Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1455 insertions, 0 deletions

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
new file mode 100644
index 000000000..411b1307b
--- /dev/null
+++ b/drivers/spi/spi-rspi.c
@@ -0,0 +1,1455 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SH RSPI driver
+ *
+ * Copyright (C) 2012, 2013  Renesas Solutions Corp.
+ * Copyright (C) 2014 Glider bvba
+ *
+ * Based on spi-sh.c:
+ * Copyright (C) 2011 Renesas Solutions Corp.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/sh_dma.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/rspi.h>
+#include <linux/spinlock.h>
+
+#define RSPI_SPCR		0x00	/* Control Register */
+#define RSPI_SSLP		0x01	/* Slave Select Polarity Register */
+#define RSPI_SPPCR		0x02	/* Pin Control Register */
+#define RSPI_SPSR		0x03	/* Status Register */
+#define RSPI_SPDR		0x04	/* Data Register */
+#define RSPI_SPSCR		0x08	/* Sequence Control Register */
+#define RSPI_SPSSR		0x09	/* Sequence Status Register */
+#define RSPI_SPBR		0x0a	/* Bit Rate Register */
+#define RSPI_SPDCR		0x0b	/* Data Control Register */
+#define RSPI_SPCKD		0x0c	/* Clock Delay Register */
+#define RSPI_SSLND		0x0d	/* Slave Select Negation Delay Register */
+#define RSPI_SPND		0x0e	/* Next-Access Delay Register */
+#define RSPI_SPCR2		0x0f	/* Control Register 2 (SH only) */
+#define RSPI_SPCMD0		0x10	/* Command Register 0 */
+#define RSPI_SPCMD1		0x12	/* Command Register 1 */
+#define RSPI_SPCMD2		0x14	/* Command Register 2 */
+#define RSPI_SPCMD3		0x16	/* Command Register 3 */
+#define RSPI_SPCMD4		0x18	/* Command Register 4 */
+#define RSPI_SPCMD5		0x1a	/* Command Register 5 */
+#define RSPI_SPCMD6		0x1c	/* Command Register 6 */
+#define RSPI_SPCMD7		0x1e	/* Command Register 7 */
+#define RSPI_SPCMD(i)		(RSPI_SPCMD0 + (i) * 2)
+#define RSPI_NUM_SPCMD		8
+#define RSPI_RZ_NUM_SPCMD	4
+#define QSPI_NUM_SPCMD		4
+
+/* RSPI on RZ only */
+#define RSPI_SPBFCR		0x20	/* Buffer Control Register */
+#define RSPI_SPBFDR		0x22	/* Buffer Data Count Setting Register */
+
+/* QSPI only */
+#define QSPI_SPBFCR		0x18	/* Buffer Control Register */
+#define QSPI_SPBDCR		0x1a	/* Buffer Data Count Register */
+#define QSPI_SPBMUL0		0x1c	/* Transfer Data Length Multiplier Setting Register 0 */
+#define QSPI_SPBMUL1		0x20	/* Transfer Data Length Multiplier Setting Register 1 */
+#define QSPI_SPBMUL2		0x24	/* Transfer Data Length Multiplier Setting Register 2 */
+#define QSPI_SPBMUL3		0x28	/* Transfer Data Length Multiplier Setting Register 3 */
+#define QSPI_SPBMUL(i)		(QSPI_SPBMUL0 + (i) * 4)
+
+/* SPCR - Control Register */
+#define SPCR_SPRIE		0x80	/* Receive Interrupt Enable */
+#define SPCR_SPE		0x40	/* Function Enable */
+#define SPCR_SPTIE		0x20	/* Transmit Interrupt Enable */
+#define SPCR_SPEIE		0x10	/* Error Interrupt Enable */
+#define SPCR_MSTR		0x08	/* Master/Slave Mode Select */
+#define SPCR_MODFEN		0x04	/* Mode Fault Error Detection Enable */
+/* RSPI on SH only */
+#define SPCR_TXMD		0x02	/* TX Only Mode (vs. Full Duplex) */
+#define SPCR_SPMS		0x01	/* 3-wire Mode (vs. 4-wire) */
+/* QSPI on R-Car Gen2 only */
+#define SPCR_WSWAP		0x02	/* Word Swap of read-data for DMAC */
+#define SPCR_BSWAP		0x01	/* Byte Swap of read-data for DMAC */
+
+/* SSLP - Slave Select Polarity Register */
+#define SSLP_SSLP(i)		BIT(i)	/* SSLi Signal Polarity Setting */
+
+/* SPPCR - Pin Control Register */
+#define SPPCR_MOIFE		0x20	/* MOSI Idle Value Fixing Enable */
+#define SPPCR_MOIFV		0x10	/* MOSI Idle Fixed Value */
+#define SPPCR_SPOM		0x04
+#define SPPCR_SPLP2		0x02	/* Loopback Mode 2 (non-inverting) */
+#define SPPCR_SPLP		0x01	/* Loopback Mode (inverting) */
+
+#define SPPCR_IO3FV		0x04	/* Single-/Dual-SPI Mode IO3 Output Fixed Value */
+#define SPPCR_IO2FV		0x04	/* Single-/Dual-SPI Mode IO2 Output Fixed Value */
+
+/* SPSR - Status Register */
+#define SPSR_SPRF		0x80	/* Receive Buffer Full Flag */
+#define SPSR_TEND		0x40	/* Transmit End */
+#define SPSR_SPTEF		0x20	/* Transmit Buffer Empty Flag */
+#define SPSR_PERF		0x08	/* Parity Error Flag */
+#define SPSR_MODF		0x04	/* Mode Fault Error Flag */
+#define SPSR_IDLNF		0x02	/* RSPI Idle Flag */
+#define SPSR_OVRF		0x01	/* Overrun Error Flag (RSPI only) */
+
+/* SPSCR - Sequence Control Register */
+#define SPSCR_SPSLN_MASK	0x07	/* Sequence Length Specification */
+
+/* SPSSR - Sequence Status Register */
+#define SPSSR_SPECM_MASK	0x70	/* Command Error Mask */
+#define SPSSR_SPCP_MASK		0x07	/* Command Pointer Mask */
+
