[PATCH v9 2/2] spi: cadence-quadpsi: Add support for the Cadence QSPI controller

[Ramuthevar,Vadivel MuruganX]

From: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>

Add support for the Cadence QSPI controller. This controller is
present in the Intel Lightning Mountain(LGM) SoCs, Altera and TI SoCs.
This driver has been tested on the Intel LGM SoCs.

This driver does not support generic SPI and also the implementation
only supports spi-mem interface to replace the existing driver in
mtd/spi-nor/cadence-quadspi.c, the existing driver only support SPI-NOR
flash memory.

Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
Signed-off-by: Ramuthevar Vadivel Murugan <vadivel.muruganx.ramuthevar@xxxxxxxxxxxxxxx>
Reported-by: kbuild test robot <lkp@xxxxxxxxx>
Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 drivers/spi/Kconfig               |    8 +
 drivers/spi/Makefile              |    1 +
 drivers/spi/spi-cadence-quadspi.c | 1508 +++++++++++++++++++++++++++++++++++++
 3 files changed, 1517 insertions(+)
 create mode 100644 drivers/spi/spi-cadence-quadspi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 870f7797b56b..22c520504cc3 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -193,6 +193,14 @@ config SPI_CADENCE
 	  This selects the Cadence SPI controller master driver
 	  used by Xilinx Zynq and ZynqMP.
 
+config SPI_CADENCE_QUADSPI
+	tristate "Cadence Quad SPI controller"
+	depends on OF && (ARM || ARM64 || COMPILE_TEST || X86)
+	help
+	  Cadence QSPI is a specialized controller for connecting an SPI
+	  Flash over 1/2/4/8-bit wide bus. This enables support for the Octal
+	  and Quad SPI variants of Cadence QSPI IP.
+
 config SPI_CLPS711X
 	tristate "CLPS711X host SPI controller"
 	depends on ARCH_CLPS711X || COMPILE_TEST
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index bb49c9e6d0a0..288f5fa903fe 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_SPI_BCM_QSPI)		+= spi-iproc-qspi.o spi-brcmstb-qspi.o spi-bcm-qspi.
 obj-$(CONFIG_SPI_BITBANG)		+= spi-bitbang.o
 obj-$(CONFIG_SPI_BUTTERFLY)		+= spi-butterfly.o
 obj-$(CONFIG_SPI_CADENCE)		+= spi-cadence.o
+obj-$(CONFIG_SPI_CADENCE_QUADSPI)	+= spi-cadence-quadspi.o
 obj-$(CONFIG_SPI_CLPS711X)		+= spi-clps711x.o
 obj-$(CONFIG_SPI_COLDFIRE_QSPI)		+= spi-coldfire-qspi.o
 obj-$(CONFIG_SPI_DAVINCI)		+= spi-davinci.o
diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
new file mode 100644
index 000000000000..86b335585fa7
--- /dev/null
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -0,0 +1,1508 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Driver for Cadence QSPI Controller
+//
+// Copyright Altera Corporation (C) 2012-2014. All rights reserved.
+// Copyright Intel Corporation (C) 2019-2020. All rights reserved.
+// Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com
+//
+#include <linux/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/sched.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-mem.h>
+#include <linux/timer.h>
+
+#define CQSPI_NAME			"cadence-qspi"
+#define CQSPI_MAX_CHIPSELECT		16
+
+/* Quirks */
+#define CQSPI_NEEDS_WR_DELAY		BIT(0)
+#define CQSPI_DISABLE_DAC_MODE		BIT(1)
+#define CQSPI_NEEDS_ADDR_SWAP		BIT(1)
+
+/* Capabilities*/
+#define CQSPI_SUPPORTS_OCTAL		BIT(0)
+
+struct cqspi_st;
+
+struct cqspi_flash_pdata {
+	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		data_width;
+	u8		cs;
+	bool		registered;
+};
+
+struct cqspi_st {
+	struct platform_device	*pdev;
+
+	struct clk		*clk;
+	unsigned int		sclk;
+
+	void __iomem		*iobase;
+	void __iomem		*ahb_base;
+	resource_size_t		ahb_size;
+	struct completion	transfer_complete;
+
+	struct dma_chan		*rx_chan;
+	struct completion	rx_dma_complete;
+	dma_addr_t		mmap_phys_base;
+
+	int			current_cs;
+	unsigned long		master_ref_clk_hz;
+	u32			fifo_depth;
+	u32			fifo_width;
+	u32			bus_num;
+	u32			num_chipselect;
+	bool			rclk_en;
+	u32			trigger_address;
+	u32			wr_delay;
+	bool			use_dac_mode;
+	struct cqspi_flash_pdata f_pdata[CQSPI_MAX_CHIPSELECT];
+};
+
+struct cqspi_driver_platdata {
+	u32 hwcaps_mask;
+	u8 quirks;
+};
+
+/* 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_INST_TYPE_OCTAL			3
+
+#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_ENB_DIR_ACC_CTRL	BIT(7)
+#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_WR_INSTR_TYPE_ADDR_MASK	3
+#define CQSPI_REG_WR_INSTR_TYPE_DATA_MASK	3
+#define CQSPI_REG_WR_INSTR_TYPE_WEL_DIS_POS	8
+
+#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_WR_COMPLETION_CTRL		0x38
+#define CQSPI_REG_WR_DISABLE_AUTO_POLL		BIT(14)
+
+#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 clr)
+{
+	u32 val;
+
+	return readl_relaxed_poll_timeout(reg, val,
+					  (((clr ? ~val : val) & mask) == mask),
+					  10, CQSPI_TIMEOUT_MS * 1000);
+}
+
+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 u32 cqspi_cmd2addr(const struct spi_mem_op *op)
+{
+	const unsigned char *addr_buf = NULL;
+	unsigned int tmpbufsize;
+	unsigned int addr = 0;
+	u8 *tmpbuf;
+	int i;
+
+	/* Invalid address return zero. */
+	if (op->addr.nbytes > 4)
+		return 0;
+
+	tmpbufsize = op->addr.nbytes + op->dummy.nbytes;
+	tmpbuf = kzalloc(tmpbufsize, GFP_KERNEL | GFP_DMA);
+	if (!tmpbuf)
+		return -ENOMEM;
+
+	if (op->addr.nbytes) {
+		for (i = 0; i < op->addr.nbytes; i++)
+			tmpbuf[i] = op->addr.val >> (8 * (op->addr.nbytes - i - 1));
+
+		addr_buf = tmpbuf;
+	}
+	/* Invalid address return zero. */
+	if (op->addr.nbytes > 4)
+		return 0;
+
+	for (i = 0; i < op->addr.nbytes; i++) {
+		addr = addr << 8;
+		addr |= addr_buf[i];
+	}
+
+	return addr;
+}
+
+static unsigned int cqspi_calc_rdreg(struct cqspi_flash_pdata *f_pdata)
+{
+	u32 rdreg = 0;
+
+	rdreg |= f_pdata->inst_width << CQSPI_REG_RD_INSTR_TYPE_INSTR_LSB;
+	rdreg |= f_pdata->addr_width << CQSPI_REG_RD_INSTR_TYPE_ADDR_LSB;
+	rdreg |= f_pdata->data_width << 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 cqspi_flash_pdata *f_pdata,
+			      const struct spi_mem_op *op)
+{
+	const struct cqspi_driver_platdata *ddata;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	struct device *dev = &cqspi->pdev->dev;
+	void __iomem *reg_base = cqspi->iobase;
+	u8 *rxbuf = op->data.buf.in;
+	u8 opcode = op->cmd.opcode;
+	size_t n_rx = op->data.nbytes;
+	unsigned int addr_value;
+	unsigned int rdreg;
+	unsigned int reg;
+	size_t read_len;
+	int status;
+
+	if (!n_rx || n_rx > CQSPI_STIG_DATA_LEN_MAX || !rxbuf) {
+		dev_err(&cqspi->pdev->dev,
+			"Invalid input argument, len %zu rxbuf 0x%p\n",
+			n_rx, rxbuf);
+		return -EINVAL;
+	}
+
+	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+
+	rdreg = cqspi_calc_rdreg(f_pdata);
+	writel(rdreg, reg_base + CQSPI_REG_RD_INSTR);
+
