#include "base.h"
#include "power/power.h"
-#define to_dev(node) container_of(node, struct device, bus_list)
-#define to_drv(node) container_of(node, struct device_driver, kobj.entry)
-
#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
#define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj)
{
struct driver_attribute * drv_attr = to_drv_attr(attr);
struct device_driver * drv = to_driver(kobj);
- ssize_t ret = 0;
+ ssize_t ret = -EIO;
if (drv_attr->show)
ret = drv_attr->show(drv, buf);
{
struct driver_attribute * drv_attr = to_drv_attr(attr);
struct device_driver * drv = to_driver(kobj);
- ssize_t ret = 0;
+ ssize_t ret = -EIO;
if (drv_attr->store)
ret = drv_attr->store(drv, buf, count);
decl_subsys(bus, &ktype_bus, NULL);
-static int __bus_for_each_dev(struct bus_type *bus, struct device *start,
- void *data, int (*fn)(struct device *, void *))
+
+#ifdef CONFIG_HOTPLUG
+
+/* Manually detach a device from its associated driver. */
+static int driver_helper(struct device *dev, void *data)
{
- struct list_head *head;
- struct device *dev;
- int error = 0;
+ const char *name = data;
- if (!(bus = get_bus(bus)))
- return -EINVAL;
+ if (strcmp(name, dev->bus_id) == 0)
+ return 1;
+ return 0;
+}
- head = &bus->devices.list;
- dev = list_prepare_entry(start, head, bus_list);
- list_for_each_entry_continue(dev, head, bus_list) {
- get_device(dev);
- error = fn(dev, data);
- put_device(dev);
- if (error)
- break;
+static ssize_t driver_unbind(struct device_driver *drv,
+ const char *buf, size_t count)
+{
+ struct bus_type *bus = get_bus(drv->bus);
+ struct device *dev;
+ int err = -ENODEV;
+
+ dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+ if (dev && dev->driver == drv) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
+ device_release_driver(dev);
+ if (dev->parent)
+ up(&dev->parent->sem);
+ err = count;
}
+ put_device(dev);
put_bus(bus);
- return error;
+ return err;
}
+static DRIVER_ATTR(unbind, S_IWUSR, NULL, driver_unbind);
-static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
- void * data, int (*fn)(struct device_driver *, void *))
+/*
+ * Manually attach a device to a driver.
+ * Note: the driver must want to bind to the device,
+ * it is not possible to override the driver's id table.
+ */
+static ssize_t driver_bind(struct device_driver *drv,
+ const char *buf, size_t count)
{
- struct list_head *head;
- struct device_driver *drv;
- int error = 0;
-
- if (!(bus = get_bus(bus)))
- return -EINVAL;
-
- head = &bus->drivers.list;
- drv = list_prepare_entry(start, head, kobj.entry);
- list_for_each_entry_continue(drv, head, kobj.entry) {
- get_driver(drv);
- error = fn(drv, data);
- put_driver(drv);
- if (error)
- break;
+ struct bus_type *bus = get_bus(drv->bus);
+ struct device *dev;
+ int err = -ENODEV;
+
+ dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+ if (dev && dev->driver == NULL) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
+ down(&dev->sem);
+ err = driver_probe_device(drv, dev);
+ up(&dev->sem);
+ if (dev->parent)
+ up(&dev->parent->sem);
+
+ if (err > 0) /* success */
+ err = count;
+ else if (err == 0) /* driver didn't accept device */
+ err = -ENODEV;
}
+ put_device(dev);
put_bus(bus);
- return error;
+ return err;
+}
+static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind);
+
+#endif
+
+static struct device * next_device(struct klist_iter * i)
+{
+ struct klist_node * n = klist_next(i);
+ return n ? container_of(n, struct device, knode_bus) : NULL;
}
/**
int bus_for_each_dev(struct bus_type * bus, struct device * start,
void * data, int (*fn)(struct device *, void *))
{
- int ret;
+ struct klist_iter i;
+ struct device * dev;
+ int error = 0;
- down_read(&bus->subsys.rwsem);
- ret = __bus_for_each_dev(bus, start, data, fn);
- up_read(&bus->subsys.rwsem);
- return ret;
+ if (!bus)
+ return -EINVAL;
+
+ klist_iter_init_node(&bus->klist_devices, &i,
+ (start ? &start->knode_bus : NULL));
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ return error;
+}
+
+/**
+ * bus_find_device - device iterator for locating a particular device.