+/* SPDCR - Data Control Register */
+#define SPDCR_TXDMY		0x80	/* Dummy Data Transmission Enable */
+#define SPDCR_SPLW1		0x40	/* Access Width Specification (RZ) */
+#define SPDCR_SPLW0		0x20	/* Access Width Specification (RZ) */
+#define SPDCR_SPLLWORD		(SPDCR_SPLW1 | SPDCR_SPLW0)
+#define SPDCR_SPLWORD		SPDCR_SPLW1
+#define SPDCR_SPLBYTE		SPDCR_SPLW0
+#define SPDCR_SPLW		0x20	/* Access Width Specification (SH) */
+#define SPDCR_SPRDTD		0x10	/* Receive Transmit Data Select (SH) */
+#define SPDCR_SLSEL1		0x08
+#define SPDCR_SLSEL0		0x04
+#define SPDCR_SLSEL_MASK	0x0c	/* SSL1 Output Select (SH) */
+#define SPDCR_SPFC1		0x02
+#define SPDCR_SPFC0		0x01
+#define SPDCR_SPFC_MASK		0x03	/* Frame Count Setting (1-4) (SH) */
+
+/* SPCKD - Clock Delay Register */
+#define SPCKD_SCKDL_MASK	0x07	/* Clock Delay Setting (1-8) */
+
+/* SSLND - Slave Select Negation Delay Register */
+#define SSLND_SLNDL_MASK	0x07	/* SSL Negation Delay Setting (1-8) */
+
+/* SPND - Next-Access Delay Register */
+#define SPND_SPNDL_MASK		0x07	/* Next-Access Delay Setting (1-8) */
+
+/* SPCR2 - Control Register 2 */
+#define SPCR2_PTE		0x08	/* Parity Self-Test Enable */
+#define SPCR2_SPIE		0x04	/* Idle Interrupt Enable */
+#define SPCR2_SPOE		0x02	/* Odd Parity Enable (vs. Even) */
+#define SPCR2_SPPE		0x01	/* Parity Enable */
+
+/* SPCMDn - Command Registers */
+#define SPCMD_SCKDEN		0x8000	/* Clock Delay Setting Enable */
+#define SPCMD_SLNDEN		0x4000	/* SSL Negation Delay Setting Enable */
+#define SPCMD_SPNDEN		0x2000	/* Next-Access Delay Enable */
+#define SPCMD_LSBF		0x1000	/* LSB First */
+#define SPCMD_SPB_MASK		0x0f00	/* Data Length Setting */
+#define SPCMD_SPB_8_TO_16(bit)	(((bit - 1) << 8) & SPCMD_SPB_MASK)
+#define SPCMD_SPB_8BIT		0x0000	/* QSPI only */
+#define SPCMD_SPB_16BIT		0x0100
+#define SPCMD_SPB_20BIT		0x0000
+#define SPCMD_SPB_24BIT		0x0100
+#define SPCMD_SPB_32BIT		0x0200
+#define SPCMD_SSLKP		0x0080	/* SSL Signal Level Keeping */
+#define SPCMD_SPIMOD_MASK	0x0060	/* SPI Operating Mode (QSPI only) */
+#define SPCMD_SPIMOD1		0x0040
+#define SPCMD_SPIMOD0		0x0020
+#define SPCMD_SPIMOD_SINGLE	0
+#define SPCMD_SPIMOD_DUAL	SPCMD_SPIMOD0
+#define SPCMD_SPIMOD_QUAD	SPCMD_SPIMOD1
+#define SPCMD_SPRW		0x0010	/* SPI Read/Write Access (Dual/Quad) */
+#define SPCMD_SSLA(i)		((i) << 4)	/* SSL Assert Signal Setting */
+#define SPCMD_BRDV_MASK		0x000c	/* Bit Rate Division Setting */
+#define SPCMD_BRDV(brdv)	((brdv) << 2)
+#define SPCMD_CPOL		0x0002	/* Clock Polarity Setting */
+#define SPCMD_CPHA		0x0001	/* Clock Phase Setting */
+
+/* SPBFCR - Buffer Control Register */
+#define SPBFCR_TXRST		0x80	/* Transmit Buffer Data Reset */
+#define SPBFCR_RXRST		0x40	/* Receive Buffer Data Reset */
+#define SPBFCR_TXTRG_MASK	0x30	/* Transmit Buffer Data Triggering Number */
+#define SPBFCR_RXTRG_MASK	0x07	/* Receive Buffer Data Triggering Number */
+/* QSPI on R-Car Gen2 */
+#define SPBFCR_TXTRG_1B		0x00	/* 31 bytes (1 byte available) */
+#define SPBFCR_TXTRG_32B	0x30	/* 0 byte (32 bytes available) */
+#define SPBFCR_RXTRG_1B		0x00	/* 1 byte (31 bytes available) */
+#define SPBFCR_RXTRG_32B	0x07	/* 32 bytes (0 byte available) */
+
+#define QSPI_BUFFER_SIZE        32u
+
+struct rspi_data {
+	void __iomem *addr;
+	u32 speed_hz;
+	struct spi_controller *ctlr;
+	struct platform_device *pdev;
+	wait_queue_head_t wait;
+	spinlock_t lock;		/* Protects RMW-access to RSPI_SSLP */
+	struct clk *clk;
+	u16 spcmd;
+	u8 spsr;
+	u8 sppcr;
+	int rx_irq, tx_irq;
+	const struct spi_ops *ops;
+
+	unsigned dma_callbacked:1;
+	unsigned byte_access:1;
+};
+
+static void rspi_write8(const struct rspi_data *rspi, u8 data, u16 offset)
+{
+	iowrite8(data, rspi->addr + offset);
+}
+
+static void rspi_write16(const struct rspi_data *rspi, u16 data, u16 offset)
+{
+	iowrite16(data, rspi->addr + offset);
+}
+
+static void rspi_write32(const struct rspi_data *rspi, u32 data, u16 offset)
+{
+	iowrite32(data, rspi->addr + offset);
+}
+
+static u8 rspi_read8(const struct rspi_data *rspi, u16 offset)
+{
+	return ioread8(rspi->addr + offset);
+}
+
+static u16 rspi_read16(const struct rspi_data *rspi, u16 offset)
+{
+	return ioread16(rspi->addr + offset);
+}
+
+static void rspi_write_data(const struct rspi_data *rspi, u16 data)
+{
+	if (rspi->byte_access)
+		rspi_write8(rspi, data, RSPI_SPDR);
+	else /* 16 bit */
+		rspi_write16(rspi, data, RSPI_SPDR);
+}
+
+static u16 rspi_read_data(const struct rspi_data *rspi)
+{
+	if (rspi->byte_access)
+		return rspi_read8(rspi, RSPI_SPDR);
