From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wolfram Sang Subject: Re: [PATCH RFC] misc/at24: distinguish between eeprom and fram chips Date: Thu, 24 Jan 2013 08:27:01 +0100 Message-ID: <20130124072701.GG8364@nekote.pengutronix.de> References: <201212041758.38600.poeschel@lemonage.de> <201212051043.07460.poeschel@lemonage.de> <20121205164153.GA5011@pengutronix.de> <201212071114.29034.poeschel@lemonage.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <201212071114.29034.poeschel@lemonage.de> Sender: linux-kernel-owner@vger.kernel.org To: Lars Poeschel Cc: gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, linux-i2c@vger.kernel.org List-Id: linux-i2c@vger.kernel.org On Fri, Dec 07, 2012 at 11:14:28AM +0100, Lars Poeschel wrote: > > > > > I wanted to use a fm24c04 i2c fram chip with linux. I grepped the > > > > > source and found nothing. I later found that my chip can be handled > > > > > by at24 eeprom driver. It creates a sysfs file called eeprom to > > > > > read from and write to the chip. Userspace has no chance to > > > > > distinguish if it is writing an eeprom or a fram chip. > > > > > > > > Why should it? > > > > > > Because writes are much faster and it doesn't have to take care on erase > > > cycles. It could use other write strategies on such devices and update > > > informations that have to survive power downs more often. > > > > I agree. I think that a seperate attribute named e.g. 'page_size' would > > be more helpful than renaming the binary file to fram? > > Yes, this is a much better solution! Adding a seperate sysfs file page_size > and a file for the type of device which would read eeprom, fram, etc then. > If you also think this is the way to go, I would spent one of my next free > timeslots to this. Oops, this mail seems to have dropped off :( I am all for the 'page_size' attribute, but still not convinced what gain the 'type' attribute would allow. For FRAM, the page size will be large. Isn't this enough information? Regards, Wolfram