[PATCH 0/7] Add USB remote wakeup driver
Chunfeng Yun
chunfeng.yun at mediatek.com
Wed Dec 20 22:48:24 PST 2017
On Fri, 2017-12-15 at 14:55 -0600, Rob Herring wrote:
> On Sat, Dec 09, 2017 at 04:45:29PM +0800, Chunfeng Yun wrote:
> > These patches introduce the SSUSB and SPM glue layer driver which is
> > used to support usb remote wakeup. Usually the glue layer is put into
> > a system controller, such as PERICFG module.
> > The old way to support usb wakeup is put into SSUSB controller drivers,
> > including xhci-mtk driver and mtu3 driver, but there are some problems:
> > 1. can't disdinguish the relation between glue layer and SSUSB IP
> > when SoCs supports multi SSUSB IPs;
> > 2. duplicated code for wakeup are put into both xhci-mtk and mtu3
> > drivers;
> > 3. the glue layer may vary on different SoCs with SSUSB IP, and will
> > make SSUSB controller drivers complicated;
> > In order to resolve these problems, it's useful to make the glue layer
> > transparent by extracting a seperated driver, meanwhile to reduce the
> > duplicated code and simplify SSUSB controller drivers.
>
> Both the driver and binding look overly complicated to me when it looks
> like you just have 2 versions of enable/disable functions which modify
> a single register. The complexity may be justified if this was a common
> binding and driver, but it is not.
>
> You already have a phandle to the system controller. Can't you add cells
> to it to handle any differences between instances? That and SoC specific
> compatible strings should be enough to handle differences.
Yes, adding cells will also work well, I'll try it, thanks a lot
>
> Rob
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