+	else /* 16 bit */
+		return rspi_read16(rspi, RSPI_SPDR);
+}
+
+/* optional functions */
+struct spi_ops {
+	int (*set_config_register)(struct rspi_data *rspi, int access_size);
+	int (*transfer_one)(struct spi_controller *ctlr,
+			    struct spi_device *spi, struct spi_transfer *xfer);
+	u16 extra_mode_bits;
+	u16 min_div;
+	u16 max_div;
+	u16 flags;
+	u16 fifo_size;
+	u8 num_hw_ss;
+};
+
+static void rspi_set_rate(struct rspi_data *rspi)
+{
+	unsigned long clksrc;
+	int brdv = 0, spbr;
+
+	clksrc = clk_get_rate(rspi->clk);
+	spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz) - 1;
+	while (spbr > 255 && brdv < 3) {
+		brdv++;
+		spbr = DIV_ROUND_UP(spbr + 1, 2) - 1;
+	}
+
+	rspi_write8(rspi, clamp(spbr, 0, 255), RSPI_SPBR);
+	rspi->spcmd |= SPCMD_BRDV(brdv);
+	rspi->speed_hz = DIV_ROUND_UP(clksrc, (2U << brdv) * (spbr + 1));
+}
+
+/*
+ * functions for RSPI on legacy SH
+ */
+static int rspi_set_config_register(struct rspi_data *rspi, int access_size)
+{
+	/* Sets output mode, MOSI signal, and (optionally) loopback */
+	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
+
+	/* Sets transfer bit rate */
+	rspi_set_rate(rspi);
+
+	/* Disable dummy transmission, set 16-bit word access, 1 frame */
+	rspi_write8(rspi, 0, RSPI_SPDCR);
+	rspi->byte_access = 0;
+
+	/* Sets RSPCK, SSL, next-access delay value */
+	rspi_write8(rspi, 0x00, RSPI_SPCKD);
+	rspi_write8(rspi, 0x00, RSPI_SSLND);
+	rspi_write8(rspi, 0x00, RSPI_SPND);
+
+	/* Sets parity, interrupt mask */
+	rspi_write8(rspi, 0x00, RSPI_SPCR2);
+
+	/* Resets sequencer */
+	rspi_write8(rspi, 0, RSPI_SPSCR);
+	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
+	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
+
+	/* Sets RSPI mode */
+	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
+
+	return 0;
+}
+
+/*
+ * functions for RSPI on RZ
+ */
+static int rspi_rz_set_config_register(struct rspi_data *rspi, int access_size)
+{
+	/* Sets output mode, MOSI signal, and (optionally) loopback */
+	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
+
+	/* Sets transfer bit rate */
+	rspi_set_rate(rspi);
+
+	/* Disable dummy transmission, set byte access */
+	rspi_write8(rspi, SPDCR_SPLBYTE, RSPI_SPDCR);
+	rspi->byte_access = 1;
+
+	/* Sets RSPCK, SSL, next-access delay value */
+	rspi_write8(rspi, 0x00, RSPI_SPCKD);
+	rspi_write8(rspi, 0x00, RSPI_SSLND);
+	rspi_write8(rspi, 0x00, RSPI_SPND);
+
+	/* Resets sequencer */
+	rspi_write8(rspi, 0, RSPI_SPSCR);
+	rspi->spcmd |= SPCMD_SPB_8_TO_16(access_size);
+	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
+
+	/* Sets RSPI mode */
+	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
+
+	return 0;
+}
+
+/*
+ * functions for QSPI
+ */
+static int qspi_set_config_register(struct rspi_data *rspi, int access_size)
+{
+	unsigned long clksrc;
+	int brdv = 0, spbr;
+
+	/* Sets output mode, MOSI signal, and (optionally) loopback */
+	rspi_write8(rspi, rspi->sppcr, RSPI_SPPCR);
+
+	/* Sets transfer bit rate */
+	clksrc = clk_get_rate(rspi->clk);
+	if (rspi->speed_hz >= clksrc) {
+		spbr = 0;
+		rspi->speed_hz = clksrc;
+	} else {
+		spbr = DIV_ROUND_UP(clksrc, 2 * rspi->speed_hz);
+		while (spbr > 255 && brdv < 3) {
+			brdv++;
+			spbr = DIV_ROUND_UP(spbr, 2);
+		}
+		spbr = clamp(spbr, 0, 255);
+		rspi->speed_hz = DIV_ROUND_UP(clksrc, (2U << brdv) * spbr);
+	}
+	rspi_write8(rspi, spbr, RSPI_SPBR);
+	rspi->spcmd |= SPCMD_BRDV(brdv);
+
+	/* Disable dummy transmission, set byte access */
+	rspi_write8(rspi, 0, RSPI_SPDCR);
+	rspi->byte_access = 1;
+
+	/* Sets RSPCK, SSL, next-access delay value */
+	rspi_write8(rspi, 0x00, RSPI_SPCKD);
+	rspi_write8(rspi, 0x00, RSPI_SSLND);
+	rspi_write8(rspi, 0x00, RSPI_SPND);
+
+	/* Data Length Setting */
+	if (access_size == 8)
+		rspi->spcmd |= SPCMD_SPB_8BIT;
+	else if (access_size == 16)
+		rspi->spcmd |= SPCMD_SPB_16BIT;
+	else
+		rspi->spcmd |= SPCMD_SPB_32BIT;
+
+	rspi->spcmd |= SPCMD_SCKDEN | SPCMD_SLNDEN | SPCMD_SPNDEN;
+
+	/* Resets transfer data length */
+	rspi_write32(rspi, 0, QSPI_SPBMUL0);
+
+	/* Resets transmit and receive buffer */
+	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
+	/* Sets buffer to allow normal operation */
+	rspi_write8(rspi, 0x00, QSPI_SPBFCR);
+
+	/* Resets sequencer */
+	rspi_write8(rspi, 0, RSPI_SPSCR);
+	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
+
+	/* Sets RSPI mode */
+	rspi_write8(rspi, SPCR_MSTR, RSPI_SPCR);
+
+	return 0;
+}
+
+static void qspi_update(const struct rspi_data *rspi, u8 mask, u8 val, u8 reg)
