From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Agner Subject: [PATCH v3 2/6] mtd: rawnand: add an option to specify NAND chip as a boot device Date: Fri, 1 Jun 2018 00:16:33 +0200 Message-ID: <20180531221637.6017-3-stefan@agner.ch> References: <20180531221637.6017-1-stefan@agner.ch> Return-path: In-Reply-To: <20180531221637.6017-1-stefan@agner.ch> Sender: linux-kernel-owner@vger.kernel.org To: boris.brezillon@bootlin.com, dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com, thierry.reding@gmail.com Cc: dev@lynxeye.de, miquel.raynal@bootlin.com, richard@nod.at, marcel@ziswiler.com, krzk@kernel.org, digetx@gmail.com, benjamin.lindqvist@endian.se, jonathanh@nvidia.com, pdeschrijver@nvidia.com, pgaikwad@nvidia.com, mirza.krak@gmail.com, stefan@agner.ch, linux-mtd@lists.infradead.org, linux-tegra@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org 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 --- 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 -- 2.17.0