Return-Path: From: Fedora Kernel Team To: Jiri Kosina , Marcel Holtmann , Niels Skou Olsen Cc: linux-kernel@vger.kernel.org, linux-input@vger.kernel.org, linux-bluetooth@vger.kernel.org, Benjamin Tissoires Subject: [PATCH 4/4] HID: core: remove the absolute need of hid_have_special_driver[] Date: Mon, 2 Oct 2017 22:18:50 +0200 Message-Id: <20171002201850.13175-5-kernel-team@fedoraproject.org> In-Reply-To: <20171002201850.13175-1-kernel-team@fedoraproject.org> References: <20171002201850.13175-1-kernel-team@fedoraproject.org> List-ID: From: Benjamin Tissoires 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 --- drivers/hid/hid-core.c | 76 ++++++++++++++++++++++++++++++----------------- drivers/hid/hid-generic.c | 68 +++++++++++++++++++++++++++++++++++++++++- include/linux/hid.h | 10 +++++++ 3 files changed, 125 insertions(+), 29 deletions(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 37127d2..e4608ff 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -830,31 +830,6 @@ static int hid_scan_report(struct hid_device *hid) break; } - /* fall back to generic driver in case specific driver doesn't exist */ - switch (hid->group) { - case HID_GROUP_MULTITOUCH_WIN_8: - /* fall-through */ - case HID_GROUP_MULTITOUCH: - if (!IS_ENABLED(CONFIG_HID_MULTITOUCH)) - hid->group = HID_GROUP_GENERIC; - break; - case HID_GROUP_SENSOR_HUB: - if (!IS_ENABLED(CONFIG_HID_SENSOR_HUB)) - hid->group = HID_GROUP_GENERIC; - break; - case HID_GROUP_RMI: - if (!IS_ENABLED(CONFIG_HID_RMI)) - hid->group = HID_GROUP_GENERIC; - break; - case HID_GROUP_WACOM: - if (!IS_ENABLED(CONFIG_HID_WACOM)) - hid->group = HID_GROUP_GENERIC; - break; - case HID_GROUP_LOGITECH_DJ_DEVICE: - if (!IS_ENABLED(CONFIG_HID_LOGITECH_DJ)) - hid->group = HID_GROUP_GENERIC; - break; - } vfree(parser); return 0; } @@ -1928,8 +1903,8 @@ static void hid_free_dynids(struct hid_driver *hdrv) spin_unlock(&hdrv->dyn_lock); } -static const struct hid_device_id *hid_match_device(struct hid_device *hdev, - struct hid_driver *hdrv) +const struct hid_device_id *hid_match_device(struct hid_device *hdev, + struct hid_driver *hdrv) { struct hid_dynid *dynid; @@ -1944,6 +1919,7 @@ static const struct hid_device_id *hid_match_device(struct hid_device *hdev, return hid_match_id(hdev, hdrv->id_table); } +EXPORT_SYMBOL_GPL(hid_match_device); static int hid_bus_match(struct device *dev, struct device_driver *drv) { @@ -1973,6 +1949,23 @@ static int hid_device_probe(struct device *dev) goto unlock; } + if (hdrv->match) { + if (!hdrv->match(hdev, hid_ignore_special_drivers)) { + ret = -ENODEV; + goto unlock; + } + } else { + /* + * hid-generic implements .match(), so if + * hid_ignore_special_drivers is set, we can safely + * return. + */ + if (hid_ignore_special_drivers) { + ret = -ENODEV; + goto unlock; + } + } + hdev->driver = hdrv; if (hdrv->probe) { ret = hdrv->probe(hdev, id); @@ -2069,7 +2062,7 @@ static int hid_uevent(struct device *dev, struct kobj_uevent_env *env) return 0; } -static struct bus_type hid_bus_type = { +struct bus_type hid_bus_type = { .name = "hid", .dev_groups = hid_dev_groups, .drv_groups = hid_drv_groups, @@ -2202,6 +2195,29 @@ void hid_destroy_device(struct hid_device *hdev) } EXPORT_SYMBOL_GPL(hid_destroy_device); + +static int __bus_add_driver(struct device_driver *drv, void *data) +{ + struct hid_driver *added_hdrv = data; + struct hid_driver *hdrv = to_hid_driver(drv); + + if (hdrv->bus_add_driver) + hdrv->bus_add_driver(added_hdrv); + + return 0; +} + +static int __bus_removed_driver(struct device_driver *drv, void *data) +{ + struct hid_driver *removed_hdrv = data; + struct hid_driver *hdrv = to_hid_driver(drv); + + if (hdrv->bus_removed_driver) + hdrv->bus_removed_driver(removed_hdrv); + + return 0; +} + int __hid_register_driver(struct hid_driver *hdrv, struct module *owner, const char *mod_name) { @@ -2213,6 +2229,8 @@ int __hid_register_driver(struct hid_driver *hdrv, struct module *owner, INIT_LIST_HEAD(&hdrv->dyn_list); spin_lock_init(&hdrv->dyn_lock); + bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_add_driver); + return driver_register(&hdrv->driver); } EXPORT_SYMBOL_GPL(__hid_register_driver); @@ -2221,6 +2239,8 @@ void hid_unregister_driver(struct hid_driver *hdrv) { driver_unregister(&hdrv->driver); hid_free_dynids(hdrv); + + bus_for_each_drv(&hid_bus_type, NULL, hdrv, __bus_removed_driver); } EXPORT_SYMBOL_GPL(hid_unregister_driver); diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c index e288a4a..3c0a1bf 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); diff --git a/include/linux/hid.h b/include/linux/hid.h index 6ba8d21..8336774 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -671,6 +671,7 @@ struct hid_usage_id { * to be called) * @dyn_list: list of dynamically added device ids * @dyn_lock: lock protecting @dyn_list + * @match: check if the given device is handled by this driver * @probe: new device inserted * @remove: device removed (NULL if not a hot-plug capable driver) * @report_table: on which reports to call raw_event (NULL means all) @@ -683,6 +684,8 @@ struct hid_usage_id { * @input_mapped: invoked on input registering after mapping an usage * @input_configured: invoked just before the device is registered * @feature_mapping: invoked on feature registering + * @bus_add_driver: invoked when a HID driver is about to be added + * @bus_removed_driver: invoked when a HID driver has been removed * @suspend: invoked on suspend (NULL means nop) * @resume: invoked on resume if device was not reset (NULL means nop) * @reset_resume: invoked on resume if device was reset (NULL means nop) @@ -711,6 +714,7 @@ struct hid_driver { struct list_head dyn_list; spinlock_t dyn_lock; + bool (*match)(struct hid_device *dev, bool ignore_special_driver); int (*probe)(struct hid_device *dev, const struct hid_device_id *id); void (*remove)(struct hid_device *dev); @@ -736,6 +740,8 @@ struct hid_driver { void (*feature_mapping)(struct hid_device *hdev, struct hid_field *field, struct hid_usage *usage); + void (*bus_add_driver)(struct hid_driver *driver); + void (*bus_removed_driver)(struct hid_driver *driver); #ifdef CONFIG_PM int (*suspend)(struct hid_device *hdev, pm_message_t message); int (*resume)(struct hid_device *hdev); @@ -814,6 +820,8 @@ extern bool hid_ignore(struct hid_device *); extern int hid_add_device(struct hid_device *); extern void hid_destroy_device(struct hid_device *); +extern struct bus_type hid_bus_type; + extern int __must_check __hid_register_driver(struct hid_driver *, struct module *, const char *mod_name); @@ -864,6 +872,8 @@ bool hid_match_one_id(const struct hid_device *hdev, const struct hid_device_id *id); const struct hid_device_id *hid_match_id(const struct hid_device *hdev, const struct hid_device_id *id); +const struct hid_device_id *hid_match_device(struct hid_device *hdev, + struct hid_driver *hdrv); s32 hid_snto32(__u32 value, unsigned n); __u32 hid_field_extract(const struct hid_device *hid, __u8 *report, unsigned offset, unsigned n); -- 2.9.5