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author | David Herrmann <dh.herrmann@googlemail.com> | 2012-06-10 15:16:14 +0200 |
---|---|---|
committer | Humberto Borba <humberos@gmail.com> | 2013-01-12 21:03:51 -0200 |
commit | 6b48868f97c76007769e6f935ef636182ff3c23a (patch) | |
tree | 03cf0fc420c4c532d18146ad83b089ad3490db27 /include | |
parent | 626b761c50ca45ea6f3c0f6c38ca6007307cbaa2 (diff) | |
download | kernel_samsung_smdk4412-6b48868f97c76007769e6f935ef636182ff3c23a.zip kernel_samsung_smdk4412-6b48868f97c76007769e6f935ef636182ff3c23a.tar.gz kernel_samsung_smdk4412-6b48868f97c76007769e6f935ef636182ff3c23a.tar.bz2 |
HID: uhid: add internal message buffer
When receiving messages from the HID subsystem, we need to process them
and store them in an internal buffer so user-space can read() on the char
device to retrieve the messages.
This adds a static buffer for 32 messages to each uhid device. Each
message is dynamically allocated so the uhid_device structure does not get
too big.
uhid_queue() adds a message to the buffer. If the buffer is full, the
message is discarded. uhid_queue_event() is an helper for messages without
payload.
This also adds a public header: uhid.h. It contains the declarations for
the user-space API. It is built around "struct uhid_event" which contains
a type field which specifies the event type and each event can then add a
variable-length payload. For now, there is only a dummy event but later
patches will add new event types and payloads.
Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/Kbuild | 1 | ||||
-rw-r--r-- | include/linux/uhid.h | 33 |
2 files changed, 34 insertions, 0 deletions
diff --git a/include/linux/Kbuild b/include/linux/Kbuild index 01f6362..2d6b7ecb 100644 --- a/include/linux/Kbuild +++ b/include/linux/Kbuild @@ -366,6 +366,7 @@ header-y += tty.h header-y += types.h header-y += udf_fs_i.h header-y += udp.h +header-y += uhid.h header-y += uinput.h header-y += uio.h header-y += ultrasound.h diff --git a/include/linux/uhid.h b/include/linux/uhid.h new file mode 100644 index 0000000..16b786a --- /dev/null +++ b/include/linux/uhid.h @@ -0,0 +1,33 @@ +#ifndef __UHID_H_ +#define __UHID_H_ + +/* + * User-space I/O driver support for HID subsystem + * Copyright (c) 2012 David Herrmann + */ + +/* + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + */ + +/* + * Public header for user-space communication. We try to keep every structure + * aligned but to be safe we also use __attribute__((__packed__)). Therefore, + * the communication should be ABI compatible even between architectures. + */ + +#include <linux/input.h> +#include <linux/types.h> + +enum uhid_event_type { + UHID_DUMMY, +}; + +struct uhid_event { + __u32 type; +} __attribute__((__packed__)); + +#endif /* __UHID_H_ */ |