1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
new file mode 100644
index 0000000..16323f9
--- /dev/null
+++ b/drivers/base/dd.c
@@ -0,0 +1,248 @@
+/*
+ *	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.)
+ *
+ *	This function must be called with @dev->sem held.
+ */
+void device_bind_driver(struct device * dev)
+{
+	pr_debug("bound device '%s' to driver '%s'\n",
+		 dev->bus_id, dev->driver->name);
+	klist_add_tail(&dev->driver->klist_devices, &dev->knode_driver);
+	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.
+ *
+ *
+ *	This function returns 1 if a match is found, an error if one
+ *	occurs (that is not -ENODEV or -ENXIO), and 0 otherwise.
+ *
+ *	This function must be called with @dev->sem held.
+ */
+int driver_probe_device(struct device_driver * drv, struct device * dev)
+{
+	int ret = 0;
+
+	if (drv->bus->match && !drv->bus->match(dev, drv))
+		goto Done;
+
+	pr_debug("%s: Matched Device %s with Driver %s\n",
+		 drv->bus->name, dev->bus_id, drv->name);
+	dev->driver = drv;
+	if (drv->probe) {
+		ret = drv->probe(dev);
+		if (ret) {
+			dev->driver = NULL;
+			goto ProbeFailed;
+		}
+	}
+	device_bind_driver(dev);
+	ret = 1;
+	pr_debug("%s: Bound Device %s to Driver %s\n",
+		 drv->bus->name, dev->bus_id, drv->name);
+	goto Done;
+
+ ProbeFailed:
+	if (ret == -ENODEV || ret == -ENXIO) {
+		/* Driver matched, but didn't support device
+		 * or device not found.
+		 * Not an error; keep going.
+		 */
+		ret = 0;
+	} else {
+		/* driver matched but the probe failed */
+		printk(KERN_WARNING
+		       "%s: probe of %s failed with error %d\n",
+		       drv->name, dev->bus_id, ret);
+	}
+ Done:
+	return ret;
+}
+
+static int __device_attach(struct device_driver * drv, void * data)
+{
+	struct device * dev = data;
+	return driver_probe_device(drv, dev);
+}
+
+/**
+ *	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.
+ *
+ *	Returns 1 if the device was bound to a driver;
+ *	0 if no matching device was found; error code otherwise.
+ */
+int device_attach(struct device * dev)
+{
+	int ret = 0;
+
+	down(&dev->sem);
+	if (dev->driver) {
+		device_bind_driver(dev);
+		ret = 1;
+	} else
+		ret = bus_for_each_drv(dev->bus, NULL, dev, __device_attach);
+	up(&dev->sem);
+	return ret;
+}
+
+static int __driver_attach(struct device * dev, void * data)
+{
+	struct device_driver * drv = data;
+
+	/*
+	 * Lock device and try to bind to it. We drop the error
+	 * here and always return 0, because we need to keep trying
+	 * to bind to devices and some drivers will return an error
+	 * simply if it didn't support the device.
+	 *
+	 * driver_probe_device() will spit a warning if there
+	 * is an error.
+	 */
+
+	down(&dev->sem);
+	if (!dev->driver)
+		driver_probe_device(drv, dev);
+	up(&dev->sem);
+
+
+	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.
+ */
+void driver_attach(struct device_driver * drv)
+{
+	bus_for_each_dev(drv->bus, NULL, drv, __driver_attach);
+}
+
+/**
+ *	device_release_driver - manually detach device from driver.
+ *	@dev:	device.
+ *
+ *	Manually detach device from driver.
+ *
+ *	__device_release_driver() must be called with @dev->sem held.
+ */
+
+static void __device_release_driver(struct device * dev)
+{
+	struct device_driver * drv;
+
+	drv = dev->driver;
+	if (drv) {
+		get_driver(drv);
+		sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
+		sysfs_remove_link(&dev->kobj, "driver");
+		klist_remove(&dev->knode_driver);
+
+		if (drv->remove)
+			drv->remove(dev);
+		dev->driver = NULL;
+		put_driver(drv);
+	}
+}
+
+void device_release_driver(struct device * dev)
+{
+	/*
+	 * If anyone calls device_release_driver() recursively from
+	 * within their ->remove callback for the same device, they
+	 * will deadlock right here.
+	 */
+	down(&dev->sem);
+	__device_release_driver(dev);
+	up(&dev->sem);
+}
+
+
+/**
+ * driver_detach - detach driver from all devices it controls.
+ * @drv: driver.
+ */
+void driver_detach(struct device_driver * drv)
+{
+	struct device * dev;
+
+	for (;;) {
+		spin_lock_irq(&drv->klist_devices.k_lock);
+		if (list_empty(&drv->klist_devices.k_list)) {
+			spin_unlock_irq(&drv->klist_devices.k_lock);
+			break;
+		}
+		dev = list_entry(drv->klist_devices.k_list.prev,
+				struct device, knode_driver.n_node);
+		get_device(dev);
+		spin_unlock_irq(&drv->klist_devices.k_lock);
+
+		down(&dev->sem);
+		if (dev->driver == drv)
+			__device_release_driver(dev);
+		up(&dev->sem);
+		put_device(dev);
+	}
+}
+
+
+EXPORT_SYMBOL_GPL(device_bind_driver);
+EXPORT_SYMBOL_GPL(device_release_driver);
+EXPORT_SYMBOL_GPL(device_attach);
+EXPORT_SYMBOL_GPL(driver_attach);
+