Re: [PATCH v1 1/3] mtd: rawnand: nand_base: support for 'NAND_IS_BOOT_MEDIUM' flag

Hello Arseniy,

Am Sun, Jun 02, 2024 at 11:08:34PM +0300 schrieb Arseniy Krasnov:
> Based on Linux kernel:
> commit f922bd798bb9 ("mtd: rawnand: add an option to specify NAND chip as a boot device")
> 
> 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: Arseniy Krasnov <[email protected]>
> ---
>  drivers/mtd/nand/raw/nand_base.c | 3 +++
>  include/linux/mtd/rawnand.h      | 6 ++++++
>  2 files changed, 9 insertions(+)
> 
> diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
> index c40a0f23d7..ed605b4af5 100644
> --- a/drivers/mtd/nand/raw/nand_base.c
> +++ b/drivers/mtd/nand/raw/nand_base.c
> @@ -4458,6 +4458,9 @@ static int nand_dt_init(struct mtd_info *mtd, struct nand_chip *chip, ofnode nod
>  	if (ret == 16)
>  		chip->options |= NAND_BUSWIDTH_16;
>  
> +	if (ofnode_read_bool(node, "nand-is-boot-medium"))
> +		chip->options |= NAND_IS_BOOT_MEDIUM;
> +
>  	if (ofnode_read_bool(node, "nand-on-flash-bbt"))
>  		chip->bbt_options |= NAND_BBT_USE_FLASH;
>  
> diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
> index fb002ae641..4eb880d8fb 100644
> --- a/include/linux/mtd/rawnand.h
> +++ b/include/linux/mtd/rawnand.h
> @@ -218,6 +218,12 @@ enum nand_ecc_algo {
>  /* Device needs 3rd row address cycle */
>  #define NAND_ROW_ADDR_3		0x00004000
>  
> +/*
> + * 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 valid for Samsung large page devices */
>  #define NAND_SAMSUNG_LP_OPTIONS NAND_CACHEPRG

The entries in that file are ordered numerically.  Comparing with the
same file in Linux this should go before NAND_KEEP_TIMINGS, not
anywhere in between.  Makes later diffs and ports from Linux easier.

Greets
Alex

>  
> -- 
> 2.35.0
>