
+What:		/sys/class/fieldbus_dev/fieldbus_devX/write_area_size
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		The size, in bytes, of the Process Memory write area.
+		Note: this area is accessible by writing to the associated
+			character device (/dev/fieldbus_devX)
+
+What:		/sys/class/fieldbus_dev/fieldbus_devX/online
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		Whether the fieldbus is online or offline.
+		Possible values:
+			'online'
+			'offline'
+		Note: userspace may monitor changes to this property using the
+			'sysfs_notify' method.
+
+What:		/sys/class/fieldbus_dev/fieldbus_devX/enabled
+KernelVersion:	4.21
+Contact:	Sven Van Asbroeck <svendev@arcx.com>
+Description:
+		Whether the device is enabled (power on) or
+			disabled (power off).
+		Possible values:
+			'enabled'
+			'disabled'
+		Normally a r/o property, but optionally r/w:
+		Writing 'enabled' enables the device (power on) with default
+			settings.
+		Writing 'disabled' disables the card (power off).
diff --git a/Documentation/fieldbus_dev/fieldbus_dev.txt b/Documentation/fieldbus_dev/fieldbus_dev.txt
new file mode 100644
index 000000000000..40ab4de0f019
--- /dev/null
+++ b/Documentation/fieldbus_dev/fieldbus_dev.txt
@@ -0,0 +1,66 @@
+                       Fieldbus-Device Subsystem
+               ============================================
+
+Part 0 - What is a Fieldbus Device ?
+------------------------------------
+
+Fieldbus is the name of a family of industrial computer network protocols used
+for real-time distributed control, standardized as IEC 61158.
+
+A complex automated industrial system — such as manufacturing assembly line —
+usually needs a distributed control system—an organized hierarchy of controller
+systems—to function. In this hierarchy, there is usually a
+Human Machine Interface (HMI) at the top, where an operator can monitor or
+operate the system. This is typically linked to a middle layer of programmable
+logic controllers (PLC) via a non-time-critical communications system
+(e.g. Ethernet). At the bottom of the control chain is the fieldbus that links
+the PLCs to the components that actually do the work, such as sensors,
+actuators, electric motors, console lights, switches, valves and contactors.
+
+(Source: Wikipedia)
+
+A "Fieldbus Device" is such an actuator, motor, console light, switch, ...
+controlled via the Fieldbus by a PLC aka. "Fieldbus Controller".
+
+Communication between PLC and device typically happens via process data memory,
+separated into input and output areas. The Fieldbus then cyclically transfers
+the PLC's output area to the device's input area, and vice versa.
+
+Part I - Why do we need this subsystem?
+---------------------------------------
+
+Fieldbus device (client) adapters are commercially available. They allow data
+exchange with a PLC aka. "Fieldbus Controller" via process data memory.
+
+They are typically used when a Linux device wants to expose itself as an
+actuator, motor, console light, switch, etc. over the fieldbus.
+
+The purpose of this subsystem is:
+a) present a general, standardized, extensible API/ABI to userspace; and
+b) present a convenient interface to drivers.
+
+Part II - How can drivers use the subsystem?
+--------------------------------------------
+
+Any driver that wants to register as a Fieldbus Device should allocate and
+populate a 'struct fieldbus_dev' (from include/linux/fieldbus_dev.h).
+Registration then happens by calling fieldbus_dev_register().
+
+Part III - How can userspace use the subsystem?
+-----------------------------------------------
+
+Fieldbus protocols and adapters are diverse and varied. However, they share
+a limited few common behaviours and properties. This allows us to define
+a simple interface consisting of a character device and a set of sysfs files:
+
+See:
+Documentation/ABI/testing/sysfs-class-fieldbus-dev
+Documentation/ABI/testing/fieldbus-dev-cdev
+
+Note that this simple interface does not provide a way to modify adapter
+configuration settings. It is therefore useful only for adapters that get their
+configuration settings some other way, e.g. non-volatile memory on the adapter,
+through the network, ...
+
+At a later phase, this simple interface can easily co-exist with a future
+(netlink-based ?) configuration settings interface.
diff --git a/drivers/Kconfig b/drivers/Kconfig
index 155f25ad3a92..d6410846a4a8 100644
--- a/drivers/Kconfig
+++ b/drivers/Kconfig
@@ -219,6 +219,8 @@ source "drivers/visorbus/Kconfig"
 
 source "drivers/siox/Kconfig"
 
+source "drivers/fieldbus/Kconfig"
+
 source "drivers/slimbus/Kconfig"
 
