openwrt-archive/target/linux/socfpga/patches-4.4/0031-mtd-spi-nor-Add-driver-for-Cadence-Quad-SPI-Flash-Co.patch

From 30e33517815b3c518fc2483a23bfe1445c0ae92d Mon Sep 17 00:00:00 2001
From: Graham Moore <grmoore@opensource.altera.com>
Date: Tue, 28 Jul 2015 12:38:03 -0500
Subject: [PATCH 31/33] mtd: spi-nor: Add driver for Cadence Quad SPI Flash
 Controller.

Add support for the Cadence QSPI controller. This controller is
present in the Altera SoCFPGA SoCs and this driver has been tested
on the Cyclone V SoC.

Signed-off-by: Graham Moore <grmoore@opensource.altera.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Alan Tull <atull@opensource.altera.com>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Graham Moore <grmoore@opensource.altera.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Yves Vandervennet <yvanderv@opensource.altera.com>
Cc: devicetree@vger.kernel.org

V2: use NULL instead of modalias in spi_nor_scan call
V3: Use existing property is-decoded-cs instead of creating duplicate.
V4: Support Micron quad mode by snooping command stream for EVCR command
    and subsequently configuring Cadence controller for quad mode.
V5: Clean up sparse and smatch complaints.  Remove snooping of Micron
    quad mode.  Add comment on XIP mode bit and dummy clock cycles.  Set
    up SRAM partition at 1:1 during init.
V6: Remove dts patch that was included by mistake.  Incorporate Vikas's
    comments regarding fifo width, SRAM partition setting, and trigger
    address.  Trigger address was added as an unsigned int, as it is not
    an IO resource per se, and does not need to be mapped. Also add
    Marek Vasut's workaround for picking up OF properties on subnodes.
V7: - Perform coding-style cleanup and type fixes. Remove ugly QSPI_*()
      macros and replace them with functions. Get rid of unused variables.
    - Implement support for nor->set_protocol() to handle Quad-command,
      this patch now depends on the following patch:
      mtd: spi-nor: notify (Q)SPI controller about protocol change
    - Replace that cqspi_fifo_read() disaster with plain old readsl()
      and cqspi_fifo_write() tentacle horror with pretty writesl().
    - Remove CQSPI_SUPPORT_XIP_CHIPS, which is broken.
    - Get rid of cqspi_find_chipselect() mess, instead just place the
      struct cqspi_st and chipselect number into struct cqspi_flash_pdata
      and set nor->priv to the struct cqspi_flash_pdata of that particular
      chip.
    - Replace the odd math in calculate_ticks_for_ns() with DIV_ROUND_UP().
    - Make variables const where applicable.
V8: - Implement a function to wait for bit being set/unset for a given
      period of time and use it to replace the ad-hoc bits of code.
    - Configure the write underflow watermark to be 1/8 if FIFO size.
    - Extract out the SPI NOR flash probing code into separate function
      to clearly mark what will soon be considered a boilerplate code.
    - Repair the handling of mode bits, which caused instability in V7.
    - Clean up the interrupt handling
    - Fix Kconfig help text and make the patch depend on OF and COMPILE_TEST.
V9: - Rename CQSPI_REG_IRQ_IND_RD_OVERFLOW to CQSPI_REG_IRQ_IND_SRAM_FULL
    - Merge cqspi_controller_disable() into cqspi_controller_enable() and
      make the mode selectable via parameter.
V10: - Update against Cyrille's new patchset and changes to linux-mtd.
     - Repair problem with multiple QSPI NOR devices having the same mtd->name,
       they are now named devname.cs , where cs is the chipselect ID.
V11: - Replace dependency on ARCH_SOCFPGA with dependency on ARM
---
 drivers/mtd/spi-nor/Kconfig           |   11 +
 drivers/mtd/spi-nor/Makefile          |    1 +
 drivers/mtd/spi-nor/cadence-quadspi.c | 1324 +++++++++++++++++++++++++++++++++
 3 files changed, 1336 insertions(+)
 create mode 100644 drivers/mtd/spi-nor/cadence-quadspi.c

diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig
index 2fe2a7e..02082ae 100644
--- a/drivers/mtd/spi-nor/Kconfig
+++ b/drivers/mtd/spi-nor/Kconfig
@@ -41,4 +41,15 @@ config SPI_NXP_SPIFI
 	  Flash. Enable this option if you have a device with a SPIFI
 	  controller and want to access the Flash as a mtd device.
 
+config SPI_CADENCE_QUADSPI
+	tristate "Cadence Quad SPI controller"
+	depends on OF && (ARM || COMPILE_TEST)
+	help
+	  Enable support for the Cadence Quad SPI Flash controller.
+
+	  Cadence QSPI is a specialized controller for connecting an SPI
+	  Flash over 1/2/4-bit wide bus. Enable this option if you have a
+	  device with a Cadence QSPI controller and want to access the
+	  Flash as an MTD device.
