[PATCH v5 8/8] mtd: spi-nor: Add Freescale QuadSPI driver

[Huang Shijie <b32955@xxxxxxxxxxxxx>]

(0) What is the QuadSPI controller?

    The QuadSPI(Quad Serial Peripheral Interface) acts as an interface to
    one single or two external serial flash devices, each with up to 4
    bidirectional data lines.

(1) The QuadSPI controller is driven by the LUT(Look-up Table) registers.
    The LUT registers are a look-up-table for sequences of instructions.
    A valid sequence consists of four LUT registers.

(2) The definition of the LUT register shows below:

    ---------------------------------------------------
    | INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 |
    ---------------------------------------------------

    There are several types of INSTRx, such as:
	CMD	: the SPI NOR command.
	ADDR	: the address for the SPI NOR command.
	DUMMY	: the dummy cycles needed by the SPI NOR command.
	....

    There are several types of PADx, such as:
	PAD1	: use a singe I/O line.
	PAD2	: use two I/O lines.
	PAD4	: use quad I/O lines.
	....

(3) Test this driver with the JFFS2 and UBIFS:

    For jffs2:
    -------------
	#flash_eraseall /dev/mtd0
	#mount -t jffs2 /dev/mtdblock0 tmp
	#bonnie++ -d tmp -u 0 -s 10 -r 5

    For ubifs:
    -------------
	#flash_eraseall /dev/mtd0
	#ubiattach /dev/ubi_ctrl -m 0
	#ubimkvol /dev/ubi0 -N test -m
	#mount -t ubifs ubi0:test tmp
	#bonnie++ -d tmp -u 0 -s 10 -r 5

Signed-off-by: Huang Shijie <b32955@xxxxxxxxxxxxx>
---
 drivers/mtd/spi-nor/Kconfig       |    6 +
 drivers/mtd/spi-nor/Makefile      |    1 +
 drivers/mtd/spi-nor/fsl-quadspi.c | 1009 +++++++++++++++++++++++++++++++++++++
 3 files changed, 1016 insertions(+), 0 deletions(-)
 create mode 100644 drivers/mtd/spi-nor/fsl-quadspi.c

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 41591af..64cfc39 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -4,3 +4,9 @@ config MTD_SPI_NOR_BASE
 	help
 	  This is the framework for the SPI NOR which can be used by the SPI
 	  device drivers and the SPI-NOR device driver.
+config SPI_FSL_QUADSPI
+	tristate "Freescale Quad SPI controller"
+	depends on ARCH_MXC && MTD_SPI_NOR_BASE
+	help
+	  This enables support for the Quad SPI controller in master mode.
+	  We only connect the NOR to this controller now.
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index 7dfe1f9..51f9d8b 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_MTD_SPI_NOR_BASE)	+= spi-nor.o
+obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
new file mode 100644
index 0000000..6dc08ed
--- /dev/null
+++ b/drivers/mtd/spi-nor/fsl-quadspi.c
@@ -0,0 +1,1009 @@
+/*
+ * Freescale QuadSPI driver.
+ *
+ * Copyright (C) 2013 Freescale Semiconductor, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/timer.h>
+#include <linux/jiffies.h>
+#include <linux/completion.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+
+/* The registers */
+#define QUADSPI_MCR			0x00
+#define QUADSPI_MCR_RESERVED_SHIFT	16
+#define QUADSPI_MCR_RESERVED_MASK	(0xF << QUADSPI_MCR_RESERVED_SHIFT)
+#define QUADSPI_MCR_MDIS_SHIFT		14
+#define QUADSPI_MCR_MDIS_MASK		(1 << QUADSPI_MCR_MDIS_SHIFT)
+#define QUADSPI_MCR_CLR_TXF_SHIFT	11
+#define QUADSPI_MCR_CLR_TXF_MASK	(1 << QUADSPI_MCR_CLR_TXF_SHIFT)
+#define QUADSPI_MCR_CLR_RXF_SHIFT	10
+#define QUADSPI_MCR_CLR_RXF_MASK	(1 << QUADSPI_MCR_CLR_RXF_SHIFT)
+#define QUADSPI_MCR_DDR_EN_SHIFT	7
+#define QUADSPI_MCR_DDR_EN_MASK		(1 << QUADSPI_MCR_DDR_EN_SHIFT)
+#define QUADSPI_MCR_END_CFG_SHIFT	2