+{
+	u8 data;
+
+	data = rspi_read8(rspi, reg);
+	data &= ~mask;
+	data |= (val & mask);
+	rspi_write8(rspi, data, reg);
+}
+
+static unsigned int qspi_set_send_trigger(struct rspi_data *rspi,
+					  unsigned int len)
+{
+	unsigned int n;
+
+	n = min(len, QSPI_BUFFER_SIZE);
+
+	if (len >= QSPI_BUFFER_SIZE) {
+		/* sets triggering number to 32 bytes */
+		qspi_update(rspi, SPBFCR_TXTRG_MASK,
+			     SPBFCR_TXTRG_32B, QSPI_SPBFCR);
+	} else {
+		/* sets triggering number to 1 byte */
+		qspi_update(rspi, SPBFCR_TXTRG_MASK,
+			     SPBFCR_TXTRG_1B, QSPI_SPBFCR);
+	}
+
+	return n;
+}
+
+static int qspi_set_receive_trigger(struct rspi_data *rspi, unsigned int len)
+{
+	unsigned int n;
+
+	n = min(len, QSPI_BUFFER_SIZE);
+
+	if (len >= QSPI_BUFFER_SIZE) {
+		/* sets triggering number to 32 bytes */
+		qspi_update(rspi, SPBFCR_RXTRG_MASK,
+			     SPBFCR_RXTRG_32B, QSPI_SPBFCR);
+	} else {
+		/* sets triggering number to 1 byte */
+		qspi_update(rspi, SPBFCR_RXTRG_MASK,
+			     SPBFCR_RXTRG_1B, QSPI_SPBFCR);
+	}
+	return n;
+}
+
+static void rspi_enable_irq(const struct rspi_data *rspi, u8 enable)
+{
+	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | enable, RSPI_SPCR);
+}
+
+static void rspi_disable_irq(const struct rspi_data *rspi, u8 disable)
+{
+	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~disable, RSPI_SPCR);
+}
+
+static int rspi_wait_for_interrupt(struct rspi_data *rspi, u8 wait_mask,
+				   u8 enable_bit)
+{
+	int ret;
+
+	rspi->spsr = rspi_read8(rspi, RSPI_SPSR);
+	if (rspi->spsr & wait_mask)
+		return 0;
+
+	rspi_enable_irq(rspi, enable_bit);
+	ret = wait_event_timeout(rspi->wait, rspi->spsr & wait_mask, HZ);
+	if (ret == 0 && !(rspi->spsr & wait_mask))
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
+static inline int rspi_wait_for_tx_empty(struct rspi_data *rspi)
+{
+	return rspi_wait_for_interrupt(rspi, SPSR_SPTEF, SPCR_SPTIE);
+}
+
+static inline int rspi_wait_for_rx_full(struct rspi_data *rspi)
+{
+	return rspi_wait_for_interrupt(rspi, SPSR_SPRF, SPCR_SPRIE);
+}
+
+static int rspi_data_out(struct rspi_data *rspi, u8 data)
+{
+	int error = rspi_wait_for_tx_empty(rspi);
+	if (error < 0) {
+		dev_err(&rspi->ctlr->dev, "transmit timeout\n");
+		return error;
+	}
+	rspi_write_data(rspi, data);
+	return 0;
+}
+
+static int rspi_data_in(struct rspi_data *rspi)
+{
+	int error;
+	u8 data;
+
+	error = rspi_wait_for_rx_full(rspi);
+	if (error < 0) {
+		dev_err(&rspi->ctlr->dev, "receive timeout\n");
+		return error;
+	}
+	data = rspi_read_data(rspi);
+	return data;
+}
+
+static int rspi_pio_transfer(struct rspi_data *rspi, const u8 *tx, u8 *rx,
+			     unsigned int n)
+{
+	while (n-- > 0) {
+		if (tx) {
+			int ret = rspi_data_out(rspi, *tx++);
+			if (ret < 0)
+				return ret;
+		}
+		if (rx) {
+			int ret = rspi_data_in(rspi);
+			if (ret < 0)
+				return ret;
+			*rx++ = ret;
+		}
+	}
+
+	return 0;
+}
+
+static void rspi_dma_complete(void *arg)
+{
+	struct rspi_data *rspi = arg;
+
+	rspi->dma_callbacked = 1;
+	wake_up_interruptible(&rspi->wait);
+}
+
+static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
+			     struct sg_table *rx)
+{
+	struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
+	u8 irq_mask = 0;
+	unsigned int other_irq = 0;
+	dma_cookie_t cookie;
+	int ret;
+
+	/* First prepare and submit the DMA request(s), as this may fail */
+	if (rx) {
+		desc_rx = dmaengine_prep_slave_sg(rspi->ctlr->dma_rx, rx->sgl,
+					rx->nents, DMA_DEV_TO_MEM,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+		if (!desc_rx) {
+			ret = -EAGAIN;
+			goto no_dma_rx;
+		}
+
+		desc_rx->callback = rspi_dma_complete;
+		desc_rx->callback_param = rspi;
+		cookie = dmaengine_submit(desc_rx);
+		if (dma_submit_error(cookie)) {
+			ret = cookie;
+			goto no_dma_rx;
+		}
+
+		irq_mask |= SPCR_SPRIE;
+	}
+
+	if (tx) {
+		desc_tx = dmaengine_prep_slave_sg(rspi->ctlr->dma_tx, tx->sgl,
+					tx->nents, DMA_MEM_TO_DEV,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+		if (!desc_tx) {
+			ret = -EAGAIN;
+			goto no_dma_tx;
+		}
+
+		if (rx) {
+			/* No callback */
+			desc_tx->callback = NULL;
+		} else {
+			desc_tx->callback = rspi_dma_complete;
+			desc_tx->callback_param = rspi;
+		}
+		cookie = dmaengine_submit(desc_tx);
+		if (dma_submit_error(cookie)) {
+			ret = cookie;
+			goto no_dma_tx;
+		}
+
+		irq_mask |= SPCR_SPTIE;
+	}
+
+	/*
+	 * DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
+	 * called. So, this driver disables the IRQ while DMA transfer.