+
 endif # MTD_SPI_NOR
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile
index e53333e..446c6b9 100644
--- a/drivers/mtd/spi-nor/Makefile
+++ b/drivers/mtd/spi-nor/Makefile
@@ -1,3 +1,4 @@
 obj-$(CONFIG_MTD_SPI_NOR)	+= spi-nor.o
+obj-$(CONFIG_SPI_CADENCE_QUADSPI)	+= cadence-quadspi.o
 obj-$(CONFIG_SPI_FSL_QUADSPI)	+= fsl-quadspi.o
 obj-$(CONFIG_SPI_NXP_SPIFI)	+= nxp-spifi.o
diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
new file mode 100644
index 0000000..7e61fba
--- /dev/null
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -0,0 +1,1324 @@
+/*
+ * Driver for Cadence QSPI Controller
+ *
+ * Copyright Altera Corporation (C) 2012-2014. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mtd/mtd.h>
+#include <linux/mtd/partitions.h>
+#include <linux/mtd/spi-nor.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/spi/spi.h>
+#include <linux/timer.h>
+
+#define CQSPI_NAME			"cadence-qspi"
+#define CQSPI_MAX_CHIPSELECT		16
+
+struct cqspi_st;
+
+struct cqspi_flash_pdata {
+	struct spi_nor	nor;
+	struct cqspi_st	*cqspi;
+	u32		clk_rate;
+	u32		read_delay;
+	u32		tshsl_ns;
+	u32		tsd2d_ns;
+	u32		tchsh_ns;
+	u32		tslch_ns;
+	u8		inst_width;
+	u8		addr_width;
+	u8		cs;
+};
+
+struct cqspi_st {
+	struct platform_device	*pdev;
+
+	struct clk		*clk;
+	unsigned int		sclk;
+
+	void __iomem		*iobase;
+	void __iomem		*ahb_base;
+	struct completion	transfer_complete;
+	struct mutex		bus_mutex;
+
+	int			current_cs;
+	unsigned long		master_ref_clk_hz;
+	bool			is_decoded_cs;
+	u32			fifo_depth;
+	u32			fifo_width;
+	u32			trigger_address;
+	struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
+};
+
+/* Operation timeout value */
+#define CQSPI_TIMEOUT_MS			500
+#define CQSPI_READ_TIMEOUT_MS			10
+
+/* Instruction type */
+#define CQSPI_INST_TYPE_SINGLE			0
+#define CQSPI_INST_TYPE_DUAL			1
+#define CQSPI_INST_TYPE_QUAD			2
+
+#define CQSPI_DUMMY_CLKS_PER_BYTE		8
+#define CQSPI_DUMMY_BYTES_MAX			4
+#define CQSPI_DUMMY_CLKS_MAX			31
+
+#define CQSPI_STIG_DATA_LEN_MAX			8
+
+/* Register map */
+#define CQSPI_REG_CONFIG			0x00
+#define CQSPI_REG_CONFIG_ENABLE_MASK		BIT(0)
+#define CQSPI_REG_CONFIG_DECODE_MASK		BIT(9)
+#define CQSPI_REG_CONFIG_CHIPSELECT_LSB		10
+#define CQSPI_REG_CONFIG_DMA_MASK		BIT(15)
+#define CQSPI_REG_CONFIG_BAUD_LSB		19
+#define CQSPI_REG_CONFIG_IDLE_LSB		31
+#define CQSPI_REG_CONFIG_CHIPSELECT_MASK	0xF
+#define CQSPI_REG_CONFIG_BAUD_MASK		0xF
+
+#define CQSPI_REG_RD_INSTR			0x04
+#define CQSPI_REG_RD_INSTR_OPCODE_LSB		0
+#define CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB	8
+#define CQSPI_REG_RD_INSTR_TYPE_ADDR_LSB	12
+#define CQSPI_REG_RD_INSTR_TYPE_DATA_LSB	16
+#define CQSPI_REG_RD_INSTR_MODE_EN_LSB		20
+#define CQSPI_REG_RD_INSTR_DUMMY_LSB		24
+#define CQSPI_REG_RD_INSTR_TYPE_INSTR_MASK	0x3
+#define CQSPI_REG_RD_INSTR_TYPE_ADDR_MASK	0x3
+#define CQSPI_REG_RD_INSTR_TYPE_DATA_MASK	0x3
+#define CQSPI_REG_RD_INSTR_DUMMY_MASK		0x1F
+
+#define CQSPI_REG_WR_INSTR			0x08
+#define CQSPI_REG_WR_INSTR_OPCODE_LSB		0
+#define CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB	12
+#define CQSPI_REG_WR_INSTR_TYPE_DATA_LSB	16
+
+#define CQSPI_REG_DELAY				0x0C
+#define CQSPI_REG_DELAY_TSLCH_LSB		0
+#define CQSPI_REG_DELAY_TCHSH_LSB		8
+#define CQSPI_REG_DELAY_TSD2D_LSB		16
+#define CQSPI_REG_DELAY_TSHSL_LSB		24
+#define CQSPI_REG_DELAY_TSLCH_MASK		0xFF
+#define CQSPI_REG_DELAY_TCHSH_MASK		0xFF
+#define CQSPI_REG_DELAY_TSD2D_MASK		0xFF
+#define CQSPI_REG_DELAY_TSHSL_MASK		0xFF
+
+#define CQSPI_REG_READCAPTURE			0x10
+#define CQSPI_REG_READCAPTURE_BYPASS_LSB	0
+#define CQSPI_REG_READCAPTURE_DELAY_LSB		1
+#define CQSPI_REG_READCAPTURE_DELAY_MASK	0xF
+
+#define CQSPI_REG_SIZE				0x14
+#define CQSPI_REG_SIZE_ADDRESS_LSB		0
+#define CQSPI_REG_SIZE_PAGE_LSB			4
+#define CQSPI_REG_SIZE_BLOCK_LSB		16
+#define CQSPI_REG_SIZE_ADDRESS_MASK		0xF
+#define CQSPI_REG_SIZE_PAGE_MASK		0xFFF
+#define CQSPI_REG_SIZE_BLOCK_MASK		0x3F
+
+#define CQSPI_REG_SRAMPARTITION			0x18
+#define CQSPI_REG_INDIRECTTRIGGER		0x1C
+
+#define CQSPI_REG_DMA				0x20
+#define CQSPI_REG_DMA_SINGLE_LSB		0
+#define CQSPI_REG_DMA_BURST_LSB			8
+#define CQSPI_REG_DMA_SINGLE_MASK		0xFF
+#define CQSPI_REG_DMA_BURST_MASK		0xFF
+
+#define CQSPI_REG_REMAP				0x24
+#define CQSPI_REG_MODE_BIT			0x28
+
+#define CQSPI_REG_SDRAMLEVEL			0x2C
+#define CQSPI_REG_SDRAMLEVEL_RD_LSB		0