+ * @bus: bus type
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the bus_for_each_dev() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device * bus_find_device(struct bus_type *bus,
+ struct device *start, void *data,
+ int (*match)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!bus)
+ return NULL;
+
+ klist_iter_init_node(&bus->klist_devices, &i,
+ (start ? &start->knode_bus : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}
+
+
+static struct device_driver * next_driver(struct klist_iter * i)
+{
+ struct klist_node * n = klist_next(i);
+ return n ? container_of(n, struct device_driver, knode_bus) : NULL;
}
/**
int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
void * data, int (*fn)(struct device_driver *, void *))
{
- int ret;
-
- down_read(&bus->subsys.rwsem);
- ret = __bus_for_each_drv(bus, start, data, fn);
- up_read(&bus->subsys.rwsem);
- return ret;
-}
-
-/**
- * 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)
-{
- if (drv->bus->match && !drv->bus->match(dev, drv))
- return -ENODEV;
-
- dev->driver = drv;
- if (drv->probe) {
- int error = drv->probe(dev);
- if (error) {
- dev->driver = NULL;
- return error;
- }
- }
-
- 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 = 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;
- }
-}
-
+ struct klist_iter i;
+ struct device_driver * drv;
+ int error = 0;
-/**
- * driver_detach - detach driver from all devices it controls.
- * @drv: driver.
- */
+ if (!bus)
+ return -EINVAL;
-static 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);
- }
+ klist_iter_init_node(&bus->klist_drivers, &i,
+ start ? &start->knode_bus : NULL);
+ while ((drv = next_driver(&i)) && !error)
+ error = fn(drv, data);
+ klist_iter_exit(&i);
+ return error;
}
static int device_add_attrs(struct bus_type * bus, struct device * dev)
int error = 0;
if (bus) {
- down_write(&dev->bus->subsys.rwsem);
pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
- list_add_tail(&dev->bus_list, &dev->bus->devices.list);
device_attach(dev);
- up_write(&dev->bus->subsys.rwsem);
- device_add_attrs(bus, dev);
- sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
+ klist_add_tail(&dev->knode_bus, &bus->klist_devices);
+ error = device_add_attrs(bus, dev);
+ if (!error) {
+ sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
+ sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
+ }
}
return error;
}
sysfs_remove_link(&dev->kobj, "bus");
sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
- down_write(&dev->bus->subsys.rwsem);
+ klist_remove(&dev->knode_bus);
pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);
device_release_driver(dev);
- list_del_init(&dev->bus_list);
- up_write(&dev->bus->subsys.rwsem);
put_bus(dev->bus);
}
}
}
}
+#ifdef CONFIG_HOTPLUG
+/*
+ * Thanks to drivers making their tables __devinit, we can't allow manual
+ * bind and unbind from userspace unless CONFIG_HOTPLUG is enabled.
+ */
+static void add_bind_files(struct device_driver *drv)
+{
+ driver_create_file(drv, &driver_attr_unbind);
+ driver_create_file(drv, &driver_attr_bind);
+}
+
+static void remove_bind_files(struct device_driver *drv)
+{
+ driver_remove_file(drv, &driver_attr_bind);
+ driver_remove_file(drv, &driver_attr_unbind);
+}
+#else
+static inline void add_bind_files(struct device_driver *drv) {}
+static inline void remove_bind_files(struct device_driver *drv) {}
+#endif
/**
* bus_add_driver - Add a driver to the bus.
