Re: [PATCH v2] mtd: spinand: fmsh: add support for FM25G{01,02}B

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Ziyang Huang <hzyitc@outlook.com>
Cc: richard@nod.at,  vigneshr@ti.com,  cnsztl@gmail.com,
	csharper2005@gmail.com,  mikhail.kshevetskiy@iopsys.eu,
	linux-mtd@lists.infradead.org,  linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] mtd: spinand: fmsh: add support for FM25G{01,02}B
Date: Tue, 28 Apr 2026 14:49:13 +0200	[thread overview]
Message-ID: <87340fdzcm.fsf@bootlin.com> (raw)
In-Reply-To: <SEYPR01MB5882D37365BB442818AEC143C9222@SEYPR01MB5882.apcprd01.prod.exchangelabs.com> (Ziyang Huang's message of "Wed, 15 Apr 2026 23:31:41 +0800")

Hello Ziyang,

On 15/04/2026 at 23:31:41 +08, Ziyang Huang <hzyitc@outlook.com> wrote:

> FM25G01B: https://www.fmsh.com/nvm/FM25G01B_ds_eng.pdf
> FM25G02B: https://www.fmsh.com/nvm/FM25G02B_ds_eng.pdf

Before giving the links, the commit could be slightly more verbose, such
as "Add support for...".

> Signed-off-by: Ziyang Huang <hzyitc@outlook.com>
> ---
> Changes since v1:
>   Fix copy-paste issue. (Correct FM25G01B size.)
>
>  drivers/mtd/nand/spi/fmsh.c | 101 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 101 insertions(+)
>
> diff --git a/drivers/mtd/nand/spi/fmsh.c b/drivers/mtd/nand/spi/fmsh.c
> index f417955f7d1c..a9b219ae6c29 100644
> --- a/drivers/mtd/nand/spi/fmsh.c
> +++ b/drivers/mtd/nand/spi/fmsh.c
> @@ -9,6 +9,16 @@
>  #include <linux/kernel.h>
>  #include <linux/mtd/spinand.h>
>  
> +#define FM25G01B_STATUS_ECC_MASK		(7 << 4)
> +	#define FM25G01B_STATUS_ECC_NO_BITFLIPS		(0 << 4)
> +	#define FM25G01B_STATUS_ECC_1_3_BITFLIPS	(1 << 4)
> +	#define FM25G01B_STATUS_ECC_4_BITFLIPS		(2 << 4)
> +	#define FM25G01B_STATUS_ECC_5_BITFLIPS		(3 << 4)
> +	#define FM25G01B_STATUS_ECC_6_BITFLIPS		(4 << 4)
> +	#define FM25G01B_STATUS_ECC_7_BITFLIPS		(5 << 4)
> +	#define FM25G01B_STATUS_ECC_8_BITFLIPS		(6 << 4)
> +	#define FM25G01B_STATUS_ECC_UNCOR_ERROR		(7 << 4)
> +
>  #define FM25S01BI3_STATUS_ECC_MASK		(7 << 4)
>  	#define FM25S01BI3_STATUS_ECC_NO_BITFLIPS	(0 << 4)
>  	#define FM25S01BI3_STATUS_ECC_1_3_BITFLIPS	(1 << 4)
> @@ -34,6 +44,72 @@ static SPINAND_OP_VARIANTS(update_cache_variants,
>  		SPINAND_PROG_LOAD_1S_1S_4S_OP(false, 0, NULL, 0),
>  		SPINAND_PROG_LOAD_1S_1S_1S_OP(false, 0, NULL, 0));
>  
> +
> +static int fm25g01b_ooblayout_ecc(struct mtd_info *mtd, int section,
> +				  struct mtd_oob_region *region)
> +{
> +	if (section)
> +		return -ERANGE;
> +
> +	region->offset = 64;
> +	region->length = 64;
> +
> +	return 0;
> +}
> +
> +static int fm25g01b_ooblayout_free(struct mtd_info *mtd, int section,
> +				   struct mtd_oob_region *region)
> +{
> +	if (section > 3)
> +		return -ERANGE;
> +
> +	if (section == 0) {
> +		/* reserve 2 bytes for the BBM */
> +		region->offset = 2;
> +		region->length = 14;
> +	} else {
> +		region->offset = section * 16;
> +		region->length = 16;
> +	}

Isn't that just one big 62 bytes section starting at 2?

> +
> +	return 0;
> +}

Rest lgtm.

Thanks,
Miquèl

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