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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-03 17:16:59 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-04-03 17:16:59 -0700 |
commit | ef1c4a6fa91bbbe9b09f770d28eba31a9edf770c (patch) | |
tree | 52f5d175031c553160d14890e876ffc5432d2467 /Documentation/media/kapi/cec-core.rst | |
parent | 147a89bc71e7db40f011454a40add7ff2d10f8d8 (diff) | |
parent | f8a695c4b43d02c89b8bba9ba6058fd5db1bc71d (diff) | |
download | linux-ef1c4a6fa91bbbe9b09f770d28eba31a9edf770c.tar.bz2 |
Merge tag 'media/v4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
- new CEC pin injection code for testing purposes
- DVB frontend cxd2099 promoted from staging
- new platform driver for Sony cxd2880 DVB devices
- new sensor drivers: mt9t112, ov2685, ov5695, ov772x, tda1997x,
tw9910.c
- removal of unused cx18 and ivtv alsa mixers
- the reneseas-ceu driver doesn't depend on soc_camera anymore and
moved from staging
- removed the mantis_vp3028 driver, unused since 2009
- s5p-mfc: add support for version 10 of the MSP
- added a decoder for imon protocol
- atomisp: lots of cleanups
- imx074 and mt9t031: don't depend on soc_camera anymore, being
promoted from staging
- added helper functions to better support DVB I2C binding
- lots of driver improvements and cleanups
* tag 'media/v4.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (438 commits)
media: v4l2-ioctl: rename a temp var that stores _IOC_SIZE(cmd)
media: fimc-capture: get rid of two warnings
media: dvb-usb-v2: fix a missing dependency of I2C_MUX
media: uvc: to the right check at uvc_ioctl_enum_framesizes()
media: cec-core: fix a bug at cec_error_inj_write()
media: tda9840: cleanup a warning
media: tm6000: avoid casting just to print pointer address
media: em28xx-input: improve error handling code
media: zr364xx: avoid casting just to print pointer address
media: vivid-radio-rx: add a cast to avoid a warning
media: saa7134-alsa: don't use casts to print a buffer address
media: solo6x10: get rid of an address space warning
media: zoran: don't cast pointers to print them
media: ir-kbd-i2c: change the if logic to avoid a warning
media: ir-kbd-i2c: improve error handling code
media: saa7134-input: improve error handling
media: s2255drv: fix a casting warning
media: ivtvfb: Cleanup some warnings
media: videobuf-dma-sg: Fix a weird cast
soc_camera: fix a weird cast on printk
...
Diffstat (limited to 'Documentation/media/kapi/cec-core.rst')
-rw-r--r-- | Documentation/media/kapi/cec-core.rst | 72 |
1 files changed, 71 insertions, 1 deletions
diff --git a/Documentation/media/kapi/cec-core.rst b/Documentation/media/kapi/cec-core.rst index 62b9a1448177..a9f53f069a2d 100644 --- a/Documentation/media/kapi/cec-core.rst +++ b/Documentation/media/kapi/cec-core.rst @@ -110,11 +110,14 @@ your driver: void (*adap_status)(struct cec_adapter *adap, struct seq_file *file); void (*adap_free)(struct cec_adapter *adap); + /* Error injection callbacks */ + ... + /* High-level callbacks */ ... }; -The five low-level ops deal with various aspects of controlling the CEC adapter +The seven low-level ops deal with various aspects of controlling the CEC adapter hardware: @@ -286,6 +289,70 @@ handling the receive interrupt. The framework expects to see the cec_transmit_do call before the cec_received_msg call, otherwise it can get confused if the received message was in reply to the transmitted message. +Optional: Implementing Error Injection Support +---------------------------------------------- + +If the CEC adapter supports Error Injection functionality, then that can +be exposed through the Error Injection callbacks: + +.. code-block:: none + + struct cec_adap_ops { + /* Low-level callbacks */ + ... + + /* Error injection callbacks */ + int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); + bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); + + /* High-level CEC message callback */ + ... + }; + +If both callbacks are set, then an ``error-inj`` file will appear in debugfs. +The basic syntax is as follows: + +Leading spaces/tabs are ignored. If the next character is a ``#`` or the end of the +line was reached, then the whole line is ignored. Otherwise a command is expected. + +This basic parsing is done in the CEC Framework. It is up to the driver to decide +what commands to implement. The only requirement is that the command ``clear`` without +any arguments must be implemented and that it will remove all current error injection +commands. + +This ensures that you can always do ``echo clear >error-inj`` to clear any error +injections without having to know the details of the driver-specific commands. + +Note that the output of ``error-inj`` shall be valid as input to ``error-inj``. +So this must work: + +.. code-block:: none + + $ cat error-inj >einj.txt + $ cat einj.txt >error-inj + +The first callback is called when this file is read and it should show the +the current error injection state: + +.. c:function:: + int (*error_inj_show)(struct cec_adapter *adap, struct seq_file *sf); + +It is recommended that it starts with a comment block with basic usage +information. It returns 0 for success and an error otherwise. + +The second callback will parse commands written to the ``error-inj`` file: + +.. c:function:: + bool (*error_inj_parse_line)(struct cec_adapter *adap, char *line); + +The ``line`` argument points to the start of the command. Any leading +spaces or tabs have already been skipped. It is a single line only (so there +are no embedded newlines) and it is 0-terminated. The callback is free to +modify the contents of the buffer. It is only called for lines containing a +command, so this callback is never called for empty lines or comment lines. + +Return true if the command was valid or false if there were syntax errors. + Implementing the High-Level CEC Adapter --------------------------------------- @@ -298,6 +365,9 @@ CEC protocol driven. The following high-level callbacks are available: /* Low-level callbacks */ ... + /* Error injection callbacks */ + ... + /* High-level CEC message callback */ int (*received)(struct cec_adapter *adap, struct cec_msg *msg); }; |