+#define QUADSPI_MCR_END_CFG_MASK	(3 << QUADSPI_MCR_END_CFG_SHIFT)
+#define QUADSPI_MCR_SWRSTHD_SHIFT	1
+#define QUADSPI_MCR_SWRSTHD_MASK	(1 << QUADSPI_MCR_SWRSTHD_SHIFT)
+#define QUADSPI_MCR_SWRSTSD_SHIFT	0
+#define QUADSPI_MCR_SWRSTSD_MASK	(1 << QUADSPI_MCR_SWRSTSD_SHIFT)
+
+#define QUADSPI_IPCR			0x08
+#define QUADSPI_IPCR_SEQID_SHIFT	24
+#define QUADSPI_IPCR_SEQID_MASK		(0xF << QUADSPI_IPCR_SEQID_SHIFT)
+
+#define QUADSPI_BUF0CR			0x10
+#define QUADSPI_BUF1CR			0x14
+#define QUADSPI_BUF2CR			0x18
+#define QUADSPI_BUFXCR_INVALID_MSTRID	0xe
+
+#define QUADSPI_BUF3CR			0x1c
+#define QUADSPI_BUF3CR_ALLMST_SHIFT	31
+#define QUADSPI_BUF3CR_ALLMST		(1 << QUADSPI_BUF3CR_ALLMST_SHIFT)
+
+#define QUADSPI_BFGENCR			0x20
+#define QUADSPI_BFGENCR_PAR_EN_SHIFT	16
+#define QUADSPI_BFGENCR_PAR_EN_MASK	(1 << (QUADSPI_BFGENCR_PAR_EN_SHIFT))
+#define QUADSPI_BFGENCR_SEQID_SHIFT	12
+#define QUADSPI_BFGENCR_SEQID_MASK	(0xF << QUADSPI_BFGENCR_SEQID_SHIFT)
+
+#define QUADSPI_BUF0IND			0x30
+#define QUADSPI_BUF1IND			0x34
+#define QUADSPI_BUF2IND			0x38
+#define QUADSPI_SFAR			0x100
+
+#define QUADSPI_SMPR			0x108
+#define QUADSPI_SMPR_DDRSMP_SHIFT	16
+#define QUADSPI_SMPR_DDRSMP_MASK	(7 << QUADSPI_SMPR_DDRSMP_SHIFT)
+#define QUADSPI_SMPR_FSDLY_SHIFT	6
+#define QUADSPI_SMPR_FSDLY_MASK		(1 << QUADSPI_SMPR_FSDLY_SHIFT)
+#define QUADSPI_SMPR_FSPHS_SHIFT	5
+#define QUADSPI_SMPR_FSPHS_MASK		(1 << QUADSPI_SMPR_FSPHS_SHIFT)
+#define QUADSPI_SMPR_HSENA_SHIFT	0
+#define QUADSPI_SMPR_HSENA_MASK		(1 << QUADSPI_SMPR_HSENA_SHIFT)
+
+#define QUADSPI_RBSR			0x10c
+#define QUADSPI_RBSR_RDBFL_SHIFT	8
+#define QUADSPI_RBSR_RDBFL_MASK		(0x3F << QUADSPI_RBSR_RDBFL_SHIFT)
+
+#define QUADSPI_RBCT			0x110
+#define QUADSPI_RBCT_WMRK_MASK		0x1F
+#define QUADSPI_RBCT_RXBRD_SHIFT	8
+#define QUADSPI_RBCT_RXBRD_USEIPS	(0x1 << QUADSPI_RBCT_RXBRD_SHIFT)
+
+#define QUADSPI_TBSR			0x150
+#define QUADSPI_TBDR			0x154
+#define QUADSPI_SR			0x15c
+#define QUADSPI_SR_IP_ACC_SHIFT		1
+#define QUADSPI_SR_IP_ACC_MASK		(0x1 << QUADSPI_SR_IP_ACC_SHIFT)
+#define QUADSPI_SR_AHB_ACC_SHIFT	2
+#define QUADSPI_SR_AHB_ACC_MASK		(0x1 << QUADSPI_SR_AHB_ACC_SHIFT)
+
+#define QUADSPI_FR			0x160
+#define QUADSPI_FR_TFF_MASK		0x1
+
+#define QUADSPI_SFA1AD			0x180
+#define QUADSPI_SFA2AD			0x184
+#define QUADSPI_SFB1AD			0x188
+#define QUADSPI_SFB2AD			0x18c
+#define QUADSPI_RBDR			0x200
+
+#define QUADSPI_LUTKEY			0x300
+#define QUADSPI_LUTKEY_VALUE		0x5AF05AF0
+
+#define QUADSPI_LCKCR			0x304
+#define QUADSPI_LCKER_LOCK		0x1
+#define QUADSPI_LCKER_UNLOCK		0x2
+
+#define QUADSPI_RSER			0x164
+#define QUADSPI_RSER_TFIE		(0x1 << 0)
+
+#define QUADSPI_LUT_BASE		0x310
+
+/*
+ * The definition of the LUT register shows below:
+ *
+ *  ---------------------------------------------------
+ *  | INSTR1 | PAD1 | OPRND1 | INSTR0 | PAD0 | OPRND0 |
+ *  ---------------------------------------------------
+ */
+#define OPRND0_SHIFT		0
+#define PAD0_SHIFT		8
+#define INSTR0_SHIFT		10
+#define OPRND1_SHIFT		16
+
+/* Instruction set for the LUT register. */
+#define LUT_STOP		0
+#define LUT_CMD			1
+#define LUT_ADDR		2
+#define LUT_DUMMY		3
+#define LUT_MODE		4
+#define LUT_MODE2		5
+#define LUT_MODE4		6
+#define LUT_READ		7
+#define LUT_WRITE		8
+#define LUT_JMP_ON_CS		9
+#define LUT_ADDR_DDR		10
+#define LUT_MODE_DDR		11
+#define LUT_MODE2_DDR		12
+#define LUT_MODE4_DDR		13
+#define LUT_READ_DDR		14
+#define LUT_WRITE_DDR		15
+#define LUT_DATA_LEARN		16
+
+/*
+ * The PAD definitions for LUT register.
