Re: [PATCH 0/7] Add USB remote wakeup driver
From: Rob Herring <hidden>
Date: 2017-12-15 20:55:10
Also in:
linux-arm-kernel, linux-mediatek, lkml
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. Rob -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html