[PATCH] RapidIO support: core base

Adds a RapidIO subsystem to the kernel.  RIO is a switched fabric interconnect
used in higher-end embedded applications.  The curious can look at the specs
over at http://www.rapidio.org

The core code implements enumeration/discovery, management of
devices/resources, and interfaces for RIO drivers.

There's a lot more to do to take advantages of all the hardware features.
However, this should provide a good base for folks with RIO hardware to start
contributing.

Signed-off-by: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 229 insertions, 0 deletions

diff --git a/drivers/rapidio/rio-driver.c b/drivers/rapidio/rio-driver.c
new file mode 100644
index 00000000000..dc749609699
--- /dev/null
+++ b/drivers/rapidio/rio-driver.c
@@ -0,0 +1,229 @@
+/*
+ * RapidIO driver support
+ *
+ * Copyright 2005 MontaVista Software, Inc.
+ * Matt Porter <mporter@kernel.crashing.org>
+ *
+ * This program is free software; you can redistribute  it and/or modify it
+ * under  the terms of  the GNU General  Public License as published by the
+ * Free Software Foundation;  either version 2 of the  License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/rio.h>
+#include <linux/rio_ids.h>
+
+#include "rio.h"
+
+/**
+ *  rio_match_device - Tell if a RIO device has a matching RIO device id structure
+ *  @id: the RIO device id structure to match against
+ *  @rdev: the RIO device structure to match against
+ *
+ *  Used from driver probe and bus matching to check whether a RIO device
+ *  matches a device id structure provided by a RIO driver. Returns the
+ *  matching &struct rio_device_id or %NULL if there is no match.
+ */
+static const struct rio_device_id *rio_match_device(const struct rio_device_id
+						    *id,
+						    const struct rio_dev *rdev)
+{
+	while (id->vid || id->asm_vid) {
+		if (((id->vid == RIO_ANY_ID) || (id->vid == rdev->vid)) &&
+		    ((id->did == RIO_ANY_ID) || (id->did == rdev->did)) &&
+		    ((id->asm_vid == RIO_ANY_ID)
+		     || (id->asm_vid == rdev->asm_vid))
+		    && ((id->asm_did == RIO_ANY_ID)
+			|| (id->asm_did == rdev->asm_did)))
+			return id;
+		id++;
+	}
+	return NULL;
+}
+
+/**
+ * rio_dev_get - Increments the reference count of the RIO device structure
+ *
+ * @rdev: RIO device being referenced
+ *
+ * Each live reference to a device should be refcounted.
+ *
+ * Drivers for RIO devices should normally record such references in
+ * their probe() methods, when they bind to a device, and release
+ * them by calling rio_dev_put(), in their disconnect() methods.
+ */
+struct rio_dev *rio_dev_get(struct rio_dev *rdev)
+{
+	if (rdev)
+		get_device(&rdev->dev);
+
+	return rdev;
+}
+
+/**
+ * rio_dev_put - Release a use of the RIO device structure
+ *
+ * @rdev: RIO device being disconnected
+ *
+ * Must be called when a user of a device is finished with it.
+ * When the last user of the device calls this function, the
+ * memory of the device is freed.
+ */
+void rio_dev_put(struct rio_dev *rdev)
+{
+	if (rdev)
+		put_device(&rdev->dev);
+}
+
+/**
+ *  rio_device_probe - Tell if a RIO device structure has a matching RIO
+ *                     device id structure
+ *  @id: the RIO device id structure to match against
+ *  @dev: the RIO device structure to match against
+ *
+ * return 0 and set rio_dev->driver when drv claims rio_dev, else error
+ */
+static int rio_device_probe(struct device *dev)
+{
+	struct rio_driver *rdrv = to_rio_driver(dev->driver);
+	struct rio_dev *rdev = to_rio_dev(dev);
+	int error = -ENODEV;
+	const struct rio_device_id *id;
+
