--- /dev/null
+/*
+ * drivers/usb/generic.c - generic driver for USB devices (not interfaces)
+ *
+ * (C) Copyright 2005 Greg Kroah-Hartman <gregkh@suse.de>
+ *
+ * based on drivers/usb/usb.c which had the following copyrights:
+ * (C) Copyright Linus Torvalds 1999
+ * (C) Copyright Johannes Erdfelt 1999-2001
+ * (C) Copyright Andreas Gal 1999
+ * (C) Copyright Gregory P. Smith 1999
+ * (C) Copyright Deti Fliegl 1999 (new USB architecture)
+ * (C) Copyright Randy Dunlap 2000
+ * (C) Copyright David Brownell 2000-2004
+ * (C) Copyright Yggdrasil Computing, Inc. 2000
+ * (usb_device_id matching changes by Adam J. Richter)
+ * (C) Copyright Greg Kroah-Hartman 2002-2003
+ *
+ */
+
+#include <linux/usb.h>
+#include "usb.h"
+
+static inline const char *plural(int n)
+{
+ return (n == 1 ? "" : "s");
+}
+
+static int choose_configuration(struct usb_device *udev)
+{
+ int i;
+ int num_configs;
+ int insufficient_power = 0;
+ struct usb_host_config *c, *best;
+
+ best = NULL;
+ c = udev->config;
+ num_configs = udev->descriptor.bNumConfigurations;
+ for (i = 0; i < num_configs; (i++, c++)) {
+ struct usb_interface_descriptor *desc = NULL;
+
+ /* It's possible that a config has no interfaces! */
+ if (c->desc.bNumInterfaces > 0)
+ desc = &c->intf_cache[0]->altsetting->desc;
+
+ /*
+ * HP's USB bus-powered keyboard has only one configuration
+ * and it claims to be self-powered; other devices may have
+ * similar errors in their descriptors. If the next test
+ * were allowed to execute, such configurations would always
+ * be rejected and the devices would not work as expected.
+ * In the meantime, we run the risk of selecting a config
+ * that requires external power at a time when that power
+ * isn't available. It seems to be the lesser of two evils.
+ *
+ * Bugzilla #6448 reports a device that appears to crash
+ * when it receives a GET_DEVICE_STATUS request! We don't
+ * have any other way to tell whether a device is self-powered,
+ * but since we don't use that information anywhere but here,
+ * the call has been removed.
+ *
+ * Maybe the GET_DEVICE_STATUS call and the test below can
+ * be reinstated when device firmwares become more reliable.
+ * Don't hold your breath.
+ */
+#if 0
+ /* Rule out self-powered configs for a bus-powered device */
+ if (bus_powered && (c->desc.bmAttributes &
+ USB_CONFIG_ATT_SELFPOWER))
+ continue;
+#endif
+
+ /*
+ * The next test may not be as effective as it should be.
+ * Some hubs have errors in their descriptor, claiming
+ * to be self-powered when they are really bus-powered.
+ * We will overestimate the amount of current such hubs
+ * make available for each port.
+ *
+ * This is a fairly benign sort of failure. It won't
+ * cause us to reject configurations that we should have
+ * accepted.
+ */
+
+ /* Rule out configs that draw too much bus current */
+ if (c->desc.bMaxPower * 2 > udev->bus_mA) {
+ insufficient_power++;
+ continue;
+ }
+
+ /* If the first config's first interface is COMM/2/0xff
+ * (MSFT RNDIS), rule it out unless Linux has host-side
+ * RNDIS support. */
+ if (i == 0 && desc
+ && desc->bInterfaceClass == USB_CLASS_COMM
+ && desc->bInterfaceSubClass == 2
+ && desc->bInterfaceProtocol == 0xff) {
+#ifndef CONFIG_USB_NET_RNDIS_HOST
+ continue;
+#else
+ best = c;
+#endif
+ }
+
+ /* From the remaining configs, choose the first one whose
+ * first interface is for a non-vendor-specific class.
+ * Reason: Linux is more likely to have a class driver
+ * than a vendor-specific driver. */
+ else if (udev->descriptor.bDeviceClass !=
+ USB_CLASS_VENDOR_SPEC &&
+ (!desc || desc->bInterfaceClass !=
+ USB_CLASS_VENDOR_SPEC)) {
+ best = c;
+ break;
+ }
+
+ /* If all the remaining configs are vendor-specific,
+ * choose the first one. */
+ else if (!best)
+ best = c;
+ }
+
+ if (insufficient_power > 0)
+ dev_info(&udev->dev, "rejected %d configuration%s "
+ "due to insufficient available bus power\n",
+ insufficient_power, plural(insufficient_power));
+
+ if (best) {
+ i = best->desc.bConfigurationValue;
+ dev_info(&udev->dev,
+ "configuration #%d chosen from %d choice%s\n",
+ i, num_configs, plural(num_configs));
+ } else {
+ i = -1;
+ dev_warn(&udev->dev,
+ "no configuration chosen from %d choice%s\n",
+ num_configs, plural(num_configs));
+ }
+ return i;
+}
+
+static int generic_probe(struct usb_device *udev)
+{
+ int err, c;
+
+ /* put device-specific files into sysfs */
+ usb_create_sysfs_dev_files(udev);
+
+ /* Choose and set the configuration. This registers the interfaces
+ * with the driver core and lets interface drivers bind to them.
+ */
+ c = choose_configuration(udev);
+ if (c >= 0) {
+ err = usb_set_configuration(udev, c);
+ if (err) {
+ dev_err(&udev->dev, "can't set config #%d, error %d\n",
+ c, err);
+ /* This need not be fatal. The user can try to
+ * set other configurations. */
+ }
+ }
+
+ /* USB device state == configured ... usable */
+ usb_notify_add_device(udev);
+
+ return 0;
+}
+
+static void generic_disconnect(struct usb_device *udev)
+{
+ usb_notify_remove_device(udev);
+
+ /* if this is only an unbind, not a physical disconnect, then
+ * unconfigure the device */
+ if (udev->actconfig)
+ usb_set_configuration(udev, 0);
+
+ usb_remove_sysfs_dev_files(udev);
+}
+
+#ifdef CONFIG_PM
+
+static int generic_suspend(struct usb_device *udev, pm_message_t msg)
+{
+ /* USB devices enter SUSPEND state through their hubs, but can be
+ * marked for FREEZE as soon as their children are already idled.
+ * But those semantics are useless, so we equate the two (sigh).
+ */
+ return usb_port_suspend(udev);
+}
+
+static int generic_resume(struct usb_device *udev)
+{
+ return usb_port_resume(udev);
+}
+
+#endif /* CONFIG_PM */
+
+struct usb_device_driver usb_generic_driver = {
+ .name = "usb",
+ .probe = generic_probe,
+ .disconnect = generic_disconnect,
+#ifdef CONFIG_PM
+ .suspend = generic_suspend,
+ .resume = generic_resume,
+#endif
+ .supports_autosuspend = 1,
+};
git://git.onelab.eu / linux-2.6.git / blobdiff