diff options
Diffstat (limited to 'drivers/base/bus.c')
| -rw-r--r-- | drivers/base/bus.c | 112 |
1 files changed, 96 insertions, 16 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 253868e03c70..1d76e2349654 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -27,6 +27,9 @@ #define to_driver(obj) container_of(obj, struct device_driver, kobj) +static int __must_check bus_rescan_devices_helper(struct device *dev, + void *data); + static ssize_t drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf) { @@ -60,8 +63,19 @@ static struct sysfs_ops driver_sysfs_ops = { static void driver_release(struct kobject * kobj) { - struct device_driver * drv = to_driver(kobj); - complete(&drv->unloaded); + /* + * Yes this is an empty release function, it is this way because struct + * device is always a static object, not a dynamic one. Yes, this is + * not nice and bad, but remember, drivers are code, reference counted + * by the module count, not a device, which is really data. And yes, + * in the future I do want to have all drivers be created dynamically, + * and am working toward that goal, but it will take a bit longer... + * + * But do not let this example give _anyone_ the idea that they can + * create a release function without any code in it at all, to do that + * is almost always wrong. If you have any questions about this, + * please send an email to <greg@kroah.com> + */ } static struct kobj_type ktype_driver = { @@ -133,7 +147,6 @@ static decl_subsys(bus, &ktype_bus, NULL); #ifdef CONFIG_HOTPLUG - /* Manually detach a device from its associated driver. */ static int driver_helper(struct device *dev, void *data) { @@ -199,6 +212,33 @@ static ssize_t driver_bind(struct device_driver *drv, } static DRIVER_ATTR(bind, S_IWUSR, NULL, driver_bind); +static ssize_t show_drivers_autoprobe(struct bus_type *bus, char *buf) +{ + return sprintf(buf, "%d\n", bus->drivers_autoprobe); +} + +static ssize_t store_drivers_autoprobe(struct bus_type *bus, + const char *buf, size_t count) +{ + if (buf[0] == '0') + bus->drivers_autoprobe = 0; + else + bus->drivers_autoprobe = 1; + return count; +} + +static ssize_t store_drivers_probe(struct bus_type *bus, + const char *buf, size_t count) +{ + struct device *dev; + + dev = bus_find_device(bus, NULL, (void *)buf, driver_helper); + if (!dev) + return -ENODEV; + if (bus_rescan_devices_helper(dev, NULL) != 0) + return -EINVAL; + return count; +} #endif static struct device * next_device(struct klist_iter * i) @@ -418,21 +458,21 @@ out_put: * - Add device to bus's list of devices. * - Try to attach to driver. */ -int bus_attach_device(struct device * dev) +void bus_attach_device(struct device * dev) { struct bus_type *bus = dev->bus; int ret = 0; if (bus) { dev->is_registered = 1; - ret = device_attach(dev); - if (ret >= 0) { + if (bus->drivers_autoprobe) + ret = device_attach(dev); + WARN_ON(ret < 0); + if (ret >= 0) klist_add_tail(&dev->knode_bus, &bus->klist_devices); - ret = 0; - } else + else dev->is_registered = 0; } - return ret; } /** @@ -515,9 +555,41 @@ static void remove_bind_files(struct device_driver *drv) driver_remove_file(drv, &driver_attr_bind); driver_remove_file(drv, &driver_attr_unbind); } + +static int add_probe_files(struct bus_type *bus) +{ + int retval; + + bus->drivers_probe_attr.attr.name = "drivers_probe"; + bus->drivers_probe_attr.attr.mode = S_IWUSR; + bus->drivers_probe_attr.attr.owner = bus->owner; + bus->drivers_probe_attr.store = store_drivers_probe; + retval = bus_create_file(bus, &bus->drivers_probe_attr); + if (retval) + goto out; + + bus->drivers_autoprobe_attr.attr.name = "drivers_autoprobe"; + bus->drivers_autoprobe_attr.attr.mode = S_IWUSR | S_IRUGO; + bus->drivers_autoprobe_attr.attr.owner = bus->owner; + bus->drivers_autoprobe_attr.show = show_drivers_autoprobe; + bus->drivers_autoprobe_attr.store = store_drivers_autoprobe; + retval = bus_create_file(bus, &bus->drivers_autoprobe_attr); + if (retval) + bus_remove_file(bus, &bus->drivers_probe_attr); +out: + return retval; +} + +static void remove_probe_files(struct bus_type *bus) +{ + bus_remove_file(bus, &bus->drivers_autoprobe_attr); + bus_remove_file(bus, &bus->drivers_probe_attr); +} #else static inline int add_bind_files(struct device_driver *drv) { return 0; } static inline void remove_bind_files(struct device_driver *drv) {} +static inline int add_probe_files(struct bus_type *bus) { return 0; } +static inline void remove_probe_files(struct bus_type *bus) {} #endif /** @@ -531,7 +603,7 @@ int bus_add_driver(struct device_driver *drv) int error = 0; if (!bus) - return 0; + return -EINVAL; pr_debug("bus %s: add driver %s\n", bus->name, drv->name); error = kobject_set_name(&drv->kobj, "%s", drv->name); @@ -541,9 +613,11 @@ int bus_add_driver(struct device_driver *drv) if ((error = kobject_register(&drv->kobj))) goto out_put_bus; - error = driver_attach(drv); - if (error) - goto out_unregister; + if (drv->bus->drivers_autoprobe) { + error = driver_attach(drv); + if (error) + goto out_unregister; + } klist_add_tail(&drv->knode_bus, &bus->klist_drivers); module_add_driver(drv->owner, drv); @@ -605,8 +679,6 @@ static int __must_check bus_rescan_devices_helper(struct device *dev, ret = device_attach(dev); if (dev->parent) up(&dev->parent->sem); - if (ret > 0) - ret = 0; } return ret < 0 ? ret : 0; } @@ -762,6 +834,12 @@ int bus_register(struct bus_type * bus) klist_init(&bus->klist_devices, klist_devices_get, klist_devices_put); klist_init(&bus->klist_drivers, NULL, NULL); + + bus->drivers_autoprobe = 1; + retval = add_probe_files(bus); + if (retval) + goto bus_probe_files_fail; + retval = bus_add_attrs(bus); if (retval) goto bus_attrs_fail; @@ -770,6 +848,8 @@ int bus_register(struct bus_type * bus) return 0; bus_attrs_fail: + remove_probe_files(bus); +bus_probe_files_fail: kset_unregister(&bus->drivers); bus_drivers_fail: kset_unregister(&bus->devices); @@ -779,7 +859,6 @@ out: return retval; } - /** * bus_unregister - remove a bus from the system * @bus: bus. @@ -791,6 +870,7 @@ void bus_unregister(struct bus_type * bus) { pr_debug("bus %s: unregistering\n", bus->name); bus_remove_attrs(bus); + remove_probe_files(bus); kset_unregister(&bus->drivers); kset_unregister(&bus->devices); subsystem_unregister(&bus->subsys); |