Re: [PATCH v9 6/9] docs: misc-devices: (smpro-misc) Add documentation

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Thu, Sep 29, 2022 at 04:43:18PM +0700, Quan Nguyen wrote:
> Adds documentation for the Ampere(R)'s Altra(R) SMpro misc driver.
> 
> Signed-off-by: Thu Nguyen <thu@os.amperecomputing.com>
> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com>
> ---
> Changes in v9:
>   + Update SPDX licence                          [Greg]
> 
> Changes in v8:
>   + Update to reflect single value per sysfs     [Quan]
> 
> Changes in v7:
>   + None
> 
> Changes in v6:
>   + First introduced in v6 [Quan]
> 
>  Documentation/misc-devices/index.rst      |  1 +
>  Documentation/misc-devices/smpro-misc.rst | 82 +++++++++++++++++++++++
>  2 files changed, 83 insertions(+)
>  create mode 100644 Documentation/misc-devices/smpro-misc.rst
> 
> diff --git a/Documentation/misc-devices/index.rst b/Documentation/misc-devices/index.rst
> index b74b3b34a235..b40cd1b402f7 100644
> --- a/Documentation/misc-devices/index.rst
> +++ b/Documentation/misc-devices/index.rst
> @@ -28,6 +28,7 @@ fit into other categories.
>     oxsemi-tornado
>     pci-endpoint-test
>     smpro-errmon
> +   smpro-misc
>     spear-pcie-gadget
>     uacce
>     xilinx_sdfec
> diff --git a/Documentation/misc-devices/smpro-misc.rst b/Documentation/misc-devices/smpro-misc.rst
> new file mode 100644
> index 000000000000..d21be4a09e69
> --- /dev/null
> +++ b/Documentation/misc-devices/smpro-misc.rst
> @@ -0,0 +1,82 @@
> +.. SPDX-License-Identifier: GPL-2.0-only
> +
> +Kernel driver Ampere(R) Altra(R) SMpro miscellaneous
> +====================================================
> +
> +Supported chips:
> +
> +  * Ampere(R) Altra(R)
> +
> +    Prefix: 'smpro'
> +
> +    Reference: Altra SoC BMC Interface Specification
> +
> +Author: Thu Nguyen <thu@os.amperecomputing.com>
> +
> +Description
> +-----------
> +
> +This driver support the monitoring and configuration of various miscellaneous
> +data provided by Ampere(R) Altra(R) SMpro processor.
> +At this time, these include:
> +
> +  * Reading Boot Progress information
> +  * Configuring SoC Power Limit
> +
> +Sysfs entries
> +-------------
> +
> +1) Boot progress
> +
> +SMpro misc driver creates the sysfs files ``boot_progress``.
> +The format of ``boot_progress`` file is as below::
> +
> +<boot stage><boot status><boot progress>
> +
> +Where:
> +
> +* Boot stage::
> +
> +    0: SMpro firmware booting.
> +    1: PMpro firmware booting.
> +    2: ATF BL1 firmware booting.
> +    3: DDR initialization.
> +    4: DDR training report status.
> +    5: ATF BL2 firmware booting.
> +    6: ATF BL31 firmware booting.
> +    7: ATF BL32 firmware booting.
> +    8: UEFI firmware booting.
> +    9: OS booting.
> +
> +* Boot status::
> +
> +    0: Not started.
> +    1: Started.
> +    2: Complete without error.
> +    3: Failure.
> +
> +* boot progress: 32 bits boot progress code
> +
> +The sysfs ``boot_progress`` only reports the boot state when the host is booting.
> +If the host is already booted, it returns latest state.
> +
> +Example::
> +
> +    #cat boot_progress
> +    0102808454A8
> +
> +2) SoC Power Limit
> +
> +SMpro misc driver creates the sysfs file ``soc_power_limit`` to get/set the SoC Power Limit.
> +
> +Reading this sysfs return the current setting of SoC Power Limit (W) in decimal string.
> +Writing the desired value in decimal string to set the SoC Power Limit in Watt (W).
> +The range of SoC Power Limit is 90-500(W) and will be ignored if out of range.
> +
> +Example::
> +
> +    #cat soc_power_limit
> +    90
> +    #echo 95 > soc_power_limit
> +    #cat soc_power_limit
> +    95
> -- 
> 2.35.1
> 

Why is this file needed at all if you have the correct
Documentation/ABI/ entries instead?

thanks,

greg k-h