From mboxrd@z Thu Jan 1 00:00:00 1970 From: paul@pwsan.com (Paul Walmsley) Date: Thu, 19 Mar 2015 18:46:59 +0000 (UTC) Subject: [PATCHv2 3/3] Documentation: DT bindings: Tegra AHB: note base address change In-Reply-To: <550B155E.9050308@wwwdotorg.org> References: <20150317083221.32662.14647.stgit@baseline> <20150317083221.32662.96822.stgit@baseline> <20150317103806.GU8656@n2100.arm.linux.org.uk> <550AEE6B.5080301@wwwdotorg.org> <550AFF52.6070503@wwwdotorg.org> <550B155E.9050308@wwwdotorg.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, 19 Mar 2015, Stephen Warren wrote: > We should not document Linux 4.1 as the cut-off. DT bindings are supposed to > be OS agnostic. While it's practically unlikely, it is entirely possible for > some other OS to have already implemented support for this binding, and the > current binding is an ABI. We have no control over if/when any non-Linux code > is updated to add support for a 0-based offset for existing SoCs, and > certainly no versions of Linux or any other OS can be updated retro-actively > except perhaps a few linux-stable versions. We can however write the binding > in such a way as support for new SoCs requires the new 0-based address, since > there is no binding specification for those new chips yet, and the time when > you add the new binding documentation is the first time any OS could possibly > add conformant support for it. > > In summary, I believe the binding document must state that T20/30/114/124 > require the offset of 4 in reg value, and newer chips require no offset in the > reg value. We can still always accept either in the Linux kernel going forward > based on the principle of being lenient re: input data. That's fine. I'll send a patch for that. - Paul