openwrtv4/target/linux/layerscape/patches-4.4/1106-mtd-fsl-quadspi-add-DDR-quad-read-for-Spansion.patch

From 16eb35ceea5b43e6f64c1a869721ea86c0da5260 Mon Sep 17 00:00:00 2001
From: Yunhui Cui <yunhui.cui@nxp.com>
Date: Thu, 25 Feb 2016 10:19:15 +0800
Subject: [PATCH 106/113] mtd: fsl-quadspi: add DDR quad read for Spansion

Add the DDR quad read support for the fsl-quadspi driver.
And, add the Spansion s25fl128s NOR flash ddr quad mode
support.

Signed-off-by: Yunhui Cui <yunhui.cui@nxp.com>
---
 drivers/mtd/spi-nor/fsl-quadspi.c |   57 +++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

--- a/drivers/mtd/spi-nor/fsl-quadspi.c
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -296,6 +296,7 @@ struct fsl_qspi {
 	u32 nor_size;
 	u32 nor_num;
 	u32 clk_rate;
+	u32 ddr_smp;
 	unsigned int chip_base_addr; /* We may support two chips. */
 	bool has_second_chip;
 	bool big_endian;
@@ -423,6 +424,19 @@ static void fsl_qspi_init_lut(struct fsl
 		qspi_writel(q, LUT0(DUMMY, PAD1, read_dm) |
 			    LUT1(FSL_READ, PAD4, rxfifo),
 				base + QUADSPI_LUT(lut_base + 1));
+	} else if (nor->flash_read == SPI_NOR_DDR_QUAD) {
+		/* read mode : 1-4-4, such as Spansion s25fl128s. */
+		qspi_writel(q, LUT0(CMD, PAD1, read_op)
+			| LUT1(ADDR_DDR, PAD4, addrlen),
+			base + QUADSPI_LUT(lut_base));
+
+		qspi_writel(q, LUT0(MODE_DDR, PAD4, 0xff)
+			| LUT1(DUMMY, PAD1, read_dm),
+			base + QUADSPI_LUT(lut_base + 1));
+
+		qspi_writel(q, LUT0(FSL_READ_DDR, PAD4, rxfifo)
+			| LUT1(JMP_ON_CS, PAD1, 0),
+			base + QUADSPI_LUT(lut_base + 2));
 	}
 
 	/* Write enable */
@@ -534,6 +548,8 @@ static void fsl_qspi_init_lut(struct fsl
 static int fsl_qspi_get_seqid(struct fsl_qspi *q, u8 cmd)
 {
 	switch (cmd) {
+	case SPINOR_OP_READ_1_4_4_D:
+	case SPINOR_OP_READ4_1_4_4_D:
 	case SPINOR_OP_READ4_1_1_4:
 	case SPINOR_OP_READ_1_1_4:
 	case SPINOR_OP_READ_FAST:
@@ -736,6 +752,32 @@ static void fsl_qspi_set_map_addr(struct
 }
 
 /*
+ * enable controller ddr quad mode to support different
+ * vender flashes ddr quad mode.
+ */
+static void set_ddr_quad_mode(struct fsl_qspi *q)
+{
+	u32 reg, reg2;
+
+	reg = qspi_readl(q, q->iobase + QUADSPI_MCR);
+
+	/* Firstly, disable the module */
+	qspi_writel(q, reg | QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
+
+	/* Set the Sampling Register for DDR */
+	reg2 = qspi_readl(q, q->iobase + QUADSPI_SMPR);
+	reg2 &= ~QUADSPI_SMPR_DDRSMP_MASK;
+	reg2 |= (((q->ddr_smp) << QUADSPI_SMPR_DDRSMP_SHIFT) &
+			QUADSPI_SMPR_DDRSMP_MASK);
+	qspi_writel(q, reg2, q->iobase + QUADSPI_SMPR);
+
+	/* Enable the module again (enable the DDR too) */
+	reg |= QUADSPI_MCR_DDR_EN_MASK;
+	qspi_writel(q, reg, q->iobase + QUADSPI_MCR);
+
+}
+
+/*
  * There are two different ways to read out the data from the flash:
  *  the "IP Command Read" and the "AHB Command Read".
  *
@@ -775,6 +817,11 @@ static void fsl_qspi_init_abh_read(struc
 	seqid = fsl_qspi_get_seqid(q, q->nor[0].read_opcode);
 	qspi_writel(q, seqid << QUADSPI_BFGENCR_SEQID_SHIFT,
 		q->iobase + QUADSPI_BFGENCR);
+
+	/* enable the DDR quad read */
+	if (q->nor->flash_read == SPI_NOR_DDR_QUAD)
+		set_ddr_quad_mode(q);
+
 }
 
 /* This function was used to prepare and enable QSPI clock */
@@ -1108,6 +1155,12 @@ static int fsl_qspi_probe(struct platfor
 		goto clk_failed;
 	}
 
+	/* find ddrsmp value */
+	ret = of_property_read_u32(dev->of_node, "fsl,ddr-sampling-point",
+				&q->ddr_smp);
+	if (ret)
+		q->ddr_smp = 0;
+
 	/* find the irq */
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0) {
@@ -1164,6 +1217,10 @@ static int fsl_qspi_probe(struct platfor
 
 		ret = of_property_read_bool(np, "m25p,fast-read");
 		mode = (ret) ? SPI_NOR_FAST : SPI_NOR_QUAD;
+		/* Can we enable the DDR Quad Read? */
+		ret = of_property_read_bool(np, "ddr-quad-read");
+		if (ret)
+			mode = SPI_NOR_DDR_QUAD;
 
 		ret = spi_nor_scan(nor, NULL, mode);
 		if (ret)