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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-24 13:21:51 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-24 13:21:51 -0400
commitab11ca34eea8fda7a1a9302d86f6ef6108ffd68f (patch)
tree987ec6c263f3dfa4a7a6f9ce4d5ece47cbc12e29 /Documentation/media-framework.txt
parentf9369910a6225b8d4892c3f20ae740a711cd5ace (diff)
parent71006fb22b0f5a2045605b3887ee99a0e9adafe4 (diff)
Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab: - some V4L2 API updates needed by embedded devices - DVB API extensions for ATSC-MH delivery system, used in US for mobile TV - new tuners for fc0011/0012/0013 and tua9001 - a new dvb driver for af9033/9035 - a new ATSC-MH frontend (lg2160) - new remote controller keymaps - Removal of a few legacy webcam driver that got replaced by gspca on several kernel versions ago - a new driver for Exynos 4/5 webcams(s5pp fimc-lite) - a new webcam sensor driver (smiapp) - a new video input driver for embedded (sta2x1xx) - several improvements, fixes, cleanups, etc inside the drivers. Manually fix up conflicts due to err() -> dev_err() conversion in drivers/staging/media/easycap/easycap_main.c * 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (484 commits) [media] saa7134-cards: Remove a PCI entry added by mistake [media] radio-sf16fmi: add support for SF16-FMD [media] rc-loopback: remove duplicate line [media] patch for Asus My Cinema PS3-100 (1043:48cd) [media] au0828: Move the Kconfig knob under V4L_USB_DRIVERS [media] em28xx: simple comment fix [media] [resend] radio-sf16fmr2: add PnP support for SF16-FMD2 [media] smiapp: Use v4l2_ctrl_new_int_menu() instead of v4l2_ctrl_new_custom() [media] smiapp: Add support for 8-bit uncompressed formats [media] smiapp: Allow generic quirk registers [media] smiapp: Use non-binning limits if the binning limit is zero [media] smiapp: Initialise rval in smiapp_read_nvm() [media] smiapp: Round minimum pre_pll up rather than down in ip_clk_freq check [media] smiapp: Use 8-bit reads only before identifying the sensor [media] smiapp: Quirk for sensors that only do 8-bit reads [media] smiapp: Pass struct sensor to register writing commands instead of i2c_client [media] smiapp: Allow using external clock from the clock framework [media] zl10353: change .read_snr() to report SNR as a 0.1 dB [media] media: add support to gspca/pac7302.c for 093a:2627 (Genius FaceCam 300) [media] m88rs2000 - only flip bit 2 on reg 0x70 on 16th try ...
Diffstat (limited to 'Documentation/media-framework.txt')
-rw-r--r--Documentation/media-framework.txt19
1 files changed, 19 insertions, 0 deletions
diff --git a/Documentation/media-framework.txt b/Documentation/media-framework.txt
index 3a0f879533ce..802875413873 100644
--- a/Documentation/media-framework.txt
+++ b/Documentation/media-framework.txt
@@ -335,6 +335,9 @@ the media_entity pipe field.
335Calls to media_entity_pipeline_start() can be nested. The pipeline pointer must 335Calls to media_entity_pipeline_start() can be nested. The pipeline pointer must
336be identical for all nested calls to the function. 336be identical for all nested calls to the function.
337 337
338media_entity_pipeline_start() may return an error. In that case, it will
339clean up any the changes it did by itself.
340
338When stopping the stream, drivers must notify the entities with 341When stopping the stream, drivers must notify the entities with
339 342
340 media_entity_pipeline_stop(struct media_entity *entity); 343 media_entity_pipeline_stop(struct media_entity *entity);
@@ -351,3 +354,19 @@ If other operations need to be disallowed on streaming entities (such as
351changing entities configuration parameters) drivers can explicitly check the 354changing entities configuration parameters) drivers can explicitly check the
352media_entity stream_count field to find out if an entity is streaming. This 355media_entity stream_count field to find out if an entity is streaming. This
353operation must be done with the media_device graph_mutex held. 356operation must be done with the media_device graph_mutex held.
357
358
359Link validation
360---------------
361
362Link validation is performed by media_entity_pipeline_start() for any
363entity which has sink pads in the pipeline. The
364media_entity::link_validate() callback is used for that purpose. In
365link_validate() callback, entity driver should check that the properties of
366the source pad of the connected entity and its own sink pad match. It is up
367to the type of the entity (and in the end, the properties of the hardware)
368what matching actually means.
369
370Subsystems should facilitate link validation by providing subsystem specific
371helper functions to provide easy access for commonly needed information, and
372in the end provide a way to use driver-specific callbacks.