[PATCH v3 12/13] mtd: spi-nor: extract read op template construction into helper

[Santhosh Kumar K]

From: Pratyush Yadav <pratyush@xxxxxxxxxx>

spi_nor_spimem_read_data() and spi_nor_create_read_dirmap() both
open-coded the same sequence: build the read spi_mem_op, call
spi_nor_spimem_setup_op(), convert dummy cycles to bytes, and—in the
dirmap case—explicitly patch data.buswidth because setup_op skips it
when data.nbytes is zero.

Introduce spi_nor_spimem_get_read_op() to centralise this logic.
Initialising the op with data.nbytes set to a non-zero value ensures
spi_nor_spimem_setup_op() populates data.buswidth, removing the need
for the manual override in the dirmap path. The dirmap template is
initialised directly from the helper; direct-read callers overwrite
addr.val, data.nbytes, and data.buf.in before submitting.

Signed-off-by: Pratyush Yadav <pratyush@xxxxxxxxxx>
Signed-off-by: Santhosh Kumar K <s-k6@xxxxxx>
---
 drivers/mtd/spi-nor/core.c | 66 +++++++++++++++++++++-----------------
 1 file changed, 36 insertions(+), 30 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index a7bc458edc5c..2c9859fb0794 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -188,6 +188,37 @@ static int spi_nor_controller_ops_erase(struct spi_nor *nor, loff_t offs)
 	return nor->controller_ops->erase(nor, offs);
 }
 
+/**
+ * spi_nor_spimem_get_read_op() - build a configured read op template
+ * @nor:	the spi-nor device
+ *
+ * Returns a spi_mem_op with the command, address format, dummy cycles,
+ * and data buswidth configured for @nor. For direct reads, the caller
+ * must fill in addr.val, data.nbytes, and data.buf.in before use.
+ */
+static struct spi_mem_op spi_nor_spimem_get_read_op(struct spi_nor *nor)
+{
+	/*
+	 * data.nbytes must be non-zero so spi_nor_spimem_setup_op()
+	 * configures the data buswidth; callers replace it with the
+	 * actual transfer length.
+	 */
+	struct spi_mem_op op =
+		SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 0),
+			   SPI_MEM_OP_ADDR(nor->addr_nbytes, 0, 0),
+			   SPI_MEM_OP_DUMMY(nor->read_dummy, 0),
+			   SPI_MEM_OP_DATA_IN(2, NULL, 0));
+
+	spi_nor_spimem_setup_op(nor, &op, nor->read_proto);
+
+	/* convert the dummy cycles to the number of bytes */
+	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
+	if (spi_nor_protocol_is_dtr(nor->read_proto))
+		op.dummy.nbytes *= 2;
+
+	return op;
+}
+
 /**
  * spi_nor_spimem_read_data() - read data from flash's memory region via
  *                              spi-mem
@@ -201,21 +232,14 @@ static int spi_nor_controller_ops_erase(struct spi_nor *nor, loff_t offs)
 static ssize_t spi_nor_spimem_read_data(struct spi_nor *nor, loff_t from,
 					size_t len, u8 *buf)
 {
-	struct spi_mem_op op =
-		SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 0),
-			   SPI_MEM_OP_ADDR(nor->addr_nbytes, from, 0),
-			   SPI_MEM_OP_DUMMY(nor->read_dummy, 0),
-			   SPI_MEM_OP_DATA_IN(len, buf, 0));
+	struct spi_mem_op op = spi_nor_spimem_get_read_op(nor);
 	bool usebouncebuf;
 	ssize_t nbytes;
 	int error;
 
-	spi_nor_spimem_setup_op(nor, &op, nor->read_proto);
-
-	/* convert the dummy cycles to the number of bytes */
-	op.dummy.nbytes = (nor->read_dummy * op.dummy.buswidth) / 8;
-	if (spi_nor_protocol_is_dtr(nor->read_proto))
-		op.dummy.nbytes *= 2;
+	op.addr.val = from;
+	op.data.nbytes = len;
+	op.data.buf.in = buf;
 
 	usebouncebuf = spi_nor_spimem_bounce(nor, &op);
 
@@ -3642,28 +3666,10 @@ static int spi_nor_create_read_dirmap(struct spi_nor *nor)
 {
 	struct spi_mem_dirmap_info info = {
 		.op_tmpl = &info.primary_op_tmpl,
-		.primary_op_tmpl = SPI_MEM_OP(SPI_MEM_OP_CMD(nor->read_opcode, 0),
-					      SPI_MEM_OP_ADDR(nor->addr_nbytes, 0, 0),
-					      SPI_MEM_OP_DUMMY(nor->read_dummy, 0),
-					      SPI_MEM_OP_DATA_IN(0, NULL, 0)),
+		.primary_op_tmpl = spi_nor_spimem_get_read_op(nor),
 		.offset = 0,
 		.length = nor->params->size,
 	};
-	struct spi_mem_op *op = info.op_tmpl;
-
-	spi_nor_spimem_setup_op(nor, op, nor->read_proto);
-
-	/* convert the dummy cycles to the number of bytes */
-	op->dummy.nbytes = (nor->read_dummy * op->dummy.buswidth) / 8;
-	if (spi_nor_protocol_is_dtr(nor->read_proto))
-		op->dummy.nbytes *= 2;
-
-	/*
-	 * Since spi_nor_spimem_setup_op() only sets buswidth when the number
-	 * of data bytes is non-zero, the data buswidth won't be set here. So,
-	 * do it explicitly.
-	 */
-	op->data.buswidth = spi_nor_get_protocol_data_nbits(nor->read_proto);
 
 	nor->dirmap.rdesc = devm_spi_mem_dirmap_create(nor->dev, nor->spimem,
 						       &info);
-- 
2.34.1