Commit 4d53b801 authored by Henrik Rydberg's avatar Henrik Rydberg Committed by Jiri Kosina
Browse files

HID: Add device group to modalias 



HID devices are only partially presented to userland.  Hotplugged
devices emit events containing a modalias based on the basic bus,
vendor and product entities. However, in practise a hid device can
depend on details such as a single usb interface or a particular item
in a report descriptor.

This patch adds a device group to the hid device id, and broadcasts it
using uevent and the device modalias.  The module alias generation is
modified to match. As a consequence, a device with a non-zero group
will be processed by the corresponding group driver instead of by the
generic hid driver.

Signed-off-by: default avatarHenrik Rydberg <rydberg@euromail.se>
Acked-by: default avatarBenjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent a7197c2e

drivers/hid/hid-core.c

+22 −2
Original line number Diff line number Diff line
@@ -1222,6 +1222,7 @@ static bool hid_match_one_id(struct hid_device *hdev, 
		const struct hid_device_id *id)

{

	return id->bus == hdev->bus &&

		(id->group == HID_GROUP_ANY || id->group == hdev->group) &&

		(id->vendor == HID_ANY_ID || id->vendor == hdev->vendor) &&

		(id->product == HID_ANY_ID || id->product == hdev->product);

}
@@ -1694,6 +1695,7 @@ static ssize_t store_new_id(struct device_driver *drv, const char *buf, 
		return -ENOMEM;



	dynid->id.bus = bus;

	dynid->id.group = HID_GROUP_ANY;

	dynid->id.vendor = vendor;

	dynid->id.product = product;

	dynid->id.driver_data = driver_data;
@@ -1817,6 +1819,23 @@ static int hid_device_remove(struct device *dev) 
	return 0;

}



static ssize_t modalias_show(struct device *dev, struct device_attribute *a,

			     char *buf)

{

	struct hid_device *hdev = container_of(dev, struct hid_device, dev);

	int len;



	len = snprintf(buf, PAGE_SIZE, "hid:b%04Xg%04Xv%08Xp%08X\n",

		       hdev->bus, hdev->group, hdev->vendor, hdev->product);



	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;

}



static struct device_attribute hid_dev_attrs[] = {

	__ATTR_RO(modalias),

	__ATTR_NULL,

};



static int hid_uevent(struct device *dev, struct kobj_uevent_env *env)

{

	struct hid_device *hdev = container_of(dev, struct hid_device, dev);
@@ -1834,8 +1853,8 @@ static int hid_uevent(struct device *dev, struct kobj_uevent_env *env) 
	if (add_uevent_var(env, "HID_UNIQ=%s", hdev->uniq))

		return -ENOMEM;



	if (add_uevent_var(env, "MODALIAS=hid:b%04Xv%08Xp%08X",

			hdev->bus, hdev->vendor, hdev->product))

	if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X",

			   hdev->bus, hdev->group, hdev->vendor, hdev->product))

		return -ENOMEM;



	return 0;
@@ -1843,6 +1862,7 @@ static int hid_uevent(struct device *dev, struct kobj_uevent_env *env) 


static struct bus_type hid_bus_type = {

	.name		= "hid",

	.dev_attrs	= hid_dev_attrs,

	.match		= hid_bus_match,

	.probe		= hid_device_probe,

	.remove		= hid_device_remove,

include/linux/hid.h

+1 −0
Original line number Diff line number Diff line
@@ -476,6 +476,7 @@ struct hid_device { /* device report descriptor */ 
	unsigned maxcollection;						/* Number of parsed collections */

	unsigned maxapplication;					/* Number of applications */

	__u16 bus;							/* BUS ID */

	__u16 group;							/* Report group */

	__u32 vendor;							/* Vendor ID */

	__u32 product;							/* Product ID */

	__u32 version;							/* HID version */

include/linux/mod_devicetable.h

+2 −1
Original line number Diff line number Diff line
@@ -132,10 +132,11 @@ struct usb_device_id { 
#define USB_DEVICE_ID_MATCH_INT_PROTOCOL	0x0200



#define HID_ANY_ID				(~0)

#define HID_GROUP_ANY				0x0000



struct hid_device_id {

	__u16 bus;

	__u16 pad1;

	__u16 group;

	__u32 vendor;

	__u32 product;

	kernel_ulong_t driver_data

scripts/mod/file2alias.c

+2 −0
Original line number Diff line number Diff line
@@ -336,10 +336,12 @@ static int do_hid_entry(const char *filename, 
			     struct hid_device_id *id, char *alias)

{

	id->bus = TO_NATIVE(id->bus);

	id->group = TO_NATIVE(id->group);

	id->vendor = TO_NATIVE(id->vendor);

	id->product = TO_NATIVE(id->product);



	sprintf(alias, "hid:b%04X", id->bus);

	ADD(alias, "g", id->group != HID_GROUP_ANY, id->group);

	ADD(alias, "v", id->vendor != HID_ANY_ID, id->vendor);

	ADD(alias, "p", id->product != HID_ANY_ID, id->product);

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