[PATCH] Documentation: user: usb: bring up to date

[Sascha Hauer]

On Thu, Jun 15, 2023 at 03:36:47PM +0200, Ahmad Fatoum wrote:
> The USB support got a few features since the docs were last touched.
> Document them.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
> ---
>  Documentation/user/usb.rst | 35 ++++++++++++++++++++++++++---------
>  1 file changed, 26 insertions(+), 9 deletions(-)

Applied, thanks

Sascha

> 
> diff --git a/Documentation/user/usb.rst b/Documentation/user/usb.rst
> index eaee342956f9..402f76d8da33 100644
> --- a/Documentation/user/usb.rst
> +++ b/Documentation/user/usb.rst
> @@ -13,9 +13,9 @@ devices are not disconnected while barebox is running.
>  USB Networking
>  ^^^^^^^^^^^^^^
>  
> -barebox supports ASIX-compatible devices and the SMSC95xx. After
> -detection, the device shows up as eth0 and can be used like a regular network
> -device.
> +barebox supports r8152, ASIX-compatible devices and the SMSC95xx. After
> +detection, the device shows up as an extra network device (e.g. eth1) and
> +can be used like a regular network device.
>  
>  To use a USB network device together with the :ref:`command_ifup` command, add the
>  following to ``/env/network/eth0-discover``:
> @@ -26,6 +26,9 @@ following to ``/env/network/eth0-discover``:
>  
>    usb
>  
> +Alternatively, a ``detect -a`` (all) can be forced in ``ifup`` by setting
> +``global.net.ifup_force_detect=1``.
> +
>  USB mass storage
>  ^^^^^^^^^^^^^^^^
>  
> @@ -39,18 +42,21 @@ barebox supports several different USB gadget drivers:
>  
>  - Device Firmware Upgrade (DFU)
>  - Android Fastboot
> +- USB mass storage
>  - serial gadget
>  
>  The recommended way to use USB gadget is with the :ref:`command_usbgadget` command.
>  While there are individual commands for :ref:`command_dfu` and :ref:`command_usbserial`,
> -the :ref:`command_usbgadget` commands supports registering composite gadgets.
> +the :ref:`command_usbgadget` commands supports registering composite gadgets, which
> +exports multiple functions at once. This happens in the "background" without impacting
> +use of the shell.
>  
>  Partition description
>  ^^^^^^^^^^^^^^^^^^^^^
>  
> -The USB gadget commands for Android Fastboot and DFU take a partition description
> -which describes which barebox partitions are exported via USB. The partition
> -description is referred to as ``<desc>`` in the command help texts. It has
> +The USB gadget commands for Android Fastboot, DFU and the mass storage gadget
> +take a partition description which describes which barebox partitions are exported via USB.
> +The partition description is referred to as ``<desc>`` in the command help texts. It has
>  the general form ``partition(name)flags,partition(name)flags,...``.
>  
>  The **partition** field is the partition as accessible in barebox. This can be a
> @@ -65,7 +71,8 @@ Several **flags** are supported, each denoted by a single character:
>  * ``r`` Readback. The partition is allowed to be read back (DFU specific)
>  * ``c`` The file shall be created if it doesn't exist. Needed when a regular file is exported.
>  * ``u`` The partition is a MTD device and shall be flashed with a UBI image.
> -* ``o`` The partition is optional, i.e. if it is not available at initialization time, it is skipped instead of aborting the initialization
> +* ``o`` The partition is optional, i.e. if it is not available at initialization time, it is skipped
> +        instead of aborting the initialization. This is currently only supported for fastboot.
>  
>  Example:
>  
> @@ -223,6 +230,16 @@ and initrd:
>    fi
>    timeout -k 5 3 fastboot -i 7531 oem exec -- bootm -o /devicetree -r /initrd /kernel
>  
> +USB Mass storage gadget
> +^^^^^^^^^^^^^^^^^^^^^^^
> +
> +Example exporting barebox block devices to a USB host::
> +
> +.. code-block:: sh
> +
> +  usbgadget -S /dev/mmc0(emmc),/dev/mmc1(sd)
> +
> +
>  USB Composite Multifunction Gadget
>  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>  
> @@ -244,7 +261,7 @@ after creating the gadget. The gadget can be removed with ``usbgadget -d``.
>  USB OTG support
>  ---------------
>  
> -barebox does not have USB OTG support. However, barebox supports some USB cores in
> +barebox does not have true USB OTG support. However, barebox supports some USB cores in
>  both host and device mode. If these are specified for otg in the device tree
>  (dr_mode = "otg";) barebox registers a OTG device which can be used to decide which
>  mode shall be used. The device has a ``mode`` parameter which by default has the
> -- 
> 2.39.2
> 
> 
> 

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