linux/include/drm/drm_debugfs_crc.h
Tomeu Vizoso 9edbf1fa60 drm: Add API for capturing frame CRCs
Adds files and directories to debugfs for controlling and reading frame
CRCs, per CRTC:

dri/0/crtc-0/crc
dri/0/crtc-0/crc/control
dri/0/crtc-0/crc/data

Drivers can implement the set_crc_source callback() in drm_crtc_funcs to
start and stop generating frame CRCs and can add entries to the output
by calling drm_crtc_add_crc_entry.

v2:
    - Lots of good fixes suggested by Thierry.
    - Added documentation.
    - Changed the debugfs layout.
    - Moved to allocate the entries circular queue once when frame
      generation gets enabled for the first time.
v3:
    - Use the control file just to select the source, and start and stop
      capture when the data file is opened and closed, respectively.
    - Make variable the number of CRC values per entry, per source.
    - Allocate entries queue each time we start capturing as now there
      isn't a fixed number of CRC values per entry.
    - Store the frame counter in the data file as a 8-digit hex number.
    - For sources that cannot provide useful frame numbers, place
      XXXXXXXX in the frame field.

v4:
    - Build only if CONFIG_DEBUG_FS is enabled.
    - Use memdup_user_nul.
    - Consolidate calculation of the size of an entry in a helper.
    - Add 0x prefix to hex numbers in the data file.
    - Remove unnecessary snprintf and strlen usage in read callback.

v5:
    - Made the crcs array in drm_crtc_crc_entry fixed-size
    - Lots of other smaller improvements suggested by Emil Velikov

v7:
    - Move definition of drm_debugfs_crtc_crc_add to drm_internal.h

v8:
    - Call debugfs_remove_recursive when we fail to create the minor
      device

v9:
    - Register the debugfs directory for a crtc from
      drm_crtc_register_all()

v10:
    - Don't let debugfs failures interrupt CRTC registration (Emil
      Velikov)

v11:
    - Remove extra brace that broke compilation. Sorry!

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1475767268-14379-3-git-send-email-tomeu.vizoso@collabora.com
2016-10-17 16:44:34 +02:00

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2.6 KiB
C

/*
* Copyright © 2016 Collabora Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef __DRM_DEBUGFS_CRC_H__
#define __DRM_DEBUGFS_CRC_H__
#define DRM_MAX_CRC_NR 10
/**
* struct drm_crtc_crc_entry - entry describing a frame's content
* @has_frame_counter: whether the source was able to provide a frame number
* @frame: number of the frame this CRC is about, if @has_frame_counter is true
* @crc: array of values that characterize the frame
*/
struct drm_crtc_crc_entry {
bool has_frame_counter;
uint32_t frame;
uint32_t crcs[DRM_MAX_CRC_NR];
};
#define DRM_CRC_ENTRIES_NR 128
/**
* struct drm_crtc_crc - data supporting CRC capture on a given CRTC
* @lock: protects the fields in this struct
* @source: name of the currently configured source of CRCs
* @opened: whether userspace has opened the data file for reading
* @entries: array of entries, with size of %DRM_CRC_ENTRIES_NR
* @head: head of circular queue
* @tail: tail of circular queue
* @values_cnt: number of CRC values per entry, up to %DRM_MAX_CRC_NR
* @wq: workqueue used to synchronize reading and writing
*/
struct drm_crtc_crc {
spinlock_t lock;
const char *source;
bool opened;
struct drm_crtc_crc_entry *entries;
int head, tail;
size_t values_cnt;
wait_queue_head_t wq;
};
#if defined(CONFIG_DEBUG_FS)
int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
uint32_t frame, uint32_t *crcs);
#else
static inline int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
uint32_t frame, uint32_t *crcs)
{
return -EINVAL;
}
#endif /* defined(CONFIG_DEBUG_FS) */
#endif /* __DRM_DEBUGFS_CRC_H__ */