+	reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
+
+	ddata  = of_device_get_match_data(dev);
+	if ((ddata->quirks & CQSPI_NEEDS_ADDR_SWAP) & op->addr.nbytes) {
+		reg |= BIT(CQSPI_REG_CMDCTRL_ADDR_EN_LSB);
+		reg |= ((op->addr.nbytes - 1) & CQSPI_REG_CMDCTRL_ADD_BYTES_MASK)
+			<< CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;
+		addr_value = cqspi_cmd2addr(op);
+
+		writel(addr_value, reg_base + CQSPI_REG_CMDADDRESS);
+	}
+
+	/* 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 cqspi_flash_pdata *f_pdata,
+			       const struct spi_mem_op *op)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	const u8 opcode = op->cmd.opcode;
+	const u8 *txbuf = op->data.buf.out;
+	size_t n_tx = op->data.nbytes;
+	unsigned int reg;
+	unsigned int data;
+	size_t write_len;
+
+	if (n_tx > CQSPI_STIG_DATA_LEN_MAX || (n_tx && !txbuf)) {
+		dev_err(&cqspi->pdev->dev,
+			"Invalid input argument, cmdlen %zu txbuf 0x%p\n",
+			n_tx, txbuf);
+		return -EINVAL;
+	}
+
+	reg = opcode << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+
+	if (op->addr.nbytes) {
+		reg |= (0x1 << CQSPI_REG_CMDCTRL_ADDR_EN_LSB);
+		reg |= ((op->addr.nbytes - 1) & CQSPI_REG_CMDCTRL_ADD_BYTES_MASK)
+		<< CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;
+
+		writel(op->addr.val, reg_base + CQSPI_REG_CMDADDRESS);
+	}
+
+	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;
+		write_len = (n_tx > 4) ? 4 : n_tx;
+		memcpy(&data, txbuf, write_len);
+		txbuf += write_len;
+		writel(data, reg_base + CQSPI_REG_CMDWRITEDATALOWER);
+
+		if (n_tx > 4) {
+			data = 0;
+			write_len = n_tx - 4;
+			memcpy(&data, txbuf, write_len);
+			writel(data, reg_base + CQSPI_REG_CMDWRITEDATAUPPER);
+		}
+	}
+
+	return cqspi_exec_flash_cmd(cqspi, reg);
+}
+
+static int cqspi_read_setup(struct cqspi_flash_pdata *f_pdata,
+			    const struct spi_mem_op *op)
+{
+	const struct cqspi_driver_platdata *ddata;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	void __iomem *reg_base = cqspi->iobase;
+	struct device *dev = &cqspi->pdev->dev;
+	unsigned int reg, addr_value;
+	unsigned int dummy_clk = 0;
+
+	ddata  = of_device_get_match_data(dev);
+	if ((ddata->quirks & CQSPI_NEEDS_ADDR_SWAP) & op->addr.nbytes) {
+		addr_value = cqspi_cmd2addr(op);
+		writel(addr_value, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
+		reg |= (op->data.buswidth & CQSPI_REG_RD_INSTR_TYPE_DATA_MASK) <<
+			CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
+	}
+
+	reg = op->cmd.opcode << CQSPI_REG_RD_INSTR_OPCODE_LSB;
+	reg |= cqspi_calc_rdreg(f_pdata);
+
+	/* Setup dummy clock cycles */
+	dummy_clk = op->dummy.nbytes * 8;
+	if (dummy_clk > CQSPI_DUMMY_CLKS_MAX)
+		dummy_clk = CQSPI_DUMMY_CLKS_MAX;
+
+	if (dummy_clk / 8)
+		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 |= (op->addr.nbytes - 1);
+	writel(reg, reg_base + CQSPI_REG_SIZE);
+	return 0;
+}
+
+static int cqspi_indirect_read_execute(struct cqspi_flash_pdata *f_pdata,
+				       u8 *rxbuf, loff_t from_addr,
+				       const size_t n_rx)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	struct device *dev = &cqspi->pdev->dev;
+	void __iomem *reg_base = cqspi->iobase;
+	void __iomem *ahb_base = cqspi->ahb_base;
+	unsigned int remaining = n_rx;
+	unsigned int mod_bytes = n_rx % 4;
+	unsigned int bytes_to_read = 0;
+	u8 *rxbuf_end = rxbuf + n_rx;
+	int ret = 0;
+
+	writel(from_addr, reg_base + CQSPI_REG_INDIRECTRDSTARTADDR);
+	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) {
+		if (!wait_for_completion_timeout(&cqspi->transfer_complete,
+				msecs_to_jiffies(CQSPI_READ_TIMEOUT_MS)))
+			ret = -ETIMEDOUT;
+
+		bytes_to_read = cqspi_get_rd_sram_level(cqspi);
+
+		if (ret && bytes_to_read == 0) {
+			dev_err(dev, "Indirect read timeout, no bytes\n");
+			goto failrd;
+		}
+
+		while (bytes_to_read != 0) {
+			unsigned int word_remain = round_down(remaining, 4);
+
+			bytes_to_read *= cqspi->fifo_width;
+			bytes_to_read = bytes_to_read > remaining ?
