Hello Linus and Andrew, Thanks for your detailed comments, I just submitted v6 of our update: _http://patchwork.ozlabs.org/cover/1139035/ _http://patchwork.ozlabs.org/patch/1139038/ _http://patchwork.ozlabs.org/patch/1139040/ please ignore my previous patches sent on 07/28, they does not have proper serial title and one of the patch is missing. --Hongwei > From: Linus Walleij <linus.walleij@xxxxxxxxxx> > Sent: Monday, July 29, 2019 5:57 PM > To: Andrew Jeffery > Cc: Hongwei Zhang; open list:GPIO SUBSYSTEM; Joel Stanley; open list:OPEN FIRMWARE AND > FLATTENED DEVICE TREE BINDINGS; linux-aspeed; Bartosz Golaszewski; Rob Herring; Mark Rutland; > linux-kernel@xxxxxxxxxxxxxxx; Linux ARM > Subject: Re: [v5 1/2] dt-bindings: gpio: aspeed: Add SGPIO support > > On Mon, Jul 29, 2019 at 2:19 AM Andrew Jeffery <andrew@xxxxxxxx> wrote: > > > The behaviour is to periodically emit the state of all enabled GPIOs > > (i.e. the ngpios value), one per bus clock cycle. There's no explicit > > addressing scheme, the protocol encodes the value for a given GPIO by > > its position in the data stream relative to a pulse on the "load data" > > (LD) line, whose envelope covers the clock cycle for the last GPIO in > > the sequence. Similar to SPI the bus has both out and in lines, which > > cater to output/input GPIOs. > > > > A rough timing diagram for a 16-GPIO configuration looks like what > > I've pasted here: > > > > https://gist.github.com/amboar/c9543af1957854474b8c05ab357f0675 > > OK that is complex. I agree we need to keep this driver together. > > Yours, > Linus Walleij
