Re: [PATCH V2 3/3] media: dvb-core: Added documentation for ca sysfs timer nodes

["Jasmin J." <jasmin@anw.at>]

Hi!

Please hold on in merging this series, because I have to investigate a hint
I got related to the buffer size handshake of the protocol driver:
  https://www.linuxtv.org/pipermail/linux-dvb/2007-July/019116.html

BR,
   Jasmin


On 12/21/2017 02:22 PM, Jasmin J. wrote:
> From: Jasmin Jessich <jasmin@anw.at>
> 
> Added the documentation for the new ca? sysfs nodes in
> /sys/class/dvb/dvb?/ca?/tim_wr_????.
> 
> Signed-off-by: Jasmin Jessich <jasmin@anw.at>
> ---
>  Documentation/ABI/testing/sysfs-class-ca        | 63 ++++++++++++++++++
>  Documentation/media/uapi/dvb/ca-sysfs-nodes.rst | 85 +++++++++++++++++++++++++
>  Documentation/media/uapi/dvb/ca.rst             |  1 +
>  3 files changed, 149 insertions(+)
>  create mode 100644 Documentation/ABI/testing/sysfs-class-ca
>  create mode 100644 Documentation/media/uapi/dvb/ca-sysfs-nodes.rst
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-ca b/Documentation/ABI/testing/sysfs-class-ca
> new file mode 100644
> index 0000000..7a2a52c
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-ca
> @@ -0,0 +1,63 @@
> +What:		/sys/class/dvb/dvbN/
> +Date:		Dec 2017
> +KernelVersion:	4.15
> +Contact:	Jasmin Jessich <jasmin@anw.at>
> +Description:
> +        The dvbN/ class sub-directory belongs to the Adapter with the
> +        index N. It is created for each found Adapter and depends on
> +        the DVB hardware.
> +
> +What:		/sys/class/dvb/dvbN/caM
> +Date:		Dec 2017
> +KernelVersion:	4.15
> +Contact:	Jasmin Jessich <jasmin@anw.at>
> +Description:
> +        The dvbN/caM/ class sub-directory belongs to the CA device with
> +        the index M on the Adapter with the index N. It is created for
> +        each found Conditional Access Interface where M is the number
> +        of the CA Interface.
> +
> +What:		/sys/class/dvb/dvbN/caM/tim_wr_high
> +Date:		Dec 2017
> +KernelVersion:	4.15
> +Contact:	Jasmin Jessich <jasmin@anw.at>
> +Description:
> +        Reading this file returns the wait time after writing the
> +        length high byte to the CAM. The default timeout it '0', which
> +        means no 'no timeout'. Any other value specifies the timeout in
> +        micro seconds.
> +          
> +        Writing a value will change the timeout.
> +             
> +        Write fails with ``EINVAL`` if an invalid value has been written
> +        (valid values are 0..100000).
> +
> +What:		/sys/class/dvb/dvbN/caM/tim_wr_low
> +Date:		Dec 2017
> +KernelVersion:	4.15
> +Contact:	Jasmin Jessich <jasmin@anw.at>
> +Description:
> +        Reading this file returns the wait time after writing the
> +        length low byte to the CAM. The default timeout it '0', which
> +        means no 'no timeout'. Any other  value specifies the timeout in
> +        micro seconds.
> +          
> +        Writing a value will change the timeout.
> +             
> +        Write fails with ``EINVAL`` if an invalid value has been written
> +        (valid values are 0..100000).
> +
> +What:		/sys/class/dvb/dvbN/caM/tim_wr_data
> +Date:		Dec 2017
> +KernelVersion:	4.15
> +Contact:	Jasmin Jessich <jasmin@anw.at>
> +Description:
> +        Reading this file returns the wait time between data bytes sent
> +        to the CAM. The default timeout it '0', which means no 'no timeout'.
> +        Any other value specifies the timeout in micro seconds.
> +
> +        Writing a value will change the timeout.
> +             
> +        Write fails with ``EINVAL`` if an invalid value has been written
