From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felipe Balbi Subject: Re: [PATCH v8 2/6] ARM: OMAP2+: cleaned-up DT support of various ECC schemes Date: Fri, 11 Oct 2013 10:55:27 -0500 Message-ID: <20131011155527.GP25706@radagast> References: <1381498603-15715-1-git-send-email-pekon@ti.com> <1381498603-15715-3-git-send-email-pekon@ti.com> Reply-To: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="90KBcPA0h13nTGdQ" Return-path: Content-Disposition: inline In-Reply-To: <1381498603-15715-3-git-send-email-pekon@ti.com> Sender: linux-omap-owner@vger.kernel.org To: Pekon Gupta Cc: mark.rutland@arm.com, robherring2@gmail.com, olof@lixom.net, computersforpeace@gmail.com, dedekind1@gmail.com, Pawel.Moll@arm.com, ijc+devicetree@hellion.org.uk, swarren@wwwdotorg.org, dwmw2@infradead.org, arnd@arndb.de, tony@atomide.com, bcousson@baylibre.com, avinashphilipk@gmail.com, balbi@ti.com, linux-mtd@lists.infradead.org, linux-omap@vger.kernel.org, devicetree@vger.kernel.org, Andrew Morton List-Id: devicetree@vger.kernel.org --90KBcPA0h13nTGdQ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Oct 11, 2013 at 07:06:39PM +0530, Pekon Gupta wrote: > OMAP NAND driver support multiple ECC scheme, which can used in following > different flavours, depending on in-build Hardware engines supported by S= oC. >=20 > +---------------------------------------+---------------+---------------+ > | ECC scheme |ECC calculation|Error detection| > +---------------------------------------+---------------+---------------+ > |OMAP_ECC_HAM1_CODE_HW |H/W (GPMC) |S/W | > +---------------------------------------+---------------+---------------+ > |OMAP_ECC_BCH8_CODE_HW_DETECTION_SW |H/W (GPMC) |S/W | > |(requires CONFIG_MTD_NAND_ECC_BCH) | | | > +---------------------------------------+---------------+---------------+ > |OMAP_ECC_BCH8_CODE_HW |H/W (GPMC) |H/W (ELM) | > |(requires CONFIG_MTD_NAND_OMAP_BCH && | | | > | ti,elm-id in DT) | | | > +---------------------------------------+---------------+---------------+ > To optimize footprint of omap2-nand driver, selection of some ECC schemes > also require enabling following Kconfigs, in addition to setting appropri= ate > DT bindings > - Kconfig:CONFIG_MTD_NAND_ECC_BCH error detection done in software > - Kconfig:CONFIG_MTD_NAND_OMAP_BCH error detection done by h/w engi= ne >=20 > DT binding updates in this patch are: > - ti,elm-id: replaces elm_id > - ti,nand-ecc-opts: supported values ham1, bch4, and bch8 > selection of h/w or s/w implementation depends on ti,elm-id >=20 > Signed-off-by: Pekon Gupta since this maintains backwards compatibility, I think it should be alright to apply Reviewed-by: Felipe Balbi > --- > .../devicetree/bindings/mtd/gpmc-nand.txt | 8 +++- > arch/arm/mach-omap2/gpmc.c | 45 ++++++++++++++++= ------ > include/linux/platform_data/mtd-nand-omap2.h | 14 +++++-- > 3 files changed, 50 insertions(+), 17 deletions(-) >=20 > diff --git a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt b/Docume= ntation/devicetree/bindings/mtd/gpmc-nand.txt > index 25ee232..5e1f31b 100644 > --- a/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > +++ b/Documentation/devicetree/bindings/mtd/gpmc-nand.txt > @@ -36,8 +36,12 @@ Optional properties: > "prefetch-dma" Prefetch enabled sDMA mode > "prefetch-irq" Prefetch enabled irq mode > =20 > - - elm_id: Specifies elm device node. This is required to support BCH > - error correction using ELM module. > + - elm_id: use "ti,elm-id" instead > + - ti,elm-id: Specifies phandle of the ELM devicetree node. > + ELM is an on-chip hardware engine on TI SoC which is used for > + locating ECC errors for BCHx algorithms. SoC devices which have > + ELM hardware engines should specify this device node in .dtsi > + Using ELM for ECC error correction frees some CPU cycles. > =20 > For inline partiton table parsing (optional): > =20 > diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c > index c9fb353..9473c9f 100644 > --- a/arch/arm/mach-omap2/gpmc.c > +++ b/arch/arm/mach-omap2/gpmc.c > @@ -1341,12 +1341,6 @@ static void __maybe_unused gpmc_read_timings_dt(st= ruct device_node *np, > =20 > #ifdef