From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 24 Nov 2014 09:22:33 -0600 (CST) From: Aaron Sierra To: Ezequiel Garcia Message-ID: <737777710.57195.1416842553156.JavaMail.zimbra@xes-inc.com> In-Reply-To: <5471308E.908@vanguardiasur.com.ar> References: <1854666513.5578.1415473916534.JavaMail.zimbra@xes-inc.com> <5471308E.908@vanguardiasur.com.ar> Subject: Re: [PATCH v2] mtd: fsl_upm: Support NAND ECC DTS properties MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: David Woodhouse , devicetree@vger.kernel.org, Brian Norris , linux-mtd@lists.infradead.org, Jordan Friendshuh List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , ----- Original Message ----- > From: "Ezequiel Garcia" > Sent: Saturday, November 22, 2014 6:55:42 PM > > On 11/08/2014 04:11 PM, Aaron Sierra wrote: > > From: Jordan Friendshuh > > > > Support the generic nand-ecc-mode and nand-ecc-strength device-tree > > properties with the Freescale UPM NAND driver. > > > > This patch preserves the default software ECC mode while adding the > > ability to use BCH ECC for larger NAND devices. > > > > Signed-off-by: Jordan Friendshuh > > Signed-off-by: Aaron Sierra > > --- > > v2: > > * Now using ECC mode and strength helpers from of_mtd.h > > * ECC mode and strength checking is more robust > > > > .../devicetree/bindings/mtd/fsl-upm-nand.txt | 2 + > > drivers/mtd/nand/Kconfig | 1 + > > drivers/mtd/nand/fsl_upm.c | 51 > > +++++++++++++++++++--- > > 3 files changed, 49 insertions(+), 5 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt > > b/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt > > index fce4894..a9906f6 100644 > > --- a/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt > > +++ b/Documentation/devicetree/bindings/mtd/fsl-upm-nand.txt > > @@ -18,6 +18,8 @@ Optional properties: > > - chip-delay : chip dependent delay for transferring data from array to > > read registers (tR). Required if property "gpios" is not used > > (R/B# pins not connected). > > +- nand-ecc-mode : as defined by nand.txt ("soft" and "soft_bch", only). > > +- nand-ecc-strength : as defined by nand.txt. > > > > The nand.txt recommends that each binding documents the way these > properties are interpreted. Ezequiel, I assume you are referring to this statement, "implementations are encouraged to further specify the value(s) they support." That is the only statement I found requesting documentation. I believe that request is satisfied, since I listed all of the modes that the driver would support with my patch applied. I used mxc-nand.txt as a reference. > Moreover, there's no nand-ecc-step usage? Are you assuming a 512-byte size? The ecc.bytes value is currently left to be calculated by the NAND_ECC_SOFT_BCH case in nand_base.c. That calculation assumes a 512-byte step size. -Aaron