spi: Add Cadence QSPI DM driver used by SoCFPGA

This driver is cloned from the Altera Rockerboard.org U-Boot
repository. I used this git tag: ACDS14.0.1_REL_GSRD_RC2. With Some
modification to support the U-Boot driver model (DM).

As mentioned above, in this new version I ported this driver to the
new driver model (DM). One big advantage of this move is that now
multiple SPI drivers can be enabled on one platform. And since the
SoCFPGA also has the Designware SPI master controller integrated,
this feature is really needed to support both controllers.

Because of this, this series needs the DT support for SoCFPGA
to be applied. For DT based probing in the SPI DM.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Chin Liang See <clsee@altera.com>
Cc: Dinh Nguyen <dinguyen@altera.com>
Cc: Vince Bridgers <vbridger@altera.com>
Cc: Marek Vasut <marex@denx.de>
Cc: Pavel Machek <pavel@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Jagannadha Sutradharudu Teki <jagannadh.teki@gmail.com>
diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
new file mode 100644
index 0000000..00a115f
--- /dev/null
+++ b/drivers/spi/cadence_qspi_apb.c
@@ -0,0 +1,898 @@
+/*
+ * Copyright (C) 2012 Altera Corporation <www.altera.com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *  - Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  - Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *  - Neither the name of the Altera Corporation nor the
+ *    names of its contributors may be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL ALTERA CORPORATION BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include "cadence_qspi.h"
+
+#define CQSPI_REG_POLL_US			(1) /* 1us */
+#define CQSPI_REG_RETRY				(10000)
+#define CQSPI_POLL_IDLE_RETRY			(3)
+
+#define CQSPI_FIFO_WIDTH			(4)
+
+/* Controller sram size in word */
+#define CQSPI_REG_SRAM_SIZE_WORD		(128)
+#define CQSPI_REG_SRAM_RESV_WORDS		(2)
+#define CQSPI_REG_SRAM_PARTITION_WR		(1)
+#define CQSPI_REG_SRAM_PARTITION_RD		\
+	(CQSPI_REG_SRAM_SIZE_WORD - CQSPI_REG_SRAM_RESV_WORDS)
+#define CQSPI_REG_SRAM_THRESHOLD_WORDS		(50)
+
+/* Transfer mode */
+#define CQSPI_INST_TYPE_SINGLE			(0)
+#define CQSPI_INST_TYPE_DUAL			(1)
+#define CQSPI_INST_TYPE_QUAD			(2)
+
+#define CQSPI_STIG_DATA_LEN_MAX			(8)
+#define CQSPI_INDIRECTTRIGGER_ADDR_MASK		(0xFFFFF)
+
+#define CQSPI_DUMMY_CLKS_PER_BYTE		(8)
+#define CQSPI_DUMMY_BYTES_MAX			(4)
+
+
+#define CQSPI_REG_SRAM_FILL_THRESHOLD	\
+	((CQSPI_REG_SRAM_SIZE_WORD / 2) * CQSPI_FIFO_WIDTH)
+/****************************************************************************
+ * Controller's configuration and status register (offset from QSPI_BASE)
+ ****************************************************************************/
+#define	CQSPI_REG_CONFIG			0x00
+#define	CQSPI_REG_CONFIG_CLK_POL_LSB		1
+#define	CQSPI_REG_CONFIG_CLK_PHA_LSB		2
+#define	CQSPI_REG_CONFIG_ENABLE_MASK		(1 << 0)
+#define	CQSPI_REG_CONFIG_DIRECT_MASK		(1 << 7)
