From e04a0442d33b8cf183bba38646447b891bb02123 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Mon, 20 Nov 2017 11:48:44 +0100 Subject: HID: core: remove the absolute need of hid_have_special_driver[] Most HID devices behave properly when they are used with hid-generic. Since kernel v4.12, we do not poll for input reports at plug in, so hid-generic should behave properly with all HID devices. There has been a long standing list of HID devices that have a special driver. It used to be just a few, but with time, this list went too big, and we can not ask users to know which HID special driver will pick up their device. We can teach hid-generic to be nice with others. If a device is not explicitly marked with HID_QUIRK_HAVE_SPECIAL_DRIVER, we can allow hid-generic to pick up the device as long as no other loaded HID driver will match the device. When the special driver appears, hid-generic can step back and let the special driver handling the device. In case this special driver is removed, this good old pal of hid-generic will rebind to the device. This basically makes the list hid_have_special_driver[] useless. It still allows to not see a hid-generic driver bound and removed during boot, so we can keep it around. This will also help other people to have a special HID driver without the need of recompiling hid-core. Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina --- drivers/hid/hid-generic.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 67 insertions(+), 1 deletion(-) (limited to 'drivers/hid/hid-generic.c') diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c index e288a4a06fe8..3c0a1bf433d7 100644 --- a/drivers/hid/hid-generic.c +++ b/drivers/hid/hid-generic.c @@ -24,8 +24,71 @@ #include +static struct hid_driver hid_generic; + +static int __unmap_hid_generic(struct device *dev, void *data) +{ + struct hid_driver *hdrv = data; + struct hid_device *hdev = to_hid_device(dev); + + /* only unbind matching devices already bound to hid-generic */ + if (hdev->driver != &hid_generic || + hid_match_device(hdev, hdrv) == NULL) + return 0; + + if (dev->parent) /* Needed for USB */ + device_lock(dev->parent); + device_release_driver(dev); + if (dev->parent) + device_unlock(dev->parent); + + return 0; +} + +static void hid_generic_add_driver(struct hid_driver *hdrv) +{ + bus_for_each_dev(&hid_bus_type, NULL, hdrv, __unmap_hid_generic); +} + +static void hid_generic_removed_driver(struct hid_driver *hdrv) +{ + int ret; + + ret = driver_attach(&hid_generic.driver); +} + +static int __check_hid_generic(struct device_driver *drv, void *data) +{ + struct hid_driver *hdrv = to_hid_driver(drv); + struct hid_device *hdev = data; + + if (hdrv == &hid_generic) + return 0; + + return hid_match_device(hdev, hdrv) != NULL; +} + +static bool hid_generic_match(struct hid_device *hdev, + bool ignore_special_driver) +{ + if (ignore_special_driver) + return true; + + if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER) + return false; + + /* + * If any other driver wants the device, leave the device to this other + * driver. + */ + if (bus_for_each_drv(&hid_bus_type, NULL, hdev, __check_hid_generic)) + return false; + + return true; +} + static const struct hid_device_id hid_table[] = { - { HID_DEVICE(HID_BUS_ANY, HID_GROUP_GENERIC, HID_ANY_ID, HID_ANY_ID) }, + { HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) }, { } }; MODULE_DEVICE_TABLE(hid, hid_table); @@ -33,6 +96,9 @@ MODULE_DEVICE_TABLE(hid, hid_table); static struct hid_driver hid_generic = { .name = "hid-generic", .id_table = hid_table, + .match = hid_generic_match, + .bus_add_driver = hid_generic_add_driver, + .bus_removed_driver = hid_generic_removed_driver, }; module_hid_driver(hid_generic); -- cgit v1.2.3-59-g8ed1b