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

Hi Pratyush,

Thank you for the feedback. I will address this in v5.

On 1/30/2021 3:49 AM, Pratyush Yadav wrote:

Hi,

On 28/01/21 01:36PM, tkuw584924@gmail.com wrote:

...

From: Takahiro Kuwano Takahiro.Kuwano@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@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

Best Regards, Takahiro