From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from buildserver.ru.mvista.com (unknown [85.21.88.6]) by ozlabs.org (Postfix) with ESMTP id 52FA7DE35D for ; Thu, 16 Oct 2008 02:51:43 +1100 (EST) Date: Wed, 15 Oct 2008 19:51:40 +0400 From: Anton Vorontsov To: Grant Likely Subject: Re: [PATCH] powerpc: SPI: specify chip select active high Message-ID: <20081015155140.GA29309@oksana.dev.rtsoft.ru> References: <1224075647.4022.33.camel@galileo.recco.de> <20081015142228.GD16262@secretlab.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1251 In-Reply-To: <20081015142228.GD16262@secretlab.ca> Cc: linuxppc-dev@ozlabs.org, Wolfgang Ocker Reply-To: avorontsov@ru.mvista.com List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Oct 15, 2008 at 08:22:28AM -0600, Grant Likely wrote: > On Wed, Oct 15, 2008 at 03:00:47PM +0200, Wolfgang Ocker wrote: > > The patch allows to specify that an SPI device needs an active high chip > > select. > > This look reasonable to me. Anyone else have comments on this binding? Looks good. I'm assuming that a spi controller has its own chip select machine, since for GPIO chip-select we can pass active-high/low stuff via gpios = <> property. But well, we can support both ways even for GPIO chip-selects, I see no problem. > g. > > > > > Signed-off-by: Wolfgang Ocker > > --- > > > > --- linux-2.6.27-rc7/drivers/of/of_spi.c.of_spi_cshigh 2008-09-22 00:29:55.000000000 +0200 > > +++ linux-2.6.27-rc7/drivers/of/of_spi.c 2008-09-29 13:43:06.000000000 +0200 > > @@ -61,6 +61,8 @@ > > spi->mode |= SPI_CPHA; > > if (of_find_property(nc, "spi-cpol", NULL)) > > spi->mode |= SPI_CPOL; > > + if (of_find_property(nc, "spi-cs-high", NULL)) > > + spi->mode |= SPI_CS_HIGH; > > > > /* Device speed */ > > prop = of_get_property(nc, "spi-max-frequency", &len); > > --- linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt.of_spi_cshigh 2008-09-29 14:14:08.000000000 +0200 > > +++ linux-2.6.27-rc7/Documentation/powerpc/booting-without-of.txt 2008-09-29 14:24:26.000000000 +0200 > > @@ -1917,6 +1917,8 @@ > > inverse clock polarity (CPOL) mode > > - spi-cpha - (optional) Empty property indicating device requires > > shifted clock phase (CPHA) mode > > + - spi-cs-high - (optional) Empty property indicating device requires > > + chip select active high > > > > SPI example for an MPC5200 SPI bus: > > spi@f00 { > > > > -- Anton Vorontsov email: cbouatmailru@gmail.com irc://irc.freenode.net/bd2