+	 */
+	if (tx)
+		disable_irq(other_irq = rspi->tx_irq);
+	if (rx && rspi->rx_irq != other_irq)
+		disable_irq(rspi->rx_irq);
+
+	rspi_enable_irq(rspi, irq_mask);
+	rspi->dma_callbacked = 0;
+
+	/* Now start DMA */
+	if (rx)
+		dma_async_issue_pending(rspi->ctlr->dma_rx);
+	if (tx)
+		dma_async_issue_pending(rspi->ctlr->dma_tx);
+
+	ret = wait_event_interruptible_timeout(rspi->wait,
+					       rspi->dma_callbacked, HZ);
+	if (ret > 0 && rspi->dma_callbacked) {
+		ret = 0;
+		if (tx)
+			dmaengine_synchronize(rspi->ctlr->dma_tx);
+		if (rx)
+			dmaengine_synchronize(rspi->ctlr->dma_rx);
+	} else {
+		if (!ret) {
+			dev_err(&rspi->ctlr->dev, "DMA timeout\n");
+			ret = -ETIMEDOUT;
+		}
+		if (tx)
+			dmaengine_terminate_sync(rspi->ctlr->dma_tx);
+		if (rx)
+			dmaengine_terminate_sync(rspi->ctlr->dma_rx);
+	}
+
+	rspi_disable_irq(rspi, irq_mask);
+
+	if (tx)
+		enable_irq(rspi->tx_irq);
+	if (rx && rspi->rx_irq != other_irq)
+		enable_irq(rspi->rx_irq);
+
+	return ret;
+
+no_dma_tx:
+	if (rx)
+		dmaengine_terminate_sync(rspi->ctlr->dma_rx);
+no_dma_rx:
+	if (ret == -EAGAIN) {
+		dev_warn_once(&rspi->ctlr->dev,
+			      "DMA not available, falling back to PIO\n");
+	}
+	return ret;
+}
+
+static void rspi_receive_init(const struct rspi_data *rspi)
+{
+	u8 spsr;
+
+	spsr = rspi_read8(rspi, RSPI_SPSR);
+	if (spsr & SPSR_SPRF)
+		rspi_read_data(rspi);	/* dummy read */
+	if (spsr & SPSR_OVRF)
+		rspi_write8(rspi, rspi_read8(rspi, RSPI_SPSR) & ~SPSR_OVRF,
+			    RSPI_SPSR);
+}
+
+static void rspi_rz_receive_init(const struct rspi_data *rspi)
+{
+	rspi_receive_init(rspi);
+	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, RSPI_SPBFCR);
+	rspi_write8(rspi, 0, RSPI_SPBFCR);
+}
+
+static void qspi_receive_init(const struct rspi_data *rspi)
+{
+	u8 spsr;
+
+	spsr = rspi_read8(rspi, RSPI_SPSR);
+	if (spsr & SPSR_SPRF)
+		rspi_read_data(rspi);   /* dummy read */
+	rspi_write8(rspi, SPBFCR_TXRST | SPBFCR_RXRST, QSPI_SPBFCR);
+	rspi_write8(rspi, 0, QSPI_SPBFCR);
+}
+
+static bool __rspi_can_dma(const struct rspi_data *rspi,
+			   const struct spi_transfer *xfer)
+{
+	return xfer->len > rspi->ops->fifo_size;
+}
+
+static bool rspi_can_dma(struct spi_controller *ctlr, struct spi_device *spi,
+			 struct spi_transfer *xfer)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
+
+	return __rspi_can_dma(rspi, xfer);
+}
+
+static int rspi_dma_check_then_transfer(struct rspi_data *rspi,
+					 struct spi_transfer *xfer)
+{
+	if (!rspi->ctlr->can_dma || !__rspi_can_dma(rspi, xfer))
+		return -EAGAIN;
+
+	/* rx_buf can be NULL on RSPI on SH in TX-only Mode */
+	return rspi_dma_transfer(rspi, &xfer->tx_sg,
+				xfer->rx_buf ? &xfer->rx_sg : NULL);
+}
+
+static int rspi_common_transfer(struct rspi_data *rspi,
+				struct spi_transfer *xfer)
+{
+	int ret;
+
+	xfer->effective_speed_hz = rspi->speed_hz;
+
+	ret = rspi_dma_check_then_transfer(rspi, xfer);
+	if (ret != -EAGAIN)
+		return ret;
+
+	ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
+	if (ret < 0)
+		return ret;
+
+	/* Wait for the last transmission */
+	rspi_wait_for_tx_empty(rspi);
+
+	return 0;
+}
+
+static int rspi_transfer_one(struct spi_controller *ctlr,
+			     struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
+	u8 spcr;
+
+	spcr = rspi_read8(rspi, RSPI_SPCR);
+	if (xfer->rx_buf) {
+		rspi_receive_init(rspi);
+		spcr &= ~SPCR_TXMD;
+	} else {
+		spcr |= SPCR_TXMD;
+	}
+	rspi_write8(rspi, spcr, RSPI_SPCR);
+
+	return rspi_common_transfer(rspi, xfer);
+}
+
+static int rspi_rz_transfer_one(struct spi_controller *ctlr,
+				struct spi_device *spi,
+				struct spi_transfer *xfer)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
+
+	rspi_rz_receive_init(rspi);
+
+	return rspi_common_transfer(rspi, xfer);
+}
+
+static int qspi_trigger_transfer_out_in(struct rspi_data *rspi, const u8 *tx,
+					u8 *rx, unsigned int len)
+{
+	unsigned int i, n;
+	int ret;
+
+	while (len > 0) {
+		n = qspi_set_send_trigger(rspi, len);
+		qspi_set_receive_trigger(rspi, len);
+		ret = rspi_wait_for_tx_empty(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
+			return ret;
+		}
+		for (i = 0; i < n; i++)
+			rspi_write_data(rspi, *tx++);
+
+		ret = rspi_wait_for_rx_full(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "receive timeout\n");
+			return ret;
+		}
+		for (i = 0; i < n; i++)
+			*rx++ = rspi_read_data(rspi);
+
+		len -= n;
+	}
+
+	return 0;
+}
+
+static int qspi_transfer_out_in(struct rspi_data *rspi,
+				struct spi_transfer *xfer)
+{
+	int ret;
+
+	qspi_receive_init(rspi);
+
+	ret = rspi_dma_check_then_transfer(rspi, xfer);
+	if (ret != -EAGAIN)
+		return ret;
+
+	return qspi_trigger_transfer_out_in(rspi, xfer->tx_buf,
+					    xfer->rx_buf, xfer->len);
+}
+