+					remaining : bytes_to_read;
+			bytes_to_read = round_down(bytes_to_read, 4);
+			/* Read 4 byte word chunks then single bytes */
+			if (bytes_to_read) {
+				ioread32_rep(ahb_base, rxbuf,
+					     (bytes_to_read / 4));
+			} else if (!word_remain && mod_bytes) {
+				unsigned int temp = ioread32(ahb_base);
+
+				bytes_to_read = mod_bytes;
+				memcpy(rxbuf, &temp, min((unsigned int)
+							 (rxbuf_end - rxbuf),
+							 bytes_to_read));
+			}
+			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(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_write_setup(struct cqspi_flash_pdata *f_pdata,
+			     const struct spi_mem_op *op)
+{
+	const struct cqspi_driver_platdata *ddata;
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	struct device *dev = &cqspi->pdev->dev;
+	void __iomem *reg_base = cqspi->iobase;
+	const u8 *txbuf = &op->cmd.opcode;
+	unsigned int reg;
+
+	/* Set opcode. */
+	reg = op->cmd.opcode << CQSPI_REG_WR_INSTR_OPCODE_LSB;
+	writel(reg, reg_base + CQSPI_REG_WR_INSTR);
+	reg = cqspi_calc_rdreg(f_pdata);
+	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
+
+	ddata  = of_device_get_match_data(dev);
+	if (ddata->quirks & CQSPI_NEEDS_ADDR_SWAP) {
+		/* Set opcode. */
+		reg = txbuf[0] << CQSPI_REG_WR_INSTR_OPCODE_LSB;
+		reg |= BIT(CQSPI_REG_WR_INSTR_TYPE_WEL_DIS_POS);
+		/* Configure the mode for address */
+		reg |= (op->addr.buswidth & CQSPI_REG_WR_INSTR_TYPE_ADDR_MASK) <<
+			CQSPI_REG_WR_INSTR_TYPE_ADDR_LSB;
+
+		/* Configure the mode for data */
+		reg |= (op->data.buswidth & CQSPI_REG_WR_INSTR_TYPE_DATA_MASK) <<
+			CQSPI_REG_WR_INSTR_TYPE_DATA_LSB;
+		writel(reg, reg_base + CQSPI_REG_WR_INSTR);
+		/* Setup write address. */
+		reg = cqspi_cmd2addr(op);
+		writel(reg, reg_base + CQSPI_REG_INDIRECTWRSTARTADDR);
+	}
+
+	reg = readl(reg_base + CQSPI_REG_SIZE);
+	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
+	reg |= (op->addr.nbytes - 1);
+	writel(reg, reg_base + CQSPI_REG_SIZE);
+	return 0;
+}
+
+static int cqspi_indirect_write_execute(struct cqspi_flash_pdata *f_pdata,
+					loff_t to_addr, const u8 *txbuf,
+					const size_t n_tx)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	struct device *dev = &cqspi->pdev->dev;
+	void __iomem *reg_base = cqspi->iobase;
+	unsigned int remaining = n_tx;
+	unsigned int write_bytes;
+	int ret;
+
+	writel(to_addr, reg_base + CQSPI_REG_INDIRECTWRSTARTADDR);
+	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);
+	/*
+	 * As per 66AK2G02 TRM SPRUHY8F section 11.15.5.3 Indirect Access
+	 * Controller programming sequence, couple of cycles of
+	 * QSPI_REF_CLK delay is required for the above bit to
+	 * be internally synchronized by the QSPI module. Provide 5
+	 * cycles of delay.