 endmenu
diff --git a/drivers/Makefile b/drivers/Makefile
index 723698ad04f3..cb278f951c99 100644
--- a/drivers/Makefile
+++ b/drivers/Makefile
@@ -187,4 +187,5 @@ obj-$(CONFIG_TEE)		+= tee/
 obj-$(CONFIG_MULTIPLEXER)	+= mux/
 obj-$(CONFIG_UNISYS_VISORBUS)	+= visorbus/
 obj-$(CONFIG_SIOX)		+= siox/
+obj-$(CONFIG_FIELDBUS_DEV)	+= fieldbus/
 obj-$(CONFIG_GNSS)		+= gnss/
diff --git a/drivers/fieldbus/Kconfig b/drivers/fieldbus/Kconfig
new file mode 100644
index 000000000000..1d1929ba7e27
--- /dev/null
+++ b/drivers/fieldbus/Kconfig
@@ -0,0 +1,19 @@
+menuconfig FIELDBUS_DEV
+        bool "Fieldbus Device Support"
+        help
+          Support for Fieldbus Device Adapters.
+
+	  Fieldbus device (client) adapters allow data exchange with a PLC aka.
+	  "Fieldbus Controller" over a fieldbus (Profinet, FLNet, etc.)
+
+	  They are typically used when a Linux device wants to expose itself
+	  as an actuator, motor, console light, switch, etc. over the fieldbus.
+
+          This framework is designed to provide a generic interface to Fieldbus
+          Devices from both the Linux Kernel and the userspace.
+
+          If unsure, say no.
+
+if FIELDBUS_DEV
+
+endif
diff --git a/drivers/fieldbus/Makefile b/drivers/fieldbus/Makefile
new file mode 100644
index 000000000000..768a116fc9c6
--- /dev/null
+++ b/drivers/fieldbus/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for fieldbus_dev drivers.
+#
+
+obj-$(CONFIG_FIELDBUS_DEV)	+= fieldbus_dev_core.o
+fieldbus_dev_core-y		:= dev_core.o
+
+# Devices
diff --git a/drivers/fieldbus/dev_core.c b/drivers/fieldbus/dev_core.c
new file mode 100644
index 000000000000..d3b026e6839a
--- /dev/null
+++ b/drivers/fieldbus/dev_core.c
@@ -0,0 +1,355 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Fieldbus Device Driver Core
+ *
+ */
+
+#include <linux/fieldbus_dev.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/idr.h>
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/poll.h>
+
+/* Maximum number of fieldbus devices */
+#define MAX_FIELDBUSES		32
+
+/* the dev_t structure to store the dynamically allocated fieldbus devices */
+static dev_t fieldbus_devt;
+static DEFINE_IDA(fieldbus_ida);
+static DEFINE_MUTEX(fieldbus_mtx);
+
+static const char ctrl_enabled[] = "enabled";
+static const char ctrl_disabled[] = "disabled";
+
+static ssize_t online_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+		fb->online ? "online" : "offline");
+}
+static DEVICE_ATTR_RO(online);
+
+static ssize_t enabled_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	if (!fb->enable_get)
+		return -EINVAL;
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+		fb->enable_get(fb) ? ctrl_enabled : ctrl_disabled);
+}
+static ssize_t enabled_store(struct device *dev, struct device_attribute *attr,
+			     const char *buf, size_t n)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+	int err;
+
+	if (!fb->simple_enable_set) {
+		n = -ENOTSUPP;
+	} else if (sysfs_streq(buf, ctrl_enabled)) {
+		err = fb->simple_enable_set(fb, true);
+		if (err < 0)
+			n = err;
+	} else if (sysfs_streq(buf, ctrl_disabled)) {
+		err = fb->simple_enable_set(fb, false);
+		if (err < 0)
+			n = err;
+	} else {
+		n = -EINVAL;
+	}
+	return n;
+}
+static DEVICE_ATTR_RW(enabled);
+
+static ssize_t card_name_show(struct device *dev, struct device_attribute *attr,
+				char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", fb->card_name);
+}
+static DEVICE_ATTR_RO(card_name);
+
+static ssize_t read_area_size_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", fb->read_area_sz);
+}
+static DEVICE_ATTR_RO(read_area_size);
+
+static ssize_t write_area_size_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return snprintf(buf, PAGE_SIZE, "%d\n", fb->write_area_sz);
+}
+static DEVICE_ATTR_RO(write_area_size);
+
+static ssize_t fieldbus_id_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+
+	return fb->fieldbus_id_get(fb, buf, PAGE_SIZE);
+}
+static DEVICE_ATTR_RO(fieldbus_id);
+
+static ssize_t fieldbus_type_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+	const char *t;
+
+	switch (fb->fieldbus_type) {
+	case FIELDBUS_DEV_TYPE_PROFINET:
+		t = "profinet";
+		break;
+	default:
+		t = "unknown";
+		break;
+	}
+
+	return snprintf(buf, PAGE_SIZE, "%s\n", t);
+}
+static DEVICE_ATTR_RO(fieldbus_type);
+
+static struct attribute *fieldbus_attrs[] = {
+	&dev_attr_enabled.attr,
+	&dev_attr_card_name.attr,
+	&dev_attr_fieldbus_id.attr,
+	&dev_attr_read_area_size.attr,
+	&dev_attr_write_area_size.attr,
+	&dev_attr_online.attr,
+	&dev_attr_fieldbus_type.attr,
+	NULL,
+};
+
+static umode_t fieldbus_is_visible(struct kobject *kobj, struct attribute *attr,
+				int n)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct fieldbus_dev *fb = dev_get_drvdata(dev);
+	umode_t mode = attr->mode;
+
+	if (attr == &dev_attr_enabled.attr) {
+		mode = 0;
+		if (fb->enable_get)
+			mode |= 0444;
+		if (fb->simple_enable_set)
+			mode |= 0200;
+	}
+
+	return mode;
+}
+
+static const struct attribute_group fieldbus_group = {
+	.attrs = fieldbus_attrs,
+	.is_visible = fieldbus_is_visible,
+};
+__ATTRIBUTE_GROUPS(fieldbus);
+
+static struct class fieldbus_class = {
+	.name =		"fieldbus_dev",
+	.owner =	THIS_MODULE,
+	.dev_groups =	fieldbus_groups,
+};
+
+struct fb_open_file {
+	struct fieldbus_dev *fbdev;
+	int dc_event;
+};
+
+static int fieldbus_open(struct inode *inode, struct file *filp)
+{
+	struct fb_open_file *of;
+	struct fieldbus_dev *fbdev = container_of(inode->i_cdev,
+						struct fieldbus_dev,
+						cdev);
+
+	of = kzalloc(sizeof(*of), GFP_KERNEL);
+	if (!of)
+		return -ENOMEM;
+	of->fbdev = fbdev;
+	filp->private_data = of;
+	return 0;
+}
+
+static int fieldbus_release(struct inode *node, struct file *filp)
+{
+	struct fb_open_file *of = filp->private_data;
+
+	kfree(of);
+	return 0;
+}
+
+static ssize_t fieldbus_read(struct file *filp, char __user *buf, size_t size,
+				loff_t *offset)
+{
+	struct fb_open_file *of = filp->private_data;
+	struct fieldbus_dev *fbdev = of->fbdev;
+
+	of->dc_event = fbdev->dc_event;
+	return fbdev->read_area(fbdev, buf, size, offset);
+}
+
+static ssize_t fieldbus_write(struct file *filp, const char __user *buf,
+			size_t size, loff_t *offset)
+{
+	struct fb_open_file *of = filp->private_data;
+	struct fieldbus_dev *fbdev = of->fbdev;
+
+	return fbdev->write_area(fbdev, buf, size, offset);
+}
+
+static unsigned int fieldbus_poll(struct file *filp, poll_table *wait)
+{
+	struct fb_open_file *of = filp->private_data;
+	struct fieldbus_dev *fbdev = of->fbdev;
+	unsigned int mask = POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM;
+
+	poll_wait(filp, &fbdev->dc_wq, wait);
+	/* data changed ? */
+	if (fbdev->dc_event != of->dc_event)
+		mask |= POLLPRI | POLLERR;
+	return mask;
+}
+
+static const struct file_operations fieldbus_fops = {
+	.open		= fieldbus_open,
+	.release	= fieldbus_release,
+	.read		= fieldbus_read,
+	.write		= fieldbus_write,
+	.poll		= fieldbus_poll,
+	.llseek		= generic_file_llseek,
+	.owner		= THIS_MODULE,
+};
+
+void fieldbus_dev_area_updated(struct fieldbus_dev *fb)
+{
+	fb->dc_event++;
+	wake_up_all(&fb->dc_wq);
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_area_updated);
+
+void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online)
+{
+	fb->online = online;
+	if (fb->online_sd)
+		sysfs_notify_dirent(fb->online_sd);
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_online_changed);
+
+static void __fieldbus_dev_unregister(struct fieldbus_dev *fb)
+{
+	if (!fb)
+		return;
+	if (fb->online_sd)
+		sysfs_put(fb->online_sd);
+	device_destroy(&fieldbus_class, fb->cdev.dev);
+	cdev_del(&fb->cdev);
+	ida_simple_remove(&fieldbus_ida, fb->id);
+}
+
+void fieldbus_dev_unregister(struct fieldbus_dev *fb)
+{
+	mutex_lock(&fieldbus_mtx);
+	__fieldbus_dev_unregister(fb);
+	mutex_unlock(&fieldbus_mtx);
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_unregister);
+
+static int __fieldbus_dev_register(struct fieldbus_dev *fb)
+{
+	dev_t devno;
+	int err;
+
+	if (!fb)
+		return -EINVAL;
+	if (!fb->read_area || !fb->write_area || !fb->fieldbus_id_get)
+		return -EINVAL;
+	fb->id = ida_simple_get(&fieldbus_ida, 0, MAX_FIELDBUSES, GFP_KERNEL);
+	if (fb->id < 0)
+		return fb->id;
+	devno = MKDEV(MAJOR(fieldbus_devt), fb->id);
+	init_waitqueue_head(&fb->dc_wq);
+	cdev_init(&fb->cdev, &fieldbus_fops);
+	err = cdev_add(&fb->cdev, devno, 1);
+	if (err) {
+		pr_err("fieldbus_dev%d unable to add device %d:%d\n",
+			fb->id, MAJOR(fieldbus_devt), fb->id);
+		goto err_cdev;
+	}
+	fb->dev = device_create(&fieldbus_class, fb->parent, devno, fb,
+				"fieldbus_dev%d", fb->id);
+	if (IS_ERR(fb->dev)) {
+		err = PTR_ERR(fb->dev);
+		goto err_dev_create;
+	}
+	fb->online_sd = sysfs_get_dirent(fb->dev->kobj.sd, "online");
+	if (!fb->online_sd)
+		dev_warn(fb->dev, "'online' notification disabled");
+	return 0;
+
+err_dev_create:
+	cdev_del(&fb->cdev);
+err_cdev:
+	ida_simple_remove(&fieldbus_ida, fb->id);
+	return err;
+}
+
+int fieldbus_dev_register(struct fieldbus_dev *fb)
+{
+	int err;
+
+	mutex_lock(&fieldbus_mtx);
+	err = __fieldbus_dev_register(fb);
+	mutex_unlock(&fieldbus_mtx);
+
+	return err;
+}
+EXPORT_SYMBOL_GPL(fieldbus_dev_register);
+
+static int __init fieldbus_init(void)
+{
+	int err;
+
+	err = class_register(&fieldbus_class);
+	if (err < 0) {
+		pr_err("fieldbus_dev: could not register class\n");
+		return err;
+	}
+	err = alloc_chrdev_region(&fieldbus_devt, 0,
+					MAX_FIELDBUSES, "fieldbus_dev");
+	if (err < 0) {
+		pr_err("fieldbus_dev: unable to allocate char dev region\n");
+		goto err_alloc;
+	}
+	return 0;
+
+err_alloc:
+	class_unregister(&fieldbus_class);
+	return err;
+}
+
+static void __exit fieldbus_exit(void)
+{
+	unregister_chrdev_region(fieldbus_devt, MAX_FIELDBUSES);
+	class_unregister(&fieldbus_class);
+}
+
+subsys_initcall(fieldbus_init);
+module_exit(fieldbus_exit);
+
+MODULE_AUTHOR("Sven Van Asbroeck <svendev@arcx.com>");
+MODULE_AUTHOR("Jonathan Stiles <jonathans@arcx.com>");
+MODULE_DESCRIPTION("Fieldbus Device Driver Core");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/fieldbus_dev.h b/include/linux/fieldbus_dev.h
new file mode 100644
index 000000000000..291376469ca7
--- /dev/null
+++ b/include/linux/fieldbus_dev.h
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Fieldbus Device Driver Core
+ *
+ */
+
+#ifndef __FIELDBUS_DEV_H
+#define __FIELDBUS_DEV_H
+
+#include <linux/cdev.h>
+#include <linux/wait.h>
+
+enum fieldbus_dev_type {
+	FIELDBUS_DEV_TYPE_UNKNOWN = 0,
+	FIELDBUS_DEV_TYPE_PROFINET,
+};
+
+/**
+ * struct fieldbus_dev - Fieldbus device
+ * @read_area:		[DRIVER] function to read the process data area of the
+ *				 device. same parameters/return values as
+ *				 the read function in struct file_operations
+ * @write_area:		[DRIVER] function to write to the process data area of
+ *				 the device. same parameters/return values as
+ *				 the write function in struct file_operations
+ * @write_area_sz	[DRIVER] size of the writable process data area
+ * @read_area_sz	[DRIVER] size of the readable process data area
+ * @card_name		[DRIVER] name of the card, e.g. "ACME Inc. profinet"
+ * @fieldbus_type	[DRIVER] fieldbus type of this device, e.g.
+ *					FIELDBUS_DEV_TYPE_PROFINET
+ * @enable_get		[DRIVER] function which returns true if the card
+ *				 is enabled, false otherwise
+ * @fieldbus_id_get	[DRIVER] function to retrieve the unique fieldbus id
+ *				 by which this device can be identified;
+ *				 return value follows the snprintf convention
+ * @simple_enable_set	[DRIVER] (optional) function to enable the device
+ *				 according to its default settings
+ * @parent		[DRIVER] (optional) the device's parent device
+ */
+struct fieldbus_dev {
+	ssize_t (*read_area)(struct fieldbus_dev *fbdev, char __user *buf,
+			size_t size, loff_t *offset);
+	ssize_t (*write_area)(struct fieldbus_dev *fbdev,
+			const char __user *buf, size_t size, loff_t *offset);
+	size_t write_area_sz, read_area_sz;
+	const char *card_name;
+	enum fieldbus_dev_type fieldbus_type;
+	bool (*enable_get)(struct fieldbus_dev *fbdev);
+	int (*fieldbus_id_get)(struct fieldbus_dev *fbdev, char *buf,
+					size_t max_size);
+	int (*simple_enable_set)(struct fieldbus_dev *fbdev, bool enable);
+	struct device *parent;
+
+	/* private data */
+	int id;
+	struct cdev cdev;
+	struct device *dev;
+	int dc_event;
+	wait_queue_head_t dc_wq;
+	bool online;
+	struct kernfs_node *online_sd;
+};
+
+#ifdef CONFIG_FIELDBUS_DEV
+
+/**
+ * fieldbus_dev_unregister()
+ *	- unregister a previously registered fieldbus device
+ * @fb:		Device structure previously registered
+ **/
+void fieldbus_dev_unregister(struct fieldbus_dev *fb);
+
+/**
+ * fieldbus_dev_register()
+ *	- register a device with the fieldbus device subsystem
+ * @fb:		Device structure filled by the device driver
+ **/
+int __must_check fieldbus_dev_register(struct fieldbus_dev *fb);
+
+/**
+ * fieldbus_dev_area_updated()
+ *	- notify the subsystem that an external fieldbus controller updated
+ *			the process data area
+ * @fb:		Device structure
+ **/
+void fieldbus_dev_area_updated(struct fieldbus_dev *fb);
+
+/**
+ * fieldbus_dev_online_changed()
+ *	- notify the subsystem that the fieldbus online status changed
+ * @fb:		Device structure
+ **/
+void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online);
+
+#else /* CONFIG_FIELDBUS_DEV */
+
+void fieldbus_dev_unregister(struct fieldbus_dev *fb) {}
+int __must_check fieldbus_dev_register(struct fieldbus_dev *fb)
+{
+	return -ENOTSUPP;
+}
+void fieldbus_dev_area_updated(struct fieldbus_dev *fb) {}
+void fieldbus_dev_online_changed(struct fieldbus_dev *fb, bool online) {}
+
+#endif /* CONFIG_FIELDBUS_DEV */
+#endif /* __FIELDBUS_DEV_H */
-- 
2.17.1

[PATCH anybus v4 2/7] fieldbus: support the Arcx anybus bridge

[thesven73]

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,
modelled as a regulator.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 drivers/fieldbus/Kconfig         |  10 +
 drivers/fieldbus/Makefile        |   1 +
 drivers/fieldbus/anybus-bridge.c | 321 +++++++++++++++++++++++++++++++
 3 files changed, 332 insertions(+)
 create mode 100644 drivers/fieldbus/anybus-bridge.c

diff --git a/drivers/fieldbus/Kconfig b/drivers/fieldbus/Kconfig
index 1d1929ba7e27..fc2e20b59b38 100644
--- a/drivers/fieldbus/Kconfig
+++ b/drivers/fieldbus/Kconfig
@@ -16,4 +16,14 @@ menuconfig FIELDBUS_DEV
 
 if FIELDBUS_DEV
 
+config ARCX_ANYBUS_BRIDGE
+	tristate "Arcx Anybus-S Bridge"
+	depends on OF && 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,
+	  modelled as a regulator.
+
 endif
diff --git a/drivers/fieldbus/Makefile b/drivers/fieldbus/Makefile
index 768a116fc9c6..a623722aace6 100644
--- a/drivers/fieldbus/Makefile
+++ b/drivers/fieldbus/Makefile
@@ -7,3 +7,4 @@ obj-$(CONFIG_FIELDBUS_DEV)	+= fieldbus_dev_core.o
 fieldbus_dev_core-y		:= dev_core.o
 