> +        (valid values are 0..100000).
> +
> diff --git a/Documentation/media/uapi/dvb/ca-sysfs-nodes.rst b/Documentation/media/uapi/dvb/ca-sysfs-nodes.rst
> new file mode 100644
> index 0000000..4a26afd
> --- /dev/null
> +++ b/Documentation/media/uapi/dvb/ca-sysfs-nodes.rst
> @@ -0,0 +1,85 @@
> +.. -*- coding: utf-8; mode: rst -*-
> +
> +.. _ca_sysfs_nodes:
> +
> +******************************
> +Conditional Access sysfs nodes
> +******************************
> +
> +As defined at ``Documentation/ABI/testing/sysfs-class-ca``, those are
> +the sysfs nodes that control the en50221 CA driver:
> +
> +
> +.. _sys_class_dvb_dvbN:
> +
> +/sys/class/dvb/dvbN/
> +====================
> +
> +The ``/sys/class/dvb/dvbN/`` class sub-directory belongs to the Adapter
> +with the index N. It is created for each found Adapter and depends on the
> +DVB hardware.
> +
> +
> +.. _sys_class_dvb_dvbN_caM:
> +
> +/sys/class/dvb/dvbN/caM
> +=======================
> +
> +The ``/sys/class/dvb/dvbN/caM`` class sub-directory belongs to the CA device
> +with the index M on the Adapter with the index N. It is created for each
> +found Conditional Access Interface where M is the number of the CA Interface.
> +A Conditional Access Module (CAM) will be inserted into the CI interface. The
> +caM device is used to communicate to the CAM.
> +
> +The communication protocol contains a length field followed by the data bytes.
> +The length is written in two parts. First the high byte of the length
> +followed by the low byte. The following sysfs nodes define three timeouts
> +which may be used to extend the communication to the CAM. Modern CAMs usually
> +do not need those timeouts, but older CAMs will produce communication errors,
> +when the bytes are written too fast. The underliying hardware has also a big
> +impact due to the access speed.
> +
> +
> +.. _sys_class_dvb_dvbN_caM_tim_wr_high:
> +
> +/sys/class/dvb/dvbN/caM/tim_wr_high
> +===================================
> +
> +Reading this file returns the wait time after writing the length high byte to
> +the CAM. The default timeout it '0', which means no 'no timeout'. Any other
> +value specifies the timeout in micro seconds.
> +
> +Writing a value will change the timeout.
> +
> +Write fails with ``EINVAL`` if an invalid value has been written (valid values
> +are 0..100000).
> +
> +
> +.. _sys_class_dvb_dvbN_caM_tim_wr_low:
> +
> +/sys/class/dvb/dvbN/caM/tim_wr_low
> +==================================
> +
> +Reading this file returns the wait time after writing the length low byte to
> +the CAM. The default timeout it '0', which means no 'no timeout'. Any other
> +value specifies the timeout in micro seconds.
> +
> +Writing a value will change the timeout.
> +
> +Write fails with ``EINVAL`` if an invalid value has been written (valid values
> +are 0..100000).
> +
> +
> +.. _sys_class_dvb_dvbN_caM_tim_wr_data:
> +
> +/sys/class/dvb/dvbN/caM/tim_wr_data
> +===================================
> +
> +Reading this file returns the wait time between data bytes sent to the CAM.
> +The default timeout it '0', which means no 'no timeout'. Any other value
> +specifies the timeout in micro seconds.
> +
> +Writing a value will change the timeout.
> +
> +Write fails with ``EINVAL`` if an invalid value has been written (valid values
> +are 0..100000).
> diff --git a/Documentation/media/uapi/dvb/ca.rst b/Documentation/media/uapi/dvb/ca.rst
> index deac72d..e790d19d 100644
> --- a/Documentation/media/uapi/dvb/ca.rst
> +++ b/Documentation/media/uapi/dvb/ca.rst
> @@ -22,3 +22,4 @@ application.
>  
>      ca_data_types
>      ca_function_calls
> +    ca-sysfs-nodes
>