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: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 9ed4ff3..cfcb69e 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -1222,6 +1222,7 @@
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 @@
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 @@
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 @@
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 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,