+static int qspi_transfer_out(struct rspi_data *rspi, struct spi_transfer *xfer)
+{
+	const u8 *tx = xfer->tx_buf;
+	unsigned int n = xfer->len;
+	unsigned int i, len;
+	int ret;
+
+	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
+		ret = rspi_dma_transfer(rspi, &xfer->tx_sg, NULL);
+		if (ret != -EAGAIN)
+			return ret;
+	}
+
+	while (n > 0) {
+		len = qspi_set_send_trigger(rspi, n);
+		ret = rspi_wait_for_tx_empty(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "transmit timeout\n");
+			return ret;
+		}
+		for (i = 0; i < len; i++)
+			rspi_write_data(rspi, *tx++);
+
+		n -= len;
+	}
+
+	/* Wait for the last transmission */
+	rspi_wait_for_tx_empty(rspi);
+
+	return 0;
+}
+
+static int qspi_transfer_in(struct rspi_data *rspi, struct spi_transfer *xfer)
+{
+	u8 *rx = xfer->rx_buf;
+	unsigned int n = xfer->len;
+	unsigned int i, len;
+	int ret;
+
+	if (rspi->ctlr->can_dma && __rspi_can_dma(rspi, xfer)) {
+		ret = rspi_dma_transfer(rspi, NULL, &xfer->rx_sg);
+		if (ret != -EAGAIN)
+			return ret;
+	}
+
+	while (n > 0) {
+		len = qspi_set_receive_trigger(rspi, n);
+		ret = rspi_wait_for_rx_full(rspi);
+		if (ret < 0) {
+			dev_err(&rspi->ctlr->dev, "receive timeout\n");
+			return ret;
+		}
+		for (i = 0; i < len; i++)
+			*rx++ = rspi_read_data(rspi);
+
+		n -= len;
+	}
+
+	return 0;
+}
+
+static int qspi_transfer_one(struct spi_controller *ctlr,
+			     struct spi_device *spi, struct spi_transfer *xfer)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
+
+	xfer->effective_speed_hz = rspi->speed_hz;
+	if (spi->mode & SPI_LOOP) {
+		return qspi_transfer_out_in(rspi, xfer);
+	} else if (xfer->tx_nbits > SPI_NBITS_SINGLE) {
+		/* Quad or Dual SPI Write */
+		return qspi_transfer_out(rspi, xfer);
+	} else if (xfer->rx_nbits > SPI_NBITS_SINGLE) {
+		/* Quad or Dual SPI Read */
+		return qspi_transfer_in(rspi, xfer);
+	} else {
+		/* Single SPI Transfer */
+		return qspi_transfer_out_in(rspi, xfer);
+	}
+}
+
+static u16 qspi_transfer_mode(const struct spi_transfer *xfer)
+{
+	if (xfer->tx_buf)
+		switch (xfer->tx_nbits) {
+		case SPI_NBITS_QUAD:
+			return SPCMD_SPIMOD_QUAD;
+		case SPI_NBITS_DUAL:
+			return SPCMD_SPIMOD_DUAL;
+		default:
+			return 0;
+		}
+	if (xfer->rx_buf)
+		switch (xfer->rx_nbits) {
+		case SPI_NBITS_QUAD:
+			return SPCMD_SPIMOD_QUAD | SPCMD_SPRW;
+		case SPI_NBITS_DUAL:
+			return SPCMD_SPIMOD_DUAL | SPCMD_SPRW;
+		default:
+			return 0;
+		}
+
+	return 0;
+}
+
+static int qspi_setup_sequencer(struct rspi_data *rspi,
+				const struct spi_message *msg)
+{
+	const struct spi_transfer *xfer;
+	unsigned int i = 0, len = 0;
+	u16 current_mode = 0xffff, mode;
+
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		mode = qspi_transfer_mode(xfer);
+		if (mode == current_mode) {
+			len += xfer->len;
+			continue;
+		}
+
+		/* Transfer mode change */
+		if (i) {
+			/* Set transfer data length of previous transfer */
+			rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
+		}
+
+		if (i >= QSPI_NUM_SPCMD) {
+			dev_err(&msg->spi->dev,
+				"Too many different transfer modes");
+			return -EINVAL;
+		}
+
+		/* Program transfer mode for this transfer */
+		rspi_write16(rspi, rspi->spcmd | mode, RSPI_SPCMD(i));
+		current_mode = mode;
+		len = xfer->len;
+		i++;
+	}
+	if (i) {
+		/* Set final transfer data length and sequence length */
+		rspi_write32(rspi, len, QSPI_SPBMUL(i - 1));
+		rspi_write8(rspi, i - 1, RSPI_SPSCR);
+	}
+
+	return 0;
+}
+
+static int rspi_setup(struct spi_device *spi)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(spi->controller);
+	u8 sslp;
+
+	if (spi->cs_gpiod)
+		return 0;
+
+	pm_runtime_get_sync(&rspi->pdev->dev);
+	spin_lock_irq(&rspi->lock);
+
+	sslp = rspi_read8(rspi, RSPI_SSLP);
+	if (spi->mode & SPI_CS_HIGH)
+		sslp |= SSLP_SSLP(spi->chip_select);
+	else
+		sslp &= ~SSLP_SSLP(spi->chip_select);
+	rspi_write8(rspi, sslp, RSPI_SSLP);
+
+	spin_unlock_irq(&rspi->lock);
+	pm_runtime_put(&rspi->pdev->dev);
+	return 0;
+}
+
+static int rspi_prepare_message(struct spi_controller *ctlr,
+				struct spi_message *msg)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
+	struct spi_device *spi = msg->spi;
+	const struct spi_transfer *xfer;
+	int ret;
+
+	/*
+	 * As the Bit Rate Register must not be changed while the device is
+	 * active, all transfers in a message must use the same bit rate.
+	 * In theory, the sequencer could be enabled, and each Command Register
+	 * could divide the base bit rate by a different value.
+	 * However, most RSPI variants do not have Transfer Data Length
+	 * Multiplier Setting Registers, so each sequence step would be limited
+	 * to a single word, making this feature unsuitable for large
+	 * transfers, which would gain most from it.
