[PATCH v4 5/9] 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 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
+
 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);
+
 	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