+ *
+ * The pad stands for the lines number of IO[0:3].
+ * For example, the Quad read need four IO lines, so you should
+ * set LUT_PAD4 which means we use four IO lines.
+ */
+#define LUT_PAD1		0
+#define LUT_PAD2		1
+#define LUT_PAD4		2
+
+/* Oprands for the LUT register. */
+#define ADDR24BIT		0x18
+#define ADDR32BIT		0x20
+
+/* Macros for constructing the LUT register. */
+#define LUT0(ins, pad, opr)						\
+		(((opr) << OPRND0_SHIFT) | ((LUT_##pad) << PAD0_SHIFT) | \
+		((LUT_##ins) << INSTR0_SHIFT))
+
+#define LUT1(ins, pad, opr)	(LUT0(ins, pad, opr) << OPRND1_SHIFT)
+
+/* other macros for LUT register. */
+#define QUADSPI_LUT(x)          (QUADSPI_LUT_BASE + (x) * 4)
+#define QUADSPI_LUT_NUM		64
+
+/* SEQID -- we can have 16 seqids at most. */
+#define SEQID_QUAD_READ		0
+#define SEQID_WREN		1
+#define SEQID_WRDI		2
+#define SEQID_RDSR		3
+#define SEQID_SE		4
+#define SEQID_CHIP_ERASE	5
+#define SEQID_PP		6
+#define SEQID_RDID		7
+#define SEQID_WRSR		8
+#define SEQID_RDCR		9
+#define SEQID_EN4B		10
+#define SEQID_BRWR		11
+
+enum fsl_qspi_devtype {
+	FSL_QUADSPI_VYBRID,
+	FSL_QUADSPI_IMX6SX,
+};
+
+struct fsl_qspi_devtype_data {
+	enum fsl_qspi_devtype devtype;
+	int rxfifo;
+	int txfifo;
+};
+
+static struct fsl_qspi_devtype_data vybrid_data = {
+	.devtype = FSL_QUADSPI_VYBRID,
+	.rxfifo = 128,
+	.txfifo = 64
+};
+
+static struct fsl_qspi_devtype_data imx6sx_data = {
+	.devtype = FSL_QUADSPI_IMX6SX,
+	.rxfifo = 128,
+	.txfifo = 512
+};
+
+#define FSL_QSPI_MAX_CHIP	4
+struct fsl_qspi {
+	struct mtd_info mtd[FSL_QSPI_MAX_CHIP];
+	struct spi_nor nor[FSL_QSPI_MAX_CHIP];
+	void __iomem *iobase;
+	void __iomem *ahb_base; /* Used when read from AHB bus */
+	u32 memmap_phy;
+	struct clk *clk, *clk_en;
+	struct device *dev;
+	struct completion c;
+	struct fsl_qspi_devtype_data *devtype_data;
+	u32 nor_size;
+	u32 nor_num;
+	u32 clk_rate;
+	unsigned int chip_base_addr; /* We may support two chips. */
+};
+
+static inline int is_vybrid_qspi(struct fsl_qspi *q)
+{
+	return q->devtype_data->devtype == FSL_QUADSPI_VYBRID;
+}
+
+static inline int is_imx6sx_qspi(struct fsl_qspi *q)
+{
+	return q->devtype_data->devtype == FSL_QUADSPI_IMX6SX;
+}
+
+/*
+ * An IC bug makes us to re-arrange the 32-bit data.
+ * The following chips, such as IMX6SLX, have fixed this bug.
+ */
+static inline u32 fsl_qspi_endian_xchg(struct fsl_qspi *q, u32 a)
+{
+	return is_vybrid_qspi(q) ? __swab32(a) : a;
+}
+
+static inline void fsl_qspi_unlock_lut(struct fsl_qspi *q)
+{
+	writel(QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
+	writel(QUADSPI_LCKER_UNLOCK, q->iobase + QUADSPI_LCKCR);
+}
+
+static inline void fsl_qspi_lock_lut(struct fsl_qspi *q)
+{
+	writel(QUADSPI_LUTKEY_VALUE, q->iobase + QUADSPI_LUTKEY);
+	writel(QUADSPI_LCKER_LOCK, q->iobase + QUADSPI_LCKCR);
+}
+
+static irqreturn_t fsl_qspi_irq_handler(int irq, void *dev_id)
+{
+	struct fsl_qspi *q = dev_id;
+	u32 reg;
+
+	/* clear interrupt */
+	reg = readl(q->iobase + QUADSPI_FR);
+	writel(reg, q->iobase + QUADSPI_FR);
+
+	if (reg & QUADSPI_FR_TFF_MASK)
+		complete(&q->c);
+
+	dev_dbg(q->dev, "QUADSPI_FR : 0x%.8x:0x%.8x\n", q->chip_base_addr, reg);
+	return IRQ_HANDLED;
+}
+
+static void fsl_qspi_init_lut(struct fsl_qspi *q)
+{
+	void *__iomem base = q->iobase;
+	int rxfifo = q->devtype_data->rxfifo;
+	u32 lut_base;
+	u8 cmd, addrlen, dummy;
+	int i;
+
+	fsl_qspi_unlock_lut(q);
+
+	/* Clear all the LUT table */
+	for (i = 0; i < QUADSPI_LUT_NUM; i++)
+		writel(0, base + QUADSPI_LUT_BASE + i * 4);
+
+	/* Quad Read */
+	lut_base = SEQID_QUAD_READ * 4;
