linux-kernel - Re: [PATCH 1/2] mtd: spi-nor: Add Global Block Unlock command

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Date:   Wed, 20 Jan 2021 17:59:07 +0530
From:   Pratyush Yadav <p.yadav@...com>
To:     Tudor Ambarus <tudor.ambarus@...rochip.com>
CC:     <michael@...le.cc>, <vigneshr@...com>, <richard@....at>,
        <linux-kernel@...r.kernel.org>, <linux-mtd@...ts.infradead.org>,
        <Kavyasree.Kotagiri@...rochip.com>, <miquel.raynal@...tlin.com>
Subject: Re: [PATCH 1/2] mtd: spi-nor: Add Global Block Unlock command

Hi Tudor,

On 20/01/21 12:54PM, Tudor Ambarus wrote:
> The Global Block Unlock command has different names depending
> on the manufacturer, but always the same command value: 0x98.
> Macronix's MX25U12835F names it Gang Block Unlock, Winbound's
> W25Q128FV names it Global Block Unlock and Microchip's
> SST26VF064B names it Global Block Protection Unlock.
> 
> Used in the Individual Block Protection mode, which is mutual

Nitpick: s/mutual/mutually/

> exclusive with the Block Protection mode (BP0-3).
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus@...rochip.com>
> ---
>  drivers/mtd/spi-nor/core.c  | 35 +++++++++++++++++++++++++++++++++++
>  drivers/mtd/spi-nor/core.h  |  1 +
>  include/linux/mtd/spi-nor.h |  1 +
>  3 files changed, 37 insertions(+)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 20df44b753da..cb275608cb7f 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -853,6 +853,41 @@ int spi_nor_wait_till_ready(struct spi_nor *nor)
>  						    DEFAULT_READY_WAIT_JIFFIES);
>  }
>  
> +/**
> + * spi_nor_global_block_unlock() - Unlock Global Block Protection.
> + * @nor:	pointer to 'struct spi_nor'.
> + *
> + * Return: 0 on success, -errno otherwise.
> + */
> +int spi_nor_global_block_unlock(struct spi_nor *nor)
> +{
> +	int ret;
> +
> +	ret = spi_nor_write_enable(nor);
> +	if (ret)
> +		return ret;
> +
> +	if (nor->spimem) {
> +		struct spi_mem_op op =
> +			SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_GBULK, 1),

Set the buswidth to 0...

> +				   SPI_MEM_OP_NO_ADDR,
> +				   SPI_MEM_OP_NO_DUMMY,
> +				   SPI_MEM_OP_NO_DATA);

... and run the op through spi_nor_spimem_setup_op().

With this fixed,

Reviewed-by: Pratyush Yadav <p.yadav@...com>

> +
> +		ret = spi_mem_exec_op(nor->spimem, &op);
> +	} else {
> +		ret = spi_nor_controller_ops_write_reg(nor, SPINOR_OP_GBULK,
> +						       NULL, 0);
> +	}
> +
> +	if (ret) {
> +		dev_dbg(nor->dev, "error %d on Global Block Unlock\n", ret);
> +		return ret;
> +	}
> +
> +	return spi_nor_wait_till_ready(nor);
> +}
> +
>  /**
>   * spi_nor_write_sr() - Write the Status Register.
>   * @nor:	pointer to 'struct spi_nor'.
> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h
> index d631ee299de3..eb26796db026 100644
> --- a/drivers/mtd/spi-nor/core.h
> +++ b/drivers/mtd/spi-nor/core.h
> @@ -434,6 +434,7 @@ int spi_nor_write_disable(struct spi_nor *nor);
>  int spi_nor_set_4byte_addr_mode(struct spi_nor *nor, bool enable);
>  int spi_nor_write_ear(struct spi_nor *nor, u8 ear);
>  int spi_nor_wait_till_ready(struct spi_nor *nor);
> +int spi_nor_global_block_unlock(struct spi_nor *nor);
>  int spi_nor_lock_and_prep(struct spi_nor *nor);
>  void spi_nor_unlock_and_unprep(struct spi_nor *nor);
>  int spi_nor_sr1_bit6_quad_enable(struct spi_nor *nor);
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index d13958de6d8a..a0d572855444 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -53,6 +53,7 @@
>  #define SPINOR_OP_WREAR		0xc5	/* Write Extended Address Register */
>  #define SPINOR_OP_SRSTEN	0x66	/* Software Reset Enable */
>  #define SPINOR_OP_SRST		0x99	/* Software Reset */
> +#define SPINOR_OP_GBULK		0x98    /* Global Block Unlock */
>  
>  /* 4-byte address opcodes - used on Spansion and some Macronix flashes. */
>  #define SPINOR_OP_READ_4B	0x13	/* Read data bytes (low frequency) */

-- 
Regards,
Pratyush Yadav
Texas Instruments India