 # Devices
+obj-$(CONFIG_ARCX_ANYBUS_BRIDGE) += anybus-bridge.o
diff --git a/drivers/fieldbus/anybus-bridge.c b/drivers/fieldbus/anybus-bridge.c
new file mode 100644
index 000000000000..9eee39efc3aa
--- /dev/null
+++ b/drivers/fieldbus/anybus-bridge.c
@@ -0,0 +1,321 @@
+// 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/consumer.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/idr.h>
+#include <linux/spinlock.h>
+#include <linux/reset-controller.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/machine.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;
+	struct gpio_desc *reset_gpiod;
+	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 struct attribute *bridge_attributes[] = {
+	&dev_attr_version.attr,
+	&dev_attr_design_number.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 int can_power_is_enabled(struct regulator_dev *rdev)
+{
+	struct bridge_priv *cd = rdev_get_drvdata(rdev);
+
+	return !(readb(cd->cpld_base + CPLD_STATUS1) & CPLD_STATUS1_CAN_POWER);
+}
+
+static struct regulator_ops can_power_ops = {
+	.is_enabled = can_power_is_enabled,
+};
+
+static const struct regulator_desc can_power_desc = {
+	.name = "regulator-can-power",
+	.id = -1,
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+	.ops = &can_power_ops,
+};
+
+static struct class *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 regulator_config config = { };
+	struct regulator_dev *regulator;
+	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_gpiod = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(cd->reset_gpiod))
+		return PTR_ERR(cd->reset_gpiod);
+
+	/* CPLD control memory, sits at index 0 */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cd->cpld_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cd->cpld_base)) {
+		dev_err(dev,
+			"failed to map cpld base address\n");
+		err = PTR_ERR(cd->cpld_base);
+		goto out_reset;
+	}
+
+	/* identify cpld */
+	status1 = readb(cd->cpld_base + CPLD_STATUS1);
+	cd->design_no = (readb(cd->cpld_base + CPLD_DESIGN_HI) << 8) |
+				readb(cd->cpld_base + CPLD_DESIGN_LO);
+	snprintf(cd->version, sizeof(cd->version), "%c%d",
+			'A' + ((status1>>5) & 0x7),
+			(status1>>2) & 0x7);
+	dev_info(dev, "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);
+		err = -ENODEV;
+		goto out_reset;
+	}
+
+	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)
+			goto out_reset;
+	}
+
+	id = ida_simple_get(&bridge_index_ida, 0, 0, GFP_KERNEL);
+	if (id < 0) {
+		err = id;
+		goto out_reset;
+	}
+	/* export can power readout as a regulator */
+	config.dev = dev;
+	config.driver_data = cd;
+	regulator = devm_regulator_register(dev, &can_power_desc, &config);
+	if (IS_ERR(regulator)) {
+		err = PTR_ERR(regulator);
+		goto out_reset;
+	}
+	/* make 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);
+out_reset:
+	gpiod_set_value_cansleep(cd->reset_gpiod, 1);
+	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);
+	gpiod_set_value_cansleep(cd->reset_gpiod, 1);
+	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 v4 3/7] dt-bindings: Add vendor prefix for arcx / Archronix

[thesven73]

arcx Inc. is an engineering company which provides advanced
embedded systems and consulting services.

Archronix is a technology design and product engineering firm
specializing in hardware control systems and enabling software.
Clients include OEM's in the transportation, aerospace,
medical and commercial sectors.

Websites:
	http://www.arcx.com/
	http://www.archronix.com/

Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 Documentation/devicetree/bindings/vendor-prefixes.txt | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
index 2c3fc512e746..2ad1128c4470 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 Inc. / Archronix Inc.
 aries	Aries Embedded GmbH
 arm	ARM Ltd.
 armadeus	ARMadeus Systems SARL
-- 
2.17.1

[PATCH anybus v4 4/7] dt-bindings: anybus-bridge: document devicetree binding

[thesven73]

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

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 .../bindings/fieldbus/arcx,anybus-bridge.txt  | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybus-bridge.txt

diff --git a/Documentation/devicetree/bindings/fieldbus/arcx,anybus-bridge.txt b/Documentation/devicetree/bindings/fieldbus/arcx,anybus-bridge.txt
new file mode 100644
index 000000000000..cb801b7568b0
--- /dev/null
+++ b/Documentation/devicetree/bindings/fieldbus/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>;
+	};
+};
-- 
2.17.1

[PATCH anybus v4 5/7] fieldbus: support HMS Anybus-S bus

[thesven73]

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/fieldbus/Kconfig        |   10 +
 drivers/fieldbus/Makefile       |    1 +
 drivers/fieldbus/anybuss-host.c | 1497 +++++++++++++++++++++++++++++++
 include/linux/anybuss-client.h  |  104 +++
 4 files changed, 1612 insertions(+)
 create mode 100644 drivers/fieldbus/anybuss-host.c
 create mode 100644 include/linux/anybuss-client.h

diff --git a/drivers/fieldbus/Kconfig b/drivers/fieldbus/Kconfig
index fc2e20b59b38..00a163a2cbe6 100644
--- a/drivers/fieldbus/Kconfig
+++ b/drivers/fieldbus/Kconfig
@@ -26,4 +26,14 @@ config ARCX_ANYBUS_BRIDGE
 	  There is also a CAN power readout, unrelated to the Anybus,
 	  modelled as a regulator.
 
+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.
+
 endif
diff --git a/drivers/fieldbus/Makefile b/drivers/fieldbus/Makefile
index a623722aace6..c47a4bd416f6 100644
--- a/drivers/fieldbus/Makefile
+++ b/drivers/fieldbus/Makefile
@@ -8,3 +8,4 @@ fieldbus_dev_core-y		:= dev_core.o
 
