From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David Woodhouse" Subject: Re: [Ksummit-2013-discuss] ARM topic: Is DT on ARM the solution, or is there something better? Date: Thu, 24 Oct 2013 12:22:18 -0000 Message-ID: References: <20131020220839.GT2443@sirena.org.uk> <5264576F.6050307@wwwdotorg.org> <52658EBC.8020800@wwwdotorg.org> <20131022093923.GC15640@ulmo.nvidia.com> <20131022150426.GF29341@beef> <20131022171346.GE4061@obsidianresearch.com> <20131023080630.GA14413@netboy> <20131023172955.GA17145@obsidianresearch.com> <20131023174458.GC5208@netboy> <1382553982.31058.10.camel@sakura.staff.proxad.net> <20131024095232.27BBCC4039D@trevor.secretlab.ca> <1382614439.6040.16.camel@sakura.staff.proxad.net> <1382615278.8522.72.camel@shinybook.infradead.org> <1382616801.6040.26.camel@sakura.staff.proxad.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1382616801.6040.26.camel@sakura.staff.proxad.net> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: mbizon@freebox.fr Cc: "devicetree@vger.kernel.org" , "ksummit-2013-discuss@lists.linuxfoundation.org" , Nicolas Pitre , Grant Likely , Thierry Reding , Matt Porter , David Woodhouse , "linux-arm-kernel@lists.infradead.org" , Jason Gunthorpe List-Id: devicetree@vger.kernel.org > > On Thu, 2013-10-24 at 12:47 +0100, David Woodhouse wrote: > >> If you can automatically infer the correct clock/interrupt/etc in order >> to do DMA correctly, despite the fact that it wasn't explicitly spelled >> out in the old DT, then the property is *not* a "required" property. >> It's optional, and you have a default behaviour for when it's not >> present. > > so inside the new version of driver-hwcrypto.c: > > if (irq_of_parse_and_map(...) == NO_IRQ) { > switch (get_soc_model()) { > case SOC1: > irq = 51; > break; > > case SOC2: > irq = 62; > break; > > [...] > } > } If you are correct to insist that DMA needs yo be supported in the new driver *even* with old firmware, then yes, maybe. The alternative is a quirk to "fix" the DT up on the affected boards and not actually doing the special cases in the driver itself. But that can be seen as an implementation detail. -- dwmw2