From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from inaccessnetworks.com (node3.inaccessnetworks.com [212.205.200.118]) by ozlabs.org (Postfix) with ESMTP id 7FE9BDDDF7 for ; Fri, 13 Jul 2007 18:58:50 +1000 (EST) Received: from localhost (localhost.localdomain [127.0.0.1]) by inaccessnetworks.com (8.13.6/8.13.5) with ESMTP id l6D8pNHx007060 for ; Fri, 13 Jul 2007 11:51:23 +0300 Received: from inaccessnetworks.com ([127.0.0.1]) by localhost (host11.inaccessnetworks.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 06809-08 for ; Fri, 13 Jul 2007 11:51:22 +0300 (EEST) Received: from phoenix (phoenix.priv.inaccessnetworks.com [192.168.1.7]) by inaccessnetworks.com (8.13.6/8.13.5) with ESMTP id l6D8pKUr007055 for ; Fri, 13 Jul 2007 11:51:20 +0300 Date: Fri, 13 Jul 2007 11:51:15 +0300 To: linuxppc-dev@ozlabs.org Subject: questions about mpc82xx_ads and porting to other, similar, platform From: "Alexandros Kostopoulos" Content-Type: text/plain; format=flowed; delsp=yes; charset=iso-8859-7 MIME-Version: 1.0 Message-ID: List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello all, I am trying to port kernel 2.6.22.1 to my own platform, which incorporat= es = an mpc8275 chip. I'm using platform code for mpc82xx_ads as a template (= is = this right in the first place?). I have a couple of questions: 1. mpc82xx_ads.c uses init_scc_ioports function to initialize the scc = uarts. However, this function is only used by the code in arch/powerpc/sysdev/fsl_soc.c, and spefically in fs_enet_of_init(), whic= h = is used to initialize the ethernet driver and not the cpm_uart driver. On the other hand, cpm_uart_of_init() function seems to be the one that = = initializes the uarts in cpm, and actually makes use of the device-id, = model, rx-clock and tx-clock properties of the scc nodes in OF tree. So,= = AFAICT, init_scc_ioports should not be there, since it won't be actually= = called at all (although I have not actually tested this - I haven't yet = = managed to boot the kernel). Instead, cpm_uart_of_init should take care = of = everything, except for the pport initialization, which is done in u-boot= = anyway (at least in my case). Any thoughts on this? 2. I have also some questions regarding the device tree. Why are there t= wo = nodes regarding the interrupt controller in there? and in the top level = = node, what does this property means: reg =3D ; ? Finally, in the memory node, the reg property defines a second mem regio= n, = (f4500000 f4500020). What is this? maybe a special memory mapped = peripheral of this board? If I have a board with many mem configurations= = (e.g. it uses a DIMM SDRAM what can be changed), what value should I pla= ce = in the mem node? I have to change dts every time I insert a new DIMM? any help would be greatly appreciated, thank you in advance Alex