+	 */
+	rspi->speed_hz = spi->max_speed_hz;
+	list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+		if (xfer->speed_hz < rspi->speed_hz)
+			rspi->speed_hz = xfer->speed_hz;
+	}
+
+	rspi->spcmd = SPCMD_SSLKP;
+	if (spi->mode & SPI_CPOL)
+		rspi->spcmd |= SPCMD_CPOL;
+	if (spi->mode & SPI_CPHA)
+		rspi->spcmd |= SPCMD_CPHA;
+	if (spi->mode & SPI_LSB_FIRST)
+		rspi->spcmd |= SPCMD_LSBF;
+
+	/* Configure slave signal to assert */
+	rspi->spcmd |= SPCMD_SSLA(spi->cs_gpiod ? rspi->ctlr->unused_native_cs
+						: spi->chip_select);
+
+	/* CMOS output mode and MOSI signal from previous transfer */
+	rspi->sppcr = 0;
+	if (spi->mode & SPI_LOOP)
+		rspi->sppcr |= SPPCR_SPLP;
+
+	rspi->ops->set_config_register(rspi, 8);
+
+	if (msg->spi->mode &
+	    (SPI_TX_DUAL | SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD)) {
+		/* Setup sequencer for messages with multiple transfer modes */
+		ret = qspi_setup_sequencer(rspi, msg);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* Enable SPI function in master mode */
+	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) | SPCR_SPE, RSPI_SPCR);
+	return 0;
+}
+
+static int rspi_unprepare_message(struct spi_controller *ctlr,
+				  struct spi_message *msg)
+{
+	struct rspi_data *rspi = spi_controller_get_devdata(ctlr);
+
+	/* Disable SPI function */
+	rspi_write8(rspi, rspi_read8(rspi, RSPI_SPCR) & ~SPCR_SPE, RSPI_SPCR);
+
+	/* Reset sequencer for Single SPI Transfers */
+	rspi_write16(rspi, rspi->spcmd, RSPI_SPCMD0);
+	rspi_write8(rspi, 0, RSPI_SPSCR);
+	return 0;
+}
+
+static irqreturn_t rspi_irq_mux(int irq, void *_sr)
+{
+	struct rspi_data *rspi = _sr;
+	u8 spsr;
+	irqreturn_t ret = IRQ_NONE;
+	u8 disable_irq = 0;
+
+	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
+	if (spsr & SPSR_SPRF)
+		disable_irq |= SPCR_SPRIE;
+	if (spsr & SPSR_SPTEF)
+		disable_irq |= SPCR_SPTIE;
+
+	if (disable_irq) {
+		ret = IRQ_HANDLED;
+		rspi_disable_irq(rspi, disable_irq);
+		wake_up(&rspi->wait);
+	}
+
+	return ret;
+}
+
+static irqreturn_t rspi_irq_rx(int irq, void *_sr)
+{
+	struct rspi_data *rspi = _sr;
+	u8 spsr;
+
+	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
+	if (spsr & SPSR_SPRF) {
+		rspi_disable_irq(rspi, SPCR_SPRIE);
+		wake_up(&rspi->wait);
+		return IRQ_HANDLED;
+	}
+
+	return 0;
+}
+
+static irqreturn_t rspi_irq_tx(int irq, void *_sr)
+{
+	struct rspi_data *rspi = _sr;
+	u8 spsr;
+
+	rspi->spsr = spsr = rspi_read8(rspi, RSPI_SPSR);
+	if (spsr & SPSR_SPTEF) {
+		rspi_disable_irq(rspi, SPCR_SPTIE);
+		wake_up(&rspi->wait);
+		return IRQ_HANDLED;
+	}
+
+	return 0;
+}
+
+static struct dma_chan *rspi_request_dma_chan(struct device *dev,
+					      enum dma_transfer_direction dir,
+					      unsigned int id,
+					      dma_addr_t port_addr)
+{
+	dma_cap_mask_t mask;
+	struct dma_chan *chan;
+	struct dma_slave_config cfg;
+	int ret;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_SLAVE, mask);
+
+	chan = dma_request_slave_channel_compat(mask, shdma_chan_filter,
+				(void *)(unsigned long)id, dev,
+				dir == DMA_MEM_TO_DEV ? "tx" : "rx");
+	if (!chan) {
+		dev_warn(dev, "dma_request_slave_channel_compat failed\n");
+		return NULL;
+	}
+
+	memset(&cfg, 0, sizeof(cfg));
+	cfg.dst_addr = port_addr + RSPI_SPDR;
+	cfg.src_addr = port_addr + RSPI_SPDR;
+	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	cfg.direction = dir;
+
+	ret = dmaengine_slave_config(chan, &cfg);
+	if (ret) {
+		dev_warn(dev, "dmaengine_slave_config failed %d\n", ret);
+		dma_release_channel(chan);
+		return NULL;
+	}
+
+	return chan;
+}
+
+static int rspi_request_dma(struct device *dev, struct spi_controller *ctlr,
+			    const struct resource *res)
+{
+	const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
+	unsigned int dma_tx_id, dma_rx_id;
+
+	if (dev->of_node) {
+		/* In the OF case we will get the slave IDs from the DT */
+		dma_tx_id = 0;
+		dma_rx_id = 0;
+	} else if (rspi_pd && rspi_pd->dma_tx_id && rspi_pd->dma_rx_id) {
+		dma_tx_id = rspi_pd->dma_tx_id;
+		dma_rx_id = rspi_pd->dma_rx_id;
+	} else {
+		/* The driver assumes no error. */
+		return 0;
+	}
+
+	ctlr->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV, dma_tx_id,
+					     res->start);
+	if (!ctlr->dma_tx)
+		return -ENODEV;
+
+	ctlr->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM, dma_rx_id,
+					     res->start);
+	if (!ctlr->dma_rx) {
+		dma_release_channel(ctlr->dma_tx);
+		ctlr->dma_tx = NULL;
+		return -ENODEV;
+	}
+
+	ctlr->can_dma = rspi_can_dma;
+	dev_info(dev, "DMA available");
+	return 0;
+}
+
+static void rspi_release_dma(struct spi_controller *ctlr)
+{
+	if (ctlr->dma_tx)
+		dma_release_channel(ctlr->dma_tx);
+	if (ctlr->dma_rx)
+		dma_release_channel(ctlr->dma_rx);
+}
+
+static int rspi_remove(struct platform_device *pdev)
+{
+	struct rspi_data *rspi = platform_get_drvdata(pdev);
+
+	rspi_release_dma(rspi->ctlr);
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct spi_ops rspi_ops = {
