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-rw-r--r--drivers/base/dd.c248
1 files changed, 248 insertions, 0 deletions
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
new file mode 100644
index 00000000000..6db3a789c54
--- /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.
+ */
+static 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);
+