+
+	if (q->nor_size <= SZ_16M) {
+		cmd = OPCODE_QUAD_READ;
+		addrlen = ADDR24BIT;
+		dummy = 8;
+	} else {
+		/* use the 4-byte address */
+		cmd = OPCODE_QUAD_READ;
+		addrlen = ADDR32BIT;
+		dummy = 8;
+	}
+
+	writel(LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
+			base + QUADSPI_LUT(lut_base));
+	writel(LUT0(DUMMY, PAD1, dummy) | LUT1(READ, PAD4, rxfifo),
+			base + QUADSPI_LUT(lut_base + 1));
+
+	/* Write enable */
+	lut_base = SEQID_WREN * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_WREN), base + QUADSPI_LUT(lut_base));
+
+	/* Page Program */
+	lut_base = SEQID_PP * 4;
+
+	if (q->nor_size <= SZ_16M) {
+		cmd = OPCODE_PP;
+		addrlen = ADDR24BIT;
+	} else {
+		/* use the 4-byte address */
+		cmd = OPCODE_PP;
+		addrlen = ADDR32BIT;
+	}
+
+	writel(LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
+			base + QUADSPI_LUT(lut_base));
+	writel(LUT0(WRITE, PAD1, 0), base + QUADSPI_LUT(lut_base + 1));
+
+	/* Read Status */
+	lut_base = SEQID_RDSR * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_RDSR) | LUT1(READ, PAD1, 0x1),
+			base + QUADSPI_LUT(lut_base));
+
+	/* Erase a sector */
+	lut_base = SEQID_SE * 4;
+
+	if (q->nor_size <= SZ_16M) {
+		cmd = OPCODE_SE;
+		addrlen = ADDR24BIT;
+	} else {
+		/* use the 4-byte address */
+		cmd = OPCODE_SE;
+		addrlen = ADDR32BIT;
+	}
+
+	writel(LUT0(CMD, PAD1, cmd) | LUT1(ADDR, PAD1, addrlen),
+			base + QUADSPI_LUT(lut_base));
+
+	/* Erase the whole chip */
+	lut_base = SEQID_CHIP_ERASE * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_CHIP_ERASE),
+			base + QUADSPI_LUT(lut_base));
+
+	/* READ ID */
+	lut_base = SEQID_RDID * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_RDID) | LUT1(READ, PAD1, 0x8),
+			base + QUADSPI_LUT(lut_base));
+
+	/* Write Register */
+	lut_base = SEQID_WRSR * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_WRSR) | LUT1(WRITE, PAD1, 0x2),
+			base + QUADSPI_LUT(lut_base));
+
+	/* Read Configuration Register */
+	lut_base = SEQID_RDCR * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_RDCR) | LUT1(READ, PAD1, 0x1),
+			base + QUADSPI_LUT(lut_base));
+
+	/* Write disable */
+	lut_base = SEQID_WRDI * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_WRDI), base + QUADSPI_LUT(lut_base));
+
+	/* Enter 4 Byte Mode (Micron) */
+	lut_base = SEQID_EN4B * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_EN4B), base + QUADSPI_LUT(lut_base));
+
+	/* Enter 4 Byte Mode (Spansion) */
+	lut_base = SEQID_BRWR * 4;
+	writel(LUT0(CMD, PAD1, OPCODE_BRWR), base + QUADSPI_LUT(lut_base));
+
+	fsl_qspi_lock_lut(q);
+}
+
+/* Get the SEQID for the command */
+static int fsl_qspi_get_seqid(struct fsl_qspi *q, u8 cmd)
+{
+	switch (cmd) {
+	case OPCODE_QUAD_READ:
+		return SEQID_QUAD_READ;
+	case OPCODE_WREN:
+		return SEQID_WREN;
+	case OPCODE_WRDI:
+		return SEQID_WRDI;
+	case OPCODE_RDSR:
+		return SEQID_RDSR;
+	case OPCODE_SE:
+		return SEQID_SE;
+	case OPCODE_CHIP_ERASE:
+		return SEQID_CHIP_ERASE;
+	case OPCODE_PP:
+		return SEQID_PP;
+	case OPCODE_RDID:
+		return SEQID_RDID;
+	case OPCODE_WRSR:
+		return SEQID_WRSR;
+	case OPCODE_RDCR:
+		return SEQID_RDCR;
+	case OPCODE_EN4B:
+		return SEQID_EN4B;
+	case OPCODE_BRWR:
+		return SEQID_BRWR;
+	default:
+		dev_err(q->dev, "Unsupported cmd 0x%.2x\n", cmd);
+		break;
+	}
+	return -EINVAL;
+}
+
+static int
+fsl_qspi_runcmd(struct fsl_qspi *q, u8 cmd, unsigned int addr, int len)
+{
+	void *__iomem base = q->iobase;
+	int seqid;
+	u32 reg, reg2;
+	int err;
+
+	init_completion(&q->c);
+	dev_dbg(q->dev, "to 0x%.8x:0x%.8x, len:%d, cmd:%.2x\n",
