From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Stigge Subject: Re: [PATCH] spi/pl022: Devicetree support w/o platform data Date: Tue, 18 Sep 2012 15:52:24 +0200 Message-ID: <50587C98.7040103@antcom.de> References: <1347972540-29667-1-git-send-email-stigge@antcom.de> <201209181313.30880.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201209181313.30880.arnd@arndb.de> Sender: linux-kernel-owner@vger.kernel.org To: Arnd Bergmann Cc: broonie@opensource.wolfsonmicro.com, grant.likely@secretlab.ca, linus.walleij@linaro.org, lee.jones@linaro.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, STEricsson_nomadik_linux@list.st.com, devicetree-discuss@lists.ozlabs.org, aletes.xgr@gmail.com, kevin.wells@nxp.com, srinivas.bakki@nxp.com List-Id: devicetree@vger.kernel.org Hi! On 09/18/2012 03:13 PM, Arnd Bergmann wrote: > On Tuesday 18 September 2012, Roland Stigge wrote: >> --- linux-2.6.orig/Documentation/devicetree/bindings/spi/spi_pl022.txt >> +++ linux-2.6/Documentation/devicetree/bindings/spi/spi_pl022.txt >> @@ -10,6 +10,15 @@ Optional properties: >> - cs-gpios : should specify GPIOs used for chipselects. >> The gpios will be referred to as reg = in the SPI child nodes. >> If unspecified, a single SPI device without a chip select can be used. >> +- pl022,bus-id : Bus ID (0, 1, ...) > > I don't understand why we need the bus-id here. My understanding is that > this is a linux-specific number that should not be necessary when all > devices are described in the device tree rather than through spi_board_info. > > Can't you just set master->bus_num to -1 when using the DT for probing? > >> +- pl022,enable-dma : enables DMA driven transfers (boolean) > > Similar thing here: Can't you just set the enable_dma flag when > a dma channel is provided in the device tree and unset it otherwise? > > It also seems a bit pointless to enable DMA mode when you don't provide > a way to specify the channel at the same time. Completely right! I'm removing pl022,bus-id, setting bus_id to -1 in the dt case. And removing pl022,enable-dma since dma is anyway only useful in the platform data case where the dma_filter() callback is specified. Thanks for pointing this out, Roland