+	 */
+	if (cqspi->wr_delay)
+		ndelay(cqspi->wr_delay);
+
+	while (remaining > 0) {
+		size_t write_words, mod_bytes;
+
+		write_bytes = remaining;
+		write_words = write_bytes / 4;
+		mod_bytes = write_bytes % 4;
+		/* Write 4 bytes at a time then single bytes. */
+		if (write_words) {
+			iowrite32_rep(cqspi->ahb_base, txbuf, write_words);
+			txbuf += (write_words * 4);
+		}
+		if (mod_bytes) {
+			unsigned int temp = 0xFFFFFFFF;
+
+			memcpy(&temp, txbuf, mod_bytes);
+			iowrite32(temp, cqspi->ahb_base);
+			txbuf += mod_bytes;
+		}
+
+		if (!wait_for_completion_timeout(&cqspi->transfer_complete,
+					msecs_to_jiffies(CQSPI_TIMEOUT_MS))) {
+			dev_err(dev, "Indirect write timeout\n");
+			ret = -ETIMEDOUT;
+			goto failwr;
+		}
+
+		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(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 void cqspi_chipselect(struct cqspi_flash_pdata *f_pdata)
+{
+	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);
+	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 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 cqspi_flash_pdata *f_pdata)
+{
+	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 = DIV_ROUND_UP(ref_clk_hz, cqspi->sclk);
+
+	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 ref_clk_hz = cqspi->master_ref_clk_hz;
+	void __iomem *reg_base = cqspi->iobase;
+	u32 reg, div;
+
+	/* Recalculate the baudrate divisor based on QSPI specification. */
+	div = DIV_ROUND_UP(ref_clk_hz, 2 * cqspi->sclk) - 1;
+
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg &= ~(CQSPI_REG_CONFIG_BAUD_MASK << CQSPI_REG_CONFIG_BAUD_LSB);
+	reg |= (div & CQSPI_REG_CONFIG_BAUD_MASK) << CQSPI_REG_CONFIG_BAUD_LSB;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+}
+
+static void cqspi_readdata_capture(struct cqspi_st *cqspi,
+				   const bool 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_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_configure(struct cqspi_flash_pdata *f_pdata,
+			    unsigned long sclk)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	int switch_cs = (cqspi->current_cs != f_pdata->cs);
+	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_chipselect(f_pdata);
+	}
+
+	/* Setup baudrate divisor and delays */
+	if (switch_ck) {
+		cqspi->sclk = sclk;
+		cqspi_config_baudrate_div(cqspi);
+		cqspi_delay(f_pdata);
+		cqspi_readdata_capture(cqspi, !cqspi->rclk_en,
+				       f_pdata->read_delay);
+	}
+
+	if (switch_cs || switch_ck)
+		cqspi_controller_enable(cqspi, 1);
+}
+
+static int cqspi_set_protocol(struct cqspi_flash_pdata *f_pdata,
+			      const struct spi_mem_op *op)
+{
+	f_pdata->inst_width = CQSPI_INST_TYPE_SINGLE;
+	f_pdata->addr_width = CQSPI_INST_TYPE_SINGLE;
+	f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
+
+	if (op->data.dir == SPI_MEM_DATA_IN) {
+		switch (op->data.buswidth) {
+		case 1:
+			f_pdata->data_width = CQSPI_INST_TYPE_SINGLE;
+			break;
+		case 2:
+			f_pdata->data_width = CQSPI_INST_TYPE_DUAL;
+			break;
+		case 4:
+			f_pdata->data_width = CQSPI_INST_TYPE_QUAD;
+			break;
+		case 8:
+			f_pdata->data_width = CQSPI_INST_TYPE_OCTAL;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static ssize_t cqspi_write(struct cqspi_flash_pdata *f_pdata,
+			   const struct spi_mem_op *op)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	loff_t to = op->addr.val;
+	size_t len = op->data.nbytes;
+	const u_char *buf = op->data.buf.out;
+	int ret;
+
+	ret = cqspi_set_protocol(f_pdata, op);
+	if (ret)
+		return ret;
+
+	ret = cqspi_write_setup(f_pdata, op);
