[PATCH v4 5/9] mtd: spi-nor-core: Add the ->ready() hook

[Pratyush Yadav]

Hi,

On 28/01/21 01:36PM, tkuw584924 at gmail.com wrote:
> From: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
> 
> For dual/quad die package devices from Spansion/Cypress, the device's
> status needs to be checked by reading status registers in all dies, by
> using Read Any Register command. To support this, a Flash specific hook
> that can overwrite the legacy status check is needed.
> 
> The spansion_sr_ready() reads status register 1 by Read Any Register
> commnad. This function is called from Flash specific hook with die address
> and dummy cycles.
> 
> Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
> ---
>  drivers/mtd/spi/spi-nor-core.c | 32 ++++++++++++++++++++++++++++++++
>  include/linux/mtd/spi-nor.h    |  4 +++-
>  2 files changed, 35 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
> index 624e730524..1c0ba5abf9 100644
> --- a/drivers/mtd/spi/spi-nor-core.c
> +++ b/drivers/mtd/spi/spi-nor-core.c
> @@ -522,6 +522,35 @@ static int set_4byte(struct spi_nor *nor, const struct flash_info *info,
>  	}
>  }
>  
> +#ifdef CONFIG_SPI_FLASH_SPANSION
> +/*
> + * Read status register 1 by using Read Any Register command to support multi
> + * die package parts.
> + */
> +static int spansion_sr_ready(struct spi_nor *nor, u32 addr_base, u8 dummy)
> +{
> +	u32 reg_addr = addr_base + SPINOR_REG_ADDR_STR1V;
> +	u8 sr;
> +	int ret;
> +
> +	ret = spansion_read_any_reg(nor, reg_addr, dummy, &sr);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (sr & (SR_E_ERR | SR_P_ERR)) {
> +		if (sr & SR_E_ERR)
> +			dev_dbg(nor->dev, "Erase Error occurred\n");
> +		else
> +			dev_dbg(nor->dev, "Programming Error occurred\n");
> +
> +		nor->write_reg(nor, SPINOR_OP_CLSR, NULL, 0);
> +		return -EIO;
> +	}
> +
> +	return !(sr & SR_WIP);
> +}
> +#endif
> +

Do not add this function in this patch. Just add the hook here. Add it 
in the patch that actually uses it.

>  static int spi_nor_sr_ready(struct spi_nor *nor)
>  {
>  	int sr = read_sr(nor);
> @@ -570,6 +599,9 @@ static int spi_nor_ready(struct spi_nor *nor)
>  {
>  	int sr, fsr;
>  
> +	if (nor->ready)
> +		return nor->ready(nor);
> +

Move the code below in a separate function and call it something like 
spi_nor_default_ready(). Then call that function from here.

>  	sr = spi_nor_sr_ready(nor);
>  	if (sr < 0)
>  		return sr;
> diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
> index e31073eb24..25234177de 100644
> --- a/include/linux/mtd/spi-nor.h
> +++ b/include/linux/mtd/spi-nor.h
> @@ -434,8 +434,9 @@ struct flash_info;
>   * @flash_lock:		[FLASH-SPECIFIC] lock a region of the SPI NOR
>   * @flash_unlock:	[FLASH-SPECIFIC] unlock a region of the SPI NOR
>   * @flash_is_locked:	[FLASH-SPECIFIC] check if a region of the SPI NOR is
> - * @quad_enable:	[FLASH-SPECIFIC] enables SPI NOR quad mode
>   *			completely locked
> + * @quad_enable:	[FLASH-SPECIFIC] enables SPI NOR quad mode
> + * @ready:		[FLASH-SPECIFIC] check if the flash is ready
>   * @priv:		the private data
>   */
>  struct spi_nor {
> @@ -481,6 +482,7 @@ struct spi_nor {
>  	int (*flash_unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
>  	int (*flash_is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
>  	int (*quad_enable)(struct spi_nor *nor);
> +	int (*ready)(struct spi_nor *nor);
>  
>  	void *priv;
>  /* Compatibility for spi_flash, remove once sf layer is merged with mtd */
> -- 
> 2.25.1
> 

-- 
Regards,
Pratyush Yadav
Texas Instruments Inc.