+			q->chip_base_addr, addr, len, cmd);
+
+	/* save the reg */
+	reg = readl(base + QUADSPI_MCR);
+
+	writel(q->memmap_phy + q->chip_base_addr + addr, base + QUADSPI_SFAR);
+	writel(QUADSPI_RBCT_WMRK_MASK | QUADSPI_RBCT_RXBRD_USEIPS,
+			base + QUADSPI_RBCT);
+	writel(reg | QUADSPI_MCR_CLR_RXF_MASK, base + QUADSPI_MCR);
+
+	do {
+		reg2 = readl(base + QUADSPI_SR);
+		if (reg2 & (QUADSPI_SR_IP_ACC_MASK | QUADSPI_SR_AHB_ACC_MASK)) {
+			udelay(1);
+			dev_dbg(q->dev, "The controller is busy, 0x%x\n", reg2);
+			continue;
+		}
+		break;
+	} while (1);
+
+	/* trigger the LUT now */
+	seqid = fsl_qspi_get_seqid(q, cmd);
+	writel((seqid << QUADSPI_IPCR_SEQID_SHIFT) | len, base + QUADSPI_IPCR);
+
+	/* Wait for the interrupt. */
+	err = wait_for_completion_timeout(&q->c, msecs_to_jiffies(1000));
+	if (!err) {
+		dev_err(q->dev,
+			"cmd 0x%.2x timeout, addr@%.8x, FR:0x%.8x, SR:0x%.8x\n",
+			cmd, addr, readl(base + QUADSPI_FR),
+			readl(base + QUADSPI_SR));
+		err = -ETIMEDOUT;
+	} else {
+		err = 0;
+	}
+
+	/* restore the MCR */
+	writel(reg, base + QUADSPI_MCR);
+
+	return err;
+}
+
+/* Read out the data from the QUADSPI_RBDR buffer registers. */
+static void fsl_qspi_read_data(struct fsl_qspi *q, int len, u8 *rxbuf)
+{
+	u32 tmp;
+	int i = 0;
+
+	while (len > 0) {
+		tmp = readl(q->iobase + QUADSPI_RBDR + i * 4);
+		tmp = fsl_qspi_endian_xchg(q, tmp);
+		dev_dbg(q->dev, "chip addr:0x%.8x, rcv:0x%.8x\n",
+				q->chip_base_addr, tmp);
+
+		if (len >= 4) {
+			*((u32 *)rxbuf) = tmp;
+			rxbuf += 4;
+		} else {
+			memcpy(rxbuf, &tmp, len);
+			break;
+		}
+
+		len -= 4;
+		i++;
+	}
+}
+
+/*
+ * If we have changed the content of the flash by writing or erasing,
+ * we need to invalidate the AHB buffer. If we do not do so, we may read out
+ * the wrong data. The spec tells us reset the AHB domain and Serial Flash
+ * domain at the same time.
+ */
+static inline void fsl_qspi_invalid(struct fsl_qspi *q)
+{
+	u32 reg;
+
+	reg = readl(q->iobase + QUADSPI_MCR);
+	reg |= QUADSPI_MCR_SWRSTHD_MASK | QUADSPI_MCR_SWRSTSD_MASK;
+	writel(reg, q->iobase + QUADSPI_MCR);
+
+	/*
+	 * The minimum delay : 1 AHB + 2 SFCK clocks.
+	 * Delay 1 us is enough.
+	 */
+	udelay(1);
+
+	reg &= ~(QUADSPI_MCR_SWRSTHD_MASK | QUADSPI_MCR_SWRSTSD_MASK);
+	writel(reg, q->iobase + QUADSPI_MCR);
+}
+
+static int fsl_qspi_nor_write(struct fsl_qspi *q, struct spi_nor *nor,
+				u8 opcode, unsigned int to, u32 *txbuf,
+				unsigned count, size_t *retlen)
+{
+	int ret, i, j;
+	u32 tmp;
+
+	dev_dbg(q->dev, "to 0x%.8x:0x%.8x, len : %d\n",
+		q->chip_base_addr, to, count);
+
+	/* clear the TX FIFO. */
+	tmp = readl(q->iobase + QUADSPI_MCR);
+	writel(tmp | QUADSPI_MCR_CLR_RXF_MASK, q->iobase + QUADSPI_MCR);
+
+	/* fill the TX data to the FIFO */
+	for (j = 0, i = ((count + 3) / 4); j < i; j++) {
+		tmp = fsl_qspi_endian_xchg(q, *txbuf);
+		writel(tmp, q->iobase + QUADSPI_TBDR);
+		txbuf++;
+	}
+
+	/* Trigger it */
+	ret = fsl_qspi_runcmd(q, opcode, to, count);
+
+	if (ret == 0 && retlen)
+		*retlen += count;
+
+	return ret;
+}
+
+static void fsl_qspi_set_map_addr(struct fsl_qspi *q)
+{
+	int nor_size = q->nor_size;
+	void __iomem *base = q->iobase;
+
+	writel(nor_size + q->memmap_phy, base + QUADSPI_SFA1AD);
+	writel(nor_size * 2 + q->memmap_phy, base + QUADSPI_SFA2AD);
+	writel(nor_size * 3 + q->memmap_phy, base + QUADSPI_SFB1AD);
+	writel(nor_size * 4 + q->memmap_phy, base + QUADSPI_SFB2AD);
+}
+
+/*
+ * There are two different ways to read out the data from the flash:
+ *  the "IP Command Read" and the "AHB Command Read".