+#define CQSPI_REG_SDRAMLEVEL_WR_LSB		16
+#define CQSPI_REG_SDRAMLEVEL_RD_MASK		0xFFFF
+#define CQSPI_REG_SDRAMLEVEL_WR_MASK		0xFFFF
+
+#define CQSPI_REG_IRQSTATUS			0x40
+#define CQSPI_REG_IRQMASK			0x44
+
+#define CQSPI_REG_INDIRECTRD			0x60
+#define CQSPI_REG_INDIRECTRD_START_MASK		BIT(0)
+#define CQSPI_REG_INDIRECTRD_CANCEL_MASK	BIT(1)
+#define CQSPI_REG_INDIRECTRD_DONE_MASK		BIT(5)
+
+#define CQSPI_REG_INDIRECTRDWATERMARK		0x64
+#define CQSPI_REG_INDIRECTRDSTARTADDR		0x68
+#define CQSPI_REG_INDIRECTRDBYTES		0x6C
+
+#define CQSPI_REG_CMDCTRL			0x90
+#define CQSPI_REG_CMDCTRL_EXECUTE_MASK		BIT(0)
+#define CQSPI_REG_CMDCTRL_INPROGRESS_MASK	BIT(1)
+#define CQSPI_REG_CMDCTRL_WR_BYTES_LSB		12
+#define CQSPI_REG_CMDCTRL_WR_EN_LSB		15
+#define CQSPI_REG_CMDCTRL_ADD_BYTES_LSB		16
+#define CQSPI_REG_CMDCTRL_ADDR_EN_LSB		19
+#define CQSPI_REG_CMDCTRL_RD_BYTES_LSB		20
+#define CQSPI_REG_CMDCTRL_RD_EN_LSB		23
+#define CQSPI_REG_CMDCTRL_OPCODE_LSB		24
+#define CQSPI_REG_CMDCTRL_WR_BYTES_MASK		0x7
+#define CQSPI_REG_CMDCTRL_ADD_BYTES_MASK	0x3
+#define CQSPI_REG_CMDCTRL_RD_BYTES_MASK		0x7
+
+#define CQSPI_REG_INDIRECTWR			0x70
+#define CQSPI_REG_INDIRECTWR_START_MASK		BIT(0)
+#define CQSPI_REG_INDIRECTWR_CANCEL_MASK	BIT(1)
+#define CQSPI_REG_INDIRECTWR_DONE_MASK		BIT(5)
+
+#define CQSPI_REG_INDIRECTWRWATERMARK		0x74
+#define CQSPI_REG_INDIRECTWRSTARTADDR		0x78
+#define CQSPI_REG_INDIRECTWRBYTES		0x7C
+
+#define CQSPI_REG_CMDADDRESS			0x94
+#define CQSPI_REG_CMDREADDATALOWER		0xA0
+#define CQSPI_REG_CMDREADDATAUPPER		0xA4
+#define CQSPI_REG_CMDWRITEDATALOWER		0xA8
+#define CQSPI_REG_CMDWRITEDATAUPPER		0xAC
+
+/* Interrupt status bits */
+#define CQSPI_REG_IRQ_MODE_ERR			BIT(0)
+#define CQSPI_REG_IRQ_UNDERFLOW			BIT(1)
+#define CQSPI_REG_IRQ_IND_COMP			BIT(2)
+#define CQSPI_REG_IRQ_IND_RD_REJECT		BIT(3)
+#define CQSPI_REG_IRQ_WR_PROTECTED_ERR		BIT(4)
+#define CQSPI_REG_IRQ_ILLEGAL_AHB_ERR		BIT(5)
+#define CQSPI_REG_IRQ_WATERMARK			BIT(6)
+#define CQSPI_REG_IRQ_IND_SRAM_FULL		BIT(12)
+
+#define CQSPI_IRQ_MASK_RD		(CQSPI_REG_IRQ_WATERMARK	| \
+					 CQSPI_REG_IRQ_IND_SRAM_FULL	| \
+					 CQSPI_REG_IRQ_IND_COMP)
+
+#define CQSPI_IRQ_MASK_WR		(CQSPI_REG_IRQ_IND_COMP		| \
+					 CQSPI_REG_IRQ_WATERMARK	| \
+					 CQSPI_REG_IRQ_UNDERFLOW)
+
+#define CQSPI_IRQ_STATUS_MASK		0x1FFFF
+
+static int cqspi_wait_for_bit(void __iomem *reg, const u32 mask, bool clear)
+{
+	unsigned long end = jiffies + msecs_to_jiffies(CQSPI_TIMEOUT_MS);
+	u32 val;
+
+	while (1) {
+		val = readl(reg);
+		if (clear)
+			val = ~val;
+		val &= mask;
+
+		if (val == mask)
+			return 0;
+
+		if (time_after(jiffies, end))
+			return -ETIMEDOUT;
+	}
+}
+
+static bool cqspi_is_idle(struct cqspi_st *cqspi)
+{
+	u32 reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
+
+	return reg & (1 << CQSPI_REG_CONFIG_IDLE_LSB);
+}
+
+static u32 cqspi_get_rd_sram_level(struct cqspi_st *cqspi)
+{
+	u32 reg = readl(cqspi->iobase + CQSPI_REG_SDRAMLEVEL);
+
+	reg >>= CQSPI_REG_SDRAMLEVEL_RD_LSB;
+	return reg & CQSPI_REG_SDRAMLEVEL_RD_MASK;
+}
+
+static irqreturn_t cqspi_irq_handler(int this_irq, void *dev)
+{
+	struct cqspi_st *cqspi = dev;
+	unsigned int irq_status;
+
+	/* Read interrupt status */
+	irq_status = readl(cqspi->iobase + CQSPI_REG_IRQSTATUS);
+
+	/* Clear interrupt */
+	writel(irq_status, cqspi->iobase + CQSPI_REG_IRQSTATUS);
+
+	irq_status &= CQSPI_IRQ_MASK_RD | CQSPI_IRQ_MASK_WR;
+
+	if (irq_status)
+		complete(&cqspi->transfer_complete);
+
+	return IRQ_HANDLED;
+}
+
+static unsigned int cqspi_calc_rdreg(struct spi_nor *nor, const u8 opcode)
+{
+	unsigned int rdreg = 0;
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+
+	rdreg |= f_pdata->inst_width << CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB;
+	rdreg |= f_pdata->addr_width << CQSPI_REG_RD_INSTR_TYPE_ADDR_LSB;
+
+	if (nor->flash_read == SPI_NOR_QUAD)
+		rdreg |= CQSPI_INST_TYPE_QUAD
+			 << CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
+	return rdreg;
+}
+
+static int cqspi_wait_idle(struct cqspi_st *cqspi)
+{
+	const unsigned int poll_idle_retry = 3;
+	unsigned int count = 0;
+	unsigned long timeout;
+
+	timeout = jiffies + msecs_to_jiffies(CQSPI_TIMEOUT_MS);
+	while (1) {
+		/*
+		 * Read few times in succession to ensure the controller
+		 * is indeed idle, that is, the bit does not transition
+		 * low again.
