From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfgang Grandegger Subject: Re: [i2c] [PATCH] powerpc: i2c-mpc: make speed registers configurable via FDT Date: Fri, 01 Aug 2008 09:29:52 +0200 Message-ID: <4892BB70.2040106@grandegger.com> References: <4889EFFE.2070201@grandegger.com> <4891F4D8.9090905@grandegger.com> <4891FC3A.7040609@freescale.com> <20080731180959.GA29057@secretlab.ca> <489200B6.9060906@freescale.com> <20080731182810.GB29097@secretlab.ca> <48920607.5040606@freescale.com> <9e4733910807311157q358640ddyef1f14865c069b8@mail.gmail.com> <9e4733910807311819i60872285ga4829c841185fdc0@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@ozlabs.org Errors-To: linuxppc-dev-bounces+glppd-linuxppc64-dev=m.gmane.org@ozlabs.org To: Trent Piepho Cc: Linuxppc-dev@ozlabs.org, Scott Wood , Timur Tabi , Linux I2C List-Id: linux-i2c@vger.kernel.org Trent Piepho wrote: > On Thu, 31 Jul 2008, Jon Smirl wrote: [...snip...] >> I don't see why we want to go through the trouble of having uboot tell >> us things about a chip that are fixed in stone. Obviously something >> like the frequency of the external crystal needs to be passed up, but >> why pass up stuff that can be computed (or recovered by reading a >> register)? > > One could also say that if U-boot has to have the code and already > calculated the value, why duplicate the code and the calculation in Linux? Right, if the "bus-frequency" property for the I2C device is not defined, the Linux I2C bus driver should just overtake the pre-defined values. That's what I (we?) wanted to implement anyhow. Wolfgang.