[U-Boot] [PATCH 1/4] sf: Add extended address register writing support

[Langer Thomas (LQDE RD ST PON SW)]

Hello Jagan,

> 
> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
> index 00aece9..232ccc0 100644
> --- a/drivers/mtd/spi/spi_flash.c
> +++ b/drivers/mtd/spi/spi_flash.c
> @@ -269,6 +269,47 @@ int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr)
>   	return 0;
>   }
>   
> +int spi_flash_cmd_extaddr_write(struct spi_flash *flash, u8 ear)
> +{
> +	u8 cmd;
> +	u8 idcode0;
> +	int ret;
> +
> +	ret = spi_flash_cmd(flash->spi, CMD_READ_ID, &idcode0, 1);
> +	if (ret) {
> +		debug("SF: fail to read read id\n");
> +		return ret;
> +	}
Instead of reading the id each time this function is executed, it should be decided during flash probing, if the
feature is available and calling this functions should be done only then.

> +
> +	if (idcode0 == 0x01)
> +		cmd = CMD_EXT_BRWR;
> +	else {
> +		printf("SF: unable to support extaddr reg write"
> +		" for %s flash\n", flash->name);
This error will be hit every time for non-Spansion flashes, after you add the calls in patch 3/4 unconditionally!

> +		return -1;
> +	}
> +
> +	ret = spi_flash_cmd_write_enable(flash);
> +	if (ret < 0) {
> +		debug("SF: enabling write failed\n");
> +		return ret;
> +	}
> +
> +	ret = spi_flash_cmd_write(flash->spi, &cmd, 1, &ear, 1);
> +	if (ret) {
> +		debug("SF: fail to write ext addr register\n");
> +		return ret;
> +	}
> +
> +	ret = spi_flash_cmd_wait_ready(flash, SPI_FLASH_PROG_TIMEOUT);
> +	if (ret < 0) {
> +		debug("SF: write config register timed out\n");
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
>   /*
>    * The following table holds all device probe functions
>    *
> diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
> index 141cfa8..dbceb81 100644
> --- a/drivers/mtd/spi/spi_flash_internal.h
> +++ b/drivers/mtd/spi/spi_flash_internal.h
> @@ -28,6 +28,9 @@
>   #define CMD_ERASE_64K			0xd8
>   #define CMD_ERASE_CHIP			0xc7
>   
> +/* Extended addr acess commands */
> +#define CMD_EXT_BRWR			0x17
Please comment, that this is the Spansion-only code.

> +
>   /* Common status */
>   #define STATUS_WIP			0x01
>   
> @@ -77,6 +80,9 @@ static inline int spi_flash_cmd_write_disable(struct spi_flash *flash)
>   /* Program the status register. */
>   int spi_flash_cmd_write_status(struct spi_flash *flash, u8 sr);
>   
> +/* Program the extended address register */
> +int spi_flash_cmd_extaddr_write(struct spi_flash *flash, u8 ear);
> +
>   /*
>    * Same as spi_flash_cmd_read() except it also claims/releases the SPI
>    * bus. Used as common part of the ->read() operation.
> 

Best Regards,
Thomas