+ *
+ * The IC guy suggests we use the "AHB Command Read" which is faster
+ * then the "IP Command Read". (What's more is that there is a bug in
+ * the "IP Command Read" in the Vybrid.)
+ *
+ * After we set up the registers for the "AHB Command Read", we can use
+ * the memcpy to read the data directly. A "missed" access to the buffer
+ * causes the controller to clear the buffer, and use the sequence pointed
+ * by the QUADSPI_BFGENCR[SEQID] to initiate a read from the flash.
+ */
+static void fsl_qspi_init_abh_read(struct fsl_qspi *q)
+{
+	void __iomem *base = q->iobase;
+	int seqid;
+
+	/* AHB configuration for access buffer 0/1/2 .*/
+	writel(QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF0CR);
+	writel(QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF1CR);
+	writel(QUADSPI_BUFXCR_INVALID_MSTRID, base + QUADSPI_BUF2CR);
+	writel(QUADSPI_BUF3CR_ALLMST, base + QUADSPI_BUF3CR);
+
+	/* We only use the buffer3 */
+	writel(0, base + QUADSPI_BUF0IND);
+	writel(0, base + QUADSPI_BUF1IND);
+	writel(0, base + QUADSPI_BUF2IND);
+
+	/* Set the default lut sequence for AHB Read. */
+	seqid = fsl_qspi_get_seqid(q, q->nor[0].read_opcode);
+	writel(seqid << QUADSPI_BFGENCR_SEQID_SHIFT,
+		q->iobase + QUADSPI_BFGENCR);
+}
+
+/* We use this function to do some basic init for spi_nor_scan(). */
+static int fsl_qspi_nor_setup(struct fsl_qspi *q)
+{
+	void __iomem *base = q->iobase;
+	u32 reg;
+	int ret;
+
+	/* the default frequency, we will change it in the future.*/
+	ret = clk_set_rate(q->clk, 66000000);
+	if (ret)
+		return ret;
+
+	/* Init the LUT table. */
+	fsl_qspi_init_lut(q);
+
+	/* Disable the module */
+	writel(QUADSPI_MCR_MDIS_MASK | QUADSPI_MCR_RESERVED_MASK,
+			base + QUADSPI_MCR);
+
+	reg = readl(base + QUADSPI_SMPR);
+	writel(reg & ~(QUADSPI_SMPR_FSDLY_MASK
+			| QUADSPI_SMPR_FSPHS_MASK
+			| QUADSPI_SMPR_HSENA_MASK
+			| QUADSPI_SMPR_DDRSMP_MASK), base + QUADSPI_SMPR);
+
+	/* Enable the module */
+	writel(QUADSPI_MCR_RESERVED_MASK | QUADSPI_MCR_END_CFG_MASK,
+			base + QUADSPI_MCR);
+
+	/* enable the interrupt */
+	writel(QUADSPI_RSER_TFIE, q->iobase + QUADSPI_RSER);
+
+	return 0;
+}
+
+static int fsl_qspi_nor_setup_last(struct fsl_qspi *q)
+{
+	unsigned long rate = q->clk_rate;
+	int ret;
+
+	if (is_imx6sx_qspi(q))
+		rate *= 4;
+
+	ret = clk_set_rate(q->clk, rate);
+	if (ret)
+		return ret;
+
+	/* Init the LUT table again. */
+	fsl_qspi_init_lut(q);
+
+	/* Init for AHB read */
+	fsl_qspi_init_abh_read(q);
+
+	return 0;
+}
+
+static struct of_device_id fsl_qspi_dt_ids[] = {
+	{ .compatible = "fsl,vf610-qspi", .data = (void *)&vybrid_data, },
+	{ .compatible = "fsl,imx6sx-qspi", .data = (void *)&imx6sx_data, },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, fsl_qspi_dt_ids);
+
+static void fsl_qspi_set_base_addr(struct fsl_qspi *q, struct spi_nor *nor)
+{
+	q->chip_base_addr = q->nor_size * (nor - q->nor);
+}
+
+static int fsl_qspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	int ret;
+	struct fsl_qspi *q = nor->priv;
+
+	ret = fsl_qspi_runcmd(q, opcode, 0, len);
+	if (ret)
+		return ret;
+
+	fsl_qspi_read_data(q, len, buf);
+	return 0;
+}
+
+static int fsl_qspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len,
+			int write_enable)
+{
+	struct fsl_qspi *q = nor->priv;
+	int ret;
+
+	if (!buf) {
+		ret = fsl_qspi_runcmd(q, opcode, 0, 1);
+		if (ret)
+			return ret;
+
+		if (opcode == OPCODE_CHIP_ERASE)
+			fsl_qspi_invalid(q);
+
+	} else if (len > 0) {
+		ret = fsl_qspi_nor_write(q, nor, opcode, 0,
+					(u32 *)buf, len, NULL);
+	} else {
+		dev_err(q->dev, "invalid cmd %d\n", opcode);
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static void fsl_qspi_write(struct spi_nor *nor, loff_t to,