+	if (ret)
+		return ret;
+
+	if (cqspi->use_dac_mode && ((to + len) <= cqspi->ahb_size)) {
+		memcpy_toio(cqspi->ahb_base + to, buf, len);
+		return cqspi_wait_idle(cqspi);
+	}
+
+	return cqspi_indirect_write_execute(f_pdata, to, buf, len);
+}
+
+static void cqspi_rx_dma_callback(void *param)
+{
+	struct cqspi_st *cqspi = param;
+
+	complete(&cqspi->rx_dma_complete);
+}
+
+static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata,
+				     u_char *buf, loff_t from, size_t len)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	struct device *ddev = cqspi->rx_chan->device->dev;
+	enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
+	dma_addr_t dma_src = (dma_addr_t)cqspi->mmap_phys_base + from;
+	int ret = 0;
+	struct dma_async_tx_descriptor *tx;
+	dma_cookie_t cookie;
+	dma_addr_t dma_dst;
+
+	if (!cqspi->rx_chan || !virt_addr_valid(buf)) {
+		memcpy_fromio(buf, cqspi->ahb_base + from, len);
+		return 0;
+	}
+
+	dma_dst = dma_map_single(ddev, buf, len, DMA_FROM_DEVICE);
+	if (dma_mapping_error(ddev, dma_dst)) {
+		dev_err(ddev, "dma mapping failed\n");
+		return -ENOMEM;
+	}
+	tx = dmaengine_prep_dma_memcpy(cqspi->rx_chan, dma_dst, dma_src,
+				       len, flags);
+	if (!tx) {
+		dev_err(ddev, "device_prep_dma_memcpy error\n");
+		ret = -EIO;
+		goto err_unmap;
+	}
+
+	tx->callback = cqspi_rx_dma_callback;
+	tx->callback_param = cqspi;
+	cookie = tx->tx_submit(tx);
+	reinit_completion(&cqspi->rx_dma_complete);
+
+	ret = dma_submit_error(cookie);
+	if (ret) {
+		dev_err(ddev, "dma_submit_error %d\n", cookie);
+		ret = -EIO;
+		goto err_unmap;
+	}
+
+	dma_async_issue_pending(cqspi->rx_chan);
+	if (!wait_for_completion_timeout(&cqspi->rx_dma_complete,
+					 msecs_to_jiffies(len))) {
+		dmaengine_terminate_sync(cqspi->rx_chan);
+		dev_err(ddev, "DMA wait_for_completion_timeout\n");
+		ret = -ETIMEDOUT;
+		goto err_unmap;
+	}
+
+err_unmap:
+	dma_unmap_single(ddev, dma_dst, len, DMA_FROM_DEVICE);
+
+	return ret;
+}
+
+static ssize_t cqspi_read(struct cqspi_flash_pdata *f_pdata,
+			  const struct spi_mem_op *op)
+{
+	struct cqspi_st *cqspi = f_pdata->cqspi;
+	loff_t from = op->addr.val;
+	size_t len = op->data.nbytes;
+	u_char *buf = op->data.buf.in;
+	int ret;
+
+	ret = cqspi_set_protocol(f_pdata, op);
+	if (ret)
+		return ret;
+
+	ret = cqspi_read_setup(f_pdata, op);
+	if (ret)
+		return ret;
+
+	if (cqspi->use_dac_mode && ((from + len) <= cqspi->ahb_size))
+		return cqspi_direct_read_execute(f_pdata, buf, from, len);
+
+	return cqspi_indirect_read_execute(f_pdata, buf, from, len);
+}
+
+static int cqspi_mem_process(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	struct cqspi_st *cqspi = spi_master_get_devdata(mem->spi->master);
+	struct cqspi_flash_pdata *f_pdata;
+
+	f_pdata = &cqspi->f_pdata[mem->spi->chip_select];
+	cqspi_configure(f_pdata, mem->spi->max_speed_hz);
+
+	if (op->data.dir == SPI_MEM_DATA_IN && op->data.buf.in) {
+		if (!op->addr.nbytes)
+			return cqspi_command_read(f_pdata, op);
+
+		return cqspi_read(f_pdata, op);
+	}
+
+	if (!op->addr.nbytes || !op->data.buf.out)
+		return cqspi_command_write(f_pdata, op);
+
+	return cqspi_write(f_pdata, op);
+}
+
+static int cqspi_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
+{
+	int ret;
+
+	ret = cqspi_mem_process(mem, op);
+	if (ret)
+		dev_err(&mem->spi->dev, "operation failed with %d\n", ret);
+
+	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 cqspi_st *cqspi)
+{
+	struct device *dev = &cqspi->pdev->dev;
+	struct device_node *np = dev->of_node;
+
