From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] ARM: bcm2835: dt: Add a fall-back Raspberry Pi tree Date: Mon, 25 Jan 2016 14:32:48 -0700 Message-ID: <56A69480.6050604@wwwdotorg.org> References: <1453754394-3639-1-git-send-email-lkundrak@v3.sk> <56A68BBF.4060405@wwwdotorg.org> <1453756150.9375.18.camel@v3.sk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1453756150.9375.18.camel-NGH9Lh4a5iE@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Lubomir Rintel Cc: linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Eric Anholt , Lee Jones List-Id: devicetree@vger.kernel.org On 01/25/2016 02:09 PM, Lubomir Rintel wrote: > On Mon, 2016-01-25 at 13:55 -0700, Stephen Warren wrote: >> On 01/25/2016 01:39 PM, Lubomir Rintel wrote: >>> U-Boot falls back to "bcm2835-rpi-other.dtb" for boards of unknown >>> identification. Let's do a bare minimum for them so that they at leat >>> boot. >>> >>> Signed-off-by: Lubomir Rintel >>> --- >>> arch/arm/boot/dts/Makefile | 1 + >>> arch/arm/boot/dts/bcm2835-rpi-other.dts | 7 +++++++ >> >> This DT shouldn't ever be used, except when a new unidentified board >> appears. In that case, I believe the correct solution is to add support >> for that new board to U-Boot and the kernel, rather than add fall-backs. >> Prior to that being done, a user can always copy whichever DT they want >> into filename bcm2835-rpi-other.dts for temporary testing/development, >> if they have reason to believe their new model is compatible with >> something else. In general, I don't think we have any reason to believe >> that even this new minimal DT is guaranteed to be compatible with any >> possible future hardware, so it seems a little risky to ship this file >> in anticipation. > > Fair enough. It just frustrates me a bit that the chance of mainline > working on a new or even older RPi board is not as good as I'd like to. > I guess I could perhaps get a bit better at quickly submitting the > device tree instead of cheap hacks then. > > By the way, I've seen you add an entry for the Zero board to U-Boot and > was thinking that you perhaps had a device tree for it? Do you plan to > include that one into mainline Linux, or do you keep your dts > elsewhere? Should I go ahead and submit one? I'm not sure if I booted Linux on it. I probably did, and simply manually copied one of the other DTs (model A or A+ I would guess) to bcm2835-rpi-zero.dtb on my SD card to make it work. > Also, the Model B entries in U-Boot version table seems incorrect to me > (sent a separate message to U-Boot list, but it got caught in > moderation now). I'm wondering what's the authoritative source for the > version information? Did you get the version numbers from the actual > hardware or is some documentation available? The information was derived from the various web pages listed in comments in board/raspberrypi/rpi/rpi.c. There may have been one or two entries contributed by other people; I don't know where that information came from. Most model numbers (for entries I added at least) are verified on real HW (yes, I have about 8 Pis.). I think I assigned the model strings/names myself in general, using names that seemed reasonably descriptive. It would be nice if the Pi Foundation published a single up-to-date/complete definitive list, but I haven't seen such a thing; everyone seems to be reverse-engineering it based on seeing models in the wild or cribbing from bits of other GPIO-related SW projects:-( -- 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