Re: [PATCH v5 3/3] usb: gadget: f_fs: virtual endpoint address mapping

[Michal Nazarewicz <mina86@mina86.com>]

On Thu, Aug 21 2014, Robert Baldyga <r.baldyga@samsung.com> wrote:
> This patch introduces virtual endpoint address mapping. It separates
> function logic form physical endpoint addresses making it more hardware
> independent.
>
> Following modifications changes user space API, so to enable them user
> have to switch on the FUNCTIONFS_VIRTUAL_ADDR flag in descriptors.
>
> Endpoints are now refered using virtual endpoint addresses chosen by
> user in endpoint descpriptors. This applies to each context when endpoint
> address can be used:
> - when accessing endpoint files in FunctionFS filesystemi (in file name),
> - in setup requests directed to specific endpoint (in wIndex field),
> - in descriptors returned by FUNCTIONFS_ENDPOINT_DESC ioctl.
>
> In endpoint file names the endpoint address number is formatted as
> double-digit hexadecimal value ("ep%02x") which has few advantages -
> it is easy to parse, allows to easly recognize endpoint direction basing
> on its name (IN endpoint number starts with digit 8, and OUT with 0)
> which can be useful for debugging purpose, and it makes easier to introduce
> further features allowing to use each endpoint number in both directions
> to have more endpoints available for function if hardware supports this
> (for example we could have ep01 which is endpoint 1 with OUT direction,
> and ep81 which is endpoint 1 with IN direction).
>
> Physical endpoint address can be still obtained using ioctl named
> FUNCTIONFS_ENDPOINT_REVMAP, but now it's not neccesary to handle
> USB transactions properly.
>
> Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>

Acked-by: Michal Nazarewicz <mina86@mina86.com>

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