Re: [RESEND PATCH v3 09/20] mtd: spi-nor: Create a ->set_4byte() method

[Vignesh Raghavendra <vigneshr@xxxxxx>]

On 26/08/19 5:38 PM, Tudor.Ambarus@xxxxxxxxxxxxx wrote:
> From: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> 
> The procedure used to enable 4 byte addressing mode depends on the NOR
> device, so let's provide a hook so that manufacturer specific handling
> can be implemented in a sane way.
> 
> Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxx>
> [tudor.ambarus@xxxxxxxxxxxxx: use nor->params.set_4byte() instead of
> nor->set_4byte()]
> Signed-off-by: Tudor Ambarus <tudor.ambarus@xxxxxxxxxxxxx>
> ---

Reviewed-by: Vignesh Raghavendra <vigneshr@xxxxxx>

Regards
Vignesh

> v3: no changes>
>  drivers/mtd/spi-nor/spi-nor.c | 76 ++++++++++++++++++++++---------------------
>  include/linux/mtd/spi-nor.h   |  2 ++
>  2 files changed, 41 insertions(+), 37 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
> index 1e7f8dc3457d..235e82a121a1 100644
> --- a/drivers/mtd/spi-nor/spi-nor.c
> +++ b/drivers/mtd/spi-nor/spi-nor.c
> @@ -633,6 +633,17 @@ static int macronix_set_4byte(struct spi_nor *nor, bool enable)
>  			      NULL, 0);
>  }
>  
> +static int st_micron_set_4byte(struct spi_nor *nor, bool enable)
> +{
> +	int ret;
> +
> +	write_enable(nor);
> +	ret = macronix_set_4byte(nor, enable);
> +	write_disable(nor);
> +
> +	return ret;
> +}
> +
>  static int spansion_set_4byte(struct spi_nor *nor, bool enable)
>  {
>  	nor->bouncebuf[0] = enable << 7;
> @@ -667,45 +678,24 @@ static int spi_nor_write_ear(struct spi_nor *nor, u8 ear)
>  	return nor->write_reg(nor, SPINOR_OP_WREAR, nor->bouncebuf, 1);
>  }
>  
> -/* Enable/disable 4-byte addressing mode. */
> -static int set_4byte(struct spi_nor *nor, bool enable)
> +static int winbond_set_4byte(struct spi_nor *nor, bool enable)
>  {
> -	int status;
> -	bool need_wren = false;
> -
> -	switch (JEDEC_MFR(nor->info)) {
> -	case SNOR_MFR_ST:
> -	case SNOR_MFR_MICRON:
> -		/* Some Micron need WREN command; all will accept it */
> -		need_wren = true;
> -		/* fall through */
> -	case SNOR_MFR_MACRONIX:
> -	case SNOR_MFR_WINBOND:
> -		if (need_wren)
> -			write_enable(nor);
> +	int ret;
>  
> -		status = macronix_set_4byte(nor, enable);
> -		if (need_wren)
> -			write_disable(nor);
> +	ret = macronix_set_4byte(nor, enable);
> +	if (ret || enable)
> +		return ret;
>  
> -		if (!status && !enable &&
> -		    JEDEC_MFR(nor->info) == SNOR_MFR_WINBOND) {
> -			/*
> -			 * On Winbond W25Q256FV, leaving 4byte mode causes
> -			 * the Extended Address Register to be set to 1, so all
> -			 * 3-byte-address reads come from the second 16M.
> -			 * We must clear the register to enable normal behavior.
> -			 */
> -			write_enable(nor);
> -			spi_nor_write_ear(nor, 0);
> -			write_disable(nor);
> -		}
> +	/*
> +	 * On Winbond W25Q256FV, leaving 4byte mode causes the Extended Address
> +	 * Register to be set to 1, so all 3-byte-address reads come from the
> +	 * second 16M. We must clear the register to enable normal behavior.
> +	 */
> +	write_enable(nor);
> +	ret = spi_nor_write_ear(nor, 0);
> +	write_disable(nor);
>  
> -		return status;
> -	default:
> -		/* Spansion style */
> -		return spansion_set_4byte(nor, enable);
> -	}
> +	return ret;
>  }
>  
>  static int spi_nor_xread_sr(struct spi_nor *nor, u8 *sr)
> @@ -4153,11 +4143,18 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor,
>  static void macronix_set_default_init(struct spi_nor *nor)
>  {
>  	nor->params.quad_enable = macronix_quad_enable;
> +	nor->params.set_4byte = macronix_set_4byte;
>  }
>  
>  static void st_micron_set_default_init(struct spi_nor *nor)
>  {
>  	nor->params.quad_enable = NULL;
> +	nor->params.set_4byte = st_micron_set_4byte;
> +}
> +
> +static void winbond_set_default_init(struct spi_nor *nor)
> +{
> +	nor->params.set_4byte = winbond_set_4byte;
>  }
>  
>  /**
> @@ -4178,6 +4175,10 @@ static void spi_nor_manufacturer_init_params(struct spi_nor *nor)
>  		st_micron_set_default_init(nor);
>  		break;
>  
> +	case SNOR_MFR_WINBOND:
> +		winbond_set_default_init(nor);
> +		break;
> +
>  	default:
>  		break;
>  	}
> @@ -4222,6 +4223,7 @@ static void spi_nor_info_init_params(struct spi_nor *nor)
>  
>  	/* Initialize legacy flash parameters and settings. */
>  	params->quad_enable = spansion_quad_enable;
> +	params->set_4byte = spansion_set_4byte;
>  
>  	/* Set SPI NOR sizes. */
>  	params->size = (u64)info->sector_size * info->n_sectors;
> @@ -4587,7 +4589,7 @@ static int spi_nor_init(struct spi_nor *nor)
>  		 */
>  		WARN_ONCE(nor->flags & SNOR_F_BROKEN_RESET,
>  			  "enabling reset hack; may not recover from unexpected reboots\n");
> -		set_4byte(nor, true);
> +		nor->params.set_4byte(nor, true);
>  	}
>  
>  	return 0;
> @@ -4611,7 +4613,7 @@ void spi_nor_restore(struct spi_nor *nor)
>  	/* restore the addressing mode */
>  	if (nor->addr_width == 4 && !(nor->flags & SNOR_F_4B_OPCODES) &&
>  	    nor->flags & SNOR_F_BROKEN_RESET)
> -		set_4byte(nor, false);
> +		nor->params.set_4byte(nor, false);
>  }
>  EXPORT_SYMBOL_GPL(spi_nor_restore);
>  
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index a86c0d9fb01d..7da89dd483cb 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -482,6 +482,7 @@ struct spi_nor;
>   * @erase_map:		the erase map parsed from the SFDP Sector Map Parameter
>   *                      Table.
>   * @quad_enable:	enables SPI NOR quad mode.
> + * @set_4byte:		puts the SPI NOR in 4 byte addressing mode.
>   */
>  struct spi_nor_flash_parameter {
>  	u64				size;
> @@ -494,6 +495,7 @@ struct spi_nor_flash_parameter {
>  	struct spi_nor_erase_map        erase_map;
>  
>  	int (*quad_enable)(struct spi_nor *nor);
> +	int (*set_4byte)(struct spi_nor *nor, bool enable);
>  };
>  
>  /**
> 

-- 
Regards
Vignesh

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