Commit e04a0442 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Jiri Kosina
Browse files

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: default avatarBenjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent f745d162
......@@ -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,
......@@ -2203,6 +2196,29 @@ 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)
{
......@@ -2214,6 +2230,8 @@ 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);
......@@ -2222,6 +2240,8 @@ 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);
......
......@@ -24,8 +24,71 @@
#include <linux/hid.h>
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);
......
......@@ -672,6 +672,7 @@ 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)
......@@ -684,6 +685,8 @@ 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)
......@@ -712,6 +715,7 @@ 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);
......@@ -737,6 +741,8 @@ 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);
......@@ -815,6 +821,8 @@ 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);
......@@ -865,6 +873,8 @@ 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);
......
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