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Date:   Tue, 25 Jan 2022 15:31:12 +0530
From:   Pratyush Yadav <p.yadav@ti.com>
To:     Ley Foon Tan <leyfoon.tan@linux.starfivetech.com>
CC:     Tudor Ambarus <tudor.ambarus@microchip.com>,
        Michael Walle <michael@walle.cc>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        <linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        Ley Foon Tan <lftan.linux@gmail.com>
Subject: Re: [PATCH] mtd: spi-nor: macronix: Add support for mx66u1g45g
Message-ID: <20220125100112.jevrd4knhxytmry2@ti.com>
References: <20220124060225.149007-1-leyfoon.tan@linux.starfivetech.com>
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In-Reply-To: <20220124060225.149007-1-leyfoon.tan@linux.starfivetech.com>
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Hi,

On 24/01/22 02:02PM, Ley Foon Tan wrote:
> The Macronix mx66u1g45g [1] is a 1.8V, 1Gbit (128MB) flash device that
> supports x1, x2, or x4 operation.
> 
> The mx66u1g45g is the smaller sibling of the mx66u2g45g that is
> already supported.
> 
> Tested on StarFive Dubhe hardware on FPGA.
> Validated by erase and read back, write and read back.
> 
> [1] https://www.macronix.com/Lists/Datasheet/Attachments/7877/MX66U1G45G,%201.8V,%201Gb,%20v1.4.pdf
> 
> Signed-off-by: Ley Foon Tan <leyfoon.tan@linux.starfivetech.com>
> ---
>  drivers/mtd/spi-nor/macronix.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/macronix.c b/drivers/mtd/spi-nor/macronix.c
> index 97dba1ae7fb1..79ee808c5442 100644
> --- a/drivers/mtd/spi-nor/macronix.c
> +++ b/drivers/mtd/spi-nor/macronix.c
> @@ -97,6 +97,9 @@ static const struct flash_info macronix_parts[] = {
>  			      SPI_NOR_QUAD_READ) },
>  	{ "mx66l1g55g",  INFO(0xc2261b, 0, 64 * 1024, 2048)
>  		NO_SFDP_FLAGS(SPI_NOR_QUAD_READ) },
> +	{ "mx66u1g45g",  INFO(0xc2253b, 0, 64 * 1024, 2048)
> +		NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)
> +		FIXUP_FLAGS(SPI_NOR_4B_OPCODES) },

This is the "legacy" way of defining flags. I see from the datasheet 
that SFDP is supported. Please use PARSE_SFDP to allow these parameters 
to be discovered via SFDP. If one of the SFDP table has wrong data then 
please use fixup hooks to correct it.

You also need to dump the SFDP table and some other flash parameters in 
the patch comments. See [0] for an example.

[0] https://patchwork.ozlabs.org/project/linux-mtd/patch/20211209190436.401946-2-tudor.ambarus@microchip.com/

>  	{ "mx66u2g45g",	 INFO(0xc2253c, 0, 64 * 1024, 4096)
>  		NO_SFDP_FLAGS(SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ)
>  		FIXUP_FLAGS(SPI_NOR_4B_OPCODES) },
> -- 
> 2.25.1
> 
> 

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.