From mboxrd@z Thu Jan 1 00:00:00 1970 From: laurent.pinchart@ideasonboard.com (Laurent Pinchart) Date: Wed, 05 Mar 2014 14:59:37 +0100 Subject: [PATCH 3/4] clk: shmobile: add CPG driver for rz-platforms In-Reply-To: <20140305135431.GA7985@katana> References: <1393621768-12568-1-git-send-email-wsa@the-dreams.de> <2207635.bd10VfTU6U@avalon> <20140305135431.GA7985@katana> Message-ID: <1460103.hdWs652aMT@avalon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Wolfram, On Wednesday 05 March 2014 14:54:32 Wolfram Sang wrote: > > > > While the parent is indeed selected at boot time only, and only one > > > > parent is thus needed, parent selection could be performed by a DIP > > > > switch connected to MD_CLK on the board for instance. In that case > > > > both parents should be available in DT, as selection will be done by > > > > the kernel at boot time, not at DT compile time. > > > > > > OK, I understand the case. I still wonder about specifying two parents, > > > though. If a board uses USB_X1, it then has to spefify a dummy EXTAL > > > clock (or an empty one), just because USB_X1 is enumerated as second > > > entry? > > > > That's a good question. Mike, would it be possible to support "holes" in > > the DT clocks lists, like the GPIO DT bindings do ? > > I talked to Magnus and we decided to start with hardcoded EXTAL for now, > and leave USB_X1 support for in incremental patch when this is actually > needed. That's fine with me (although given the low complexity I would probably have gone directly to supporting both clocks) as long as we can ensure both forward and backward compatibility. Should we give a name to the clock input through the clock-names property for that reason ? > Note that the devkit will most likely be the only board ever with a > selectable root clock. Most probably, but that's no reason not to support it :-) -- Regards, Laurent Pinchart -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 490 bytes Desc: This is a digitally signed message part. URL: