From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from foss.arm.com ([217.140.101.70])
 by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux))
 id 1YW0lJ-0003Ke-Ud
 for linux-mtd@lists.infradead.org; Thu, 12 Mar 2015 10:54:46 +0000
Date: Thu, 12 Mar 2015 10:53:52 +0000
From: Mark Rutland <mark.rutland@arm.com>
To: =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= <zajec5@gmail.com>
Subject: Re: [PATCH 1/2] Documentation: devicetree: m25p80: add "nor-jedec"
 binding
Message-ID: <20150312105352.GC30145@leverpostej>
References: <1426111046-29900-1-git-send-email-computersforpeace@gmail.com>
 <CAMuHMdUv2w0chGPK37oYaY5f64X4XK+Ab+aP7egxv2fnWa8k-g@mail.gmail.com>
 <CACna6rz-4nKE_iV2-8aG3ZEcrpN88A0iX4cHC+FudJ-==H9p7w@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <CACna6rz-4nKE_iV2-8aG3ZEcrpN88A0iX4cHC+FudJ-==H9p7w@mail.gmail.com>
Cc: Marek Vasut <marex@denx.de>,
 "devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
 MTD Maling List <linux-mtd@lists.infradead.org>,
 Ezequiel Garcia <ezequiel.garcia@free-electrons.com>,
 Geert Uytterhoeven <geert@linux-m68k.org>,
 Brian Norris <computersforpeace@gmail.com>
List-Id: Linux MTD discussion mailing list <linux-mtd.lists.infradead.org>
List-Unsubscribe: <http://lists.infradead.org/mailman/options/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=unsubscribe>
List-Archive: <http://lists.infradead.org/pipermail/linux-mtd/>
List-Post: <mailto:linux-mtd@lists.infradead.org>
List-Help: <mailto:linux-mtd-request@lists.infradead.org?subject=help>
List-Subscribe: <http://lists.infradead.org/mailman/listinfo/linux-mtd>,
 <mailto:linux-mtd-request@lists.infradead.org?subject=subscribe>

On Thu, Mar 12, 2015 at 10:36:29AM +0000, Rafał Miłecki wrote:
> On 12 March 2015 at 11:19, Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> > On Wed, Mar 11, 2015 at 10:57 PM, Brian Norris
> > <computersforpeace@gmail.com> wrote:
> >> diff --git a/Documentation/devicetree/bindings/mtd/m25p80.txt b/Documentation/devicetree/bindings/mtd/m25p80.txt
> >> index 4611aa83531b..1b2997d4cee4 100644
> >> --- a/Documentation/devicetree/bindings/mtd/m25p80.txt
> >> +++ b/Documentation/devicetree/bindings/mtd/m25p80.txt
> >> @@ -3,9 +3,12 @@
> >>  Required properties:
> >>  - #address-cells, #size-cells : Must be present if the device has sub-nodes
> >>    representing partitions.
> >> -- compatible : Should be the manufacturer and the name of the chip. Bear in mind
> >> +- compatible : Should be "nor-jedec" for any SPI NOR flash that can be
> >> +               identified by the JEDEC READ ID opcode (0x95).
> >> +               Additionally, may include a device-specific string consisting of
> >> +               the manufacturer and name of the chip. Bear in mind
> >
> > For the casual reader, this suggests putting "nor-jedec" first, which is not
> > what we want. So I would write it like e.g.
> >
> > "Should be the manufacturer and the name of the chip. Additionally,
> >  should contain "nor-jedec" for any SPI NOR flash that can be
> >  identified by the JEDEC READ ID opcode (0x95)."
> 
> I don't really like above. It suggests using manufacturer,name
> always/in most cases. This is what we want to avoid. Let's use
> "nor-jedec" wherever possible (when dealing with JEDEC compatible
> flashes).

The compatible property is a list. We should have "nor-jedec" in the
list, but a more specific string should come first. If we don't
recognise the more specific string, we'll still recognise nor-jedec, if
we do recognise it then we can do more advacned things with the HW (or
work around errata).

Mark.