From mboxrd@z Thu Jan 1 00:00:00 1970 From: arnd@arndb.de (Arnd Bergmann) Date: Mon, 7 May 2012 11:21:53 +0000 Subject: [PATCH 1/2] mfd: max8925: request resource region In-Reply-To: References: <1336360249-29963-1-git-send-email-haojian.zhuang@gmail.com> <201205071014.03632.arnd@arndb.de> Message-ID: <201205071121.53302.arnd@arndb.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 07 May 2012, Haojian Zhuang wrote: > Even we append a new IORESOURCE type. We still meet similar issue. So > it means that we can't use any IORESOURCE for this kind of i2c usage. Is > it right? Yes, basically the concept of IORESOURCE is incompatible here, unless you want to add a new IORESOURCE type for each one of these drivers, or you find a way to put all these devices into one global register space at unique addresses, which doesn't sound any better. Can you explain why you need this kind of arbitration to start with? Can't you just ensure that each client of the max8925 only sees a fixed set of nonconflicting registers, and provide a higher-level abstractions for the registers that are indeed shared between clients? Wouldn't you always know which drivers potentially coexist here? Arnd