+#define	CQSPI_REG_CONFIG_DECODE_MASK		(1 << 9)
+#define	CQSPI_REG_CONFIG_XIP_IMM_MASK		(1 << 18)
+#define	CQSPI_REG_CONFIG_CHIPSELECT_LSB		10
+#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_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_READLCAPTURE			0x10
+#define	CQSPI_READLCAPTURE_BYPASS_LSB		0
+#define	CQSPI_READLCAPTURE_DELAY_LSB		1
+#define	CQSPI_READLCAPTURE_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_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		(1 << 0)
+#define	CQSPI_REG_INDIRECTRD_CANCEL_MASK	(1 << 1)
+#define	CQSPI_REG_INDIRECTRD_INPROGRESS_MASK	(1 << 2)
+#define	CQSPI_REG_INDIRECTRD_DONE_MASK		(1 << 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		(1 << 0)
+#define	CQSPI_REG_CMDCTRL_INPROGRESS_MASK	(1 << 1)
+#define	CQSPI_REG_CMDCTRL_DUMMY_LSB		7
+#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_DUMMY_MASK		0x1F
+#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_CMDCTRL_OPCODE_MASK		0xFF
+
+#define	CQSPI_REG_INDIRECTWR			0x70
+#define	CQSPI_REG_INDIRECTWR_START_MASK		(1 << 0)
+#define	CQSPI_REG_INDIRECTWR_CANCEL_MASK	(1 << 1)
+#define	CQSPI_REG_INDIRECTWR_INPROGRESS_MASK	(1 << 2)
+#define	CQSPI_REG_INDIRECTWR_DONE_MASK		(1 << 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
+
+#define CQSPI_REG_IS_IDLE(base)					\
+	((readl(base + CQSPI_REG_CONFIG) >>		\
+		CQSPI_REG_CONFIG_IDLE_LSB) & 0x1)
+
+#define CQSPI_CAL_DELAY(tdelay_ns, tref_ns, tsclk_ns)		\
+	((((tdelay_ns) - (tsclk_ns)) / (tref_ns)))
+
+#define CQSPI_GET_RD_SRAM_LEVEL(reg_base)			\
+	(((readl(reg_base + CQSPI_REG_SDRAMLEVEL)) >>	\
+	CQSPI_REG_SDRAMLEVEL_RD_LSB) & CQSPI_REG_SDRAMLEVEL_RD_MASK)
+
+#define CQSPI_GET_WR_SRAM_LEVEL(reg_base)			\
+	(((readl(reg_base + CQSPI_REG_SDRAMLEVEL)) >>	\
+	CQSPI_REG_SDRAMLEVEL_WR_LSB) & CQSPI_REG_SDRAMLEVEL_WR_MASK)
+
+static unsigned int cadence_qspi_apb_cmd2addr(const unsigned char *addr_buf,
+	unsigned int addr_width)
+{
+	unsigned int addr;
+
+	addr = (addr_buf[0] << 16) | (addr_buf[1] << 8) | addr_buf[2];
+
+	if (addr_width == 4)
+		addr = (addr << 8) | addr_buf[3];
+
+	return addr;
+}
+
+static void cadence_qspi_apb_read_fifo_data(void *dest,
+	const void *src_ahb_addr, unsigned int bytes)
+{
+	unsigned int temp;
+	int remaining = bytes;
+	unsigned int *dest_ptr = (unsigned int *)dest;
+	unsigned int *src_ptr = (unsigned int *)src_ahb_addr;
+
+	while (remaining > 0) {
+		if (remaining >= CQSPI_FIFO_WIDTH) {
+			*dest_ptr = readl(src_ptr);
+			remaining -= CQSPI_FIFO_WIDTH;
+		} else {
+			/* dangling bytes */
+			temp = readl(src_ptr);
+			memcpy(dest_ptr, &temp, remaining);
+			break;
+		}
+		dest_ptr++;
+	}
+
+	return;
+}
+
+static void cadence_qspi_apb_write_fifo_data(const void *dest_ahb_addr,
+	const void *src, unsigned int bytes)
+{
+	unsigned int temp;
+	int remaining = bytes;
+	unsigned int *dest_ptr = (unsigned int *)dest_ahb_addr;
+	unsigned int *src_ptr = (unsigned int *)src;
+