+	if (of_property_read_u32(np, "cdns,fifo-depth", &cqspi->fifo_depth)) {
+		dev_err(dev, "couldn't determine fifo-depth\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,fifo-width", &cqspi->fifo_width)) {
+		dev_err(dev, "couldn't determine fifo-width\n");
+		return -ENXIO;
+	}
+
+	if (of_property_read_u32(np, "cdns,trigger-address",
+				 &cqspi->trigger_address)) {
+		dev_err(dev, "couldn't determine trigger-address\n");
+		return -ENXIO;
+	}
+
+	cqspi->rclk_en = of_property_read_bool(np, "cdns,rclk-en");
+
+	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);
+
+	if (!cqspi->use_dac_mode) {
+		u32 reg;
+
+		reg = readl(cqspi->iobase + CQSPI_REG_CONFIG);
+		reg &= ~CQSPI_REG_CONFIG_ENB_DIR_ACC_CTRL;
+		writel(reg, cqspi->iobase + CQSPI_REG_CONFIG);
+
+		reg = readl(cqspi->iobase + CQSPI_REG_WR_COMPLETION_CTRL);
+		reg |= CQSPI_REG_WR_DISABLE_AUTO_POLL;
+		writel(reg, cqspi->iobase + CQSPI_REG_WR_COMPLETION_CTRL);
+	}
+
+	cqspi_controller_enable(cqspi, 1);
+}
+
+static int cqspi_request_mmap_dma(struct cqspi_st *cqspi)
+{
+	dma_cap_mask_t mask;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+
+	cqspi->rx_chan = dma_request_chan_by_mask(&mask);
+	if (IS_ERR(cqspi->rx_chan)) {
+		int ret = PTR_ERR(cqspi->rx_chan);
+
+		if (ret != -EPROBE_DEFER)
+			dev_err(&cqspi->pdev->dev, "No Rx DMA available\n");
+		cqspi->rx_chan = NULL;
+
+		return ret;
+	}
+	init_completion(&cqspi->rx_dma_complete);
+
+	return 0;
+}
+
+static const struct spi_controller_mem_ops cqspi_mem_ops = {
+	.exec_op = cqspi_exec_mem_op,
+};
+
+static int cqspi_setup_flash(struct cqspi_st *cqspi)
+{
+	struct platform_device *pdev = cqspi->pdev;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct cqspi_flash_pdata *f_pdata;
+	unsigned int cs;
+	int ret;
+
+	/* Get flash device data */
+	for_each_available_child_of_node(dev->of_node, np) {
+		ret = of_property_read_u32(np, "reg", &cs);
+		if (ret) {
+			dev_err(dev, "Couldn't determine chip select.\n");
+			return -EINVAL;
+		}
+
+		if (cs >= CQSPI_MAX_CHIPSELECT) {
+			dev_err(dev, "Chip select %d out of range.\n", cs);
+			return -EINVAL;
+		}
+
+		f_pdata = &cqspi->f_pdata[cs];
+		f_pdata->cqspi = cqspi;
+		f_pdata->cs = cs;
+
+		return cqspi_of_get_flash_pdata(pdev, f_pdata, np);
+	}
+
+	return 0;
+}
+
+static int cqspi_probe(struct platform_device *pdev)
+{
+	const struct cqspi_driver_platdata *ddata;
+	struct reset_control *rstc, *rstc_ocp;
+	struct device *dev = &pdev->dev;
+	struct spi_master *master;
+	struct resource *res_ahb;
+	struct cqspi_st *cqspi;
+	struct resource *res;
+	int ret;
+	int irq;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(*cqspi));
+	if (!master) {
+		dev_err(&pdev->dev, "spi_alloc_master failed\n");
+		return -ENOMEM;
+	}
+	master->mode_bits = SPI_RX_QUAD | SPI_TX_DUAL | SPI_RX_DUAL;
+	master->mem_ops = &cqspi_mem_ops;
+	master->dev.of_node = pdev->dev.of_node;
+
+	cqspi = spi_master_get_devdata(master);
+
+	cqspi->pdev = pdev;
+
+	/* Obtain configuration from OF. */
+	ret = cqspi_of_get_pdata(cqspi);
+	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);
+	}
+	cqspi->mmap_phys_base = (dma_addr_t)res_ahb->start;
+	cqspi->ahb_size = resource_size(res_ahb);
+
+	init_completion(&cqspi->transfer_complete);
+
+	/* Obtain IRQ line. */
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return -ENXIO;
+
+	pm_runtime_enable(dev);
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0) {
+		pm_runtime_put_noidle(dev);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(cqspi->clk);
+	if (ret) {