CONFIG_MTD_NAND > =20 > -static const char * const nand_ecc_opts[] =3D { > - [OMAP_ECC_HAM1_CODE_HW] =3D "ham1", > - [OMAP_ECC_BCH4_CODE_HW] =3D "bch4", > - [OMAP_ECC_BCH8_CODE_HW] =3D "bch8", > -}; > - > static const char * const nand_xfer_types[] =3D { > [NAND_OMAP_PREFETCH_POLLED] =3D "prefetch-polled", > [NAND_OMAP_POLLED] =3D "polled", > @@ -1376,12 +1370,39 @@ static int gpmc_probe_nand_child(struct platform_= device *pdev, > gpmc_nand_data->cs =3D val; > gpmc_nand_data->of_node =3D child; > =20 > - if (!of_property_read_string(child, "ti,nand-ecc-opt", &s)) > - for (val =3D 0; val < ARRAY_SIZE(nand_ecc_opts); val++) > - if (!strcasecmp(s, nand_ecc_opts[val])) { > - gpmc_nand_data->ecc_opt =3D val; > - break; > - } > + /* Detect availability of ELM module */ > + gpmc_nand_data->elm_of_node =3D of_parse_phandle(child, "ti,elm-id", 0); > + if (gpmc_nand_data->elm_of_node =3D=3D NULL) > + gpmc_nand_data->elm_of_node =3D > + of_parse_phandle(child, "elm_id", 0); > + if (gpmc_nand_data->elm_of_node =3D=3D NULL) > + pr_warn("%s: ti,elm-id property not found\n", __func__); > + > + /* select NAND ecc-opt */ > + if (of_property_read_string(child, "ti,nand-ecc-opt", &s)) { > + pr_err("%s: ti,nand-ecc-opt not found\n", __func__); > + return -ENODEV; > + } > + if (!strcmp(s, "ham1") || !strcmp(s, "sw") || > + !strcmp(s, "hw") || !strcmp(s, "hw-romcode")) > + gpmc_nand_data->ecc_opt =3D > + OMAP_ECC_HAM1_CODE_HW; > + else if (!strcmp(s, "bch4")) > + if (gpmc_nand_data->elm_of_node) > + gpmc_nand_data->ecc_opt =3D > + OMAP_ECC_BCH4_CODE_HW; > + else > + gpmc_nand_data->ecc_opt =3D > + OMAP_ECC_BCH4_CODE_HW_DETECTION_SW; > + else if (!strcmp(s, "bch8")) > + if (gpmc_nand_data->elm_of_node) > + gpmc_nand_data->ecc_opt =3D > + OMAP_ECC_BCH8_CODE_HW; > + else > + gpmc_nand_data->ecc_opt =3D > + OMAP_ECC_BCH8_CODE_HW_DETECTION_SW; > + else > + pr_err("%s: ti,nand-ecc-opt invalid value\n", __func__); > =20 > if (!of_property_read_string(child, "ti,nand-xfer-type", &s)) > for (val =3D 0; val < ARRAY_SIZE(nand_xfer_types); val++) > diff --git a/include/linux/platform_data/mtd-nand-omap2.h b/include/linux= /platform_data/mtd-nand-omap2.h > index cb5a54a..4da5bfa 100644 > --- a/include/linux/platform_data/mtd-nand-omap2.h > +++ b/include/linux/platform_data/mtd-nand-omap2.h > @@ -23,9 +23,16 @@ enum nand_io { > }; > =20 > enum omap_ecc { > - OMAP_ECC_HAM1_CODE_HW =3D 0, /* 1-bit Hamming ecc code */ > - OMAP_ECC_BCH4_CODE_HW, /* 4-bit BCH ecc code */ > - OMAP_ECC_BCH8_CODE_HW, /* 8-bit BCH ecc code */ > + /* 1-bit ECC calculation by GPMC, Error detection by Software */ > + OMAP_ECC_HAM1_CODE_HW =3D 0, > + /* 4-bit ECC calculation by GPMC, Error detection by Software */ > + OMAP_ECC_BCH4_CODE_HW_DETECTION_SW, > + /* 4-bit ECC calculation by GPMC, Error detection by ELM */ > + OMAP_ECC_BCH4_CODE_HW, > + /* 8-bit ECC calculation by GPMC, Error detection by Software */ > + OMAP_ECC_BCH8_CODE_HW_DETECTION_SW, > + /* 8-bit ECC calculation by GPMC, Error detection by ELM */ > + OMAP_ECC_BCH8_CODE_HW, > }; > =20 > struct gpmc_nand_regs { > @@ -59,5 +66,6 @@ struct omap_nand_platform_data { > =20 > /* for passing the partitions */ > struct device_node *of_node; > + struct device_node *elm_of_node; > }; > #endif > --=20 > 1.8.1 >=20 --=20 balbi --90KBcPA0h13nTGdQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIcBAEBAgAGBQJSWB9vAAoJEIaOsuA1yqREBwIP/i7wXrn14+njf0eW2sYbb1TZ NV2meJo+yAGbj5uo4J6KCoruB/fADbk8W/27H5eKWdAZT+Sef1w5D2inzXqU1tmL iqSqwaqLhpsQsC3tjHQz67mc4GUbay9vTvyqA31PV+5OHqRKMajIKenigii55O2I UIQTFDHhxnqfB/qu/HlBov7zigaSCASs3XwpherjNJXTlCfBx2fcqTGETMB5rhvD Os77v+OaxTnZ2df02pT/VbbUSnFWSvUNfkU7Y7g/vsHhy6MoMdI0EfolJ55VnIio dP3c32gzg9lzD/ODLiZQmKugPqyGC/guNPDfRa+oetgEzYLRNZdqaCFfVz2VeARy teAJG4zTGXzC/IXf3ss9PIgGdiUWxsiE87RlCptJ7ILEJOkj4Khfk8sY1LBlE1uv ecRYeE3NwLUdkSwGgvX61O1zKLR/MtUk/4ecWwokIm/gzK4HIwK0DrnPaCTE8bQb AnJ06dH1IRcz4NlA9Kj0gEj+HYAppersk3mPeBV5rMXqxmI9pyrZaOSOxzDTu7UW R1wz+vSo2pjKD8OD6Itz/Kah/DqNeZoR4nBuaH8BWX4+WOuPRTGzzlPuJR3C7RFH xKWR+b+DZ3oeCxCNT4qaUUeEuCwysQ/NUPFxrPK0u5qrwfQk18Exa4XFxug5x7ik xttsBiRQiYnCKqA/Lnqe =0S6H -----END PGP SIGNATURE----- --90KBcPA0h13nTGdQ--