[PATCH] Move device/driver code to drivers/base/dd.c
This relocates the driver binding/unbinding code to drivers/base/dd.c. This is done
for two reasons: One, it's not code related to the bus_type itself; it uses some from
that, some from devices, and some from drivers. And Two, it will make it easier to do
some of the upcoming lock removal on that code..
Signed-off-by: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
new file mode 100644
index 0000000..b709b1e
--- /dev/null
+++ b/drivers/base/dd.c
@@ -0,0 +1,200 @@
+/*
+ * drivers/base/dd.c - The core device/driver interactions.
+ *
+ * This file contains the (sometimes tricky) code that controls the
+ * interactions between devices and drivers, which primarily includes
+ * driver binding and unbinding.
+ *
+ * All of this code used to exist in drivers/base/bus.c, but was
+ * relocated to here in the name of compartmentalization (since it wasn't
+ * strictly code just for the 'struct bus_type'.
+ *
+ * Copyright (c) 2002-5 Patrick Mochel
+ * Copyright (c) 2002-3 Open Source Development Labs
+ *
+ * This file is released under the GPLv2
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+
+#include "base.h"
+#include "power/power.h"
+
+#define to_drv(node) container_of(node, struct device_driver, kobj.entry)
+
+
+/**
+ * device_bind_driver - bind a driver to one device.
+ * @dev: device.
+ *
+ * Allow manual attachment of a driver to a device.
+ * Caller must have already set @dev->driver.
+ *
+ * Note that this does not modify the bus reference count
+ * nor take the bus's rwsem. Please verify those are accounted
+ * for before calling this. (It is ok to call with no other effort
+ * from a driver's probe() method.)
+ */
+void device_bind_driver(struct device * dev)
+{
+ pr_debug("bound device '%s' to driver '%s'\n",
+ dev->bus_id, dev->driver->name);
+ list_add_tail(&dev->driver_list, &dev->driver->devices);
+ sysfs_create_link(&dev->driver->kobj, &dev->kobj,
+ kobject_name(&dev->kobj));
+ sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
+}
+
+/**
+ * driver_probe_device - attempt to bind device & driver.
+ * @drv: driver.
+ * @dev: device.
+ *
+ * First, we call the bus's match function, if one present, which
+ * should compare the device IDs the driver supports with the
+ * device IDs of the device. Note we don't do this ourselves
+ * because we don't know the format of the ID structures, nor what
+ * is to be considered a match and what is not.
+ *
+ * If we find a match, we call @drv->probe(@dev) if it exists, and
+ * call device_bind_driver() above.
+ */
+int driver_probe_device(struct device_driver * drv, struct device * dev)
+{
+ int error = 0;
+
+ if (drv->bus->match && !drv->bus->match(dev, drv))
+ return -ENODEV;
+
+ down(&dev->sem);
+ dev->driver = drv;
+ if (drv->probe) {
+ error = drv->probe(dev);
+ if (error) {
+ dev->driver = NULL;
+ up(&dev->sem);
+ return error;
+ }
+ }
+ up(&dev->sem);
+ device_bind_driver(dev);
+ return 0;
+}
+
+/**
+ * device_attach - try to attach device to a driver.
+ * @dev: device.
+ *
+ * Walk the list of drivers that the bus has and call
+ * driver_probe_device() for each pair. If a compatible
+ * pair is found, break out and return.
+ */
+int device_attach(struct device * dev)
+{
+ struct bus_type * bus = dev->bus;
+ struct list_head * entry;
+ int error;
+
+ if (dev->driver) {
+ device_bind_driver(dev);
+ return 1;
+ }
+
+ if (bus->match) {
+ list_for_each(entry, &bus->drivers.list) {
+ struct device_driver * drv = to_drv(entry);
+ error = driver_probe_device(drv, dev);
+ if (!error)
+ /* success, driver matched */
+ return 1;
+ if (error != -ENODEV && error != -ENXIO)
+ /* driver matched but the probe failed */
+ printk(KERN_WARNING
+ "%s: probe of %s failed with error %d\n",
+ drv->name, dev->bus_id, error);
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * driver_attach - try to bind driver to devices.
+ * @drv: driver.
+ *
+ * Walk the list of devices that the bus has on it and try to
+ * match the driver with each one. If driver_probe_device()
+ * returns 0 and the @dev->driver is set, we've found a
+ * compatible pair.
+ *
+ * Note that we ignore the -ENODEV error from driver_probe_device(),
+ * since it's perfectly valid for a driver not to bind to any devices.
+ */
+void driver_attach(struct device_driver * drv)
+{
+ struct bus_type * bus = drv->bus;
+ struct list_head * entry;
+ int error;
+
+ if (!bus->match)
+ return;
+
+ list_for_each(entry, &bus->devices.list) {
+ struct device * dev = container_of(entry, struct device, bus_list);
+ if (!dev->driver) {
+ error = driver_probe_device(drv, dev);
+ if (error && (error != -ENODEV))
+ /* driver matched but the probe failed */
+ printk(KERN_WARNING
+ "%s: probe of %s failed with error %d\n",
+ drv->name, dev->bus_id, error);
+ }
+ }
+}
+
+/**
+ * device_release_driver - manually detach device from driver.
+ * @dev: device.
+ *
+ * Manually detach device from driver.
+ * Note that this is called without incrementing the bus
+ * reference count nor taking the bus's rwsem. Be sure that
+ * those are accounted for before calling this function.
+ */
+void device_release_driver(struct device * dev)
+{
+ struct device_driver * drv;
+
+ down(&dev->sem);
+ drv = dev->driver;
+ if (drv) {
+ sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
+ sysfs_remove_link(&dev->kobj, "driver");
+ list_del_init(&dev->driver_list);
+ if (drv->remove)
+ drv->remove(dev);
+ dev->driver = NULL;
+ }
+ up(&dev->sem);
+}
+
+/**
+ * driver_detach - detach driver from all devices it controls.
+ * @drv: driver.
+ */
+void driver_detach(struct device_driver * drv)
+{
+ while (!list_empty(&drv->devices)) {
+ struct device * dev = container_of(drv->devices.next, struct device, driver_list);
+ device_release_driver(dev);
+ }
+}
+
+
+EXPORT_SYMBOL_GPL(driver_probe_device);
+EXPORT_SYMBOL_GPL(device_bind_driver);
+EXPORT_SYMBOL_GPL(device_release_driver);
+EXPORT_SYMBOL_GPL(device_attach);
+EXPORT_SYMBOL_GPL(driver_attach);
+