[PATCH v5 05/10] mtd: spi-nor-core: Add the ->ready() hook

[tkuw584924 at gmail.com]

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 change in spi-nor.h depends on:
https://patchwork.ozlabs.org/project/uboot/patch/20210205041119.145784-4-seanga2@gmail.com/ 

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
---
Changes in v5:
  - Move spansion_sr_ready() to different patch
  - Move original code in spi_nor_ready() to newly created
    spi_nor_default_ready()

 drivers/mtd/spi/spi-nor-core.c | 10 +++++++++-
 include/linux/mtd/spi-nor.h    |  2 ++
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 87c9fce408..821617bc0d 100644
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -566,7 +566,7 @@ static int spi_nor_fsr_ready(struct spi_nor *nor)
 	return fsr & FSR_READY;
 }
 
-static int spi_nor_ready(struct spi_nor *nor)
+static int spi_nor_default_ready(struct spi_nor *nor)
 {
 	int sr, fsr;
 
@@ -579,6 +579,14 @@ static int spi_nor_ready(struct spi_nor *nor)
 	return sr && fsr;
 }
 
+static int spi_nor_ready(struct spi_nor *nor)
+{
+	if (nor->ready)
+		return nor->ready(nor);
+
+	return spi_nor_default_ready(nor);
+}
+
 /*
  * Service routine to read status register until ready, or timeout occurs.
  * Returns non-zero if error.
diff --git a/include/linux/mtd/spi-nor.h b/include/linux/mtd/spi-nor.h
index d79f8b37ef..2f2ad20e8e 100644
--- a/include/linux/mtd/spi-nor.h
+++ b/include/linux/mtd/spi-nor.h
@@ -435,6 +435,7 @@ struct flash_info;
  * @flash_is_locked:	[FLASH-SPECIFIC] check if a region of the SPI NOR is
  *			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 {
@@ -480,6 +481,7 @@ 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