From mboxrd@z Thu Jan 1 00:00:00 1970 From: Boris Brezillon Subject: Re: [PATCH v3 2/6] mtd: rawnand: add an option to specify NAND chip as a boot device Date: Fri, 1 Jun 2018 09:26:52 +0200 Message-ID: <20180601092652.2e9716ac@bbrezillon> References: <20180531221637.6017-1-stefan@agner.ch> <20180531221637.6017-3-stefan@agner.ch> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180531221637.6017-3-stefan@agner.ch> Sender: linux-kernel-owner@vger.kernel.org To: Stefan Agner Cc: dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com, thierry.reding@gmail.com, benjamin.lindqvist@endian.se, pgaikwad@nvidia.com, dev@lynxeye.de, mirza.krak@gmail.com, richard@nod.at, pdeschrijver@nvidia.com, linux-kernel@vger.kernel.org, krzk@kernel.org, jonathanh@nvidia.com, devicetree@vger.kernel.org, linux-mtd@lists.infradead.org, marcel@ziswiler.com, miquel.raynal@bootlin.com, linux-tegra@vger.kernel.org, digetx@gmail.com List-Id: devicetree@vger.kernel.org On Fri, 1 Jun 2018 00:16:33 +0200 Stefan Agner wrote: > Allow to define a NAND chip as a boot device. This can be helpful > for the selection of the ECC algorithm and strength in case the boot > ROM supports only a subset of controller provided options. > > Signed-off-by: Stefan Agner Reviewed-by: Boris Brezillon > --- > Documentation/devicetree/bindings/mtd/nand.txt | 4 ++++ > drivers/mtd/nand/raw/nand_base.c | 3 +++ > include/linux/mtd/rawnand.h | 6 ++++++ > 3 files changed, 13 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mtd/nand.txt b/Documentation/devicetree/bindings/mtd/nand.txt > index 8bb11d809429..8daf81b9748c 100644 > --- a/Documentation/devicetree/bindings/mtd/nand.txt > +++ b/Documentation/devicetree/bindings/mtd/nand.txt > @@ -43,6 +43,10 @@ Optional NAND chip properties: > This is particularly useful when only the in-band area is > used by the upper layers, and you want to make your NAND > as reliable as possible. > +- nand-is-boot-medium: Whether the NAND chip is a boot medium. Drivers might use > + this information to select ECC algorithms supported by > + the boot ROM or similar restrictions. > + > - nand-rb: shall contain the native Ready/Busy ids. > > The ECC strength and ECC step size properties define the correction capability > diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c > index 9eb5678dd6d0..c8fb7c9855e2 100644 > --- a/drivers/mtd/nand/raw/nand_base.c > +++ b/drivers/mtd/nand/raw/nand_base.c > @@ -5826,6 +5826,9 @@ static int nand_dt_init(struct nand_chip *chip) > if (of_get_nand_bus_width(dn) == 16) > chip->options |= NAND_BUSWIDTH_16; > > + if (of_property_read_bool(dn, "nand-is-boot-medium")) > + chip->options |= NAND_IS_BOOT_MEDIUM; > + > if (of_get_nand_on_flash_bbt(dn)) > chip->bbt_options |= NAND_BBT_USE_FLASH; > > diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h > index 6a82da8c44ce..8e54fcf2fa94 100644 > --- a/include/linux/mtd/rawnand.h > +++ b/include/linux/mtd/rawnand.h > @@ -212,6 +212,12 @@ enum nand_ecc_algo { > */ > #define NAND_WAIT_TCCS 0x00200000 > > +/* > + * Whether the NAND chip is a boot medium. Drivers might use this information > + * to select ECC algorithms supported by the boot ROM or similar restrictions. > + */ > +#define NAND_IS_BOOT_MEDIUM 0x00400000 > + > /* Options set by nand scan */ > /* Nand scan has allocated controller struct */ > #define NAND_CONTROLLER_ALLOC 0x80000000