[PATCH v4 09/16] mtd: spi-nor: use dummy cycle and address width info from SFDP

[Pratyush Yadav <p.yadav@xxxxxx>]

The xSPI Profile 1.0 table specifies how many dummy cycles and address
bytes are needed for the Read Status Register command in octal DTR mode.
Use that information to send the correct Read SR command.

Signed-off-by: Pratyush Yadav <p.yadav@xxxxxx>
---
 drivers/mtd/spi-nor/core.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index 9c92fc897fb4..3d181c7deda7 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -357,6 +357,8 @@ int spi_nor_write_disable(struct spi_nor *nor)
 static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
 {
 	int ret;
+	u8 addr_bytes = nor->params->rdsr_addr_nbytes;
+	u8 dummy = nor->params->rdsr_dummy;
 
 	if (nor->spimem) {
 		struct spi_mem_op op =
@@ -365,10 +367,21 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
 				   SPI_MEM_OP_NO_DUMMY,
 				   SPI_MEM_OP_DATA_IN(1, sr, 1));
 
+		if (spi_nor_protocol_is_dtr(nor->reg_proto)) {
+			op.addr.nbytes = addr_bytes;
+			op.addr.val = 0;
+			op.dummy.nbytes = dummy;
+		}
+
+		spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
+
 		ret = spi_mem_exec_op(nor->spimem, &op);
 	} else {
-		ret = nor->controller_ops->read_reg(nor, SPINOR_OP_RDSR,
-						    sr, 1);
+		if (spi_nor_protocol_is_dtr(nor->reg_proto))
+			ret = -ENOTSUPP;
+		else
+			ret = nor->controller_ops->read_reg(nor, SPINOR_OP_RDSR,
+							    sr, 1);
 	}
 
 	if (ret)
@@ -388,6 +401,8 @@ static int spi_nor_read_sr(struct spi_nor *nor, u8 *sr)
 static int spi_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
 {
 	int ret;
+	u8 addr_bytes = nor->params->rdsr_addr_nbytes;
+	u8 dummy = nor->params->rdsr_dummy;
 
 	if (nor->spimem) {
 		struct spi_mem_op op =
@@ -396,6 +411,12 @@ static int spi_nor_read_fsr(struct spi_nor *nor, u8 *fsr)
 				   SPI_MEM_OP_NO_DUMMY,
 				   SPI_MEM_OP_DATA_IN(1, fsr, 1));
 
+		if (spi_nor_protocol_is_dtr(nor->reg_proto)) {
+			op.addr.nbytes = addr_bytes;
+			op.addr.val = 0;
+			op.dummy.nbytes = dummy;
+		}
+
 		spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
 
 		ret = spi_mem_exec_op(nor->spimem, &op);
-- 
2.25.0