+	while (remaining > 0) {
+		if (remaining >= CQSPI_FIFO_WIDTH) {
+			writel(*src_ptr, dest_ptr);
+			remaining -= sizeof(unsigned int);
+		} else {
+			/* dangling bytes */
+			memcpy(&temp, src_ptr, remaining);
+			writel(temp, dest_ptr);
+			break;
+		}
+		src_ptr++;
+	}
+
+	return;
+}
+
+/* Read from SRAM FIFO with polling SRAM fill level. */
+static int qspi_read_sram_fifo_poll(const void *reg_base, void *dest_addr,
+			const void *src_addr,  unsigned int num_bytes)
+{
+	unsigned int remaining = num_bytes;
+	unsigned int retry;
+	unsigned int sram_level = 0;
+	unsigned char *dest = (unsigned char *)dest_addr;
+
+	while (remaining > 0) {
+		retry = CQSPI_REG_RETRY;
+		while (retry--) {
+			sram_level = CQSPI_GET_RD_SRAM_LEVEL(reg_base);
+			if (sram_level)
+				break;
+			udelay(1);
+		}
+
+		if (!retry) {
+			printf("QSPI: No receive data after polling for %d times\n",
+			       CQSPI_REG_RETRY);
+			return -1;
+		}
+
+		sram_level *= CQSPI_FIFO_WIDTH;
+		sram_level = sram_level > remaining ? remaining : sram_level;
+
+		/* Read data from FIFO. */
+		cadence_qspi_apb_read_fifo_data(dest, src_addr, sram_level);
+		dest += sram_level;
+		remaining -= sram_level;
+		udelay(1);
+	}
+	return 0;
+}
+
+/* Write to SRAM FIFO with polling SRAM fill level. */
+static int qpsi_write_sram_fifo_push(struct cadence_spi_platdata *plat,
+				const void *src_addr, unsigned int num_bytes)
+{
+	const void *reg_base = plat->regbase;
+	void *dest_addr = plat->ahbbase;
+	unsigned int retry = CQSPI_REG_RETRY;
+	unsigned int sram_level;
+	unsigned int wr_bytes;
+	unsigned char *src = (unsigned char *)src_addr;
+	int remaining = num_bytes;
+	unsigned int page_size = plat->page_size;
+	unsigned int sram_threshold_words = CQSPI_REG_SRAM_THRESHOLD_WORDS;
+
+	while (remaining > 0) {
+		retry = CQSPI_REG_RETRY;
+		while (retry--) {
+			sram_level = CQSPI_GET_WR_SRAM_LEVEL(reg_base);
+			if (sram_level <= sram_threshold_words)
+				break;
+		}
+		if (!retry) {
+			printf("QSPI: SRAM fill level (0x%08x) not hit lower expected level (0x%08x)",
+			       sram_level, sram_threshold_words);
+			return -1;
+		}
+		/* Write a page or remaining bytes. */
+		wr_bytes = (remaining > page_size) ?
+					page_size : remaining;
+
+		cadence_qspi_apb_write_fifo_data(dest_addr, src, wr_bytes);
+		src += wr_bytes;
+		remaining -= wr_bytes;
+	}
+
+	return 0;
+}
+
+void cadence_qspi_apb_controller_enable(void *reg_base)
+{
+	unsigned int reg;
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg |= CQSPI_REG_CONFIG_ENABLE_MASK;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+	return;
+}
+
+void cadence_qspi_apb_controller_disable(void *reg_base)
+{
+	unsigned int reg;
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg &= ~CQSPI_REG_CONFIG_ENABLE_MASK;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+	return;
+}
+
+/* Return 1 if idle, otherwise return 0 (busy). */
+static unsigned int cadence_qspi_wait_idle(void *reg_base)
