RE: [PATCH v2 1/3] Revert "mtd: spi-nor: remove Fujitsu MB85RS1MT support"

[Takahiro.Kuwano]

Hi,

> This reverts commit d9cd5c9a6fe26d544551cfaa94fb0abc50c0b895.
> 
> The commit that removed support for this chip claimed that the at25
> driver was the correct driver to use for this chip. However, the at25
> driver exposes the chip as an NVMEM device, not a MTD device, so it's
> not a suitable replacement for users that want to mount a file system
> over the chip.
> 

What file system do you use?
The size of FRAM chips (hundreds of KB) sounds too small for file
systems.

> Revert the change that removed support for the MB85RS1MT FRAM chip.
> 
> Signed-off-by: Ronan Dalton <ronan.dalton@xxxxxxxxxxxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-mtd@xxxxxxxxxxxxxxxxxxx
> Cc: Pratyush Yadav <pratyush@xxxxxxxxxx>
> Cc: Michael Walle <mwalle@xxxxxxxxxx>
> Cc: Takahiro Kuwano <takahiro.kuwano@xxxxxxxxxxxx>
> Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> Cc: Richard Weinberger <richard@xxxxxx>
> Cc: Vignesh Raghavendra <vigneshr@xxxxxx>
> Cc: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> Cc: Aryan Srivastava <aryan.srivastava@xxxxxxxxxxxxxxxxxxx>
> ---
> Changes in v2:
> - No changes
> 
>  drivers/mtd/spi-nor/Makefile  |  1 +
>  drivers/mtd/spi-nor/core.c    |  1 +
>  drivers/mtd/spi-nor/core.h    |  1 +
>  drivers/mtd/spi-nor/fujitsu.c | 21 +++++++++++++++++++++
>  4 files changed, 24 insertions(+)
>  create mode 100644 drivers/mtd/spi-nor/fujitsu.c
> 
> diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
> index 5dd9c35f6b6f..9216a5a29a2b 100644
> --- a/drivers/mtd/spi-nor/Makefile
> +++ b/drivers/mtd/spi-nor/Makefile
> @@ -5,6 +5,7 @@ spi-nor-objs                    += atmel.o
>  spi-nor-objs                   += eon.o
>  spi-nor-objs                   += esmt.o
>  spi-nor-objs                   += everspin.o
> +spi-nor-objs                   += fujitsu.o
>  spi-nor-objs                   += gigadevice.o
>  spi-nor-objs                   += intel.o
>  spi-nor-objs                   += issi.o
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index ccf4396cdcd0..d5ebbfd3fa7f 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -2009,6 +2009,7 @@ static const struct spi_nor_manufacturer *manufacturers[] = {
>         &spi_nor_eon,
>         &spi_nor_esmt,
>         &spi_nor_everspin,
> +       &spi_nor_fujitsu,
>         &spi_nor_gigadevice,
>         &spi_nor_intel,
>         &spi_nor_issi,
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index ba2d1a862c9d..a4d906e6d07d 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -606,6 +606,7 @@ extern const struct spi_nor_manufacturer spi_nor_atmel;
>  extern const struct spi_nor_manufacturer spi_nor_eon;
>  extern const struct spi_nor_manufacturer spi_nor_esmt;
>  extern const struct spi_nor_manufacturer spi_nor_everspin;
> +extern const struct spi_nor_manufacturer spi_nor_fujitsu;
>  extern const struct spi_nor_manufacturer spi_nor_gigadevice;
>  extern const struct spi_nor_manufacturer spi_nor_intel;
>  extern const struct spi_nor_manufacturer spi_nor_issi;
> diff --git a/drivers/mtd/spi-nor/fujitsu.c b/drivers/mtd/spi-nor/fujitsu.c
> new file mode 100644
> index 000000000000..69cffc5c73ef
> --- /dev/null
> +++ b/drivers/mtd/spi-nor/fujitsu.c
> @@ -0,0 +1,21 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2005, Intec Automation Inc.
> + * Copyright (C) 2014, Freescale Semiconductor, Inc.
> + */
> +
> +#include <linux/mtd/spi-nor.h>
> +
> +#include "core.h"
> +
> +static const struct flash_info fujitsu_nor_parts[] = {
> +       /* Fujitsu */
> +       { "mb85rs1mt", INFO(0x047f27, 0, 128 * 1024, 1)
> +               FLAGS(SPI_NOR_NO_ERASE) },
> +};
> +
> +const struct spi_nor_manufacturer spi_nor_fujitsu = {
> +       .name = "fujitsu",
> +       .parts = fujitsu_nor_parts,
> +       .nparts = ARRAY_SIZE(fujitsu_nor_parts),
> +};
> --
> 2.54.0

Thanks,
Takahiro