linux-kernel - [RFC PATCH v2 04/12] mtd: spi-nor: extract read operation setup into helper

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Message-ID: <20260113141617.1905039-5-s-k6@ti.com>
Date: Tue, 13 Jan 2026 19:46:09 +0530
From: Santhosh Kumar K <s-k6@...com>
To: <broonie@...nel.org>, <robh@...nel.org>, <krzk+dt@...nel.org>,
	<conor+dt@...nel.org>, <miquel.raynal@...tlin.com>, <richard@....at>,
	<vigneshr@...com>, <tudor.ambarus@...aro.org>, <pratyush@...nel.org>,
	<mwalle@...nel.org>
CC: <linux-spi@...r.kernel.org>, <devicetree@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>, <linux-mtd@...ts.infradead.org>,
	<praneeth@...com>, <u-kumar1@...com>, <p-mantena@...com>, <a-dutta@...com>,
	<s-k6@...com>
Subject: [RFC PATCH v2 04/12] mtd: spi-nor: extract read operation setup into helper

From: Pratyush Yadav <pratyush@...nel.org>

spi_nor_spimem_read_data() and spi_nor_create_read_dirmap() duplicate
the logic for constructing read operations: both create a spi_mem_op,
call spi_nor_spimem_setup_op(), and convert dummy cycles to bytes.

Extract this into spi_nor_spimem_get_read_op() to eliminate duplication.
The helper returns a configured template that callers populate with
address, data length, and buffer.

Signed-off-by: Pratyush Yadav <pratyush@...nel.org>
Signed-off-by: Santhosh Kumar K <s-k6@...com>
---
 drivers/mtd/spi-nor/core.c | 60 +++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 30 deletions(-)

diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
index d3f8a78efd3b..63f3051d7a6b 100644
--- a/drivers/mtd/spi-nor/core.c
+++ b/drivers/mtd/spi-nor/core.c
@@ -188,6 +188,31 @@ 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() - get spi_mem read operation template
+ * @nor:	the spi-nor device
+ *
+ * Returns a read operation template with buswidths and dummy cycles
+ * configured. Caller must set address, data length, and data buffer.
+ */
+static struct spi_mem_op spi_nor_spimem_get_read_op(struct spi_nor *nor)
+{
+	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(1, 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 +226,14 @@ 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);
 
@@ -3641,28 +3659,10 @@ EXPORT_SYMBOL_GPL(spi_nor_scan);
 static int spi_nor_create_read_dirmap(struct spi_nor *nor)
 {
 	struct spi_mem_dirmap_info info = {
-		.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)),
+		.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