Re: [RFC 0/3] drivers: Add an API to read device specific config data

From: Alban <albeu@free.fr>
To: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Aban Bedel <albeu@free.fr>,
	linux-kernel@vger.kernel.org, linux-mtd@lists.infradead.org,
	Cyrille Pitchen <cyrille.pitchen@atmel.com>,
	Richard Weinberger <richard@nod.at>,
	Marek Vasut <marek.vasut@gmail.com>,
	Brian Norris <computersforpeace@gmail.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Moritz Fischer <moritz.fischer@ettus.com>
Subject: Re: [RFC 0/3] drivers: Add an API to read device specific config data
Date: Mon, 27 Feb 2017 23:41:52 +0100	[thread overview]
Message-ID: <20170227234152.5c4a90dd@tock> (raw)
In-Reply-To: <20170227214230.53f05677@bbrezillon>

[-- Attachment #1: Type: text/plain, Size: 1654 bytes --]

On Mon, 27 Feb 2017 21:42:30 +0100
Boris Brezillon <boris.brezillon@free-electrons.com> wrote:

> +Moritz
> 
> Hi Alban,
> 
> On Mon, 27 Feb 2017 21:28:09 +0100
> Alban <albeu@free.fr> wrote:
> 
> > Hi all,
> > 
> > while looking at adding OF support for the ath9k driver I had the problem of
> > reading the EEPROM data. On the SoC platforms this data is stored in an SPI
> > flash along with a few other things. In OpenWRT/LEDE this data is read from
> > the board init code using the fact that the flash is (normaly) readable from
> > a memory map. A bit too hackish for my taste.
> > 
> > This is just one example, there is various other similar cases, mostly with
> > MAC addresses. I thought it would be nicer if we had a clean API for this,
> > similar to the firmware API but per device instance instead of beeing per
> > driver. The device driver wouldn't have to care where the data is stored,
> > they just request it and the backend take care of reading the EEPROM, MTD
> > or whatever is used on the board.
> > 
> > This series implement such an API along with an implementation for MTD
> > devices and a use in the ath9k driver. As this is an RFC I didn't yet
> > write the OF binding documentation, that will come later if the feedback
> > is positive.  
> 
> What you're looking for already exists and it's called nvmem[1]. Some
> work has been done to expose MTD partitions as nvmem cells [2], but
> it's never been finished.
> Can you please finish Moritz implementation instead of creating a new
> API?

I didn't knew about the nvmem API :/ I'll look into finishing the MTD
support then.

Alban

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 819 bytes --]