+		size_t len, size_t *retlen, const u_char *buf)
+{
+	struct fsl_qspi *q = nor->priv;
+
+	fsl_qspi_nor_write(q, nor, nor->program_opcode, to,
+				(u32 *)buf, len, retlen);
+
+	/* invalid the data in the AHB buffer. */
+	fsl_qspi_invalid(q);
+}
+
+static int fsl_qspi_read(struct spi_nor *nor, loff_t from,
+		size_t len, size_t *retlen, u_char *buf)
+{
+	struct fsl_qspi *q = nor->priv;
+	u8 cmd = nor->read_opcode;
+	int ret;
+
+	dev_dbg(q->dev, "cmd [%x],read from (0x%p, 0x%.8x, 0x%.8x),len:%d\n",
+		cmd, q->ahb_base, q->chip_base_addr, (unsigned int)from, len);
+
+	/* Wait until the previous command is finished. */
+	ret = nor->wait_till_ready(nor);
+	if (ret)
+		return ret;
+
+	/* Read out the data directly from the AHB buffer.*/
+	memcpy(buf, q->ahb_base + q->chip_base_addr + from, len);
+
+	*retlen += len;
+	return 0;
+}
+
+static int fsl_qspi_erase(struct spi_nor *nor, loff_t offs)
+{
+	struct fsl_qspi *q = nor->priv;
+	int ret;
+
+	dev_dbg(nor->dev, "%dKiB at 0x%08x:0x%08x\n",
+		nor->mtd->erasesize / 1024, q->chip_base_addr, (u32)offs);
+
+	/* Wait until finished previous write command. */
+	ret = nor->wait_till_ready(nor);
+	if (ret)
+		return ret;
+
+	/* Send write enable, then erase commands. */
+	ret = nor->write_reg(nor, OPCODE_WREN, NULL, 0, 0);
+	if (ret)
+		return ret;
+
+	ret = fsl_qspi_runcmd(q, nor->erase_opcode, offs, 0);
+	if (ret)
+		return ret;
+
+	fsl_qspi_invalid(q);
+	return 0;
+}
+
+static int fsl_qspi_prep(struct spi_nor *nor, enum spi_nor_ops ops)
+{
+	struct fsl_qspi *q = nor->priv;
+	int ret;
+
+	ret = clk_enable(q->clk_en);
+	if (ret)
+		return ret;
+
+	ret = clk_enable(q->clk);
+	if (ret) {
+		clk_disable(q->clk_en);
+		return ret;
+	}
+
+	fsl_qspi_set_base_addr(q, nor);
+	return 0;
+}
+
+static void fsl_qspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
+{
+	struct fsl_qspi *q = nor->priv;
+
+	clk_disable(q->clk);
+	clk_disable(q->clk_en);
+}
+
+static int fsl_qspi_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct mtd_part_parser_data ppdata;
+	struct device *dev = &pdev->dev;
+	struct fsl_qspi *q;
+	struct resource *res;
+	struct spi_nor *nor;
+	struct mtd_info *mtd;
+	int ret, i = 0;
+	bool has_second_chip = false;
+	const struct of_device_id *of_id =
+			of_match_device(fsl_qspi_dt_ids, &pdev->dev);
+
+	q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
+	if (!q)
+		return -ENOMEM;
+
+	q->nor_num = of_get_child_count(dev->of_node);
+	if (!q->nor_num || q->nor_num > FSL_QSPI_MAX_CHIP)
+		return -ENODEV;
+
+	/* find the resources */
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "QuadSPI");
+	q->iobase = devm_ioremap_resource(dev, res);
+	if (IS_ERR(q->iobase)) {
+		ret = PTR_ERR(q->iobase);
+		goto map_failed;
+	}
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
+					"QuadSPI-memory");
+	q->ahb_base = devm_ioremap_resource(dev, res);
+	if (IS_ERR(q->ahb_base)) {
+		ret = PTR_ERR(q->ahb_base);
+		goto map_failed;
+	}
+	q->memmap_phy = res->start;
+
+	/* find the clocks */
+	q->clk_en = devm_clk_get(dev, "qspi_en");
+	if (IS_ERR(q->clk_en)) {
+		ret = PTR_ERR(q->clk_en);
+		goto map_failed;
+	}
+
+	q->clk = devm_clk_get(dev, "qspi");
+	if (IS_ERR(q->clk)) {
+		ret = PTR_ERR(q->clk);
+		goto map_failed;
+	}
+
+	ret = clk_prepare_enable(q->clk_en);
+	if (ret) {
+		dev_err(dev, "can not enable the qspi_en clock\n");
+		goto map_failed;
+	}
+
+	ret = clk_prepare_enable(q->clk);
+	if (ret) {
+		clk_disable_unprepare(q->clk_en);
+		dev_err(dev, "can not enable the qspi clock\n");
+		goto map_failed;
+	}
+
+	/* find the irq */
+	ret = platform_get_irq(pdev, 0);
+	if (ret < 0) {
