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authorKay Sievers <kay.sievers@vrfy.org>2007-02-16 17:33:36 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2007-04-27 10:57:28 -0700
commitb8c5cec23d5c33b767a1cddebd4f8813a9563e3c (patch)
treecffec2c5df58866aa6e7ed5540c2718a166c3246 /drivers/base
parenta456b7023e0abf80bb03b0bdf5471b48878e5c49 (diff)
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Driver core: udev triggered device-<>driver binding
We get two per-bus sysfs files: ls-l /sys/subsystem/usb drwxr-xr-x 2 root root 0 2007-02-16 16:42 devices drwxr-xr-x 7 root root 0 2007-02-16 14:55 drivers -rw-r--r-- 1 root root 4096 2007-02-16 16:42 drivers_autoprobe --w------- 1 root root 4096 2007-02-16 16:42 drivers_probe The flag "drivers_autoprobe" controls the behavior of the bus to bind devices by default, or just initialize the device and leave it alone. The command "drivers_probe" accepts a bus_id and the bus tries to bind a driver to this device. Systems who want to control the driver binding with udev, switch off the bus initiated probing: echo 0 > /sys/subsystem/usb/drivers_autoprobe echo 0 > /sys/subsystem/pcmcia/drivers_autoprobe ... and initiate the probing with udev rules like: ACTION=="add", SUBSYSTEM=="usb", ATTR{subsystem/drivers_probe}="$kernel" ACTION=="add", SUBSYSTEM=="pcmcia", ATTR{subsystem/drivers_probe}="$kernel" ... Custom driver binding can happen in earlier rules by something like: ACTION=="add", SUBSYSTEM=="usb", \ ATTRS{idVendor}=="1234", ATTRS{idProduct}=="5678" \ ATTR{subsystem/drivers/<custom-driver>/bind}="$kernel" This is intended to solve the modprobe.conf mess with "install-rules", custom bind/unbind-scripts and all the weird things people invented over the years. It should also provide the functionality "libusual" was supposed to do. With udev, one can just write a udev rule to drive all USB-disks at the third port of USB-hub by the "ub" driver, and everything else by usb-storage. One can also instruct udev to bind different wireless drivers to identical cards - just selected by the pcmcia slot-number, and whatever ... To use the mentioned rules, it needs udev version 106, to be able to write ATTR{}="$kernel" to sysfs files. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/bus.c84
1 files changed, 78 insertions, 6 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 253868e03c70..9df2e6dff519 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)
{
@@ -133,7 +136,6 @@ 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 +201,33 @@ 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)
@@ -425,7 +454,8 @@ int bus_attach_device(struct device * dev)
if (bus) {
dev->is_registered = 1;
- ret = device_attach(dev);
+ if (bus->drivers_autoprobe)
+ ret = device_attach(dev);
if (ret >= 0) {
klist_add_tail(&dev->knode_bus, &bus->klist_devices);
ret = 0;
@@ -515,9 +545,41 @@ 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
/**
@@ -541,9 +603,11 @@ 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);
@@ -762,6 +826,12 @@ 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 +840,8 @@ 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 +851,6 @@ out:
return retval;
}
-
/**
* bus_unregister - remove a bus from the system
* @bus: bus.
@@ -791,6 +862,7 @@ 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);