+		 */
+		if (cqspi_is_idle(cqspi))
+			count++;
+		else
+			count = 0;
+
+		if (count >= poll_idle_retry)
+			return 0;
+
+		if (time_after(jiffies, timeout)) {
+			/* Timeout, in busy mode. */
+			dev_err(&cqspi->pdev->dev,
+				"QSPI is still busy after %dms timeout.\n",
+				CQSPI_TIMEOUT_MS);
+			return -ETIMEDOUT;
+		}
+
+		cpu_relax();
+	}
+}
+
+static int cqspi_exec_flash_cmd(struct cqspi_st *cqspi, unsigned int reg)
+{
+	void __iomem *reg_base = cqspi->iobase;
+	int ret;
+
+	/* Write the CMDCTRL without start execution. */
+	writel(reg, reg_base + CQSPI_REG_CMDCTRL);
+	/* Start execute */
+	reg |= CQSPI_REG_CMDCTRL_EXECUTE_MASK;
+	writel(reg, reg_base + CQSPI_REG_CMDCTRL);
+
+	/* Polling for completion. */
+	ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_CMDCTRL,
+				 CQSPI_REG_CMDCTRL_INPROGRESS_MASK, 1);
+	if (ret) {
+		dev_err(&cqspi->pdev->dev,
+			"Flash command execution timed out.\n");
+		return ret;
+	}
+
+	/* Polling QSPI idle status. */
+	return cqspi_wait_idle(cqspi);
+}
+
+static int cqspi_command_read(struct spi_nor *nor,
+			      const u8 *txbuf, const unsigned n_tx,
+			      u8 *rxbuf, const unsigned n_rx)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int rdreg;
+	unsigned int reg;
+	unsigned int read_len;
+	int status;
+
+	if (!n_rx || n_rx > CQSPI_STIG_DATA_LEN_MAX || !rxbuf) {
+		dev_err(nor->dev, "Invalid input argument, len %d rxbuf 0x%p\n",
+			n_rx, rxbuf);
+		return -EINVAL;
+	}
+
+	reg = txbuf[0] << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+
+	rdreg = cqspi_calc_rdreg(nor, txbuf[0]);
+	writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
+
+	reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
+
+	/* 0 means 1 byte. */
+	reg |= (((n_rx - 1) & CQSPI_REG_CMDCTRL_RD_BYTES_MASK)
+		<< CQSPI_REG_CMDCTRL_RD_BYTES_LSB);
+	status = cqspi_exec_flash_cmd(cqspi, reg);
+	if (status)
+		return status;
+
+	reg = readl(reg_base + CQSPI_REG_CMDREADDATALOWER);
+
+	/* Put the read value into rx_buf */
+	read_len = (n_rx > 4) ? 4 : n_rx;
+	memcpy(rxbuf, &reg, read_len);
+	rxbuf += read_len;
+
+	if (n_rx > 4) {
+		reg = readl(reg_base + CQSPI_REG_CMDREADDATAUPPER);
+
+		read_len = n_rx - read_len;
+		memcpy(rxbuf, &reg, read_len);
+	}
+
+	return 0;
+}
+
+static int cqspi_command_write(struct spi_nor *nor, const u8 opcode,
+			       const u8 *txbuf, const unsigned n_tx)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int reg;
+	unsigned int data;
+	int ret;
+
+	if (n_tx > 4 || (n_tx && !txbuf)) {
+		dev_err(nor->dev,
+			"Invalid input argument, cmdlen %d txbuf 0x%p\n",
+			n_tx, txbuf);
+		return -EINVAL;
+	}
+
+	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+	if (n_tx) {
+		reg |= (0x1 << CQSPI_REG_CMDCTRL_WR_EN_LSB);
+		reg |= ((n_tx - 1) & CQSPI_REG_CMDCTRL_WR_BYTES_MASK)
+			<< CQSPI_REG_CMDCTRL_WR_BYTES_LSB;
+		data = 0;
+		memcpy(&data, txbuf, n_tx);
+		writel(data, reg_base + CQSPI_REG_CMDWRITEDATALOWER);
+	}
+
+	ret = cqspi_exec_flash_cmd(cqspi, reg);
+	return ret;
+}
+
+static int cqspi_command_write_addr(struct spi_nor *nor,
+				    const u8 opcode, const unsigned int addr)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int reg;
+
+	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+	reg |= (0x1 << CQSPI_REG_CMDCTRL_ADDR_EN_LSB);
+	reg |= ((nor->addr_width - 1) & CQSPI_REG_CMDCTRL_ADD_BYTES_MASK)
+		<< CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;
+
+	writel(addr, reg_base + CQSPI_REG_CMDADDRESS);
+
+	return cqspi_exec_flash_cmd(cqspi, reg);
+}
+
+static int cqspi_indirect_read_setup(struct spi_nor *nor,
+				     const unsigned int from_addr)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int dummy_clk = 0;
+	unsigned int reg;
+
+	writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
+
+	reg = nor->read_opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
+	reg |= cqspi_calc_rdreg(nor, nor->read_opcode);
+
+	/* Setup dummy clock cycles */
+	dummy_clk = nor->read_dummy;
+	if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
+		dummy_clk = CQSPI_DUMMY_CLKS_MAX;
+
+	if (dummy_clk / 8) {
+		reg |= (1 << CQSPI_REG_RD_INSTR_MODE_EN_LSB);
+		/* Set mode bits high to ensure chip doesn't enter XIP */
+		writel(0xFF, reg_base + CQSPI_REG_MODE_BIT);
+
+		/* Need to subtract the mode byte (8 clocks). */
+		if (f_pdata->inst_width != CQSPI_INST_TYPE_QUAD)
+			dummy_clk -= 8;
+
+		if (dummy_clk)
+			reg |= (dummy_clk & CQSPI_REG_RD_INSTR_DUMMY_MASK)
+			       << CQSPI_REG_RD_INSTR_DUMMY_LSB;
+	}
+
+	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
+
+	/* Set address width */
+	reg = readl(reg_base + CQSPI_REG_SIZE);
+	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
+	reg |= (nor->addr_width - 1);
+	writel(reg, reg_base + CQSPI_REG_SIZE);
+	return 0;
+}
+
+static int cqspi_indirect_read_execute(struct spi_nor *nor,
+				       u8 *rxbuf, const unsigned n_rx)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	void __iomem *ahb_base = cqspi->ahb_base;
+	unsigned int remaining = n_rx;
+	unsigned int bytes_to_read = 0;
+	int ret = 0;
+
+	writel(remaining, reg_base + CQSPI_REG_INDIRECTRDBYTES);
+
+	/* Clear all interrupts. */
+	writel(CQSPI_IRQ_STATUS_MASK, reg_base + CQSPI_REG_IRQSTATUS);
+
+	writel(CQSPI_IRQ_MASK_RD, reg_base + CQSPI_REG_IRQMASK);
+
+	reinit_completion(&cqspi->transfer_complete);
+	writel(CQSPI_REG_INDIRECTRD_START_MASK,
+	       reg_base + CQSPI_REG_INDIRECTRD);
+
+	while (remaining > 0) {
+		ret = wait_for_completion_timeout(&cqspi->transfer_complete,
+						  msecs_to_jiffies
+						  (CQSPI_READ_TIMEOUT_MS));
+
+		bytes_to_read = cqspi_get_rd_sram_level(cqspi);
+
+		if (!ret && bytes_to_read == 0) {
+			dev_err(nor->dev, "Indirect read timeout, no bytes\n");
+			ret = -ETIMEDOUT;
+			goto failrd;
+		}
+
+		while (bytes_to_read != 0) {
+			bytes_to_read *= cqspi->fifo_width;
+			bytes_to_read = bytes_to_read > remaining ?