+	if (!rdev->driver && rdrv->probe) {
+		if (!rdrv->id_table)
+			return error;
+		id = rio_match_device(rdrv->id_table, rdev);
+		rio_dev_get(rdev);
+		if (id)
+			error = rdrv->probe(rdev, id);
+		if (error >= 0) {
+			rdev->driver = rdrv;
+			error = 0;
+			rio_dev_put(rdev);
+		}
+	}
+	return error;
+}
+
+/**
+ *  rio_device_remove - Remove a RIO device from the system
+ *
+ *  @dev: the RIO device structure to match against
+ *
+ * Remove a RIO device from the system. If it has an associated
+ * driver, then run the driver remove() method.  Then update
+ * the reference count.
+ */
+static int rio_device_remove(struct device *dev)
+{
+	struct rio_dev *rdev = to_rio_dev(dev);
+	struct rio_driver *rdrv = rdev->driver;
+
+	if (rdrv) {
+		if (rdrv->remove)
+			rdrv->remove(rdev);
+		rdev->driver = NULL;
+	}
+
+	rio_dev_put(rdev);
+
+	return 0;
+}
+
+/**
+ *  rio_register_driver - register a new RIO driver
+ *  @rdrv: the RIO driver structure to register
+ *
+ *  Adds a &struct rio_driver to the list of registered drivers
+ *  Returns a negative value on error, otherwise 0. If no error
+ *  occurred, the driver remains registered even if no device
+ *  was claimed during registration.
+ */
+int rio_register_driver(struct rio_driver *rdrv)
+{
+	/* initialize common driver fields */
+	rdrv->driver.name = rdrv->name;
+	rdrv->driver.bus = &rio_bus_type;
+	rdrv->driver.probe = rio_device_probe;
+	rdrv->driver.remove = rio_device_remove;
+
+	/* register with core */
+	return driver_register(&rdrv->driver);
+}
+
+/**
+ *  rio_unregister_driver - unregister a RIO driver
+ *  @rdrv: the RIO driver structure to unregister
+ *
+ *  Deletes the &struct rio_driver from the list of registered RIO
+ *  drivers, gives it a chance to clean up by calling its remove()
+ *  function for each device it was responsible for, and marks those
+ *  devices as driverless.
+ */
+void rio_unregister_driver(struct rio_driver *rdrv)
+{
+	driver_unregister(&rdrv->driver);
+}
+
+/**
+ *  rio_match_bus - Tell if a RIO device structure has a matching RIO
+ *                  driver device id structure
+ *  @dev: the standard device structure to match against
+ *  @drv: the standard driver structure containing the ids to match against
+ *
+ *  Used by a driver to check whether a RIO device present in the
+ *  system is in its list of supported devices. Returns 1 if
+ *  there is a matching &struct rio_device_id or 0 if there is
+ *  no match.
+ */
+static int rio_match_bus(struct device *dev, struct device_driver *drv)
+{
+	struct rio_dev *rdev = to_rio_dev(dev);
+	struct rio_driver *rdrv = to_rio_driver(drv);
+	const struct rio_device_id *id = rdrv->id_table;
+	const struct rio_device_id *found_id;
+
+	if (!id)
+		goto out;
+
+	found_id = rio_match_device(id, rdev);
+
+	if (found_id)
+		return 1;
+
+      out:return 0;
+}
+
+static struct device rio_bus = {
+	.bus_id = "rapidio",
+};
+
+struct bus_type rio_bus_type = {
+	.name = "rapidio",
+	.match = rio_match_bus,
+	.dev_attrs = rio_dev_attrs
+};
+
+/**
+ *  rio_bus_init - Register the RapidIO bus with the device model
+ *
+ *  Registers the RIO bus device and RIO bus type with the Linux
+ *  device model.
+ */
+static int __init rio_bus_init(void)
+{
+	if (device_register(&rio_bus) < 0)
+		printk("RIO: failed to register RIO bus device\n");
+	return bus_register(&rio_bus_type);
+}
+
+postcore_initcall(rio_bus_init);
+
+EXPORT_SYMBOL_GPL(rio_register_driver);
+EXPORT_SYMBOL_GPL(rio_unregister_driver);
+EXPORT_SYMBOL_GPL(rio_bus_type);
+EXPORT_SYMBOL_GPL(rio_dev_get);
+EXPORT_SYMBOL_GPL(rio_dev_put);