+		dev_err(dev, "failed to get the irq\n");
+		goto irq_failed;
+	}
+
+	ret = devm_request_irq(dev, ret,
+			fsl_qspi_irq_handler, 0, pdev->name, q);
+	if (ret) {
+		dev_err(dev, "failed to request irq.\n");
+		goto irq_failed;
+	}
+
+	q->dev = dev;
+	q->devtype_data = (struct fsl_qspi_devtype_data *)of_id->data;
+	platform_set_drvdata(pdev, q);
+
+	ret = fsl_qspi_nor_setup(q);
+	if (ret)
+		goto irq_failed;
+
+	if (of_get_property(np, "fsl,qspi-has-second-chip", NULL))
+		has_second_chip = true;
+
+	/* iterate the subnodes. */
+	for_each_available_child_of_node(dev->of_node, np) {
+		const struct spi_device_id *id;
+		char modalias[40];
+
+		/* skip the holes */
+		if (!has_second_chip)
+			i *= 2;
+
+		nor = &q->nor[i];
+		mtd = &q->mtd[i];
+
+		nor->mtd = mtd;
+		nor->dev = dev;
+		nor->priv = q;
+		mtd->priv = nor;
+
+		/* fill the hooks */
+		nor->read_reg = fsl_qspi_read_reg;
+		nor->write_reg = fsl_qspi_write_reg;
+		nor->read = fsl_qspi_read;
+		nor->write = fsl_qspi_write;
+		nor->erase = fsl_qspi_erase;
+
+		nor->prepare = fsl_qspi_prep;
+		nor->unprepare = fsl_qspi_unprep;
+
+		if (of_modalias_node(np, modalias, sizeof(modalias)) < 0)
+			goto map_failed;
+
+		id = spi_nor_match_id(modalias);
+		if (!id)
+			goto map_failed;
+
+		ret = of_property_read_u32(np, "spi-max-frequency",
+				&q->clk_rate);
+		if (ret < 0)
+			goto map_failed;
+
+		/* set the chip address for READID */
+		fsl_qspi_set_base_addr(q, nor);
+
+		ret = spi_nor_scan(nor, id, SPI_NOR_QUAD);
+		if (ret)
+			goto map_failed;
+
+		ppdata.of_node = np;
+		ret = mtd_device_parse_register(mtd, NULL, &ppdata, NULL, 0);
+		if (ret)
+			goto map_failed;
+
+		/* Set the correct NOR size now. */
+		if (q->nor_size == 0) {
+			q->nor_size = mtd->size;
+
+			/* Map the SPI NOR to accessiable address */
+			fsl_qspi_set_map_addr(q);
+		}
+
+		/*
+		 * The TX FIFO is 64 bytes in the Vybrid, but the Page Program
+		 * may writes 265 bytes per time. The write is working in the
+		 * unit of the TX FIFO, not in the unit of the SPI NOR's page
+		 * size.
+		 *
+		 * So shrink the spi_nor->page_size if it is larger then the
+		 * TX FIFO.
+		 */
+		if (nor->page_size > q->devtype_data->txfifo)
+			nor->page_size = q->devtype_data->txfifo;
+
+		i++;
+	}
+
+	/* finish the rest init. */
+	ret = fsl_qspi_nor_setup_last(q);
+	if (ret)
+		goto last_init_failed;
+
+	clk_disable(q->clk);
+	clk_disable(q->clk_en);
+	dev_info(dev, "QuadSPI SPI NOR flash driver\n");
+	return 0;
+
+last_init_failed:
+	for (i = 0; i < q->nor_num; i++)
+		mtd_device_unregister(&q->mtd[i]);
+
+irq_failed:
+	clk_disable_unprepare(q->clk);
+	clk_disable_unprepare(q->clk_en);
+map_failed:
+	dev_err(dev, "Freescale QuadSPI probe failed\n");
+	return ret;
+}
+
+static int fsl_qspi_remove(struct platform_device *pdev)
+{
+	struct fsl_qspi *q = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < q->nor_num; i++)
+		mtd_device_unregister(&q->mtd[i]);
+
+	/* disable the hardware */
+	writel(QUADSPI_MCR_MDIS_MASK, q->iobase + QUADSPI_MCR);
+	writel(0x0, q->iobase + QUADSPI_RSER);
+
+	clk_unprepare(q->clk);
+	clk_unprepare(q->clk_en);
+	return 0;
+}
+
+static struct platform_driver fsl_qspi_driver = {
+	.driver = {
+		.name	= "fsl-quadspi",
+		.bus	= &platform_bus_type,
+		.owner	= THIS_MODULE,
+		.of_match_table = fsl_qspi_dt_ids,
+	},
+	.probe          = fsl_qspi_probe,
+	.remove		= fsl_qspi_remove,
+};
+module_platform_driver(fsl_qspi_driver);
+
+MODULE_DESCRIPTION("Freescale QuadSPI Controller Driver");
+MODULE_AUTHOR("Freescale Semiconductor Inc.");
+MODULE_LICENSE("GPL v2");
-- 
1.7.2.rc3


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