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From:   Tudor Ambarus <tudor.ambarus@microchip.com>
To:     <p.yadav@ti.com>, <michael@walle.cc>,
        <Takahiro.Kuwano@infineon.com>
CC:     <miquel.raynal@bootlin.com>, <richard@nod.at>, <vigneshr@ti.com>,
        <linux-mtd@lists.infradead.org>, <linux-kernel@vger.kernel.org>,
        <nicolas.ferre@microchip.com>, <zhengxunli@mxic.com.tw>,
        <jaimeliao@mxic.com.tw>, <Bacem.Daassi@infineon.com>,
        Tudor Ambarus <tudor.ambarus@microchip.com>
Subject: [PATCH 2/3] mtd: spi-nor: micron-st: Rework spi_nor_micron_octal_dtr_enable()
Date:   Thu, 10 Feb 2022 04:33:33 +0200
Message-ID: <20220210023334.408926-3-tudor.ambarus@microchip.com>
In-Reply-To: <20220210023334.408926-1-tudor.ambarus@microchip.com>
References: <20220210023334.408926-1-tudor.ambarus@microchip.com>
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Introduce template operation to remove code duplication.
Split spi_nor_micron_octal_dtr_enable() in spi_nor_micron_octal_dtr_en()
and spi_nor_micron_octal_dtr_dis() as it no longer made sense to try to
keep everything alltogether: too many "if (enable)" throughout the code,
which made the code difficult to follow.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
---
 drivers/mtd/spi-nor/micron-st.c | 105 +++++++++++++++++---------------
 1 file changed, 55 insertions(+), 50 deletions(-)

diff --git a/drivers/mtd/spi-nor/micron-st.c b/drivers/mtd/spi-nor/micron-st.c
index 7f66b5943ceb..013aa6a52737 100644
--- a/drivers/mtd/spi-nor/micron-st.c
+++ b/drivers/mtd/spi-nor/micron-st.c
@@ -17,73 +17,72 @@
 #define SPINOR_MT_OCT_DTR	0xe7	/* Enable Octal DTR. */
 #define SPINOR_MT_EXSPI		0xff	/* Enable Extended SPI (default) */
 
-static int spi_nor_micron_octal_dtr_enable(struct spi_nor *nor, bool enable)
+/* Micron ST SPI NOR flash operations. */
+#define SPI_NOR_MICRON_WR_ANY_REG_OP(naddr, addr, ndata, buf)		\
+	SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 0),		\
+		   SPI_MEM_OP_ADDR(naddr, addr, 0),			\
+		   SPI_MEM_OP_NO_DUMMY,					\
+		   SPI_MEM_OP_DATA_OUT(ndata, buf, 0))
+
+static int spi_nor_micron_octal_dtr_en(struct spi_nor *nor)
 {
 	struct spi_mem_op op;
 	u8 *buf = nor->bouncebuf;
 	int ret;
 
-	if (enable) {
-		/* Use 20 dummy cycles for memory array reads. */
-		ret = spi_nor_write_enable(nor);
-		if (ret)
-			return ret;
-
-		*buf = 20;
-		op = (struct spi_mem_op)
-			SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 1),
-				   SPI_MEM_OP_ADDR(3, SPINOR_REG_MT_CFR1V, 1),
-				   SPI_MEM_OP_NO_DUMMY,
-				   SPI_MEM_OP_DATA_OUT(1, buf, 1));
-
-		ret = spi_mem_exec_op(nor->spimem, &op);
-		if (ret)
-			return ret;
+	/* Use 20 dummy cycles for memory array reads. */
+	*buf = 20;
+	op = (struct spi_mem_op)
+		SPI_NOR_MICRON_WR_ANY_REG_OP(3, SPINOR_REG_MT_CFR1V, 1, buf);
+	ret = spi_nor_write_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
+	ret = spi_nor_wait_till_ready(nor);
+	if (ret)
+		return ret;
 
