From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: Re: [PATCH 1/3] of: mtd: add helper reading "nand-ecc-algo" from DT Date: Wed, 24 Feb 2016 14:46:52 +0100 Message-ID: <20160224144652.14068468@bbrezillon> References: <1455300685-27009-1-git-send-email-zajec5@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <1455300685-27009-1-git-send-email-zajec5-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Brian Norris , linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Kamal Dasu , Hauke Mehrtens , Rob Herring , Grant Likely , Frank Rowand List-Id: devicetree@vger.kernel.org Hi Rafal, On Fri, 12 Feb 2016 19:11:23 +0100 Rafa=C5=82 Mi=C5=82ecki wrote: > This allows specifying algorithm used for NAND ECC. There are two > available values: "bch" and "hamming". It's important as having just > ECC parameters (step, strength) isn't enough to determine algorithm, > e.g. you can't distinct BCH-1 and Hamming. >=20 > Signed-off-by: Rafa=C5=82 Mi=C5=82ecki > --- > Documentation/devicetree/bindings/mtd/nand.txt | 3 +++ > drivers/of/of_mtd.c | 33 ++++++++++++++++= ++++++++++ > include/linux/mtd/nand.h | 5 ++++ > include/linux/of_mtd.h | 6 +++++ > 4 files changed, 47 insertions(+) >=20 > diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documen= tation/devicetree/bindings/mtd/nand.txt > index b53f92e..a2c2df5 100644 > --- a/Documentation/devicetree/bindings/mtd/nand.txt > +++ b/Documentation/devicetree/bindings/mtd/nand.txt > @@ -3,6 +3,9 @@ > - nand-ecc-mode : String, operation mode of the NAND ecc mode. > Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob= _first", > "soft_bch". > +- nand-ecc-algo : string, algorithm of NAND ecc. > + Supported values are: "bch", "hamming". The default one is > + "bch". I like the idea of specifying which ECC algorithm should be used, and this is IMO clearer than putting the information directly in nand-ecc-mode (as is already done for the "soft" and "soft_bch" modes, which are respectively encoding software hamming and software bch implementations). But shouldn't we take this even further and add new DT properties to encode the ECC layout (syndrome, oob_first), and another one to specify the implementation type (software or hardware)? nand-ecc-layout =3D "nornal", "syndrome" or "oob_first" nand-ecc-engine =3D "none", "soft" or "hw" ("on-die" ?) Note that it's not something I ask you to do right now, I just want to bring the topic on the table. Best Regards, Boris --=20 Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from down.free-electrons.com ([37.187.137.238] helo=mail.free-electrons.com) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1aYZmw-0004Sj-78 for linux-mtd@lists.infradead.org; Wed, 24 Feb 2016 13:47:39 +0000 Date: Wed, 24 Feb 2016 14:46:52 +0100 From: Boris Brezillon To: =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?= Cc: Brian Norris , linux-mtd@lists.infradead.org, devicetree@vger.kernel.org, Kamal Dasu , Hauke Mehrtens , Rob Herring , Grant Likely , Frank Rowand Subject: Re: [PATCH 1/3] of: mtd: add helper reading "nand-ecc-algo" from DT Message-ID: <20160224144652.14068468@bbrezillon> In-Reply-To: <1455300685-27009-1-git-send-email-zajec5@gmail.com> References: <1455300685-27009-1-git-send-email-zajec5@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hi Rafal, On Fri, 12 Feb 2016 19:11:23 +0100 Rafa=C5=82 Mi=C5=82ecki wrote: > This allows specifying algorithm used for NAND ECC. There are two > available values: "bch" and "hamming". It's important as having just > ECC parameters (step, strength) isn't enough to determine algorithm, > e.g. you can't distinct BCH-1 and Hamming. >=20 > Signed-off-by: Rafa=C5=82 Mi=C5=82ecki > --- > Documentation/devicetree/bindings/mtd/nand.txt | 3 +++ > drivers/of/of_mtd.c | 33 ++++++++++++++++++++= ++++++ > include/linux/mtd/nand.h | 5 ++++ > include/linux/of_mtd.h | 6 +++++ > 4 files changed, 47 insertions(+) >=20 > diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentati= on/devicetree/bindings/mtd/nand.txt > index b53f92e..a2c2df5 100644 > --- a/Documentation/devicetree/bindings/mtd/nand.txt > +++ b/Documentation/devicetree/bindings/mtd/nand.txt > @@ -3,6 +3,9 @@ > - nand-ecc-mode : String, operation mode of the NAND ecc mode. > Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_fir= st", > "soft_bch". > +- nand-ecc-algo : string, algorithm of NAND ecc. > + Supported values are: "bch", "hamming". The default one is > + "bch". I like the idea of specifying which ECC algorithm should be used, and this is IMO clearer than putting the information directly in nand-ecc-mode (as is already done for the "soft" and "soft_bch" modes, which are respectively encoding software hamming and software bch implementations). But shouldn't we take this even further and add new DT properties to encode the ECC layout (syndrome, oob_first), and another one to specify the implementation type (software or hardware)? nand-ecc-layout =3D "nornal", "syndrome" or "oob_first" nand-ecc-engine =3D "none", "soft" or "hw" ("on-die" ?) Note that it's not something I ask you to do right now, I just want to bring the topic on the table. Best Regards, Boris --=20 Boris Brezillon, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com