1 files changed, 248 insertions, 0 deletions

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
new file mode 100644
index 000000000000..6db3a789c54f
--- /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);
+