From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <48920F69.6020909@freescale.com> Date: Thu, 31 Jul 2008 14:15:53 -0500 From: Scott Wood MIME-Version: 1.0 To: Timur Tabi Subject: Re: [PATCH] powerpc: i2c-mpc: make speed registers configurable via FDT References: <4889EFFE.2070201@grandegger.com> <4889FD1D.4010804@freescale.com> <20080727012722.GH12191@secretlab.ca> <4891A744.6060005@grandegger.com> <9e4733910807310849g7e5612dbk9536733e061af8ad@mail.gmail.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> <48920C1A.7010605@freescale.com> <48920D9B.5060406@freescale.com> In-Reply-To: <48920D9B.5060406@freescale.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Linuxppc-dev@ozlabs.org, Linux I2C List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Timur Tabi wrote: > Scott Wood wrote: >> A clock-frequency property is OK, and is in line with what we do in >> other types of nodes. However, in the long run it might be nice to >> introduce some sort of clock binding where, for example, the i2c node >> can point to a clock elsewhere in the device tree as an input clock. > > The only problem with that is that the actual input clock to the I2C device is > not the same as any other device. It's a unique clock. Look at the code I had > to write to figure out this clock just on 85xx: IIRC, only the divider is unique, and the divider that is applied to the input clock can be specified in the i2c node (either implicitly in compatible, or explicitly via a property). -Scott