+		dev_err(dev, "Cannot enable QSPI clock.\n");
+		goto probe_clk_failed;
+	}
+
+	/* Obtain QSPI reset control */
+	rstc = devm_reset_control_get_optional_exclusive(dev, "qspi");
+	if (IS_ERR(rstc)) {
+		dev_err(dev, "Cannot get QSPI reset.\n");
+		goto probe_reset_failed;
+	}
+
+	rstc_ocp = devm_reset_control_get_optional_exclusive(dev, "qspi-ocp");
+	if (IS_ERR(rstc_ocp)) {
+		dev_err(dev, "Cannot get QSPI OCP reset.\n");
+		goto probe_reset_failed;
+	}
+
+	reset_control_assert(rstc);
+	reset_control_deassert(rstc);
+
+	reset_control_assert(rstc_ocp);
+	reset_control_deassert(rstc_ocp);
+
+	cqspi->master_ref_clk_hz = clk_get_rate(cqspi->clk);
+	ddata  = of_device_get_match_data(dev);
+	if (ddata) {
+		if (ddata->quirks & CQSPI_NEEDS_WR_DELAY)
+			cqspi->wr_delay = 5 * DIV_ROUND_UP(NSEC_PER_SEC,
+						cqspi->master_ref_clk_hz);
+		if (ddata->hwcaps_mask & CQSPI_SUPPORTS_OCTAL)
+			master->mode_bits |= SPI_RX_OCTAL;
+		if (!(ddata->quirks & CQSPI_DISABLE_DAC_MODE))
+			cqspi->use_dac_mode = true;
+		if (ddata->quirks & CQSPI_NEEDS_ADDR_SWAP) {
+			master->bus_num = 0;
+			master->num_chipselect = 2;
+		}
+	}
+
+	ret = devm_request_irq(dev, irq, cqspi_irq_handler, 0,
+			       pdev->name, cqspi);
+	if (ret) {
+		dev_err(dev, "Cannot request IRQ.\n");
+		goto probe_reset_failed;
+	}
+
+	cqspi_wait_idle(cqspi);
+	cqspi_controller_init(cqspi);
+	cqspi->current_cs = -1;
+	cqspi->sclk = 0;
+
+	ret = cqspi_setup_flash(cqspi);
+	if (ret) {
+		dev_err(dev, "failed to setup flash parameters %d\n", ret);
+		goto probe_setup_failed;
+	}
+
+	if (cqspi->use_dac_mode) {
+		ret = cqspi_request_mmap_dma(cqspi);
+		if (ret == -EPROBE_DEFER)
+			goto probe_setup_failed;
+	}
+
+	ret = devm_spi_register_master(dev, master);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register SPI ctlr %d\n", ret);
+		goto probe_setup_failed;
+	}
+
+	return 0;
+probe_setup_failed:
+	cqspi_controller_enable(cqspi, 0);
+probe_reset_failed:
+	clk_disable_unprepare(cqspi->clk);
+probe_clk_failed:
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+	return ret;
+}
+
+static int cqspi_remove(struct platform_device *pdev)
+{
+	struct cqspi_st *cqspi = platform_get_drvdata(pdev);
+
+	cqspi_controller_enable(cqspi, 0);
+
+	if (cqspi->rx_chan)
+		dma_release_channel(cqspi->rx_chan);
+
+	clk_disable_unprepare(cqspi->clk);
+
+	pm_runtime_put_sync(&pdev->dev);
+	pm_runtime_disable(&pdev->dev);
+
+	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 const struct cqspi_driver_platdata cdns_qspi = {
+	.quirks = CQSPI_DISABLE_DAC_MODE,
+};
+
+static const struct cqspi_driver_platdata k2g_qspi = {
+	.quirks = CQSPI_NEEDS_WR_DELAY,
+};
+
+static const struct cqspi_driver_platdata am654_ospi = {
+	.hwcaps_mask = CQSPI_SUPPORTS_OCTAL,
+	.quirks = CQSPI_NEEDS_WR_DELAY,
+};
+
+static const struct cqspi_driver_platdata intel_lgm_qspi = {
+	.quirks = CQSPI_NEEDS_ADDR_SWAP,
+};
+
+static const struct of_device_id cqspi_dt_ids[] = {
+	{
+		.compatible = "cdns,qspi-nor",
+		.data = &cdns_qspi,
+	},
+	{
+		.compatible = "ti,k2g-qspi",
+		.data = &k2g_qspi,
+	},
+	{
+		.compatible = "ti,am654-ospi",
+		.data = &am654_ospi,
+	},
+	{
+		.compatible = "intel,lgm-qspi",
+		.data = &intel_lgm_qspi,
+	},
+	{ /* 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@xxxxxxxxxx>");
+MODULE_AUTHOR("Graham Moore <grmoore@xxxxxxxxxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Vadivel Murugan R <vadivel.muruganx.ramuthevar@xxxxxxxxx>");
+MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@xxxxxx>");
-- 
2.11.0