[PATCH v5 5/6] mtd: spi-nor: spansion: Add status check for multi-die parts

[tkuw584924 at gmail.com]

From: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>

The multi-die package parts from Spansion/Cypress require to check
the status register value in each die to detemine the device is
ready. This patch adds a helper that queries status of each die by
Read Any Register command. The device specific ->ready() hook will
call this helper with the number of dummy cycles and die size.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano at infineon.com>
Reviewed-by: Pratyush Yadav <p.yadav at ti.com>
---
Changes in v5:
  - No change
  
Changes in v4:
  - Reword 'legacy' to 'default' in function header comments

Changes in v3:
  - New in v3

 drivers/mtd/spi-nor/spansion.c | 46 ++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/drivers/mtd/spi-nor/spansion.c b/drivers/mtd/spi-nor/spansion.c
index 0eac092f6c95..79d3249ed0aa 100644
--- a/drivers/mtd/spi-nor/spansion.c
+++ b/drivers/mtd/spi-nor/spansion.c
@@ -10,6 +10,7 @@
 
 #define SPINOR_OP_RD_ANY_REG			0x65	/* Read any register */
 #define SPINOR_OP_WR_ANY_REG			0x71	/* Write any register */
+#define SPINOR_REG_CYPRESS_STR1V		0x00800000
 #define SPINOR_REG_CYPRESS_CFR1V		0x00800002
 #define SPINOR_REG_CYPRESS_CFR1V_QUAD_EN	BIT(1)	/* Quad Enable */
 #define SPINOR_REG_CYPRESS_CFR2V		0x00800003
@@ -183,6 +184,51 @@ static int spansion_quad_enable_volatile(struct spi_nor *nor, u8 reg_dummy,
 	return 0;
 }
 
+/**
+ * spansion_mdp_ready() - Query the Status Register via Read Any Register
+ *                        command for multi-die package parts that do not
+ *                        support default RDSR(05h)
+ * @nor:	pointer to 'struct spi_nor'.
+ * @reg_dummy:	number of dummy cycles for register read
+ * @die_size:	size of each die to determine the number of dies
+ *
+ * Return: 1 if ready, 0 if not ready, -errno on errors.
+ */
+static int spansion_mdp_ready(struct spi_nor *nor, u8 reg_dummy, u32 die_size)
+{
+	int ret;
+	u32 base;
+	u8 sr;
+
+	for (base = 0; base < nor->params->size; base += die_size) {
+		ret = spansion_read_any_reg(nor,
+					    base + SPINOR_REG_CYPRESS_STR1V,
+					    reg_dummy, &sr);
+		if (ret)
+			return ret;
+
+		if (sr & (SR_E_ERR | SR_P_ERR)) {
+			if (sr & SR_E_ERR)
+				dev_err(nor->dev, "Erase Error occurred\n");
+			else
+				dev_err(nor->dev, "Programming Error occurred\n");
+
+			spi_nor_clear_sr(nor);
+
+			ret = spi_nor_write_disable(nor);
+			if (ret)
+				return ret;
+
+			return -EIO;
+		}
+
+		if (sr & SR_WIP)
+			return 0;
+	}
+
+	return 1;
+}
+
 /**
  * spi_nor_cypress_octal_dtr_enable() - Enable octal DTR on Cypress flashes.
  * @nor:		pointer to a 'struct spi_nor'
-- 
2.25.1