+{
+	unsigned int start, count = 0;
+	/* timeout in unit of ms */
+	unsigned int timeout = 5000;
+
+	start = get_timer(0);
+	for ( ; get_timer(start) < timeout ; ) {
+		if (CQSPI_REG_IS_IDLE(reg_base))
+			count++;
+		else
+			count = 0;
+		/*
+		 * Ensure the QSPI controller is in true idle state after
+		 * reading back the same idle status consecutively
+		 */
+		if (count >= CQSPI_POLL_IDLE_RETRY)
+			return 1;
+	}
+
+	/* Timeout, still in busy mode. */
+	printf("QSPI: QSPI is still busy after poll for %d times.\n",
+	       CQSPI_REG_RETRY);
+	return 0;
+}
+
+void cadence_qspi_apb_readdata_capture(void *reg_base,
+				unsigned int bypass, unsigned int delay)
+{
+	unsigned int reg;
+	cadence_qspi_apb_controller_disable(reg_base);
+
+	reg = readl(reg_base + CQSPI_READLCAPTURE);
+
+	if (bypass)
+		reg |= (1 << CQSPI_READLCAPTURE_BYPASS_LSB);
+	else
+		reg &= ~(1 << CQSPI_READLCAPTURE_BYPASS_LSB);
+
+	reg &= ~(CQSPI_READLCAPTURE_DELAY_MASK
+		<< CQSPI_READLCAPTURE_DELAY_LSB);
+
+	reg |= ((delay & CQSPI_READLCAPTURE_DELAY_MASK)
+		<< CQSPI_READLCAPTURE_DELAY_LSB);
+
+	writel(reg, reg_base + CQSPI_READLCAPTURE);
+
+	cadence_qspi_apb_controller_enable(reg_base);
+	return;
+}
+
+void cadence_qspi_apb_config_baudrate_div(void *reg_base,
+	unsigned int ref_clk_hz, unsigned int sclk_hz)
+{
+	unsigned int reg;
+	unsigned int div;
+
+	cadence_qspi_apb_controller_disable(reg_base);
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg &= ~(CQSPI_REG_CONFIG_BAUD_MASK << CQSPI_REG_CONFIG_BAUD_LSB);
+
+	div = ref_clk_hz / sclk_hz;
+
+	if (div > 32)
+		div = 32;
+
+	/* Check if even number. */
+	if ((div & 1)) {
+		div = (div / 2);
+	} else {
+		if (ref_clk_hz % sclk_hz)
+			/* ensure generated SCLK doesn't exceed user
+			specified sclk_hz */
+			div = (div / 2);
+		else
+			div = (div / 2) - 1;
+	}
+
+	debug("%s: ref_clk %dHz sclk %dHz Div 0x%x\n", __func__,
+	      ref_clk_hz, sclk_hz, div);
+
+	div = (div & CQSPI_REG_CONFIG_BAUD_MASK) << CQSPI_REG_CONFIG_BAUD_LSB;
+	reg |= div;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+
+	cadence_qspi_apb_controller_enable(reg_base);
+	return;
+}
+
+void cadence_qspi_apb_set_clk_mode(void *reg_base,
+	unsigned int clk_pol, unsigned int clk_pha)
+{
+	unsigned int reg;
+
+	cadence_qspi_apb_controller_disable(reg_base);
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg &= ~(1 <<
+		(CQSPI_REG_CONFIG_CLK_POL_LSB | CQSPI_REG_CONFIG_CLK_PHA_LSB));
+
+	reg |= ((clk_pol & 0x1) << CQSPI_REG_CONFIG_CLK_POL_LSB);
+	reg |= ((clk_pha & 0x1) << CQSPI_REG_CONFIG_CLK_PHA_LSB);
+
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+
+	cadence_qspi_apb_controller_enable(reg_base);
+	return;
+}
+
+void cadence_qspi_apb_chipselect(void *reg_base,
+	unsigned int chip_select, unsigned int decoder_enable)
+{
+	unsigned int reg;
+
+	cadence_qspi_apb_controller_disable(reg_base);
+
+	debug("%s : chipselect %d decode %d\n", __func__, chip_select,
