RE: [PATCH v2 00/10] Introduced new Cadence USBSSP DRD Driver.
From: Pawel Laszczak
Date: Mon Nov 09 2020 - 04:33:15 EST
Hi,
>
>On Fri, Nov 06, 2020 at 12:42:50PM +0100, Pawel Laszczak wrote:
>> This patch introduce new Cadence USBSS DRD driver to linux kernel.
>>
>> The Cadence USBSS DRD Controller is a highly configurable IP Core which
>> can be instantiated as Dual-Role Device (DRD), Peripheral Only and
>> Host Only (XHCI)configurations.
>>
>> The current driver has been validated with FPGA burned. We have support
>> for PCIe bus, which is used on FPGA prototyping.
>>
>> The host side of USBSS-DRD controller is compliance with XHCI
>> specification, so it works with standard XHCI Linux driver.
>>
>> The device side of USBSS DRD controller is compliant with XHCI.
>> The architecture for device side is almost the same as for host side,
>> and most of the XHCI specification can be used to understand how
>> this controller operates.
>>
>> This controller and driver support Full Speed, Hight Speed, Supper Speed
>> and Supper Speed Plus USB protocol.
>>
>> The prefix cdnsp used in driver has chosen by analogy to cdn3 driver.
>> The last letter of this acronym means PLUS. The formal name of controller
>> is USBSSP but it's to generic so I've decided to use CDNSP.
>>
>> The patch 1: adds support for DRD CDNSP.
>> The patch 2: separates common code that can be reusable by cdnsp driver.
>> The patch 3: moves reusable code to separate module.
>> The patch 4: changes prefixes in reusable code from cdns3 to common cdns.
>> The patch 5: adopts gadget_dev pointer in cdns structure to make possible
>> use it in both drivers.
>> The patches 6-8: add the main part of driver and has been intentionally
>> split into 3 part. In my opinion such division should not
>> affect understanding and reviewing the driver, and cause that
>> main patch (7/8) is little smaller. Patch 6 introduces main
>> header file for driver, 7 is the main part that implements all
>> functionality of driver and 8 introduces tracepoints.
>> The patch 9: Adds cdns3 prefixes to files related with USBSS driver.
>> the patch 10: Adds USBSSP DRD IP driver entry to MAINTAINERS file.
>>
>> Changlog from v1:
>> - updated common code to latest cdns3 driver
>> - moved cdnsp driver files to cdns3 as sugested by Peter Chan
>> - removed duplicate code from cdnsp_ep0_set_config function
>> - added cdns3 prefixes to file related with USBSS driver
>> - updated MAINTAINERS file
>> - fixed issue with U1
>> - fixed issue with L1
>> - some less improtant changes sugested by Chunfeng Yun
>
>After a quick review, I don't see anything wrong with this series, nice
>work.
>
>It does feel odd you need to split things into a "common" and then 2
>other modules, but I guess it makes sense. Worst case, over time, you
>merge them back together after everyone just ends up enabling both of
>them :)
>
>Felipe, want me to take these directly, or should they go through your
>tree after you review them? I never remember with this driver whose it
>goes through.
>
Thanks Greg for fast review.
It could be good to take these from Peter Chen branch.
Let's wait for Peter review and opinion.
There are some changes that can have impact on existing cdns3 driver.
Regards,
Pawel