From mboxrd@z Thu Jan 1 00:00:00 1970 From: Srinivas Kandagatla Subject: Re: [PATCH RFC] eeprom: at24: extend driver to plug into the NVMEM framework Date: Mon, 17 Aug 2015 16:41:48 +0100 Message-ID: <55D200BC.3040104@linaro.org> References: <1439693649-10809-1-git-send-email-andrew@lunn.ch> <2080648987.23864.1439713686409.JavaMail.open-xchange@oxbsltgw04.schlund.de> <20150816131130.GC10094@lunn.ch> <1511754934.28154.1439739426390.JavaMail.open-xchange@oxbsltgw00.schlund.de> <55D1DB24.8090602@linaro.org> <20150817130945.GE7537@lunn.ch> <55D1F6CB.2010606@linaro.org> <20150817152504.GI7537@lunn.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150817152504.GI7537-g2DYL2Zd6BY@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andrew Lunn Cc: Stefan Wahren , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org, Maxime Ripard List-Id: linux-i2c@vger.kernel.org On 17/08/15 16:25, Andrew Lunn wrote: > On Mon, Aug 17, 2015 at 03:59:23PM +0100, Srinivas Kandagatla wrote: >> >> >> On 17/08/15 14:09, Andrew Lunn wrote: >>> On Mon, Aug 17, 2015 at 02:01:24PM +0100, Srinivas Kandagatla wrote: >>>> >>>> +Adding Maxime in the loop >>>> >>>> On 16/08/15 16:37, Stefan Wahren wrote: >>>>>>> Another question which spring to mind is, do we want the eeprom to be >>>>>>> in /sys twice, the old and the new way? Backwards compatibility says >>>>>>> the old must stay. Do we want a way to suppress the new? Or should we >>>>>>> be going as far as refractoring the code into a core library, and two >>>>>>> wrapper drivers, old and new? >>>>> I think these are questions for the framework maintainers. >>>>> >>>> One of the reasons for the NVMEM framework is to remove that >>>> duplicate code in the every driver. There was no framework/ABI >>>> which was guiding such old eeprom sysfs entry in first place, so I >>>> dont see an issue in removing it for good. Correct me if am wrong. >>> >>> The reason for keeping it is backwards compatibility. Having the >>> contents of the EEPROM as a file in /sys via this driver is now a part >>> of the Linux ABI. You cannot argue it is not an ABI, just because >>> there is no framework. Userspace will be assuming it exists at the >>> specified location. So we cannot remove it, for existing uses of the >>> driver. >> Am Ok as long as someone is happy to maintain it. > > Wolfram Sang has been maintaining the AT24 driver since 2008. We need > his ACK to this change, and since this is an i2c driver, he is also > probably the path into mainline for this change. > > But we should also look at the bigger picture. The AT25, MAX6875 and > sunxi_sid drivers also have a binary file in /sys. It would be good to > have some sort of plan what to do with these drivers, even if at the > moment only AT24 is under discussion.# +1 > > Andrew >