+	      decoder_enable);
+
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	/* docoder */
+	if (decoder_enable) {
+		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);
+
+	cadence_qspi_apb_controller_enable(reg_base);
+	return;
+}
+
+void cadence_qspi_apb_delay(void *reg_base,
+	unsigned int ref_clk, unsigned int sclk_hz,
+	unsigned int tshsl_ns, unsigned int tsd2d_ns,
+	unsigned int tchsh_ns, unsigned int tslch_ns)
+{
+	unsigned int ref_clk_ns;
+	unsigned int sclk_ns;
+	unsigned int tshsl, tchsh, tslch, tsd2d;
+	unsigned int reg;
+
+	cadence_qspi_apb_controller_disable(reg_base);
+
+	/* Convert to ns. */
+	ref_clk_ns = (1000000000) / ref_clk;
+
+	/* Convert to ns. */
+	sclk_ns = (1000000000) / sclk_hz;
+
+	/* Plus 1 to round up 1 clock cycle. */
+	tshsl = CQSPI_CAL_DELAY(tshsl_ns, ref_clk_ns, sclk_ns) + 1;
+	tchsh = CQSPI_CAL_DELAY(tchsh_ns, ref_clk_ns, sclk_ns) + 1;
+	tslch = CQSPI_CAL_DELAY(tslch_ns, ref_clk_ns, sclk_ns) + 1;
+	tsd2d = CQSPI_CAL_DELAY(tsd2d_ns, ref_clk_ns, sclk_ns) + 1;
+
+	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, reg_base + CQSPI_REG_DELAY);
+
+	cadence_qspi_apb_controller_enable(reg_base);
+	return;
+}
+
+void cadence_qspi_apb_controller_init(struct cadence_spi_platdata *plat)
+{
+	unsigned reg;
+
+	cadence_qspi_apb_controller_disable(plat->regbase);
+
+	/* Configure the device size and address bytes */
+	reg = readl(plat->regbase + CQSPI_REG_SIZE);
+	/* Clear the previous value */
+	reg &= ~(CQSPI_REG_SIZE_PAGE_MASK << CQSPI_REG_SIZE_PAGE_LSB);
+	reg &= ~(CQSPI_REG_SIZE_BLOCK_MASK << CQSPI_REG_SIZE_BLOCK_LSB);
+	reg |= (plat->page_size << CQSPI_REG_SIZE_PAGE_LSB);
+	reg |= (plat->block_size << CQSPI_REG_SIZE_BLOCK_LSB);
+	writel(reg, plat->regbase + CQSPI_REG_SIZE);
+
+	/* Configure the remap address register, no remap */
+	writel(0, plat->regbase + CQSPI_REG_REMAP);
+
+	/* Disable all interrupts */
+	writel(0, plat->regbase + CQSPI_REG_IRQMASK);
+
+	cadence_qspi_apb_controller_enable(plat->regbase);
+	return;
+}
+
+static int cadence_qspi_apb_exec_flash_cmd(void *reg_base,
+	unsigned int reg)
+{
+	unsigned int retry = CQSPI_REG_RETRY;
+
+	/* 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);
+
+	while (retry--) {
+		reg = readl(reg_base + CQSPI_REG_CMDCTRL);
+		if ((reg & CQSPI_REG_CMDCTRL_INPROGRESS_MASK) == 0)
+			break;
+		udelay(1);
+	}
+
+	if (!retry) {
+		printf("QSPI: flash command execution timeout\n");
+		return -EIO;
+	}
+
+	/* Polling QSPI idle status. */
+	if (!cadence_qspi_wait_idle(reg_base))
+		return -EIO;
+
+	return 0;
+}
+
+/* For command RDID, RDSR. */
+int cadence_qspi_apb_command_read(void *reg_base,
+	unsigned int cmdlen, const u8 *cmdbuf, unsigned int rxlen,
+	u8 *rxbuf)
+{
+	unsigned int reg;
+	unsigned int read_len;
+	int status;
+
+	if (!cmdlen || rxlen > CQSPI_STIG_DATA_LEN_MAX || rxbuf == NULL) {
+		printf("QSPI: Invalid input arguments cmdlen %d rxlen %d\n",
+		       cmdlen, rxlen);
+		return -EINVAL;
