From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sylwester Nawrocki Subject: Re: [RFC/PATCH 02/13] media: s5p-csis: Add device tree support Date: Tue, 31 Jul 2012 14:38:35 +0200 Message-ID: <5017D1CB.80709@samsung.com> References: <4FBFE1EC.9060209@samsung.com> <24452426.AaRH9zzLOy@avalon> <4835930.8zRiqxUPR0@avalon> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <4835930.8zRiqxUPR0@avalon> Sender: linux-media-owner@vger.kernel.org To: Laurent Pinchart Cc: Guennadi Liakhovetski , Sylwester Nawrocki , linux-media@vger.kernel.org, kyungmin.park@samsung.com, m.szyprowski@samsung.com, riverful.kim@samsung.com, sw0312.kim@samsung.com, devicetree-discuss@lists.ozlabs.org, linux-samsung-soc@vger.kernel.org, b.zolnierkie@samsung.com List-Id: devicetree@vger.kernel.org On 07/31/2012 01:05 PM, Laurent Pinchart wrote: >>>>> What about CSI receivers that can reroute the lanes internally ? We >>>>> would >>>>> need to specify lane indices for each lane then, maybe with something >>>>> like >>>>> >>>>> clock-lane =<0>; >>>>> data-lanes =<2 3 1>; >>>> >>>> Sounds good to me. And the clock-lane could be made optional, as not all >>>> devices would need it. >>>> >>>> However, as far as I can see, there is currently no generic API for >>>> handling this kind of data structure. E.g. number of cells for the >>>> "interrupts" property is specified with an additional >>>> "#interrupt-cells" property. >>>> >>>> It would have been much easier to handle something like: >>>> >>>> data-lanes = <2>, <3>, <1>; >>>> >>>> i.e. an array of the lane indexes. >>> >>> I'm fine with that. >> >> ...on a second thought: shouldn't this be handled by pinctrl? Or is it >> some CSI-2 module internal lane switching, not the global SoC pin function >> configuration? > > On the hardware I came across, it's handled by the CSI2 receiver, not the SoC > pinmux feature. Same here. Is there any hardware known to mux those MIPI-CSI D-PHY high speed differential signals with general purpose IO pins ? Or are there mostly dedicated pins used ? However, if there are cases the lane configuration is done solely at CSI2 receiver level, there seems little point in involving the pinctrl API. -- Regards, Sylwester