 # Devices
 obj-$(CONFIG_ARCX_ANYBUS_BRIDGE) += anybus-bridge.o
+obj-$(CONFIG_HMS_ANYBUSS_HOST)	+= anybuss-host.o
diff --git a/drivers/fieldbus/anybuss-host.c b/drivers/fieldbus/anybuss-host.c
new file mode 100644
index 000000000000..ebccd236a8e2
--- /dev/null
+++ b/drivers/fieldbus/anybuss-host.c
@@ -0,0 +1,1497 @@
+// 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.
+ *
+ * [1] https://www.anybus.com/docs/librariesprovider7/default-document-library/
+ *	manuals-design-guides/hms-hmsi-27-275.pdf
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/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/kref.h>
+#include <linux/of_address.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
+
+/*
+ * ---------------------------------------------------------------
+ * Anybus mailbox messages - definitions
+ * ---------------------------------------------------------------
+ * note that we're depending on the layout of these structures being
+ * exactly as advertised.
+ */
+
+struct anybus_mbox_hdr {
+	__be16 id;
+	__be16 info;
+	__be16 cmd_num;
+	__be16 data_size;
+	__be16 frame_count;
+	__be16 frame_num;
+	__be16 offset_high;
+	__be16 offset_low;
+	__be16 extended[8];
+};
+
+struct msgAnybusInit {
+	__be16 input_io_len;
+	__be16 input_dpram_len;
+	__be16 input_total_len;
+	__be16 output_io_len;
+	__be16 output_dpram_len;
+	__be16 output_total_len;
+	__be16 op_mode;
+	__be16 notif_config;
+	__be16 wd_val;
+};
+
+/* ------------- ref counted tasks ------------- */
+
+struct ab_task;
+typedef int (*ab_task_fn_t)(struct anybuss_host *cd,
+					struct ab_task *t);
+typedef void (*ab_done_fn_t)(struct anybuss_host *cd);
+
+struct area_priv {
+	bool is_write;
+	u16 flags;
+	u16 addr;
+	size_t count;
+	u8 buf[MAX_DATA_AREA_SZ];
+};
+
+struct mbox_priv {
+	struct anybus_mbox_hdr hdr;
+	size_t msg_out_sz;
+	size_t msg_in_sz;
+	u8 msg[MAX_MBOX_MSG_SZ];
+};
+
+struct ab_task {
+	struct kmem_cache	*cache;
+	struct kref		refcount;
+	ab_task_fn_t		task_fn;
+	ab_done_fn_t		done_fn;
+	int			result;
+	struct completion	done;
+	unsigned long		start_jiffies;
+	union {
+		struct area_priv area_pd;
+		struct mbox_priv mbox_pd;
+	};
+};
+
+static struct ab_task *ab_task_create_get(struct kmem_cache *cache,
+			ab_task_fn_t task_fn)
+{
+	struct ab_task *t;
+
+	t = kmem_cache_alloc(cache, GFP_KERNEL);
+	if (!t)
+		return NULL;
+	t->cache = cache;
+	kref_init(&t->refcount);
+	t->task_fn = task_fn;
+	t->done_fn = NULL;
+	t->result = 0;
+	init_completion(&t->done);
+	return t;
+}
+
+static void __ab_task_destroy(struct kref *refcount)
+{
+	struct ab_task *t = container_of(refcount, struct ab_task, refcount);
+	struct kmem_cache *cache = t->cache;
+
+	kmem_cache_free(cache, t);
+}
+
+static void ab_task_put(struct ab_task *t)
+{
+	kref_put(&t->refcount, __ab_task_destroy);
+}
+
+static struct ab_task *__ab_task_get(struct ab_task *t)
+{
+	kref_get(&t->refcount);
+	return t;
+}
+
+static void __ab_task_finish(struct ab_task *t, struct anybuss_host *cd)
+{
+	if (t->done_fn)
+		t->done_fn(cd);
+	complete(&t->done);
+}
+
+static void
+ab_task_dequeue_finish_put(struct kfifo *q, struct anybuss_host *cd)
+{
+	int ret;
+	struct ab_task *t;
+
+	ret = kfifo_out(q, &t, sizeof(t));
+	WARN_ON(!ret);
+	__ab_task_finish(t, cd);
+	ab_task_put(t);
+}
+
+static int
+ab_task_enqueue(struct ab_task *t, struct kfifo *q, spinlock_t *slock,
+		wait_queue_head_t *wq)
+{
+	int ret;
+
+	t->start_jiffies = jiffies;
+	__ab_task_get(t);
+	ret = kfifo_in_spinlocked(q, &t, sizeof(t), slock);
+	if (!ret) {
+		ab_task_put(t);
+		return -ENOMEM;
+	}
+	wake_up(wq);
+	return 0;
+}
+
+static int
+ab_task_enqueue_wait(struct ab_task *t, struct kfifo *q, spinlock_t *slock,
+		     wait_queue_head_t *wq)
+{
+	int ret;
+
+	ret = ab_task_enqueue(t, q, slock, wq);
+	if (ret)
+		return ret;
+	ret = wait_for_completion_interruptible(&t->done);
+	if (ret)
+		return ret;
+	return t->result;
+}
+
+/* ------------------------ anybus hardware ------------------------ */
+
+struct anybuss_host {
+	struct device *dev;
+	struct anybuss_client *client;
+	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;
+};
+
+static int test_dpram(struct regmap *regmap)
+{
+	int i;
+	unsigned int val;
+
+	for (i = 0; i < DPRAM_SIZE; i++)
+		regmap_write(regmap, i, (u8)i);
+	for (i = 0; i < DPRAM_SIZE; i++) {
+		regmap_read(regmap, i, &val);
+		if ((u8)val != (u8)i)
+			return -EIO;
+	}
+	return 0;
+}
+
+static int read_ind_ab(struct regmap *regmap)
+{
+	unsigned long timeout = jiffies + HZ/2;
+	unsigned int a, b, i = 0;
+
+	while (time_before_eq(jiffies, timeout)) {
+		regmap_read(regmap, REG_IND_AB, &a);
+		regmap_read(regmap, REG_IND_AB, &b);
+		if (likely(a == b))
+			return (int)a;
+		if (i < 10) {
+			cpu_relax();
+			i++;
+		} else {
+			usleep_range(500, 1000);
+		}
+	}
+	WARN(1, "IND_AB register not stable");
+	return -ETIMEDOUT;
+}
+
+static int write_ind_ap(struct regmap *regmap, unsigned int ind_ap)
+{
+	unsigned long timeout = jiffies + HZ/2;
+	unsigned int v, i = 0;
+
+	while (time_before_eq(jiffies, timeout)) {
+		regmap_write(regmap, REG_IND_AP, ind_ap);
+		regmap_read(regmap, REG_IND_AP, &v);
+		if (likely(ind_ap == v))
+			return 0;
+		if (i < 10) {
+			cpu_relax();
+			i++;
+		} else {
+			usleep_range(500, 1000);
+		}
+	}
+	WARN(1, "IND_AP register not stable");
+	return -ETIMEDOUT;
+}
+
+static irqreturn_t irq_handler(int irq, void *data)
+{
+	struct anybuss_host *cd = data;
+	int ind_ab;
+
+	/*
+	 * irq handler needs exclusive access to the IND_AB register,
+	 * because the act of reading the register acks the interrupt.
+	 *
+	 * store the register value in cd->ind_ab (an atomic_t), so that the
+	 * queue thread is able to read it without causing an interrupt ack
+	 * side-effect (and without spuriously acking an interrupt).
+	 */
+	ind_ab = read_ind_ab(cd->regmap);
+	if (ind_ab < 0)
+		return IRQ_NONE;
+	atomic_set(&cd->ind_ab, ind_ab);
+	complete(&cd->card_boot);
+	wake_up(&cd->wq);
+	return IRQ_HANDLED;
+}
+
+/* ------------------------ power on/off tasks --------------------- */
+
+static int task_fn_power_off(struct anybuss_host *cd,
+				struct ab_task *t)
+{
+	struct anybuss_client *client = cd->client;
+
+	if (!cd->power_on)
+		return 0;
+	disable_irq(cd->irq);
+	reset_control_assert(cd->reset);
+	atomic_set(&cd->ind_ab, IND_AB_UPDATED);
+	if (client->on_online_changed)
+		client->on_online_changed(client, false);
+	cd->power_on = false;
+	return 0;
+}
+
+static int task_fn_power_on_2(struct anybuss_host *cd,
+				struct ab_task *t)
+{
+	if (completion_done(&cd->card_boot)) {
+		cd->power_on = true;
+		return 0;
+	}
+	if (time_after(jiffies, t->start_jiffies + TIMEOUT)) {
+		disable_irq(cd->irq);
+		reset_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(t, cd->powerq, &cd->qlock, &cd->wq);
+	ab_task_put(t);
+	return err;
+}
+EXPORT_SYMBOL_GPL(anybuss_set_power);
+
+/* ---------------------------- area tasks ------------------------ */
+
+static int task_fn_area_3(struct anybuss_host *cd, struct ab_task *t)
+{
+	struct area_priv *pd = &t->area_pd;
+
+	if (!cd->power_on)
+		return -EIO;
+	if (atomic_read(&cd->ind_ab) & pd->flags) {
+		/* area not released yet */
+		if (time_after(jiffies, t->start_jiffies + TIMEOUT))
+			return -ETIMEDOUT;
+		return -EINPROGRESS;
+	}
+	return 0;
+}
+
+static int task_fn_area_2(struct anybuss_host *cd, struct ab_task *t)
+{
+	struct area_priv *pd = &t->area_pd;
+	unsigned int ind_ap;
+	int ret;
+
+	if (!cd->power_on)
+		return -EIO;
+	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
+	if (!(atomic_read(&cd->ind_ab) & pd->flags)) {
+		/* we don't own the area yet */
+		if (time_after(jiffies, t->start_jiffies + TIMEOUT)) {
+			dev_warn(cd->dev, "timeout waiting for area");
+			dump_stack();
+			return -ETIMEDOUT;
+		}
+		return -EINPROGRESS;
+	}
+	/* we own the area, do what we're here to do */
+	if (pd->is_write)
+		regmap_bulk_write(cd->regmap, pd->addr, pd->buf,
+							pd->count);
+	else
+		regmap_bulk_read(cd->regmap, pd->addr, pd->buf,
+							pd->count);
+	/* ask to release the area, must use unlocked release */
+	ind_ap &= ~IND_AP_ABITS;
+	ind_ap |= pd->flags;
+	ret = write_ind_ap(cd->regmap, ind_ap);
+	if (ret)
+		return ret;
+	t->task_fn = task_fn_area_3;
+	return -EINPROGRESS;
+}
+
+static int task_fn_area(struct anybuss_host *cd, struct ab_task *t)
+{
+	struct area_priv *pd = &t->area_pd;
+	unsigned int ind_ap;
+	int ret;
+
+	if (!cd->power_on)
+		return -EIO;
+	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
+	/* ask to take the area */
+	ind_ap &= ~IND_AP_ABITS;
+	ind_ap |= pd->flags | IND_AP_ACTION | IND_AP_LOCK;
+	ret = write_ind_ap(cd->regmap, ind_ap);
+	if (ret)
+		return ret;
+	t->task_fn = task_fn_area_2;
+	return -EINPROGRESS;
+}
+
+static struct ab_task *
+create_area_reader(struct kmem_cache *qcache, u16 flags, u16 addr,
+				size_t count)
+{
+	struct ab_task *t;
+	struct area_priv *ap;
+
+	t = ab_task_create_get(qcache, task_fn_area);
+	if (!t)
+		return NULL;
+	ap = &t->area_pd;
+	ap->flags = flags;
+	ap->addr = addr;
+	ap->is_write = false;
+	ap->count = count;
+	return t;
+}
+
+static struct ab_task *
+create_area_writer(struct kmem_cache *qcache, u16 flags, u16 addr,
+				const void *buf, size_t count)
+{
+	struct ab_task *t;
+	struct area_priv *ap;
+
+	t = ab_task_create_get(qcache, task_fn_area);
+	if (!t)
+		return NULL;
+	ap = &t->area_pd;
+	ap->flags = flags;
+	ap->addr = addr;
+	ap->is_write = true;
+	ap->count = count;
+	memcpy(ap->buf, buf, count);
+	return t;
+}
+
+static struct ab_task *
+create_area_user_writer(struct kmem_cache *qcache, u16 flags, u16 addr,
+				const void __user *buf, size_t count)
+{
+	struct ab_task *t;
+	struct area_priv *ap;
+
+	t = ab_task_create_get(qcache, task_fn_area);
+	if (!t)
+		return ERR_PTR(-ENOMEM);
+	ap = &t->area_pd;
+	ap->flags = flags;
+	ap->addr = addr;
+	ap->is_write = true;
+	ap->count = count;
+	if (copy_from_user(ap->buf, buf, count)) {
+		ab_task_put(t);
+		return ERR_PTR(-EFAULT);
+	}
+	return t;
+}
+
+static bool area_range_ok(u16 addr, size_t count, u16 area_start,
+							size_t area_sz)
+{
+	u16 area_end_ex = area_start + area_sz;
+	u16 addr_end_ex;
+
+	if (addr < area_start)
+		return false;
+	if (addr >= area_end_ex)
+		return false;
+	addr_end_ex = addr + count;
+	if (addr_end_ex > area_end_ex)
+		return false;
+	return true;
+}
+
+/* -------------------------- mailbox tasks ----------------------- */
+
+static int task_fn_mbox_2(struct anybuss_host *cd, struct ab_task *t)
+{
+	struct mbox_priv *pd = &t->mbox_pd;
+	unsigned int ind_ap;
+
+	if (!cd->power_on)
+		return -EIO;
+	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
+	if (((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_MOUT) == 0) {
+		/* output message not here */
+		if (time_after(jiffies, t->start_jiffies + TIMEOUT))
+			return -ETIMEDOUT;
+		return -EINPROGRESS;
+	}
+	/* grab the returned header and msg */
+	regmap_bulk_read(cd->regmap, MBOX_OUT_AREA, &pd->hdr,
+		sizeof(pd->hdr));
+	regmap_bulk_read(cd->regmap, MBOX_OUT_AREA + sizeof(pd->hdr),
+		pd->msg, pd->msg_in_sz);
+	/* tell anybus we've consumed the message */
+	ind_ap ^= IND_AX_MOUT;
+	return write_ind_ap(cd->regmap, ind_ap);
+}
+
+static int task_fn_mbox(struct anybuss_host *cd, struct ab_task *t)
+{
+	struct mbox_priv *pd = &t->mbox_pd;
+	unsigned int ind_ap;
+	int ret;
+
+	if (!cd->power_on)
+		return -EIO;
+	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
+	if ((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_MIN) {
+		/* mbox input area busy */
+		if (time_after(jiffies, t->start_jiffies + TIMEOUT))
+			return -ETIMEDOUT;
+		return -EINPROGRESS;
+	}
+	/* write the header and msg to input area */
+	regmap_bulk_write(cd->regmap, MBOX_IN_AREA, &pd->hdr,
+					sizeof(pd->hdr));
+	regmap_bulk_write(cd->regmap, MBOX_IN_AREA + sizeof(pd->hdr),
+					pd->msg, pd->msg_out_sz);
+	/* tell anybus we gave it a message */
+	ind_ap ^= IND_AX_MIN;
+	ret = write_ind_ap(cd->regmap, ind_ap);
+	if (ret)
+		return ret;
+	t->start_jiffies = jiffies;
+	t->task_fn = task_fn_mbox_2;
+	return -EINPROGRESS;
+}
+
+static void log_invalid_other(struct device *dev,
+				struct anybus_mbox_hdr *hdr)
+{
+	size_t ext_offs = ARRAY_SIZE(hdr->extended) - 1;
+	u16 code = be16_to_cpu(hdr->extended[ext_offs]);
+
+	dev_err(dev, "   Invalid other: [0x%02X]", code);
+}
+
+static const char * const EMSGS[] = {
+	"Invalid Message ID",
+	"Invalid Message Type",
+	"Invalid Command",
+	"Invalid Data Size",
+	"Message Header Malformed (offset 008h)",
+	"Message Header Malformed (offset 00Ah)",
+	"Message Header Malformed (offset 00Ch - 00Dh)",
+	"Invalid Address",
+	"Invalid Response",
+	"Flash Config Error",
+};
+
+static int mbox_cmd_err(struct device *dev, struct mbox_priv *mpriv)
+{
+	int i;
+	u8 ecode;
+	struct anybus_mbox_hdr *hdr = &mpriv->hdr;
+	u16 info = be16_to_cpu(hdr->info);
+	u8 *phdr = (u8 *)hdr;
+	u8 *pmsg = mpriv->msg;
+
+	if (!(info & 0x8000))
+		return 0;
+	ecode = (info >> 8) & 0x0F;
+	dev_err(dev, "mailbox command failed:");
+	if (ecode == 0x0F)
+		log_invalid_other(dev, hdr);
+	else if (ecode < ARRAY_SIZE(EMSGS))
+		dev_err(dev, "   Error code: %s (0x%02X)",
+			EMSGS[ecode], ecode);
+	else
+		dev_err(dev, "   Error code: 0x%02X\n", ecode);
+	dev_err(dev, "Failed command:");
+	dev_err(dev, "Message Header:");
+	for (i = 0; i < sizeof(mpriv->hdr); i += 2)
+		dev_err(dev, "%02X%02X", phdr[i], phdr[i+1]);
+	dev_err(dev, "Message Data:");
+	for (i = 0; i < mpriv->msg_in_sz; i += 2)
+		dev_err(dev, "%02X%02X", pmsg[i], pmsg[i+1]);
+	dev_err(dev, "Stack dump:");
+	dump_stack();
+	return -EIO;
+}
+
+static int _anybus_mbox_cmd(struct anybuss_host *cd,
+				u16 cmd_num, bool is_fb_cmd,
+				const void *msg_out, size_t msg_out_sz,
+				void *msg_in, size_t msg_in_sz,
+				const void *ext, size_t ext_sz)
+{
+	struct ab_task *t;
+	struct mbox_priv *pd;
+	struct anybus_mbox_hdr *h;
+	size_t msg_sz = max(msg_in_sz, msg_out_sz);
+	u16 info;
+	int err;
+
+	if (msg_sz > MAX_MBOX_MSG_SZ)
+		return -EINVAL;
+	if (ext && (ext_sz > sizeof(h->extended)))
+		return -EINVAL;
+	t = ab_task_create_get(cd->qcache, task_fn_mbox);
+	if (!t)
+		return -ENOMEM;
+	pd = &t->mbox_pd;
+	h = &pd->hdr;
+	info = is_fb_cmd ? INFO_TYPE_FB : INFO_TYPE_APP;
+	/*
+	 * prevent uninitialized memory in the header from being sent
+	 * across the anybus
+	 */
+	memset(h, 0, sizeof(*h));
+	h->info = cpu_to_be16(info | INFO_COMMAND);
+	h->cmd_num = cpu_to_be16(cmd_num);
+	h->data_size = cpu_to_be16(msg_out_sz);
+	h->frame_count = cpu_to_be16(1);
+	h->frame_num = cpu_to_be16(1);
+	h->offset_high = cpu_to_be16(0);
+	h->offset_low = cpu_to_be16(0);
+	if (ext)
+		memcpy(h->extended, ext, ext_sz);
+	memcpy(pd->msg, msg_out, msg_out_sz);
+	pd->msg_out_sz = msg_out_sz;
+	pd->msg_in_sz = msg_in_sz;
+	err = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
+	if (err)
+		goto out;
+	/*
+	 * mailbox mechanism worked ok, but maybe the mbox response
+	 * contains an error ?
+	 */
+	err = mbox_cmd_err(cd->dev, pd);
+	if (err)
+		goto out;
+	memcpy(msg_in, pd->msg, msg_in_sz);
+out:
+	ab_task_put(t);
+	return err;
+}
+
+/* ------------------------ anybus queues ------------------------ */
+
+static void process_q(struct anybuss_host *cd, struct kfifo *q)
+{
+	struct ab_task *t;
+	int ret;
+
+	ret = kfifo_out_peek(q, &t, sizeof(t));
+	if (!ret)
+		return;
+	t->result = t->task_fn(cd, t);
+	if (t->result != -EINPROGRESS)
+		ab_task_dequeue_finish_put(q, cd);
+}
+
+static bool qs_have_work(struct kfifo *qs, size_t num)
+{
+	size_t i;
+	struct ab_task *t;
+	int ret;
+
+	for (i = 0; i < num; i++, qs++) {
+		ret = kfifo_out_peek(qs, &t, sizeof(t));
+		if (ret && (t->result != -EINPROGRESS))
+			return true;
+	}
+	return false;
+}
+
+static void process_qs(struct anybuss_host *cd)
+{
+	size_t i;
+	struct kfifo *qs = cd->qs;
+	size_t nqs = ARRAY_SIZE(cd->qs);
+
+	for (i = 0; i < nqs; i++, qs++)
+		process_q(cd, qs);
+}
+
+static void softint_ack(struct anybuss_host *cd)
+{
+	unsigned int ind_ap;
+
+	cd->softint_pending = false;
+	if (!cd->power_on)
+		return;
+	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
+	ind_ap &= ~IND_AX_EVNT;
+	ind_ap |= atomic_read(&cd->ind_ab) & IND_AX_EVNT;
+	write_ind_ap(cd->regmap, ind_ap);
+}
+
+static void process_softint(struct anybuss_host *cd)
+{
+	struct anybuss_client *client = cd->client;
+	static const u8 zero;
+	int ret;
+	unsigned int ind_ap, ev;
+	struct ab_task *t;
+
+	if (!cd->power_on)
+		return;
+	if (cd->softint_pending)
+		return;
+	regmap_read(cd->regmap, REG_IND_AP, &ind_ap);
+	if (!((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_EVNT))
+		return;
+	/* process software interrupt */
+	regmap_read(cd->regmap, REG_EVENT_CAUSE, &ev);
+	if (ev & EVENT_CAUSE_FBON) {
+		if (client->on_online_changed)
+			client->on_online_changed(client, true);
+		dev_dbg(cd->dev, "Fieldbus ON");
+	}
+	if (ev & EVENT_CAUSE_FBOF) {
+		if (client->on_online_changed)
+			client->on_online_changed(client, false);
+		dev_dbg(cd->dev, "Fieldbus OFF");
+	}
+	if (ev & EVENT_CAUSE_DC) {
+		if (client->on_area_updated)
+			client->on_area_updated(client);
+		dev_dbg(cd->dev, "Fieldbus data changed");
+	}
+	/*
+	 * reset the event cause bits.
+	 * this must be done while owning the fbctrl area, so we'll
+	 * enqueue a task to do that.
+	 */
+	t = create_area_writer(cd->qcache, IND_AX_FBCTRL,
+		REG_EVENT_CAUSE, &zero, sizeof(zero));
+	if (!t) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	t->done_fn = softint_ack;
+	ret = ab_task_enqueue(t, cd->powerq, &cd->qlock, &cd->wq);
+	ab_task_put(t);
+	cd->softint_pending = true;
+out:
+	WARN_ON(ret);
+	if (ret)
+		softint_ack(cd);
+}
+
+static int qthread_fn(void *data)
+{
+	struct anybuss_host *cd = data;
+	struct kfifo *qs = cd->qs;
+	size_t nqs = ARRAY_SIZE(cd->qs);
+	unsigned int ind_ab;
+
+	/*
+	 * this kernel thread has exclusive access to the anybus's memory.
+	 * only exception: the IND_AB register, which is accessed exclusively
+	 * by the interrupt service routine (ISR). This thread must not touch
+	 * the IND_AB register, but it does require access to its value.
+	 *
+	 * the interrupt service routine stores the register's value in
+	 * cd->ind_ab (an atomic_t), where we may safely access it, with the
+	 * understanding that it can be modified by the ISR at any time.
+	 */
+
+	while (!kthread_should_stop()) {
+		/*
+		 * make a local copy of IND_AB, so we can go around the loop
+		 * again in case it changed while processing queues and softint.
+		 */
+		ind_ab = atomic_read(&cd->ind_ab);
+		process_qs(cd);
+		process_softint(cd);
+		wait_event_timeout(cd->wq,
+			(atomic_read(&cd->ind_ab) != ind_ab) ||
+				qs_have_work(qs, nqs) ||
+				kthread_should_stop(),
+			HZ);
+		/*
+		 * time out so even 'stuck' tasks will run eventually,
+		 * and can time out.
+		 */
+	}
+
+	return 0;
+}
+
+/* ------------------------ anybus exports ------------------------ */
+
+int anybuss_start_init(struct anybuss_client *client,
+			const struct anybuss_memcfg *cfg)
+{
+	int ret;
+	u16 op_mode;
+	struct anybuss_host *cd = client->host;
+	struct 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(t, cd->powerq, &cd->qlock, &cd->wq);
+	if (ret)
+		goto out;
+	memcpy(buf, t->area_pd.buf, count);
+out:
+	ab_task_put(t);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(anybuss_read_fbctrl);
+
+int anybuss_write_input(struct anybuss_client *client,
+				const char __user *buf, size_t size,
+				loff_t *offset)
+{
+	ssize_t len = min_t(loff_t, MAX_DATA_AREA_SZ - *offset, size);
+	struct anybuss_host *cd = client->host;
+	struct ab_task *t;
+	int ret;
+
+	if (len <= 0)
+		return 0;
+	t = create_area_user_writer(cd->qcache, IND_AX_IN,
+		DATA_IN_AREA + *offset, buf, len);
+	if (IS_ERR(t))
+		return PTR_ERR(t);
+	ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
+	ab_task_put(t);
+	if (ret)
+		return ret;
+	/* success */
+	*offset += len;
+	return len;
+}
+EXPORT_SYMBOL_GPL(anybuss_write_input);
+
+int anybuss_read_output(struct anybuss_client *client,
+				char __user *buf, size_t size,
+				loff_t *offset)
+{
+	ssize_t len = min_t(loff_t, MAX_DATA_AREA_SZ - *offset, size);
+	struct anybuss_host *cd = client->host;
+	struct ab_task *t;
+	int ret;
+
+	if (len <= 0)
+		return 0;
+	t = create_area_reader(cd->qcache, IND_AX_OUT,
+		DATA_OUT_AREA + *offset, len);
+	if (!t)
+		return -ENOMEM;
+	ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq);
+	if (ret)
+		goto out;
+	if (copy_to_user(buf, t->area_pd.buf, len))
+		ret = -EFAULT;
+out:
+	ab_task_put(t);
+	if (ret)
+		return ret;
+	/* success */
+	*offset += len;
+	return len;
+}
+EXPORT_SYMBOL_GPL(anybuss_read_output);
+
+int anybuss_send_msg(struct anybuss_client *client, u16 cmd_num,
+				const void *buf, size_t count)
+{
+	struct anybuss_host *cd = client->host;
+
+	return _anybus_mbox_cmd(cd, cmd_num, true, buf, count, NULL, 0,
+					NULL, 0);
+}
+EXPORT_SYMBOL_GPL(anybuss_send_msg);
+
+int anybuss_send_ext(struct anybuss_client *client, u16 cmd_num,
+	const void *buf, size_t count)
+{
+	struct anybuss_host *cd = client->host;
+
+	return _anybus_mbox_cmd(cd, cmd_num, true, NULL, 0, NULL, 0,
+					buf, count);
+}
+EXPORT_SYMBOL_GPL(anybuss_send_ext);
+
+int anybuss_recv_msg(struct anybuss_client *client, u16 cmd_num,
+	void *buf, size_t count)
+{
+	struct anybuss_host *cd = client->host;
+
+	return _anybus_mbox_cmd(cd, cmd_num, true, NULL, 0, buf, count,
+					NULL, 0);
+}
+EXPORT_SYMBOL_GPL(anybuss_recv_msg);
+
+/* ------------------------ bus functions ------------------------ */
+
+static int anybus_bus_match(struct device *dev,
+				struct device_driver *drv)
+{
+	struct anybuss_client_driver *adrv =
+		to_anybuss_client_driver(drv);
+	struct anybuss_client *adev =
+		to_anybuss_client(dev);
+
+	return adrv->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);
+
+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_of_get_fieldbus(struct device_node *np)
+{
+	const __be32 *fieldbus_type;
+
+	fieldbus_type = of_get_address(np, 0, NULL, NULL);
+	if (!fieldbus_type)
+		return -ENOENT;
+	return __be32_to_cpu(*fieldbus_type);
+}
+
+static struct device_node *anybus_of_find_child_device(
+			struct platform_device *pdev, int fieldbus_type)
+{
+	struct device_node *node;
+
+	if (!pdev || !pdev->dev.of_node)
+		return NULL;
+	for_each_child_of_node(pdev->dev.of_node, node) {
+		if (anybus_of_get_fieldbus(node) == fieldbus_type)
+			return node;
+	}
+	return NULL;
+}
+
+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);
+	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);
+	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_threaded_irq(dev, cd->irq, NULL, irq_handler,
+			IRQF_ONESHOT, dev_name(dev), cd);
+	if (ret) {
+		dev_err(dev, "could not request irq");
+		goto err_qcache;
+	}
+	/*
+	 * startup sequence:
+	 *   perform dummy IND_AB read to prevent false 'init done' irq
+	 *     (already done by test_dpram() above)
+	 *   release reset
+	 *   wait for first interrupt
+	 *   interrupt came in: ready to go !
+	 */
+	reset_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);
+	/* fire up the queue thread */
+	cd->qthread = kthread_run(qthread_fn, cd, dev_name(dev));
+	if (IS_ERR(cd->qthread)) {
+		dev_err(dev, "could not create kthread");
+		ret = PTR_ERR(cd->qthread);
+		goto err_reset;
+	}
+	/*
+	 * now advertise that we've detected a client device (card).
+	 * the bus infrastructure will match it to a client driver.
+	 */
+	cd->client = kzalloc(sizeof(*cd->client), GFP_KERNEL);
+	if (!cd->client) {
+		ret = -ENOMEM;
+		goto err_kthread;
+	}
+	cd->client->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;
+	cd->client->dev.of_node =
+		anybus_of_find_child_device(pdev, fieldbus_type);
+	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_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);
+	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..a90b89eb5e26
--- /dev/null
+++ b/include/linux/anybuss-client.h
@@ -0,0 +1,104 @@
+/* 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;
+	/*
+	 * these can be optionally set by the client to receive event
+	 * notifications from the host.
+	 */
+	void (*on_area_updated)(struct anybuss_client *client);
+	void (*on_online_changed)(struct anybuss_client *client, bool online);
+};
+
+struct anybuss_client_driver {
+	struct device_driver driver;
+	int (*probe)(struct anybuss_client *adev);
+	int (*remove)(struct anybuss_client *adev);
+	u16 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,
+				char __user *buf, size_t size,
+				loff_t *offset);
+
+#endif /* __LINUX_ANYBUSS_CLIENT_H__ */
-- 
2.17.1

[PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[thesven73]

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

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 .../bindings/fieldbus/arcx,anybuss-host.txt   | 66 +++++++++++++++++++
 1 file changed, 66 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt

diff --git a/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt b/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
new file mode 100644
index 000000000000..456587f288c1
--- /dev/null
+++ b/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
@@ -0,0 +1,66 @@
+* 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.
+
+Optional: use of subnodes
+-------------------------
+
+The card connected to a host may need additional properties. These can be
+specified in subnodes to the host node.
+
+The subnodes are identified by the standard 'reg' property. Which information
+exactly can be specified depends on the bindings for the function driver
+for the subnode.
+
+Required host node properties when using subnodes:
+- #address-cells: should be one.
+- #size-cells: should be zero.
+
+Required subnode properties:
+- reg: Must contain the fieldbus type of the card this subnode describes.
+
+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>;
+		/*
+		 * optional subnode for a profinet card
+		 * (fieldbus type = 0x0089)
+		 */
+		#address-cells = <1>;
+		#size-cells = <0>;
+		profinet@0 {
+			reg = <0x0089>;
+			/* profinet specific properties go here */
+		};
+	};
+
+};
-- 
2.17.1

[PATCH anybus v4 7/7] fieldbus_dev: support HMS Profinet IRT industrial controller

[thesven73]

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 registers itself as a fieldbus_dev,
and userspace can access it through the fieldbus_dev interface.

Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
---
 drivers/fieldbus/Kconfig        |  17 +++
 drivers/fieldbus/Makefile       |   1 +
 drivers/fieldbus/hms-profinet.c | 223 ++++++++++++++++++++++++++++++++
 3 files changed, 241 insertions(+)
 create mode 100644 drivers/fieldbus/hms-profinet.c

diff --git a/drivers/fieldbus/Kconfig b/drivers/fieldbus/Kconfig
index 00a163a2cbe6..12b0fef591fb 100644
--- a/drivers/fieldbus/Kconfig
+++ b/drivers/fieldbus/Kconfig
@@ -36,4 +36,21 @@ config HMS_ANYBUSS_HOST
 	  typically provide fieldbus and industrial ethernet
 	  functionality.
 
+config HMS_PROFINET
+	tristate "HMS Profinet IRT Controller (Anybus-S)"
+	depends on FIELDBUS_DEV
+	select HMS_ANYBUSS_HOST
+	help
+	 If you say yes here you get support for the HMS Industrial
+	 Networks Profinet IRT Controller.
+
+	 It will be registered with the kernel as a fieldbus_dev,
+	 so userspace can interact with it via the fieldbus_dev userspace
+	 interface(s).
+
+	 This driver can also be built as a module. If so, the module
+	 will be called hms-profinet.
+
+	 If unsure, say N.
+
 endif
diff --git a/drivers/fieldbus/Makefile b/drivers/fieldbus/Makefile
index c47a4bd416f6..c3161c5ce0f1 100644
--- a/drivers/fieldbus/Makefile
+++ b/drivers/fieldbus/Makefile
@@ -9,3 +9,4 @@ fieldbus_dev_core-y		:= dev_core.o
 # Devices
 obj-$(CONFIG_ARCX_ANYBUS_BRIDGE) += anybus-bridge.o
 obj-$(CONFIG_HMS_ANYBUSS_HOST)	+= anybuss-host.o
+obj-$(CONFIG_HMS_PROFINET)	+= hms-profinet.o
diff --git a/drivers/fieldbus/hms-profinet.c b/drivers/fieldbus/hms-profinet.c
new file mode 100644
index 000000000000..434437829339
--- /dev/null
+++ b/drivers/fieldbus/hms-profinet.c
@@ -0,0 +1,223 @@
+// 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/fieldbus_dev.h>
+#include <linux/anybuss-client.h>
+
+#define PROFI_DPRAM_SIZE	512
+
+/*
+ * ---------------------------------------------------------------
+ * Anybus Profinet mailbox messages - definitions
+ * ---------------------------------------------------------------
+ * note that we're depending on the layout of these structures being
+ * exactly as advertised.
+ */
+
+struct msgMacAddr {
+	u8 addr[6];
+};
+
+struct profi_priv {
+	struct fieldbus_dev fbdev;
+	struct anybuss_client *client;
+	struct mutex enable_lock;
+	bool power_on;
+};
+
+static ssize_t
+profi_read_area(struct fieldbus_dev *fbdev, char __user *buf, size_t size,
+			loff_t *offset)
+{
+	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
+
+	return anybuss_read_output(priv->client, buf, size, offset);
+}
+
+static ssize_t
+profi_write_area(struct fieldbus_dev *fbdev, const char __user *buf,
+			size_t size, loff_t *offset)
+{
+	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
+
+	return anybuss_write_input(priv->client, buf, size, offset);
+}
+
+static int profi_id_get(struct fieldbus_dev *fbdev, char *buf,
+				size_t max_size)
+{
+	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
+	struct msgMacAddr response;
+	int ret;
+
+	ret = anybuss_recv_msg(priv->client, 0x0010, &response,
+						sizeof(response));
+	if (ret < 0)
+		return ret;
+	return snprintf(buf, max_size, "%02X:%02X:%02X:%02X:%02X:%02X\n",
+		response.addr[0], response.addr[1],
+		response.addr[2], response.addr[3],
+		response.addr[4], response.addr[5]);
+}
+
+static bool profi_enable_get(struct fieldbus_dev *fbdev)
+{
+	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
+	bool power_on;
+
+	mutex_lock(&priv->enable_lock);
+	power_on = priv->power_on;
+	mutex_unlock(&priv->enable_lock);
+
+	return power_on;
+}
+
+static int __profi_enable(struct profi_priv *priv)
+{
+	int ret;
+	struct anybuss_client *client = priv->client;
+	/* Initialization Sequence, Generic Anybus Mode */
+	const struct anybuss_memcfg mem_cfg = {
+		.input_io = 220,
+		.input_dpram = PROFI_DPRAM_SIZE,
+		.input_total = PROFI_DPRAM_SIZE,
+		.output_io = 220,
+		.output_dpram = PROFI_DPRAM_SIZE,
+		.output_total = PROFI_DPRAM_SIZE,
+		.offl_mode = AB_OFFL_MODE_CLEAR,
+	};
+
+	/*
+	 * switch anybus off then on, this ensures we can do a complete
+	 * configuration cycle in case anybus was already on.
+	 */
+	anybuss_set_power(client, false);
+	ret = anybuss_set_power(client, true);
+	if (ret)
+		goto err;
+	ret = anybuss_start_init(client, &mem_cfg);
+	if (ret)
+		goto err;
+	ret = anybuss_finish_init(client);
+	if (ret)
+		goto err;
+	priv->power_on = true;
+	return 0;
+
+err:
+	anybuss_set_power(client, false);
+	priv->power_on = false;
+	return ret;
+}
+
+static int __profi_disable(struct profi_priv *priv)
+{
+	struct anybuss_client *client = priv->client;
+
+	anybuss_set_power(client, false);
+	priv->power_on = false;
+	return 0;
+}
+
+static int profi_simple_enable(struct fieldbus_dev *fbdev, bool enable)
+{
+	int ret;
+	struct profi_priv *priv = container_of(fbdev, struct profi_priv, fbdev);
+
+	mutex_lock(&priv->enable_lock);
+	if (enable)
+		ret = __profi_enable(priv);
+	else
+		ret = __profi_disable(priv);
+	mutex_unlock(&priv->enable_lock);
+
+	return ret;
+}
+
+static void profi_on_area_updated(struct anybuss_client *client)
+{
+	struct profi_priv *priv = anybuss_get_drvdata(client);
+
+	fieldbus_dev_area_updated(&priv->fbdev);
+}
+
+static void profi_on_online_changed(struct anybuss_client *client, bool online)
+{
+	struct profi_priv *priv = anybuss_get_drvdata(client);
+
+	fieldbus_dev_online_changed(&priv->fbdev, online);
+}
+
+static int profinet_probe(struct anybuss_client *client)
+{
+	struct profi_priv *priv;
+	struct device *dev = &client->dev;
+	int err;
+
+	client->on_area_updated = profi_on_area_updated;
+	client->on_online_changed = profi_on_online_changed;
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	mutex_init(&priv->enable_lock);
+	priv->client = client;
+	priv->fbdev.read_area_sz = priv->fbdev.write_area_sz = PROFI_DPRAM_SIZE;
+	priv->fbdev.card_name = "HMS Profinet IRT (Anybus-S)";
+	priv->fbdev.fieldbus_type = FIELDBUS_DEV_TYPE_PROFINET;
+	priv->fbdev.read_area = profi_read_area;
+	priv->fbdev.write_area = profi_write_area;
+	priv->fbdev.fieldbus_id_get = profi_id_get;
+	priv->fbdev.enable_get = profi_enable_get;
+	priv->fbdev.simple_enable_set = profi_simple_enable;
+	priv->fbdev.parent = dev;
+	err = fieldbus_dev_register(&priv->fbdev);
+	if (err < 0)
+		return err;
+	dev_info(dev, "card detected, registered as %s",
+				dev_name(priv->fbdev.dev));
+	anybuss_set_drvdata(client, priv);
+
+	return 0;
+}
+
+static int profinet_remove(struct anybuss_client *client)
+{
+	struct profi_priv *priv = anybuss_get_drvdata(client);
+
+	fieldbus_dev_unregister(&priv->fbdev);
+	return 0;
+}
+
+static struct anybuss_client_driver profinet_driver = {
+	.probe = profinet_probe,
+	.remove = profinet_remove,
+	.driver		= {
+		.name   = "hms-profinet",
+		.owner	= THIS_MODULE,
+	},
+	.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");
-- 
2.17.1

Re: [PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[Rob Herring]

On Wed, Nov 21, 2018 at 10:07:08AM -0500, thesven73@gmail.com wrote:
> This patch adds devicetree binding documentation for the
> Arcx Anybus-S host.
> 
> Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>
> ---
>  .../bindings/fieldbus/arcx,anybuss-host.txt   | 66 +++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
> 
> diff --git a/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt b/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
> new file mode 100644
> index 000000000000..456587f288c1
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/fieldbus/arcx,anybuss-host.txt
> @@ -0,0 +1,66 @@
> +* 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.
> +
> +Optional: use of subnodes
> +-------------------------
> +
> +The card connected to a host may need additional properties. These can be
> +specified in subnodes to the host node.
> +
> +The subnodes are identified by the standard 'reg' property. Which information
> +exactly can be specified depends on the bindings for the function driver
> +for the subnode.
> +
> +Required host node properties when using subnodes:
> +- #address-cells: should be one.
> +- #size-cells: should be zero.
> +
> +Required subnode properties:
> +- reg: Must contain the fieldbus type of the card this subnode describes.
> +
> +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>;

I'm still not clear what a bridge vs. host is. Both examples are on WEIM 
bus CS0?

> +		/* fsl,weim-cs-timing is a i.MX WEIM bus specific property */
> +		fsl,weim-cs-timing = <0x024400b1 0x00001010 0x20081100
> +				0x00000000 0xa0000240 0x00000000>;
> +		/*
> +		 * optional subnode for a profinet card
> +		 * (fieldbus type = 0x0089)
> +		 */
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +		profinet@0 {

Unit-addresses are based on 'reg'. So this should either be '89' or 
based on a definition for the bus (e.g. PCI uses dev and func).

> +			reg = <0x0089>;

Is fieldbus type how one addresses a device on the bus?