+					remaining : bytes_to_read;
+			readsl(ahb_base, rxbuf, DIV_ROUND_UP(bytes_to_read, 4));
+			rxbuf += bytes_to_read;
+			remaining -= bytes_to_read;
+			bytes_to_read = cqspi_get_rd_sram_level(cqspi);
+		}
+
+		if (remaining > 0)
+			reinit_completion(&cqspi->transfer_complete);
+	}
+
+	/* Check indirect done status */
+	ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_INDIRECTRD,
+				 CQSPI_REG_INDIRECTRD_DONE_MASK, 0);
+	if (ret) {
+		dev_err(nor->dev,
+			"Indirect read completion error (%i)\n", ret);
+		goto failrd;
+	}
+
+	/* Disable interrupt */
+	writel(0, reg_base + CQSPI_REG_IRQMASK);
+
+	/* Clear indirect completion status */
+	writel(CQSPI_REG_INDIRECTRD_DONE_MASK, reg_base + CQSPI_REG_INDIRECTRD);
+
+	return 0;
+
+failrd:
+	/* Disable interrupt */
+	writel(0, reg_base + CQSPI_REG_IRQMASK);
+
+	/* Cancel the indirect read */
+	writel(CQSPI_REG_INDIRECTWR_CANCEL_MASK,
+	       reg_base + CQSPI_REG_INDIRECTRD);
+	return ret;
+}
+
+static int cqspi_indirect_write_setup(struct spi_nor *nor,
+				      const unsigned int to_addr)
+{
+	unsigned int reg;
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+
+	/* Set opcode. */
+	reg = nor->program_opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
+	writel(reg, reg_base + CQSPI_REG_WR_INSTR);
+	reg = cqspi_calc_rdreg(nor, nor->program_opcode);
+	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
+
+	writel(to_addr, reg_base + CQSPI_REG_INDIRECTWRSTARTADDR);
+
+	reg = readl(reg_base + CQSPI_REG_SIZE);
+	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
+	reg |= (nor->addr_width - 1);
+	writel(reg, reg_base + CQSPI_REG_SIZE);
+	return 0;
+}
+
+static int cqspi_indirect_write_execute(struct spi_nor *nor,
+					const u8 *txbuf, const unsigned n_tx)
+{
+	const unsigned int page_size = nor->page_size;
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int remaining = n_tx;
+	unsigned int write_bytes;
+	int ret;
+
+	writel(remaining, reg_base + CQSPI_REG_INDIRECTWRBYTES);
+
+	/* Clear all interrupts. */
+	writel(CQSPI_IRQ_STATUS_MASK, reg_base + CQSPI_REG_IRQSTATUS);
+
+	writel(CQSPI_IRQ_MASK_WR, reg_base + CQSPI_REG_IRQMASK);
+
+	reinit_completion(&cqspi->transfer_complete);
+	writel(CQSPI_REG_INDIRECTWR_START_MASK,
+	       reg_base + CQSPI_REG_INDIRECTWR);
+
+	while (remaining > 0) {
+		write_bytes = remaining > page_size ? page_size : remaining;
+		writesl(cqspi->ahb_base, txbuf, DIV_ROUND_UP(write_bytes, 4));
+
+		ret = wait_for_completion_timeout(&cqspi->transfer_complete,
+						  msecs_to_jiffies
+						  (CQSPI_TIMEOUT_MS));
+		if (!ret) {
+			dev_err(nor->dev, "Indirect write timeout\n");
+			ret = -ETIMEDOUT;
+			goto failwr;
+		}
+
+		txbuf += write_bytes;
+		remaining -= write_bytes;
+
+		if (remaining > 0)
+			reinit_completion(&cqspi->transfer_complete);
+	}
+
+	/* Check indirect done status */
+	ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_INDIRECTWR,
+				 CQSPI_REG_INDIRECTWR_DONE_MASK, 0);
+	if (ret) {
+		dev_err(nor->dev,
+			"Indirect write completion error (%i)\n", ret);
+		goto failwr;
+	}
+
+	/* Disable interrupt. */
+	writel(0, reg_base + CQSPI_REG_IRQMASK);
+
+	/* Clear indirect completion status */
+	writel(CQSPI_REG_INDIRECTWR_DONE_MASK, reg_base + CQSPI_REG_INDIRECTWR);
+
+	cqspi_wait_idle(cqspi);
+
+	return 0;
+
+failwr:
+	/* Disable interrupt. */
+	writel(0, reg_base + CQSPI_REG_IRQMASK);
+
+	/* Cancel the indirect write */
+	writel(CQSPI_REG_INDIRECTWR_CANCEL_MASK,
+	       reg_base + CQSPI_REG_INDIRECTWR);
+	return ret;
+}
+
+static int cqspi_set_protocol(struct spi_nor *nor, enum spi_nor_protocol proto)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+
+	switch (proto) {
+	case SNOR_PROTO_1_1_1:
+	case SNOR_PROTO_1_1_2:
+	case SNOR_PROTO_1_1_4:
+	case SNOR_PROTO_1_2_2:
+	case SNOR_PROTO_1_4_4:
+		f_pdata->inst_width = CQSPI_INST_TYPE_SINGLE;
+		break;
+	case SNOR_PROTO_2_2_2:
+		f_pdata->inst_width = CQSPI_INST_TYPE_DUAL;
+		break;
+	case SNOR_PROTO_4_4_4:
+		f_pdata->inst_width = CQSPI_INST_TYPE_QUAD;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (proto) {
+	case SNOR_PROTO_1_1_1:
+	case SNOR_PROTO_1_1_2:
+	case SNOR_PROTO_1_1_4:
+		f_pdata->addr_width = CQSPI_INST_TYPE_SINGLE;
+		break;
+	case SNOR_PROTO_1_2_2:
+	case SNOR_PROTO_2_2_2:
+		f_pdata->addr_width = CQSPI_INST_TYPE_DUAL;
+		break;
+	case SNOR_PROTO_1_4_4:
+	case SNOR_PROTO_4_4_4:
+		f_pdata->addr_width = CQSPI_INST_TYPE_QUAD;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static void cqspi_write(struct spi_nor *nor, loff_t to,
+			size_t len, size_t *retlen, const u_char *buf)
+{
+	int ret;
+
+	ret = cqspi_set_protocol(nor, nor->write_proto);
+	if (ret)
+		return;
+
+	ret = cqspi_indirect_write_setup(nor, to);
+	if (ret)
+		return;
+
+	ret = cqspi_indirect_write_execute(nor, buf, len);
+	if (ret)
+		return;
+
+	*retlen += len;
+}
+
+static int cqspi_read(struct spi_nor *nor, loff_t from,
+		      size_t len, size_t *retlen, u_char *buf)
+{
+	int ret;
+
+	ret = cqspi_set_protocol(nor, nor->read_proto);
+	if (ret)
+		return ret;
+
+	ret = cqspi_indirect_read_setup(nor, from);
+	if (ret)
+		return ret;
+
+	ret = cqspi_indirect_read_execute(nor, buf, len);
+	if (ret)
+		return ret;
+
+	*retlen += len;
+	return ret;
+}
+
+static int cqspi_erase(struct spi_nor *nor, loff_t offs)
+{
+	int ret;
+
+	ret = cqspi_set_protocol(nor, nor->erase_proto);
+	if (ret)
+		return ret;
+
+	/* Send write enable, then erase commands. */
+	ret = nor->write_reg(nor, SPINOR_OP_WREN, NULL, 0);
+	if (ret)
+		return ret;
+
+	/* Set up command buffer. */
+	ret = cqspi_command_write_addr(nor, nor->erase_opcode, offs);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static unsigned int calculate_ticks_for_ns(const unsigned int ref_clk_hz,
+					   const unsigned int ns_val)
+{
+	unsigned int ticks;
+
+	ticks = ref_clk_hz / 1000;	/* kHz */
+	ticks = DIV_ROUND_UP(ticks * ns_val, 1000000);
+
+	return ticks;
+}
+
+static void cqspi_delay(struct spi_nor *nor, const unsigned int sclk_hz)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *iobase = cqspi->iobase;
+	const unsigned int ref_clk_hz = cqspi->master_ref_clk_hz;
+	unsigned int tshsl, tchsh, tslch, tsd2d;
+	unsigned int reg;
+	unsigned int tsclk;
+
+	/* calculate the number of ref ticks for one sclk tick */
+	tsclk = (ref_clk_hz + sclk_hz - 1) / sclk_hz;
+
+	tshsl = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tshsl_ns);
+	/* this particular value must be at least one sclk */
+	if (tshsl < tsclk)
+		tshsl = tsclk;
+
+	tchsh = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tchsh_ns);
+	tslch = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tslch_ns);
+	tsd2d = calculate_ticks_for_ns(ref_clk_hz, f_pdata->tsd2d_ns);
+
+	reg = (tshsl & CQSPI_REG_DELAY_TSHSL_MASK)
+	       << CQSPI_REG_DELAY_TSHSL_LSB;
+	reg |= (tchsh & CQSPI_REG_DELAY_TCHSH_MASK)
+		<< CQSPI_REG_DELAY_TCHSH_LSB;
+	reg |= (tslch & CQSPI_REG_DELAY_TSLCH_MASK)
+		<< CQSPI_REG_DELAY_TSLCH_LSB;
+	reg |= (tsd2d & CQSPI_REG_DELAY_TSD2D_MASK)
+		<< CQSPI_REG_DELAY_TSD2D_LSB;
+	writel(reg, iobase + CQSPI_REG_DELAY);
+}
+
+static void cqspi_config_baudrate_div(struct cqspi_st *cqspi,
+				      const unsigned int sclk_hz)
+{
+	const unsigned int ref_clk_hz = cqspi->master_ref_clk_hz;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int reg;
+	unsigned int div;
+
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg &= ~(CQSPI_REG_CONFIG_BAUD_MASK << CQSPI_REG_CONFIG_BAUD_LSB);
+
+	div = ref_clk_hz / sclk_hz;
+
+	/* Recalculate the baudrate divisor based on QSPI specification. */
+	if (div > 32)
+		div = 32;
+
+	/* Check if even number. */
+	if (div & 1)
+		div = (div / 2);
+	else
+		div = (div / 2) - 1;
+
+	div = (div & CQSPI_REG_CONFIG_BAUD_MASK) << CQSPI_REG_CONFIG_BAUD_LSB;
+	reg |= div;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+}
+
+static void cqspi_readdata_capture(struct cqspi_st *cqspi,
+				   const unsigned int bypass,
+				   const unsigned int delay)
+{
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int reg;
+
+	reg = readl(reg_base + CQSPI_REG_READCAPTURE);
+
+	if (bypass)
+		reg |= (1 << CQSPI_REG_READCAPTURE_BYPASS_LSB);
+	else
+		reg &= ~(1 << CQSPI_REG_READCAPTURE_BYPASS_LSB);
+
+	reg &= ~(CQSPI_REG_READCAPTURE_DELAY_MASK
+		 << CQSPI_REG_READCAPTURE_DELAY_LSB);
+
+	reg |= (delay & CQSPI_REG_READCAPTURE_DELAY_MASK)
+		<< CQSPI_REG_READCAPTURE_DELAY_LSB;
+
+	writel(reg, reg_base + CQSPI_REG_READCAPTURE);
+}
+
+static void cqspi_chipselect(struct spi_nor *nor)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int chip_select = f_pdata->cs;
+	unsigned int reg;
+
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	if (cqspi->is_decoded_cs) {
+		reg |= CQSPI_REG_CONFIG_DECODE_MASK;
+	} else {
+		reg &= ~CQSPI_REG_CONFIG_DECODE_MASK;
+
+		/* Convert CS if without decoder.