+	}
+
+	reg = cmdbuf[0] << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+
+	reg |= (0x1 << CQSPI_REG_CMDCTRL_RD_EN_LSB);
+
+	/* 0 means 1 byte. */
+	reg |= (((rxlen - 1) & CQSPI_REG_CMDCTRL_RD_BYTES_MASK)
+		<< CQSPI_REG_CMDCTRL_RD_BYTES_LSB);
+	status = cadence_qspi_apb_exec_flash_cmd(reg_base, reg);
+	if (status != 0)
+		return status;
+
+	reg = readl(reg_base + CQSPI_REG_CMDREADDATALOWER);
+
+	/* Put the read value into rx_buf */
+	read_len = (rxlen > 4) ? 4 : rxlen;
+	memcpy(rxbuf, &reg, read_len);
+	rxbuf += read_len;
+
+	if (rxlen > 4) {
+		reg = readl(reg_base + CQSPI_REG_CMDREADDATAUPPER);
+
+		read_len = rxlen - read_len;
+		memcpy(rxbuf, &reg, read_len);
+	}
+	return 0;
+}
+
+/* For commands: WRSR, WREN, WRDI, CHIP_ERASE, BE, etc. */
+int cadence_qspi_apb_command_write(void *reg_base, unsigned int cmdlen,
+	const u8 *cmdbuf, unsigned int txlen,  const u8 *txbuf)
+{
+	unsigned int reg = 0;
+	unsigned int addr_value;
+	unsigned int wr_data;
+	unsigned int wr_len;
+
+	if (!cmdlen || cmdlen > 5 || txlen > 8 || cmdbuf == NULL) {
+		printf("QSPI: Invalid input arguments cmdlen %d txlen %d\n",
+		       cmdlen, txlen);
+		return -EINVAL;
+	}
+
+	reg |= cmdbuf[0] << CQSPI_REG_CMDCTRL_OPCODE_LSB;
+
+	if (cmdlen == 4 || cmdlen == 5) {
+		/* Command with address */
+		reg |= (0x1 << CQSPI_REG_CMDCTRL_ADDR_EN_LSB);
+		/* Number of bytes to write. */
+		reg |= ((cmdlen - 2) & CQSPI_REG_CMDCTRL_ADD_BYTES_MASK)
+			<< CQSPI_REG_CMDCTRL_ADD_BYTES_LSB;
+		/* Get address */
+		addr_value = cadence_qspi_apb_cmd2addr(&cmdbuf[1],
+			cmdlen >= 5 ? 4 : 3);
+
+		writel(addr_value, reg_base + CQSPI_REG_CMDADDRESS);
+	}
+
+	if (txlen) {
+		/* writing data = yes */
+		reg |= (0x1 << CQSPI_REG_CMDCTRL_WR_EN_LSB);
+		reg |= ((txlen - 1) & CQSPI_REG_CMDCTRL_WR_BYTES_MASK)
+			<< CQSPI_REG_CMDCTRL_WR_BYTES_LSB;
+
+		wr_len = txlen > 4 ? 4 : txlen;
+		memcpy(&wr_data, txbuf, wr_len);
+		writel(wr_data, reg_base +
+			CQSPI_REG_CMDWRITEDATALOWER);
+
+		if (txlen > 4) {
+			txbuf += wr_len;
+			wr_len = txlen - wr_len;
+			memcpy(&wr_data, txbuf, wr_len);
+			writel(wr_data, reg_base +
+				CQSPI_REG_CMDWRITEDATAUPPER);
+		}
+	}
+
+	/* Execute the command */
+	return cadence_qspi_apb_exec_flash_cmd(reg_base, reg);
+}
+
+/* Opcode + Address (3/4 bytes) + dummy bytes (0-4 bytes) */
+int cadence_qspi_apb_indirect_read_setup(struct cadence_spi_platdata *plat,
+	unsigned int cmdlen, const u8 *cmdbuf)
+{
+	unsigned int reg;
+	unsigned int rd_reg;
+	unsigned int addr_value;
+	unsigned int dummy_clk;
+	unsigned int dummy_bytes;
+	unsigned int addr_bytes;
+
+	/*
+	 * Identify addr_byte. All NOR flash device drivers are using fast read
+	 * which always expecting 1 dummy byte, 1 cmd byte and 3/4 addr byte.
+	 * With that, the length is in value of 5 or 6. Only FRAM chip from
+	 * ramtron using normal read (which won't need dummy byte).
+	 * Unlikely NOR flash using normal read due to performance issue.
