[PATCH v2 09/11] mtd: spi-nor: use dummy cycle and address width info from SFDP

[Pratyush Yadav]

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/spi-nor.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
index 22784c403d77..06cfc525260c 100644
--- a/drivers/mtd/spi-nor/spi-nor.c
+++ b/drivers/mtd/spi-nor/spi-nor.c
@@ -525,6 +525,8 @@ static 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 =
@@ -533,10 +535,21 @@ 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)
-- 
2.25.0