+		 * CS0 to 4b'1110
+		 * CS1 to 4b'1101
+		 * CS2 to 4b'1011
+		 * CS3 to 4b'0111
+		 */
+		chip_select = 0xF & ~(1 << chip_select);
+	}
+
+	reg &= ~(CQSPI_REG_CONFIG_CHIPSELECT_MASK
+		 << CQSPI_REG_CONFIG_CHIPSELECT_LSB);
+	reg |= (chip_select & CQSPI_REG_CONFIG_CHIPSELECT_MASK)
+	    << CQSPI_REG_CONFIG_CHIPSELECT_LSB;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+}
+
+static void cqspi_controller_enable(struct cqspi_st *cqspi, bool enable)
+{
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int reg;
+
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+
+	if (enable)
+		reg |= CQSPI_REG_CONFIG_ENABLE_MASK;
+	else
+		reg &= ~CQSPI_REG_CONFIG_ENABLE_MASK;
+
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+}
+
+static void cqspi_switch_cs(struct spi_nor *nor)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *iobase = cqspi->iobase;
+	unsigned int reg;
+
+	/* configure page size and block size. */
+	reg = readl(iobase + CQSPI_REG_SIZE);
+	reg &= ~(CQSPI_REG_SIZE_PAGE_MASK << CQSPI_REG_SIZE_PAGE_LSB);
+	reg &= ~(CQSPI_REG_SIZE_BLOCK_MASK << CQSPI_REG_SIZE_BLOCK_LSB);
+	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
+	reg |= (nor->page_size << CQSPI_REG_SIZE_PAGE_LSB);
+	reg |= (ilog2(nor->mtd.erasesize) << CQSPI_REG_SIZE_BLOCK_LSB);
+	reg |= (nor->addr_width - 1);
+	writel(reg, iobase + CQSPI_REG_SIZE);
+
+	/* configure the chip select */
+	cqspi_chipselect(nor);
+}
+
+static int cqspi_prep_unlocked(struct spi_nor *nor, enum spi_nor_ops ops)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	const unsigned int sclk = f_pdata->clk_rate;
+	const int switch_cs = (cqspi->current_cs != f_pdata->cs);
+	const int switch_ck = (cqspi->sclk != sclk);
+
+	if (switch_cs || switch_ck)
+		cqspi_controller_enable(cqspi, 0);
+
+	/* Switch chip select. */
+	if (switch_cs) {
+		cqspi->current_cs = f_pdata->cs;
+		cqspi_switch_cs(nor);
+	}
+
+	/* Setup baudrate divisor and delays */
+	if (switch_ck) {
+		cqspi->sclk = sclk;
+		cqspi_config_baudrate_div(cqspi, sclk);
+		cqspi_delay(nor, sclk);
+		cqspi_readdata_capture(cqspi, 1, f_pdata->read_delay);
+	}
+
+	if (switch_cs || switch_ck)
+		cqspi_controller_enable(cqspi, 1);
+
+	return 0;
+}
+
+static int cqspi_prep(struct spi_nor *nor, enum spi_nor_ops ops)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+
+	mutex_lock(&cqspi->bus_mutex);
+
+	return cqspi_prep_unlocked(nor, ops);
+}
+
+static void cqspi_unprep(struct spi_nor *nor, enum spi_nor_ops ops)
+{
+	struct cqspi_flash_pdata *f_pdata = nor->priv;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+
+	mutex_unlock(&cqspi->bus_mutex);
+}
+
+static int cqspi_read_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	int ret;
+
+	ret = cqspi_set_protocol(nor, nor->reg_proto);
+	if (ret)
+		goto exit;
+
+	cqspi_prep_unlocked(nor, SPI_NOR_OPS_READ);
+
+	ret = cqspi_command_read(nor, &opcode, 1, buf, len);
+exit:
+	return ret;
+}
+
+static int cqspi_write_reg(struct spi_nor *nor, u8 opcode, u8 *buf, int len)
+{
+	int ret;
+
+	ret = cqspi_set_protocol(nor, nor->reg_proto);
+	if (ret)
+		goto exit;
+
+	cqspi_prep_unlocked(nor, SPI_NOR_OPS_WRITE);
+
+	ret = cqspi_command_write(nor, opcode, buf, len);
+exit:
+	return ret;
+}
+
+static int cqspi_of_get_flash_pdata(struct platform_device *pdev,
+				    struct cqspi_flash_pdata *f_pdata,
+				    struct device_node *np)
+{
+	if (of_property_read_u32(np, "cdns,read-delay", &f_pdata->read_delay)) {
+		dev_err(&pdev->dev, "couldn't determine read-delay\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,tshsl-ns", &f_pdata->tshsl_ns)) {
+		dev_err(&pdev->dev, "couldn't determine tshsl-ns\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,tsd2d-ns", &f_pdata->tsd2d_ns)) {
+		dev_err(&pdev->dev, "couldn't determine tsd2d-ns\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,tchsh-ns", &f_pdata->tchsh_ns)) {
+		dev_err(&pdev->dev, "couldn't determine tchsh-ns\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,tslch-ns", &f_pdata->tslch_ns)) {
+		dev_err(&pdev->dev, "couldn't determine tslch-ns\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "spi-max-frequency", &f_pdata->clk_rate)) {
+		dev_err(&pdev->dev, "couldn't determine spi-max-frequency\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static int cqspi_of_get_pdata(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct cqspi_st *cqspi = platform_get_drvdata(pdev);
+
+	cqspi->is_decoded_cs = of_property_read_bool(np, "cdns,is-decoded-cs");
+
+	if (of_property_read_u32(np, "cdns,fifo-depth", &cqspi->fifo_depth)) {
+		dev_err(&pdev->dev, "couldn't determine fifo-depth\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,fifo-width", &cqspi->fifo_width)) {
+		dev_err(&pdev->dev, "couldn't determine fifo-width\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,trigger-address",
+				 &cqspi->trigger_address)) {
+		dev_err(&pdev->dev, "couldn't determine trigger-address\n");
+		return -ENXIO;
+	}
+
+	return 0;
+}
+
+static void cqspi_controller_init(struct cqspi_st *cqspi)
+{
+	cqspi_controller_enable(cqspi, 0);
+
+	/* Configure the remap address register, no remap */
+	writel(0, cqspi->iobase + CQSPI_REG_REMAP);
+
+	/* Disable all interrupts. */
+	writel(0, cqspi->iobase + CQSPI_REG_IRQMASK);
+
+	/* Configure the SRAM split to 1:1 . */
+	writel(cqspi->fifo_depth / 2, cqspi->iobase + CQSPI_REG_SRAMPARTITION);
+
+	/* Load indirect trigger address. */
+	writel(cqspi->trigger_address,
+	       cqspi->iobase + CQSPI_REG_INDIRECTTRIGGER);
+
+	/* Program read watermark -- 1/2 of the FIFO. */
+	writel(cqspi->fifo_depth * cqspi->fifo_width / 2,
+	       cqspi->iobase + CQSPI_REG_INDIRECTRDWATERMARK);
