HID: uhid: report to user-space whether reports are numbered

This makes UHID_START include a "dev_flags" field that describes details
of the hid-device in the kernel. The first flags we introduce describe
whether a given report-type uses numbered reports. This is useful for
transport layers that force report-numbers and therefore might have to
prefix kernel-provided HID-messages with the report-number.

Currently, only HoG needs this and the spec only talks about "global
report numbers". That is, it's a global boolean not a per-type boolean.
However, given the quirks we already have in kernel-space, a per-type
value seems much more appropriate.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
index 62aac0e4edf3..aaa86d6bd1dd 100644
--- a/include/uapi/linux/uhid.h
+++ b/include/uapi/linux/uhid.h
@@ -54,6 +54,16 @@ struct uhid_create2_req {
         __u8 rd_data[HID_MAX_DESCRIPTOR_SIZE];
 } __attribute__((__packed__));
 
+enum uhid_dev_flag {
+        UHID_DEV_NUMBERED_FEATURE_REPORTS                       = (1ULL << 0),
+        UHID_DEV_NUMBERED_OUTPUT_REPORTS                        = (1ULL << 1),
+        UHID_DEV_NUMBERED_INPUT_REPORTS                         = (1ULL << 2),
+};
+
+struct uhid_start_req {
+        __u64 dev_flags;
+};
+
 #define UHID_DATA_MAX 4096
 
 enum uhid_report_type {
@@ -182,6 +192,7 @@ struct uhid_event {
                 struct uhid_input2_req input2;
                 struct uhid_set_report_req set_report;
                 struct uhid_set_report_reply_req set_report_reply;
+                struct uhid_start_req start;
         } u;
 } __attribute__((__packed__));