return error;
}
- down_write(&bus->subsys.rwsem);
driver_attach(drv);
- up_write(&bus->subsys.rwsem);
+ klist_add_tail(&drv->knode_bus, &bus->klist_drivers);
module_add_driver(drv->owner, drv);
driver_add_attrs(bus, drv);
+ add_bind_files(drv);
}
return error;
}
void bus_remove_driver(struct device_driver * drv)
{
if (drv->bus) {
+ remove_bind_files(drv);
driver_remove_attrs(drv->bus, drv);
- down_write(&drv->bus->subsys.rwsem);
+ klist_remove(&drv->knode_bus);
pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);
driver_detach(drv);
- up_write(&drv->bus->subsys.rwsem);
module_remove_driver(drv);
kobject_unregister(&drv->kobj);
put_bus(drv->bus);
/* Helper for bus_rescan_devices's iter */
static int bus_rescan_devices_helper(struct device *dev, void *data)
{
- int *count = data;
-
- if (!dev->driver && device_attach(dev))
- (*count)++;
-
+ if (!dev->driver) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
+ device_attach(dev);
+ if (dev->parent)
+ up(&dev->parent->sem);
+ }
return 0;
}
-
/**
- * bus_rescan_devices - rescan devices on the bus for possible drivers
- * @bus: the bus to scan.
+ * bus_rescan_devices - rescan devices on the bus for possible drivers
+ * @bus: the bus to scan.
*
- * This function will look for devices on the bus with no driver
- * attached and rescan it against existing drivers to see if it
- * matches any. Calls device_attach(). Returns the number of devices
- * that were sucessfully bound to a driver.
+ * This function will look for devices on the bus with no driver
+ * attached and rescan it against existing drivers to see if it matches
+ * any by calling device_attach() for the unbound devices.
*/
-int bus_rescan_devices(struct bus_type * bus)
+void bus_rescan_devices(struct bus_type * bus)
{
- int count = 0;
+ bus_for_each_dev(bus, NULL, NULL, bus_rescan_devices_helper);
+}
- down_write(&bus->subsys.rwsem);
- __bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper);
- up_write(&bus->subsys.rwsem);
+/**
+ * device_reprobe - remove driver for a device and probe for a new driver
+ * @dev: the device to reprobe
+ *
+ * This function detaches the attached driver (if any) for the given
+ * device and restarts the driver probing process. It is intended
+ * to use if probing criteria changed during a devices lifetime and
+ * driver attachment should change accordingly.
+ */
+void device_reprobe(struct device *dev)
+{
+ if (dev->driver) {
+ if (dev->parent) /* Needed for USB */
+ down(&dev->parent->sem);
+ device_release_driver(dev);
+ if (dev->parent)
+ up(&dev->parent->sem);
+ }
- return count;
+ bus_rescan_devices_helper(dev, NULL);
}
-
+EXPORT_SYMBOL_GPL(device_reprobe);
struct bus_type * get_bus(struct bus_type * bus)
{
}
}
+static void klist_devices_get(struct klist_node *n)
+{
+ struct device *dev = container_of(n, struct device, knode_bus);
+
+ get_device(dev);
+}
+
+static void klist_devices_put(struct klist_node *n)
+{
+ struct device *dev = container_of(n, struct device, knode_bus);
+
+ put_device(dev);
+}
+
+static void klist_drivers_get(struct klist_node *n)
+{
+ struct device_driver *drv = container_of(n, struct device_driver,
+ knode_bus);
+
+ get_driver(drv);
+}
+
+static void klist_drivers_put(struct klist_node *n)
+{
+ struct device_driver *drv = container_of(n, struct device_driver,
+ knode_bus);
+
+ put_driver(drv);
+}
+
/**
* bus_register - register a bus with the system.
* @bus: bus.
retval = kset_register(&bus->drivers);
if (retval)
goto bus_drivers_fail;
+
+ klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put);
+ klist_init(&bus->klist_drivers, klist_drivers_get, klist_drivers_put);
bus_add_attrs(bus);
pr_debug("bus type '%s' registered\n", bus->name);
EXPORT_SYMBOL_GPL(bus_for_each_dev);
+EXPORT_SYMBOL_GPL(bus_find_device);
EXPORT_SYMBOL_GPL(bus_for_each_drv);
-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);
-
EXPORT_SYMBOL_GPL(bus_add_device);
EXPORT_SYMBOL_GPL(bus_remove_device);
EXPORT_SYMBOL_GPL(bus_register);
git://git.onelab.eu / linux-2.6.git / blobdiff