> +			/* profinet specific properties go here */
> +		};
> +	};
> +
> +};
> -- 
> 2.17.1
> 

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Greg KH]

On Wed, Nov 21, 2018 at 10:07:03AM -0500, thesven73@gmail.com wrote:
> Fieldbus device (client) adapters allow data exchange with a PLC aka.
> "Fieldbus Controller" over a fieldbus (Profinet, FLNet, etc.)
> 
> They are typically used when a Linux device wants to expose itself
> as an actuator, motor, console light, switch, etc. over the fieldbus.
> 
> This framework is designed to provide a generic interface to Fieldbus
> Devices from both the Linux Kernel and the userspace.
> 
> Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>

License nit:

> --- /dev/null
> +++ b/drivers/fieldbus/dev_core.c
> @@ -0,0 +1,355 @@
> +// SPDX-License-Identifier: GPL-2.0

That's great, but then you write:

> +MODULE_LICENSE("GPL");

Which means "GPLv2+".  So this MODULE_LICENSE() should be "GPL v2",
right?

thanks,

greg k-h

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Greg KH]

On Wed, Nov 21, 2018 at 10:07:03AM -0500, thesven73@gmail.com wrote:
> Fieldbus device (client) adapters allow data exchange with a PLC aka.
> "Fieldbus Controller" over a fieldbus (Profinet, FLNet, etc.)
> 
> They are typically used when a Linux device wants to expose itself
> as an actuator, motor, console light, switch, etc. over the fieldbus.
> 
> This framework is designed to provide a generic interface to Fieldbus
> Devices from both the Linux Kernel and the userspace.
> 
> Signed-off-by: Sven Van Asbroeck <svendev@arcx.com>

Your "From:" line does not match this address or name at all, which
means no one can apply this :(

Please fix for your next round of patches.

thanks,

greg k-h

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Greg KH]

On Wed, Nov 21, 2018 at 10:07:03AM -0500, thesven73@gmail.com wrote:
> +static struct attribute *fieldbus_attrs[] = {
> +	&dev_attr_enabled.attr,
> +	&dev_attr_card_name.attr,
> +	&dev_attr_fieldbus_id.attr,
> +	&dev_attr_read_area_size.attr,
> +	&dev_attr_write_area_size.attr,
> +	&dev_attr_online.attr,
> +	&dev_attr_fieldbus_type.attr,
> +	NULL,
> +};
> +
> +static umode_t fieldbus_is_visible(struct kobject *kobj, struct attribute *attr,
> +				int n)
> +{
> +	struct device *dev = container_of(kobj, struct device, kobj);
> +	struct fieldbus_dev *fb = dev_get_drvdata(dev);
> +	umode_t mode = attr->mode;
> +
> +	if (attr == &dev_attr_enabled.attr) {
> +		mode = 0;
> +		if (fb->enable_get)
> +			mode |= 0444;
> +		if (fb->simple_enable_set)
> +			mode |= 0200;
> +	}
> +
> +	return mode;
> +}
> +
> +static const struct attribute_group fieldbus_group = {
> +	.attrs = fieldbus_attrs,
> +	.is_visible = fieldbus_is_visible,
> +};
> +__ATTRIBUTE_GROUPS(fieldbus);

Why not just use ATTRIBUTE_GROUPS()?

> +static int __fieldbus_dev_register(struct fieldbus_dev *fb)
> +{
> +	dev_t devno;
> +	int err;
> +
> +	if (!fb)
> +		return -EINVAL;
> +	if (!fb->read_area || !fb->write_area || !fb->fieldbus_id_get)
> +		return -EINVAL;
> +	fb->id = ida_simple_get(&fieldbus_ida, 0, MAX_FIELDBUSES, GFP_KERNEL);
> +	if (fb->id < 0)
> +		return fb->id;
> +	devno = MKDEV(MAJOR(fieldbus_devt), fb->id);
> +	init_waitqueue_head(&fb->dc_wq);
> +	cdev_init(&fb->cdev, &fieldbus_fops);
> +	err = cdev_add(&fb->cdev, devno, 1);
> +	if (err) {
> +		pr_err("fieldbus_dev%d unable to add device %d:%d\n",
> +			fb->id, MAJOR(fieldbus_devt), fb->id);
> +		goto err_cdev;
> +	}

Why do you have a static cdev?

> +	fb->dev = device_create(&fieldbus_class, fb->parent, devno, fb,
> +				"fieldbus_dev%d", fb->id);
> +	if (IS_ERR(fb->dev)) {
> +		err = PTR_ERR(fb->dev);
> +		goto err_dev_create;
> +	}
> +	fb->online_sd = sysfs_get_dirent(fb->dev->kobj.sd, "online");

Ick, what?  Why?  Why are you messing around with a raw sysfs attribute?

Also, you are creating sysfs files and you are not documenting any of
them in Documentation/ABI/ which is not allowed.  Please add that to
this patch for the next round.

thanks,

greg k-h

Re: [PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[Sven Van Asbroeck]

Rob, thank you so much for the review !

On Mon, Nov 26, 2018 at 5:08 PM Rob Herring <robh@kernel.org> wrote:

> Unit-addresses are based on 'reg'. So this should either be '89' or
> based on a definition for the bus (e.g. PCI uses dev and func).
>
>> +                     reg = <0x0089>;
>
> Is fieldbus type how one addresses a device on the bus?

I'm afraid not. Anybus cards don't have an address, because only a single card
can be connected to an anybus at a time.

Fieldbus type defines the type/functionality of the connected card. Like pci
device ids.

The current patchset allows devicetree nodes to be provided depending on
the type of card connected to the bus. It identifies the card by type,
not location.

Is this not desired / allowed ?

> I'm still not clear what a bridge vs. host is. Both examples are on WEIM
> bus CS0?

I agree that the terminology is too confusing. I'm looking to change it.

Let's compare current anybus with a well-established bus architecture like pci:

                                pci                     anybus
--------------------------------------------------------------------------------
Common bus code (spec),         pci/pci_driver.c        fieldbus/anybuss-host.c
  calls bus_register()                                  must be parallel bus
                                                        subnode
                                no of compatible        has of compatible
--------------------------------------------------------------------------------
Device on bus, calls
  XXX_client_driver_register()  hwmon/k8temp.c          fieldbus/hms-profinet.c
--------------------------------------------------------------------------------
Controller, silicon driver      pci/pcie-tango.c        fieldbus/anybus-bridge.c
                                platform_driver calls   platform_driver does not
                                pci_host_probe()        register with anybus

I should probably rework this so it conforms more closely to the way it's done
on pci. Would the following look any better?

                                pci                     anybus
--------------------------------------------------------------------------------
Common bus code (spec),         pci/pci_driver.c        anybus/anybus_driver.c
  calls bus_register()          no of compatible        no of compatible
--------------------------------------------------------------------------------
Device on bus, calls
  XXX_client_driver_register()  hwmon/k8temp.c          fieldbus/hms-profinet.c
--------------------------------------------------------------------------------
Controller, silicon driver      pci/pcie-tango.c        anybus/arcx-controller.c
                                platform_driver calls   platform_driver calls
                                pci_host_probe()        anybus_host_probe()

Of course, the analogy is not perfect, as there can only be a single card
(device) connected to an anybus at a time.

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Sven Van Asbroeck]

Wow Greg, thanks for the review, this is awesome !!

On Tue, Nov 27, 2018 at 2:54 AM Greg KH <gregkh@linuxfoundation.org> wrote:

>> +     cdev_init(&fb->cdev, &fieldbus_fops);
>> +     err = cdev_add(&fb->cdev, devno, 1);
>> +     if (err) {
>> +             pr_err("fieldbus_dev%d unable to add device %d:%d\n",
>> +                     fb->id, MAJOR(fieldbus_devt), fb->id);
>> +             goto err_cdev;
>> +     }
>
> Why do you have a static cdev?

The proposed fieldbus API needs a single /dev/fieldbus_devX node for every
device. I just looked around the drivers/ tree to see how others accomplish
this.

Is there a better way?

>> +     fb->online_sd = sysfs_get_dirent(fb->dev->kobj.sd, "online");
>
> Ick, what?  Why?  Why are you messing around with a raw sysfs attribute?

The proposed fieldbus API has a sysfs attribute that can be poll/select'ed on.
Is this behaviour still allowed / ok?
If so, you're saying that I should not store the raw attribute, but just do:
sysfs_notify(&fb->dev->kobj, NULL, "online") ?

Now that I (hopefully) have a few seconds of your attention...
I suppose the fieldbus API in this patch can't go anywhere, without buy-in from
multiple people who also want to use fieldbus. Right now, there are none.

This might be a chicken-and-egg problem. Perhaps here are no fieldbus
devices because
there's no good general API. There's no good general API because there are no
fieldbus devices yet.

 Is there a tried and tested way to break this deadlock?

Re: [PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[Rob Herring]

On Wed, Nov 28, 2018 at 9:38 AM Sven Van Asbroeck <thesven73@gmail.com> wrote:
>
> Rob, thank you so much for the review !
>
> On Mon, Nov 26, 2018 at 5:08 PM Rob Herring <robh@kernel.org> wrote:
>
> > Unit-addresses are based on 'reg'. So this should either be '89' or
> > based on a definition for the bus (e.g. PCI uses dev and func).
> >
> >> +                     reg = <0x0089>;
> >
> > Is fieldbus type how one addresses a device on the bus?
>
> I'm afraid not. Anybus cards don't have an address, because only a single card
> can be connected to an anybus at a time.

Then you don't need reg as you should only have 1 child node.

> Fieldbus type defines the type/functionality of the connected card. Like pci
> device ids.

Which for PCI can be overridden in DT, but is part of reg.

> The current patchset allows devicetree nodes to be provided depending on
> the type of card connected to the bus. It identifies the card by type,
> not location.
>
> Is this not desired / allowed ?

No, 'reg' is how you address a device. You could use 'type' in the
compatible string if type implies some sort of standard class
interface.

> > I'm still not clear what a bridge vs. host is. Both examples are on WEIM
> > bus CS0?
>
> I agree that the terminology is too confusing. I'm looking to change it.
>
> Let's compare current anybus with a well-established bus architecture like pci:
>
>                                 pci                     anybus
> --------------------------------------------------------------------------------
> Common bus code (spec),         pci/pci_driver.c        fieldbus/anybuss-host.c
>   calls bus_register()                                  must be parallel bus
>                                                         subnode
>                                 no of compatible        has of compatible
> --------------------------------------------------------------------------------
> Device on bus, calls
>   XXX_client_driver_register()  hwmon/k8temp.c          fieldbus/hms-profinet.c
> --------------------------------------------------------------------------------
> Controller, silicon driver      pci/pcie-tango.c        fieldbus/anybus-bridge.c
>                                 platform_driver calls   platform_driver does not
>                                 pci_host_probe()        register with anybus
>
> I should probably rework this so it conforms more closely to the way it's done
> on pci. Would the following look any better?

Yes, this looks better.

>                                 pci                     anybus
> --------------------------------------------------------------------------------
> Common bus code (spec),         pci/pci_driver.c        anybus/anybus_driver.c

Maybe just anybus/core.c or anybus/bus.c. I'm guessing your
implementation will be *much* more simple than PCI.

>   calls bus_register()          no of compatible        no of compatible
> --------------------------------------------------------------------------------
> Device on bus, calls
>   XXX_client_driver_register()  hwmon/k8temp.c          fieldbus/hms-profinet.c
> --------------------------------------------------------------------------------
> Controller, silicon driver      pci/pcie-tango.c        anybus/arcx-controller.c
>                                 platform_driver calls   platform_driver calls
>                                 pci_host_probe()        anybus_host_probe()
>
> Of course, the analogy is not perfect, as there can only be a single card
> (device) connected to an anybus at a time.

Right, that should simplify the bus code a lot.

Rob

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Greg KH]

On Wed, Nov 28, 2018 at 10:39:41AM -0500, Sven Van Asbroeck wrote:
> Wow Greg, thanks for the review, this is awesome !!
> 
> On Tue, Nov 27, 2018 at 2:54 AM Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> >> +     cdev_init(&fb->cdev, &fieldbus_fops);
> >> +     err = cdev_add(&fb->cdev, devno, 1);
> >> +     if (err) {
> >> +             pr_err("fieldbus_dev%d unable to add device %d:%d\n",
> >> +                     fb->id, MAJOR(fieldbus_devt), fb->id);
> >> +             goto err_cdev;
> >> +     }
> >
> > Why do you have a static cdev?
> 
> The proposed fieldbus API needs a single /dev/fieldbus_devX node for every
> device. I just looked around the drivers/ tree to see how others accomplish
> this.
> 
> Is there a better way?

It depends on what you want to do with this device node.  You can use a
static one in your structure if you use it to "cast back" to your real
structure in the open() call, do you do that?  If not, just create one
dynamically.

Or use a misc device?  How many of these do you need?