+	/* Program write watermark -- 1/8 of the FIFO. */
+	writel(cqspi->fifo_depth * cqspi->fifo_width / 8,
+	       cqspi->iobase + CQSPI_REG_INDIRECTWRWATERMARK);
+
+	cqspi_controller_enable(cqspi, 1);
+}
+
+static int cqspi_setup_flash(struct cqspi_st *cqspi, struct device_node *np)
+{
+	struct platform_device *pdev = cqspi->pdev;
+	struct device *dev = &pdev->dev;
+	struct cqspi_flash_pdata *f_pdata;
+	struct spi_nor *nor;
+	struct mtd_info *mtd;
+	unsigned int cs;
+	int i, ret;
+
+	/* Get flash device data */
+	for_each_available_child_of_node(dev->of_node, np) {
+		if (of_property_read_u32(np, "reg", &cs)) {
+			dev_err(dev, "Couldn't determine chip select.\n");
+			goto err;
+		}
+
+		if (cs > CQSPI_MAX_CHIPSELECT) {
+			dev_err(dev, "Chip select %d out of range.\n", cs);
+			goto err;
+		}
+
+		f_pdata = &cqspi->f_pdata[cs];
+		f_pdata->cqspi = cqspi;
+		f_pdata->cs = cs;
+
+		ret = cqspi_of_get_flash_pdata(pdev, f_pdata, np);
+		if (ret)
+			goto err;
+
+		nor = &f_pdata->nor;
+		mtd = &nor->mtd;
+
+		mtd->priv = nor;
+
+		nor->dev = dev;
+		spi_nor_set_flash_node(nor, np);
+		nor->priv = f_pdata;
+
+		nor->read_reg = cqspi_read_reg;
+		nor->write_reg = cqspi_write_reg;
+		nor->read = cqspi_read;
+		nor->write = cqspi_write;
+		nor->erase = cqspi_erase;
+		nor->prepare = cqspi_prep;
+		nor->unprepare = cqspi_unprep;
+
+		mtd->name = kasprintf(GFP_KERNEL, "%s.%d", dev_name(dev), cs);
+		if (!mtd->name) {
+			ret = -ENOMEM;
+			goto err;
+		}
+
+		ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD);
+		if (ret)
+			goto err;
+
+		ret = mtd_device_register(mtd, NULL, 0);
+		if (ret)
+			goto err;
+	}
+
+	return 0;
+
+err:
+	for (i = 0; i < CQSPI_MAX_CHIPSELECT; i++)
+		if (cqspi->f_pdata[i].nor.mtd.name) {
+			mtd_device_unregister(&cqspi->f_pdata[i].nor.mtd);
+			kfree(cqspi->f_pdata[i].nor.mtd.name);
+		}
+	return ret;
+}
+
+static int cqspi_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct cqspi_st *cqspi;
+	struct resource *res;
+	struct resource *res_ahb;
+	int ret;
+	int irq;
+
+	cqspi = devm_kzalloc(dev, sizeof(*cqspi), GFP_KERNEL);
+	if (!cqspi)
+		return -ENOMEM;
+
+	mutex_init(&cqspi->bus_mutex);
+	cqspi->pdev = pdev;
+	platform_set_drvdata(pdev, cqspi);
+
+	/* Obtain configuration from OF. */
+	ret = cqspi_of_get_pdata(pdev);
+	if (ret) {
+		dev_err(dev, "Cannot get mandatory OF data.\n");
+		return -ENODEV;
+	}
+
+	/* Obtain QSPI clock. */
+	cqspi->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(cqspi->clk)) {
+		dev_err(dev, "Cannot claim QSPI clock.\n");
+		return PTR_ERR(cqspi->clk);
+	}
+
+	/* Obtain and remap controller address. */
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cqspi->iobase = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cqspi->iobase)) {
+		dev_err(dev, "Cannot remap controller address.\n");
+		return PTR_ERR(cqspi->iobase);
+	}
+
+	/* Obtain and remap AHB address. */
+	res_ahb = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	cqspi->ahb_base = devm_ioremap_resource(dev, res_ahb);
+	if (IS_ERR(cqspi->ahb_base)) {
+		dev_err(dev, "Cannot remap AHB address.\n");
+		return PTR_ERR(cqspi->ahb_base);
+	}
+
+	init_completion(&cqspi->transfer_complete);
+
+	/* Obtain IRQ line. */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "Cannot obtain IRQ.\n");
+		return -ENXIO;
+	}
+
+	ret = clk_prepare_enable(cqspi->clk);
+	if (ret) {
+		dev_err(dev, "Cannot enable QSPI clock.\n");
+		return ret;
+	}
+
+	cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk);
+
+	ret = devm_request_irq(dev, irq, cqspi_irq_handler, 0,
+			       pdev->name, cqspi);
+	if (ret) {
+		dev_err(dev, "Cannot request IRQ.\n");
+		goto probe_irq_failed;
+	}
+
+	cqspi_wait_idle(cqspi);
+	cqspi_controller_init(cqspi);
+	cqspi->current_cs = -1;
+	cqspi->sclk = 0;
+
+	ret = cqspi_setup_flash(cqspi, np);
+	if (ret) {
+		dev_err(dev, "Cadence QSPI NOR probe failed %d\n", ret);
+		goto probe_setup_failed;
+	}
+
+	return ret;
+probe_irq_failed:
+	cqspi_controller_enable(cqspi, 0);
+probe_setup_failed:
+	clk_disable_unprepare(cqspi->clk);
+	return ret;
+}
+
+static int cqspi_remove(struct platform_device *pdev)
+{
+	struct cqspi_st *cqspi = platform_get_drvdata(pdev);
+	int i;
+
+	cqspi_controller_enable(cqspi, 0);
+
+	for (i = 0; i < CQSPI_MAX_CHIPSELECT; i++)
+		if (cqspi->f_pdata[i].nor.mtd.name) {
+			mtd_device_unregister(&cqspi->f_pdata[i].nor.mtd);
+			kfree(cqspi->f_pdata[i].nor.mtd.name);
+		}
+
+	clk_disable_unprepare(cqspi->clk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int cqspi_suspend(struct device *dev)
+{
+	struct cqspi_st *cqspi = dev_get_drvdata(dev);
+
+	cqspi_controller_enable(cqspi, 0);
+	return 0;
+}
+
+static int cqspi_resume(struct device *dev)
+{
+	struct cqspi_st *cqspi = dev_get_drvdata(dev);
+
+	cqspi_controller_enable(cqspi, 1);
+	return 0;
+}
+
+static const struct dev_pm_ops cqspi__dev_pm_ops = {
+	.suspend = cqspi_suspend,
+	.resume = cqspi_resume,
+};
+
+#define CQSPI_DEV_PM_OPS	(&cqspi__dev_pm_ops)
+#else
+#define CQSPI_DEV_PM_OPS	NULL
+#endif
+
+static struct of_device_id const cqspi_dt_ids[] = {
+	{.compatible = "cdns,qspi-nor",},
+	{ /* end of table */ }
+};
+
+MODULE_DEVICE_TABLE(of, cqspi_dt_ids);
+
+static struct platform_driver cqspi_platform_driver = {
+	.probe = cqspi_probe,
+	.remove = cqspi_remove,
+	.driver = {
+		.name = CQSPI_NAME,
+		.pm = CQSPI_DEV_PM_OPS,
+		.of_match_table = cqspi_dt_ids,
+	},
+};
+
+module_platform_driver(cqspi_platform_driver);
+
+MODULE_DESCRIPTION("Cadence QSPI Controller Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" CQSPI_NAME);
+MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
+MODULE_AUTHOR("Graham Moore <grmoore@opensource.altera.com>");
-- 
2.8.1