+	 */
+	if (cmdlen >= 5)
+		/* to cater fast read where cmd + addr + dummy */
+		addr_bytes = cmdlen - 2;
+	else
+		/* for normal read (only ramtron as of now) */
+		addr_bytes = cmdlen - 1;
+
+	/* Setup the indirect trigger address */
+	writel(((u32)plat->ahbbase & CQSPI_INDIRECTTRIGGER_ADDR_MASK),
+	       plat->regbase + CQSPI_REG_INDIRECTTRIGGER);
+
+	/* Configure SRAM partition for read. */
+	writel(CQSPI_REG_SRAM_PARTITION_RD, plat->regbase +
+	       CQSPI_REG_SRAMPARTITION);
+
+	/* Configure the opcode */
+	rd_reg = cmdbuf[0] << CQSPI_REG_RD_INSTR_OPCODE_LSB;
+
+#if (CONFIG_SPI_FLASH_QUAD == 1)
+	/* Instruction and address at DQ0, data at DQ0-3. */
+	rd_reg |= CQSPI_INST_TYPE_QUAD << CQSPI_REG_RD_INSTR_TYPE_DATA_LSB;
+#endif
+
+	/* Get address */
+	addr_value = cadence_qspi_apb_cmd2addr(&cmdbuf[1], addr_bytes);
+	writel(addr_value, plat->regbase + CQSPI_REG_INDIRECTRDSTARTADDR);
+
+	/* The remaining lenght is dummy bytes. */
+	dummy_bytes = cmdlen - addr_bytes - 1;
+	if (dummy_bytes) {
+		if (dummy_bytes > CQSPI_DUMMY_BYTES_MAX)
+			dummy_bytes = CQSPI_DUMMY_BYTES_MAX;
+
+		rd_reg |= (1 << CQSPI_REG_RD_INSTR_MODE_EN_LSB);
+#if defined(CONFIG_SPL_SPI_XIP) && defined(CONFIG_SPL_BUILD)
+		writel(0x0, plat->regbase + CQSPI_REG_MODE_BIT);
+#else
+		writel(0xFF, plat->regbase + CQSPI_REG_MODE_BIT);
+#endif
+
+		/* Convert to clock cycles. */
+		dummy_clk = dummy_bytes * CQSPI_DUMMY_CLKS_PER_BYTE;
+		/* Need to minus the mode byte (8 clocks). */
+		dummy_clk -= CQSPI_DUMMY_CLKS_PER_BYTE;
+
+		if (dummy_clk)
+			rd_reg |= (dummy_clk & CQSPI_REG_RD_INSTR_DUMMY_MASK)
+				<< CQSPI_REG_RD_INSTR_DUMMY_LSB;
+	}
+
+	writel(rd_reg, plat->regbase + CQSPI_REG_RD_INSTR);
+
+	/* set device size */
+	reg = readl(plat->regbase + CQSPI_REG_SIZE);
+	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
+	reg |= (addr_bytes - 1);
+	writel(reg, plat->regbase + CQSPI_REG_SIZE);
+	return 0;
+}
+
+int cadence_qspi_apb_indirect_read_execute(struct cadence_spi_platdata *plat,
+	unsigned int rxlen, u8 *rxbuf)
+{
+	unsigned int reg;
+
+	writel(rxlen, plat->regbase + CQSPI_REG_INDIRECTRDBYTES);
+
+	/* Start the indirect read transfer */
+	writel(CQSPI_REG_INDIRECTRD_START_MASK,
+	       plat->regbase + CQSPI_REG_INDIRECTRD);
+
+	if (qspi_read_sram_fifo_poll(plat->regbase, (void *)rxbuf,
+				     (const void *)plat->ahbbase, rxlen))
+		goto failrd;
+
+	/* Check flash indirect controller */
+	reg = readl(plat->regbase + CQSPI_REG_INDIRECTRD);
+	if (!(reg & CQSPI_REG_INDIRECTRD_DONE_MASK)) {
+		reg = readl(plat->regbase + CQSPI_REG_INDIRECTRD);
+		printf("QSPI: indirect completion status error with reg 0x%08x\n",
+		       reg);
+		goto failrd;
+	}
+
+	/* Clear indirect completion status */
+	writel(CQSPI_REG_INDIRECTRD_DONE_MASK,
+	       plat->regbase + CQSPI_REG_INDIRECTRD);
+	return 0;
+
+failrd:
+	/* Cancel the indirect read */
+	writel(CQSPI_REG_INDIRECTRD_CANCEL_MASK,
+	       plat->regbase + CQSPI_REG_INDIRECTRD);
+	return -1;
+}
+
+/* Opcode + Address (3/4 bytes) */
+int cadence_qspi_apb_indirect_write_setup(struct cadence_spi_platdata *plat,
