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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 23:58:31 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-27 23:58:31 +0200 |
commit | ff9a082fda424257976f08fce942609f358015e0 (patch) | |
tree | 478e6b449b19baaf842369a13923499ce83ef895 /Documentation/video4linux/cx2341x/fw-calling.txt | |
parent | Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi (diff) | |
parent | Merge branch 'topic/docs-next' into v4l_for_linus (diff) | |
download | linux-ff9a082fda424257976f08fce942609f358015e0.tar.xz linux-ff9a082fda424257976f08fce942609f358015e0.zip |
Merge tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media documentation updates from Mauro Carvalho Chehab:
"This patch series does the conversion of all media documentation stuff
to Restrutured Text markup format and add them to the
Documentation/index.rst file.
The media documentation was grouped into 4 books:
- media uAPI
- media kAPI
- V4L driver-specific documentation
- DVB driver-specific documentation
It also contains several documentation improvements and one fixup
patch for a core issue with cropcap.
PS. After this patch series, the media DocBook is deprecated and
should be removed. I'll add such patch on a future pull request"
* tag 'media/v4.8-4' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (322 commits)
[media] cx23885-cardlist.rst: add a new card
[media] doc-rst: add some needed escape codes
[media] doc-rst: kapi: use :c:func: instead of :cpp:func
doc-rst: kernel-doc: fix a change introduced by mistake
[media] v4l2-ioctl.h add debug info for struct v4l2_ioctl_ops
[media] dvb_ringbuffer.h: some documentation improvements
[media] v4l2-ctrls.h: fully document the header file
[media] doc-rst: Fix some typedef ugly warnings
[media] doc-rst: reorganize the kAPI v4l2 chapters
[media] rename v4l2-framework.rst to v4l2-intro.rst
[media] move V4L2 clocks to a separate .rst file
[media] v4l2-fh.rst: add cross references and markups
[media] v4l2-fh.rst: add fh contents from v4l2-framework.rst
[media] v4l2-fh.h: add documentation for it
[media] v4l2-event.rst: add cross-references and markups
[media] v4l2-event.h: document all functions
[media] v4l2-event.rst: add text from v4l2-framework.rst
[media] v4l2-framework.rst: remove videobuf quick chapter
[media] v4l2-dev: add cross-references and improve markup
[media] doc-rst: move v4l2-dev doc to a separate file
...
Diffstat (limited to 'Documentation/video4linux/cx2341x/fw-calling.txt')
-rw-r--r-- | Documentation/video4linux/cx2341x/fw-calling.txt | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/Documentation/video4linux/cx2341x/fw-calling.txt b/Documentation/video4linux/cx2341x/fw-calling.txt deleted file mode 100644 index 8d21181de537..000000000000 --- a/Documentation/video4linux/cx2341x/fw-calling.txt +++ /dev/null @@ -1,69 +0,0 @@ -This page describes how to make calls to the firmware api. - -How to call -=========== - -The preferred calling convention is known as the firmware mailbox. The -mailboxes are basically a fixed length array that serves as the call-stack. - -Firmware mailboxes can be located by searching the encoder and decoder memory -for a 16 byte signature. That signature will be located on a 256-byte boundary. - -Signature: -0x78, 0x56, 0x34, 0x12, 0x12, 0x78, 0x56, 0x34, -0x34, 0x12, 0x78, 0x56, 0x56, 0x34, 0x12, 0x78 - -The firmware implements 20 mailboxes of 20 32-bit words. The first 10 are -reserved for API calls. The second 10 are used by the firmware for event -notification. - - Index Name - ----- ---- - 0 Flags - 1 Command - 2 Return value - 3 Timeout - 4-19 Parameter/Result - - -The flags are defined in the following table. The direction is from the -perspective of the firmware. - - Bit Direction Purpose - --- --------- ------- - 2 O Firmware has processed the command. - 1 I Driver has finished setting the parameters. - 0 I Driver is using this mailbox. - - -The command is a 32-bit enumerator. The API specifics may be found in the -fw-*-api.txt documents. - -The return value is a 32-bit enumerator. Only two values are currently defined: -0=success and -1=command undefined. - -There are 16 parameters/results 32-bit fields. The driver populates these fields -with values for all the parameters required by the call. The driver overwrites -these fields with result values returned by the call. The API specifics may be -found in the fw-*-api.txt documents. - -The timeout value protects the card from a hung driver thread. If the driver -doesn't handle the completed call within the timeout specified, the firmware -will reset that mailbox. - -To make an API call, the driver iterates over each mailbox looking for the -first one available (bit 0 has been cleared). The driver sets that bit, fills -in the command enumerator, the timeout value and any required parameters. The -driver then sets the parameter ready bit (bit 1). The firmware scans the -mailboxes for pending commands, processes them, sets the result code, populates -the result value array with that call's return values and sets the call -complete bit (bit 2). Once bit 2 is set, the driver should retrieve the results -and clear all the flags. If the driver does not perform this task within the -time set in the timeout register, the firmware will reset that mailbox. - -Event notifications are sent from the firmware to the host. The host tells the -firmware which events it is interested in via an API call. That call tells the -firmware which notification mailbox to use. The firmware signals the host via -an interrupt. Only the 16 Results fields are used, the Flags, Command, Return -value and Timeout words are not used. - |