From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from imap.sh.mvista.com (unknown [63.81.120.155]) by ozlabs.org (Postfix) with ESMTP id 5379FDDE49 for ; Mon, 4 Jun 2007 02:08:51 +1000 (EST) Message-ID: <4662E7EA.70506@ru.mvista.com> Date: Sun, 03 Jun 2007 20:10:18 +0400 From: Sergei Shtylyov MIME-Version: 1.0 To: Benjamin Herrenschmidt Subject: Re: [PATCH] powerpc: Create "rom" (MTD) device prpmc2800 References: <7fc919fce0761f861be3069a853d3169@bga.com> <1180769992.14025.1.camel@localhost.localdomain> In-Reply-To: <1180769992.14025.1.camel@localhost.localdomain> Content-Type: text/plain; charset=us-ascii; format=flowed Cc: ppcdev , Milton Miller List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello. Benjamin Herrenschmidt wrote: > On Fri, 2007-06-01 at 23:30 -0500, Milton Miller wrote: > >>Actually, looking back at your device tree {1], your list several >>properties for flash, including bank-width and partition names. >>Perhaps first compatible should be direct-mapped-partitioned-flash, >>direct-mapped-partitioned-rom, direct-mapped-rom (to me a >>direct-mapped-rom driver would expose one section of address space >>read-only). I'm assuming that your driver for this "direct-mapped" >>device will look at these properties from the of device node and >>call the mtd layer somewhat directly with their contents. > If it's a flash, compatible should be the chip type, and maybe as a > second entry, what type of flash protocol (amd, intel, cfi, ...) it's > compatible. As I've already (and repatedly) stated before, this gets you *nothing* WRT selecting the proper driver in the current Linux MTD subsystem. What it actually *needs* to know is flash mapping information, the CFI/JEDEC interface then can be deduced by probing -- so, this property ("ptobe-type"), although specified in Documentation/powerpc/booting-without-of.txt, is optional. > Ben. WBR, Sergei