+	unsigned int cmdlen, const u8 *cmdbuf)
+{
+	unsigned int reg;
+	unsigned int addr_bytes = cmdlen > 4 ? 4 : 3;
+
+	if (cmdlen < 4 || cmdbuf == NULL) {
+		printf("QSPI: iInvalid input argument, len %d cmdbuf 0x%08x\n",
+		       cmdlen, (unsigned int)cmdbuf);
+		return -EINVAL;
+	}
+	/* Setup the indirect trigger address */
+	writel(((u32)plat->ahbbase & CQSPI_INDIRECTTRIGGER_ADDR_MASK),
+	       plat->regbase + CQSPI_REG_INDIRECTTRIGGER);
+
+	writel(CQSPI_REG_SRAM_PARTITION_WR,
+	       plat->regbase + CQSPI_REG_SRAMPARTITION);
+
+	/* Configure the opcode */
+	reg = cmdbuf[0] << CQSPI_REG_WR_INSTR_OPCODE_LSB;
+	writel(reg, plat->regbase + CQSPI_REG_WR_INSTR);
+
+	/* Setup write address. */
+	reg = cadence_qspi_apb_cmd2addr(&cmdbuf[1], addr_bytes);
+	writel(reg, plat->regbase + CQSPI_REG_INDIRECTWRSTARTADDR);
+
+	reg = readl(plat->regbase + CQSPI_REG_SIZE);
+	reg &= ~CQSPI_REG_SIZE_ADDRESS_MASK;
+	reg |= (addr_bytes - 1);
+	writel(reg, plat->regbase + CQSPI_REG_SIZE);
+	return 0;
+}
+
+int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat,
+	unsigned int txlen, const u8 *txbuf)
+{
+	unsigned int reg = 0;
+	unsigned int retry;
+
+	/* Configure the indirect read transfer bytes */
+	writel(txlen, plat->regbase + CQSPI_REG_INDIRECTWRBYTES);
+
+	/* Start the indirect write transfer */
+	writel(CQSPI_REG_INDIRECTWR_START_MASK,
+	       plat->regbase + CQSPI_REG_INDIRECTWR);
+
+	if (qpsi_write_sram_fifo_push(plat, (const void *)txbuf, txlen))
+		goto failwr;
+
+	/* Wait until last write is completed (FIFO empty) */
+	retry = CQSPI_REG_RETRY;
+	while (retry--) {
+		reg = CQSPI_GET_WR_SRAM_LEVEL(plat->regbase);
+		if (reg == 0)
+			break;
+
+		udelay(1);
+	}
+
+	if (reg != 0) {
+		printf("QSPI: timeout for indirect write\n");
+		goto failwr;
+	}
+
+	/* Check flash indirect controller status */
+	retry = CQSPI_REG_RETRY;
+	while (retry--) {
+		reg = readl(plat->regbase + CQSPI_REG_INDIRECTWR);
+		if (reg & CQSPI_REG_INDIRECTWR_DONE_MASK)
+			break;
+		udelay(1);
+	}
+
+	if (!(reg & CQSPI_REG_INDIRECTWR_DONE_MASK)) {
+		printf("QSPI: indirect completion status error with reg 0x%08x\n",
+		       reg);
+		goto failwr;
+	}
+
+	/* Clear indirect completion status */
+	writel(CQSPI_REG_INDIRECTWR_DONE_MASK,
+	       plat->regbase + CQSPI_REG_INDIRECTWR);
+	return 0;
+
+failwr:
+	/* Cancel the indirect write */
+	writel(CQSPI_REG_INDIRECTWR_CANCEL_MASK,
+	       plat->regbase + CQSPI_REG_INDIRECTWR);
+	return -1;
+}
+
+void cadence_qspi_apb_enter_xip(void *reg_base, char xip_dummy)
+{
+	unsigned int reg;
+
+	/* enter XiP mode immediately and enable direct mode */
+	reg = readl(reg_base + CQSPI_REG_CONFIG);
+	reg |= CQSPI_REG_CONFIG_ENABLE_MASK;
+	reg |= CQSPI_REG_CONFIG_DIRECT_MASK;
+	reg |= CQSPI_REG_CONFIG_XIP_IMM_MASK;
+	writel(reg, reg_base + CQSPI_REG_CONFIG);
+
+	/* keep the XiP mode */
+	writel(xip_dummy, reg_base + CQSPI_REG_MODE_BIT);
+
+	/* Enable mode bit at devrd */
+	reg = readl(reg_base + CQSPI_REG_RD_INSTR);
+	reg |= (1 << CQSPI_REG_RD_INSTR_MODE_EN_LSB);
+	writel(reg, reg_base + CQSPI_REG_RD_INSTR);
+}