-		ret = spi_nor_wait_till_ready(nor);
-		if (ret)
-			return ret;
-	}
+	buf[0] = SPINOR_MT_OCT_DTR;
+	op = (struct spi_mem_op)
+		SPI_NOR_MICRON_WR_ANY_REG_OP(3, SPINOR_REG_MT_CFR0V, 1, buf);
+	ret = spi_nor_write_reg(nor, &op, nor->reg_proto);
+	if (ret)
+		return ret;
 
-	ret = spi_nor_write_enable(nor);
+	/* Read flash ID to make sure the switch was successful. */
+	ret = spi_nor_read_id(nor, 0, 8, buf, SNOR_PROTO_8_8_8_DTR);
 	if (ret)
 		return ret;
 
-	if (enable) {
-		buf[0] = SPINOR_MT_OCT_DTR;
-	} else {
-		/*
-		 * The register is 1-byte wide, but 1-byte transactions are not
-		 * allowed in 8D-8D-8D mode. The next register is the dummy
-		 * cycle configuration register. Since the transaction needs to
-		 * be at least 2 bytes wide, set the next register to its
-		 * default value. This also makes sense because the value was
-		 * changed when enabling 8D-8D-8D mode, it should be reset when
-		 * disabling.
-		 */
-		buf[0] = SPINOR_MT_EXSPI;
-		buf[1] = SPINOR_REG_MT_CFR1V_DEF;
-	}
+	if (memcmp(buf, nor->info->id, nor->info->id_len))
+		return -EINVAL;
 
-	op = (struct spi_mem_op)
-		SPI_MEM_OP(SPI_MEM_OP_CMD(SPINOR_OP_MT_WR_ANY_REG, 1),
-			   SPI_MEM_OP_ADDR(enable ? 3 : 4,
-					   SPINOR_REG_MT_CFR0V, 1),
-			   SPI_MEM_OP_NO_DUMMY,
-			   SPI_MEM_OP_DATA_OUT(enable ? 1 : 2, buf, 1));
+	return 0;
+}
 
-	if (!enable)
-		spi_nor_spimem_setup_op(nor, &op, SNOR_PROTO_8_8_8_DTR);
+static int spi_nor_micron_octal_dtr_dis(struct spi_nor *nor)
+{
+	struct spi_mem_op op;
+	u8 *buf = nor->bouncebuf;
+	int ret;
 
-	ret = spi_mem_exec_op(nor->spimem, &op);
+	/*
+	 * The register is 1-byte wide, but 1-byte transactions are not allowed
+	 * in 8D-8D-8D mode. The next register is the dummy cycle configuration
+	 * register. Since the transaction needs to be at least 2 bytes wide,
+	 * set the next register to its default value. This also makes sense
+	 * because the value was changed when enabling 8D-8D-8D mode, it should
+	 * be reset when disabling.
+	 */
+	buf[0] = SPINOR_MT_EXSPI;
+	buf[1] = SPINOR_REG_MT_CFR1V_DEF;
+	op = (struct spi_mem_op)
+		SPI_NOR_MICRON_WR_ANY_REG_OP(4, SPINOR_REG_MT_CFR0V, 2, buf);
+	ret = spi_nor_write_reg(nor, &op, SNOR_PROTO_8_8_8_DTR);
 	if (ret)
 		return ret;
 
 	/* Read flash ID to make sure the switch was successful. */
-	if (enable)
-		ret = spi_nor_read_id(nor, 0, 8, buf, SNOR_PROTO_8_8_8_DTR);
-	else
-		ret = spi_nor_read_id(nor, 0, 0, buf, nor->reg_proto);
+	ret = spi_nor_read_id(nor, 0, 0, buf, nor->reg_proto);
 	if (ret)
 		return ret;
 
@@ -93,6 +92,12 @@ static int spi_nor_micron_octal_dtr_enable(struct spi_nor *nor, bool enable)
 	return 0;
 }
 
+static int spi_nor_micron_octal_dtr_enable(struct spi_nor *nor, bool enable)
+{
+	return enable ? spi_nor_micron_octal_dtr_en(nor) :
+			spi_nor_micron_octal_dtr_dis(nor);
+}
+
 static void mt35xu512aba_default_init(struct spi_nor *nor)
 {
 	nor->params->octal_dtr_enable = spi_nor_micron_octal_dtr_enable;
-- 
2.25.1