> >> +     fb->online_sd = sysfs_get_dirent(fb->dev->kobj.sd, "online");
> >
> > Ick, what?  Why?  Why are you messing around with a raw sysfs attribute?
> 
> The proposed fieldbus API has a sysfs attribute that can be poll/select'ed on.
> Is this behaviour still allowed / ok?

For an online/offline attribute, no need to poll on it, just do a
'kobject change' event for online/offline and all should be fine.  This
is not a high-frequency event, right?

> Now that I (hopefully) have a few seconds of your attention...
> I suppose the fieldbus API in this patch can't go anywhere, without buy-in from
> multiple people who also want to use fieldbus. Right now, there are none.

Hey, if no one wants to use it, either no need to write any code at all,
or you get to decide everything.  Either way, you're in charge!  :)

But you do need to document the thing, in Documentation/ABI/ to get it
correct and able to be reviewed.

thanks,

greg k-h

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Sven Van Asbroeck]

On Wed, Nov 28, 2018 at 12:42 PM Greg KH <gregkh@linuxfoundation.org> wrote:

> It depends on what you want to do with this device node.  You can use a
> static one in your structure if you use it to "cast back" to your real
> structure in the open() call, do you do that?

I do...

static int fieldbus_open(struct inode *inode, struct file *filp)
{
        struct fieldbus_dev *fbdev = container_of(inode->i_cdev,
                                                struct fieldbus_dev,
                                                cdev);

> Or use a misc device?  How many of these do you need?

Just one per fieldbus device.
But my main concern is naming in sysfs. A misc device will always show up as
/sys/class/misc/..., right? Given that this is a userspace fieldbus API,
we'd prefer /sys/class/fieldbus_dev/..., and cdev is the only way?

> For an online/offline attribute, no need to poll on it, just do a
> 'kobject change' event for online/offline and all should be fine.  This
> is not a high-frequency event, right?

Grepping... you mean kobject_uevent(KOBJ_CHANGE) ?
THAT mechanism seems to fit much better, thanks !!

> Hey, if no one wants to use it, either no need to write any code at all,
> or you get to decide everything.  Either way, you're in charge!  :)

I did get the impression that people are reluctant to take my patch partly
because of an unproven userspace API. Maybe they are (rightly) worried that,
once in, we will have to support this userspace API for evermore.

I'd love to get others involved in Fieldbus on Linux, but I'm not sure
how.

> But you do need to document the thing, in Documentation/ABI/ to get it
> correct and able to be reviewed.

The documentation is already included in this patch? Should I indicate this
in some standardized fashion?

 create mode 100644 Documentation/ABI/testing/fieldbus-dev-cdev
 create mode 100644 Documentation/ABI/testing/sysfs-class-fieldbus-dev

Thanks :)
Sven

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Greg KH]

On Wed, Nov 28, 2018 at 01:19:05PM -0500, Sven Van Asbroeck wrote:
> On Wed, Nov 28, 2018 at 12:42 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> 
> > It depends on what you want to do with this device node.  You can use a
> > static one in your structure if you use it to "cast back" to your real
> > structure in the open() call, do you do that?
> 
> I do...
> 
> static int fieldbus_open(struct inode *inode, struct file *filp)
> {
>         struct fieldbus_dev *fbdev = container_of(inode->i_cdev,
>                                                 struct fieldbus_dev,
>                                                 cdev);

Ok, good, that's a nice way to use this, nevermind my objection.

> > Or use a misc device?  How many of these do you need?
> 
> Just one per fieldbus device.
> But my main concern is naming in sysfs. A misc device will always show up as
> /sys/class/misc/..., right? Given that this is a userspace fieldbus API,
> we'd prefer /sys/class/fieldbus_dev/..., and cdev is the only way?

Ah, the common misunderstanding.

A cdev has NOTHING to do with the /sys/class/ entries.  It is only there
to register a char device with the kernel core and to handle the file
operations that are caused by it.  It does not do much, and not even the
/dev/NODE stuff either.  That is up to your class device code.

So you still need a char device, and you will have have a load of them,
just use the misc device api.  It's simple, clean, and is hard to get
wrong.  The cdev api is hard, complex, and trivial to get wrong in any
number of different ways that it can be used :)

That being said, it looks like you used it correctly, so all should be
fine here.

And your /sys/class/fieldbus_dev/ is "interesting", why name it that?

> > For an online/offline attribute, no need to poll on it, just do a
> > 'kobject change' event for online/offline and all should be fine.  This
> > is not a high-frequency event, right?
> 
> Grepping... you mean kobject_uevent(KOBJ_CHANGE) ?
> THAT mechanism seems to fit much better, thanks !!

Yes, use that please.

> > Hey, if no one wants to use it, either no need to write any code at all,
> > or you get to decide everything.  Either way, you're in charge!  :)
> 
> I did get the impression that people are reluctant to take my patch partly
> because of an unproven userspace API. Maybe they are (rightly) worried that,
> once in, we will have to support this userspace API for evermore.
> 
> I'd love to get others involved in Fieldbus on Linux, but I'm not sure
> how.

Adding a new driver subsystem is messy, it takes a lot of work and
finding the right reviewers is hard.  It's not just you, it happens all
the time (look at how long the i3c code took to get merged as one
example...)

So keep submitting, I'll try to review it the next time around, and all
should be fine.  But keep your user api as simple as possible for now,
only doing what you need it to do, worry about future stuff then.


> > But you do need to document the thing, in Documentation/ABI/ to get it
> > correct and able to be reviewed.
> 
> The documentation is already included in this patch? Should I indicate this
> in some standardized fashion?
> 
>  create mode 100644 Documentation/ABI/testing/fieldbus-dev-cdev
>  create mode 100644 Documentation/ABI/testing/sysfs-class-fieldbus-dev

Ah, sorry, I didn't read it, my fault :(

Why not just /sys/class/fieldbus/ ?  No need for "dev", right?

greg k-h

Re: [PATCH anybus v4 1/7] fieldbus_dev: add Fieldbus Device subsystem.

[Sven Van Asbroeck]

On Wed, Nov 28, 2018 at 1:36 PM Greg KH <gregkh@linuxfoundation.org> wrote:

> So you still need a char device, and you will have have a load of them,
> just use the misc device api.  It's simple, clean, and is hard to get
> wrong.  The cdev api is hard, complex, and trivial to get wrong in any
> number of different ways that it can be used :)

Awesome little nugget! These things you just can't tell by reading the kernel
tree. In many cases, it's not immediately obvious to me which of the various
methods are 'recommended', and which ones are historic leftovers.

> And your /sys/class/fieldbus_dev/ is "interesting", why name it that?

Not sure why it's interesting? I figured it would allow userspace to enumerate
all fieldbus devices simply by going to /sys/class/fieldbus_dev/ and process
every subdirectory.

Example with 3 fieldbus cards:
/sys/class/fieldbus_dev/fieldbus_dev0/name etc
/sys/class/fieldbus_dev/fieldbus_dev1/name etc
/sys/class/fieldbus_dev/fieldbus_dev2/name etc

Is there a better way?

> So keep submitting, I'll try to review it the next time around, and all
> should be fine.  But keep your user api as simple as possible for now,
> only doing what you need it to do, worry about future stuff then.

Thanks, that's awesome !!

I figured that I should take baby steps. I simplified the userspace API to the
absolute bare minimum. To the point that the profinet card isn't useable in
our company's specific use case, because there's no configuration API yet.

> Why not just /sys/class/fieldbus/ ?  No need for "dev", right?

Good question... Two very different classes of devices sit on a fieldbus:
Fieldbus device     is like a slave
Fieldbus controller is like a master

This subsystem is specific for fieldbus *devices*. I figured I'd encode this
in the API name, in case someone wants to support fieldbus controllers later.

Re: [PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[Sven Van Asbroeck]

Rob,

Eliminating the 'compatible' property for the anybus gives me an interesting
devicetree problem.

The imx-weim code naively loops through all subnodes, applying timing settings
to the CS in the first reg entry.
In the example below, WEIM CS0 is programmed with the settings in
fsl,weim-cs-timing, because the CS part of reg is 0:


weim: weim@21b8000 {
        compatible = "fsl,imx6q-weim";
        reg = <0x021b8000 0x4000>;
        clocks = <&clks 196>;
        #address-cells = <2>;
        #size-cells = <1>;
        ranges = <0 0 0x08000000 0x08000000>;
        fsl,weim-cs-gpr = <&gpr>;

        nor@0,0 {
                compatible = "cfi-flash";
                reg = <0 0 0x02000000>;
                #address-cells = <1>;
                #size-cells = <1>;
                bank-width = <2>;
                fsl,weim-cs-timing = <0x00620081 0x00000001 0x1c022000
                                0x0000c000 0x1404a38e 0x00000000>;
        };
};

The problem is that my 'anybus controller' hardware spans chip selects.
It requires access to various memory areas. In the example below, CS1
will not be programmed with timing settings:

weim {
        controller@0 {
                compatible = "arcx,anybus-controller";
                reg = <0 0 0x100>, <0 0x400000 0x800>, <1 0x400000 0x800>;
                fsl,weim-cs-timing = ...;
        };
};

I've coped with this in the past by creating a 'dummy' subnode, without a
compatible property. But it's ugly:

weim {
        controller@0 {
                compatible = "arcx,anybus-controller";
                reg = <0 0 0x100>, <0 0x400000 0x800>, <1 0x400000 0x800>;
                fsl,weim-cs-timing = ...;
        };
        dummy@1 { /* this works ! */
                reg = <1 0 0>;
                fsl,weim-cs-timing = ...;
        };
};

Is there a better way? I've looked and looked, but can't find anything that's
similar.

Or should I extend the imx-weim driver to cope?

Re: [PATCH anybus v4 6/7] dt-bindings: anybuss-host: document devicetree binding

[Rob Herring]

On Thu, Nov 29, 2018 at 2:59 PM Sven Van Asbroeck <thesven73@gmail.com> wrote:
>
> Rob,
>
> Eliminating the 'compatible' property for the anybus gives me an interesting
> devicetree problem.
>
> The imx-weim code naively loops through all subnodes, applying timing settings
> to the CS in the first reg entry.
> In the example below, WEIM CS0 is programmed with the settings in
> fsl,weim-cs-timing, because the CS part of reg is 0:
>
>
> weim: weim@21b8000 {
>         compatible = "fsl,imx6q-weim";
>         reg = <0x021b8000 0x4000>;
>         clocks = <&clks 196>;
>         #address-cells = <2>;
>         #size-cells = <1>;
>         ranges = <0 0 0x08000000 0x08000000>;
>         fsl,weim-cs-gpr = <&gpr>;
>
>         nor@0,0 {
>                 compatible = "cfi-flash";
>                 reg = <0 0 0x02000000>;
>                 #address-cells = <1>;
>                 #size-cells = <1>;
>                 bank-width = <2>;
>                 fsl,weim-cs-timing = <0x00620081 0x00000001 0x1c022000
>                                 0x0000c000 0x1404a38e 0x00000000>;
>         };
> };
>
> The problem is that my 'anybus controller' hardware spans chip selects.
> It requires access to various memory areas. In the example below, CS1
> will not be programmed with timing settings:
>
> weim {
>         controller@0 {
>                 compatible = "arcx,anybus-controller";
>                 reg = <0 0 0x100>, <0 0x400000 0x800>, <1 0x400000 0x800>;
>                 fsl,weim-cs-timing = ...;
>         };
> };
>
> I've coped with this in the past by creating a 'dummy' subnode, without a
> compatible property. But it's ugly:
>
> weim {
>         controller@0 {
>                 compatible = "arcx,anybus-controller";
>                 reg = <0 0 0x100>, <0 0x400000 0x800>, <1 0x400000 0x800>;
>                 fsl,weim-cs-timing = ...;
>         };
>         dummy@1 { /* this works ! */
>                 reg = <1 0 0>;
>                 fsl,weim-cs-timing = ...;
>         };
> };
>
> Is there a better way? I've looked and looked, but can't find anything that's
> similar.
>
> Or should I extend the imx-weim driver to cope?

Yes, I think it should iterate on child reg properties not just nodes.
Hopefully, you don't need different timing for each CS though.

Rob