[PATCH v2 12/14] mtd: spinand: Add adjust_op() in Winbond manufacturer_ops

[Apurva Nandan <a-nandan@xxxxxx>]

Add implementation of adjust_op() manufacturer_ops for Winbond. This
handles the variations introduced in read register, read vcr, blk
erase, page read and program exec ops when operating in Octal DTR mode.
Read register operation requires 7 dummy cycles and read VCR operation
requires 8 dummy cycles in Octal DTR mode instead of default 0 dummy
cycle. Block erase, page read and program exec operations require
2 byte address in Octal DTR mode instead of default 3 bytes.

Datasheet: https://www.winbond.com/export/sites/winbond/datasheet/W35N01JW_Datasheet_Brief.pdf

Signed-off-by: Apurva Nandan <a-nandan@xxxxxx>
---
 drivers/mtd/nand/spi/winbond.c | 45 ++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/drivers/mtd/nand/spi/winbond.c b/drivers/mtd/nand/spi/winbond.c
index e2cb82d68f96..d962221d4082 100644
--- a/drivers/mtd/nand/spi/winbond.c
+++ b/drivers/mtd/nand/spi/winbond.c
@@ -16,6 +16,13 @@
 
 #define WINBOND_CFG_BUF_READ		BIT(3)
 
+#define WINBOND_BLK_ERASE_OPCODE	0xD8
+#define WINBOND_PAGE_READ_OPCODE	0x13
+#define WINBOND_PROG_EXEC_OPCODE	0x10
+#define WINBOND_READ_REG_OPCODE_1	0x05
+#define WINBOND_READ_REG_OPCODE_2	0x0F
+#define WINBOND_READ_VCR_OPCODE		0x85
+
 /* Octal DTR SPI mode (8D-8D-8D) with Data Strobe output*/
 #define WINBOND_IO_MODE_VCR_OCTAL_DTR	0xE7
 #define WINBOND_IO_MODE_VCR_ADDR	0x00
@@ -197,9 +204,47 @@ static int winbond_spinand_octal_dtr_enable(struct spinand_device *spinand)
 	return 0;
 }
 
+static void winbond_spinand_adjust_op(struct spi_mem_op *op,
+				      const enum spinand_proto reg_proto)
+{
+	/*
+	 * To support both 1 byte opcode and 2 byte opcodes, extract the MSB
+	 * byte from the opcode as the LSB byte in 2 byte opcode is treated as
+	 * don't care.
+	 */
+	u8 opcode = op->cmd.opcode >> (8 * (op->cmd.nbytes - 1));
+
+	if (reg_proto == SPINAND_OCTAL_DTR) {
+		switch (opcode) {
+		case WINBOND_READ_REG_OPCODE_1:
+		case WINBOND_READ_REG_OPCODE_2:
+			op->dummy.nbytes = 14;
+			op->dummy.buswidth = 8;
+			op->dummy.dtr = true;
+			return;
+
+		case WINBOND_READ_VCR_OPCODE:
+			op->dummy.nbytes = 16;
+			op->dummy.buswidth = 8;
+			op->dummy.dtr = true;
+			return;
+
+		case WINBOND_BLK_ERASE_OPCODE:
+		case WINBOND_PAGE_READ_OPCODE:
+		case WINBOND_PROG_EXEC_OPCODE:
+			op->addr.nbytes = 2;
+			return;
+
+		default:
+			return;
+		}
+	}
+}
+
 static const struct spinand_manufacturer_ops winbond_spinand_manuf_ops = {
 	.init = winbond_spinand_init,
 	.octal_dtr_enable = winbond_spinand_octal_dtr_enable,
+	.adjust_op = winbond_spinand_adjust_op,
 };
 
 const struct spinand_manufacturer winbond_spinand_manufacturer = {
-- 
2.25.1