From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Wed, 17 Dec 2014 22:49:55 +0100 Subject: at91: dt: dma usage In-Reply-To: <20141217201622.GE4885@piout.net> References: <54477097.1050909@aksignal.cz> <20141217201622.GE4885@piout.net> Message-ID: <2831487.RTCyiHWGfY@wuerfel> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday 17 December 2014 21:16:22 Alexandre Belloni wrote: > On 22/10/2014 at 10:53:43 +0200, Ji?? Prchal wrote : > > in fact that in at91sam chips has a lot of peripherals but only 2*8 dma channels > > and as my patch in last week "at91: sam9x5 dt: add usart dma definitions to dt" > > adds only dma definitions, not make to use them, leave it on board definition, > > shouldn't do the same all other peripherals definitions? > > I think that I2C, SPI are not as necessary as USART, but thous are always "on". > > Not much discussion happened on that and I have the feeling this is > something we have to sort out. Until the dma driver are able to allocate > channels dynamically, it is true that this may be something we shouldn't > enable in the dtsi and let people activate dma in the board dts. Could you use the drivers/dma/virt-dma.c infrastructure in the driver to do this? Are you already planning to use it? Arnd