+	.set_config_register =	rspi_set_config_register,
+	.transfer_one =		rspi_transfer_one,
+	.min_div =		2,
+	.max_div =		4096,
+	.flags =		SPI_CONTROLLER_MUST_TX,
+	.fifo_size =		8,
+	.num_hw_ss =		2,
+};
+
+static const struct spi_ops rspi_rz_ops = {
+	.set_config_register =	rspi_rz_set_config_register,
+	.transfer_one =		rspi_rz_transfer_one,
+	.min_div =		2,
+	.max_div =		4096,
+	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
+	.fifo_size =		8,	/* 8 for TX, 32 for RX */
+	.num_hw_ss =		1,
+};
+
+static const struct spi_ops qspi_ops = {
+	.set_config_register =	qspi_set_config_register,
+	.transfer_one =		qspi_transfer_one,
+	.extra_mode_bits =	SPI_TX_DUAL | SPI_TX_QUAD |
+				SPI_RX_DUAL | SPI_RX_QUAD,
+	.min_div =		1,
+	.max_div =		4080,
+	.flags =		SPI_CONTROLLER_MUST_RX | SPI_CONTROLLER_MUST_TX,
+	.fifo_size =		32,
+	.num_hw_ss =		1,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id rspi_of_match[] = {
+	/* RSPI on legacy SH */
+	{ .compatible = "renesas,rspi", .data = &rspi_ops },
+	/* RSPI on RZ/A1H */
+	{ .compatible = "renesas,rspi-rz", .data = &rspi_rz_ops },
+	/* QSPI on R-Car Gen2 */
+	{ .compatible = "renesas,qspi", .data = &qspi_ops },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(of, rspi_of_match);
+
+static void rspi_reset_control_assert(void *data)
+{
+	reset_control_assert(data);
+}
+
+static int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
+{
+	struct reset_control *rstc;
+	u32 num_cs;
+	int error;
+
+	/* Parse DT properties */
+	error = of_property_read_u32(dev->of_node, "num-cs", &num_cs);
+	if (error) {
+		dev_err(dev, "of_property_read_u32 num-cs failed %d\n", error);
+		return error;
+	}
+
+	ctlr->num_chipselect = num_cs;
+
+	rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
+	if (IS_ERR(rstc))
+		return dev_err_probe(dev, PTR_ERR(rstc),
+					     "failed to get reset ctrl\n");
+
+	error = reset_control_deassert(rstc);
+	if (error) {
+		dev_err(dev, "failed to deassert reset %d\n", error);
+		return error;
+	}
+
+	error = devm_add_action_or_reset(dev, rspi_reset_control_assert, rstc);
+	if (error) {
+		dev_err(dev, "failed to register assert devm action, %d\n", error);
+		return error;
+	}
+
+	return 0;
+}
+#else
+#define rspi_of_match	NULL
+static inline int rspi_parse_dt(struct device *dev, struct spi_controller *ctlr)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_OF */
+
+static int rspi_request_irq(struct device *dev, unsigned int irq,
+			    irq_handler_t handler, const char *suffix,
+			    void *dev_id)
+{
+	const char *name = devm_kasprintf(dev, GFP_KERNEL, "%s:%s",
+					  dev_name(dev), suffix);
+	if (!name)
+		return -ENOMEM;
+
+	return devm_request_irq(dev, irq, handler, 0, name, dev_id);
+}
+
+static int rspi_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct spi_controller *ctlr;
+	struct rspi_data *rspi;
+	int ret;
+	const struct rspi_plat_data *rspi_pd;
+	const struct spi_ops *ops;
+	unsigned long clksrc;
+
+	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct rspi_data));
+	if (ctlr == NULL)
+		return -ENOMEM;
+
+	ops = of_device_get_match_data(&pdev->dev);
+	if (ops) {
+		ret = rspi_parse_dt(&pdev->dev, ctlr);
+		if (ret)
+			goto error1;
+	} else {
+		ops = (struct spi_ops *)pdev->id_entry->driver_data;
+		rspi_pd = dev_get_platdata(&pdev->dev);
+		if (rspi_pd && rspi_pd->num_chipselect)
+			ctlr->num_chipselect = rspi_pd->num_chipselect;
+		else
+			ctlr->num_chipselect = 2; /* default */
+	}
+
+	rspi = spi_controller_get_devdata(ctlr);
+	platform_set_drvdata(pdev, rspi);
+	rspi->ops = ops;
+	rspi->ctlr = ctlr;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	rspi->addr = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(rspi->addr)) {
+		ret = PTR_ERR(rspi->addr);
+		goto error1;
+	}
+
+	rspi->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(rspi->clk)) {
+		dev_err(&pdev->dev, "cannot get clock\n");
+		ret = PTR_ERR(rspi->clk);
+		goto error1;
+	}
+
+	rspi->pdev = pdev;
+	pm_runtime_enable(&pdev->dev);
+
+	init_waitqueue_head(&rspi->wait);
+	spin_lock_init(&rspi->lock);
+
+	ctlr->bus_num = pdev->id;
+	ctlr->setup = rspi_setup;
+	ctlr->auto_runtime_pm = true;
+	ctlr->transfer_one = ops->transfer_one;
+	ctlr->prepare_message = rspi_prepare_message;
+	ctlr->unprepare_message = rspi_unprepare_message;
+	ctlr->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST |
+			  SPI_LOOP | ops->extra_mode_bits;
+	clksrc = clk_get_rate(rspi->clk);
+	ctlr->min_speed_hz = DIV_ROUND_UP(clksrc, ops->max_div);
+	ctlr->max_speed_hz = DIV_ROUND_UP(clksrc, ops->min_div);
+	ctlr->flags = ops->flags;
+	ctlr->dev.of_node = pdev->dev.of_node;
+	ctlr->use_gpio_descriptors = true;
+	ctlr->max_native_cs = rspi->ops->num_hw_ss;
+
+	ret = platform_get_irq_byname_optional(pdev, "rx");
+	if (ret < 0) {
+		ret = platform_get_irq_byname_optional(pdev, "mux");
+		if (ret < 0)
+			ret = platform_get_irq(pdev, 0);
+		if (ret >= 0)
+			rspi->rx_irq = rspi->tx_irq = ret;
+	} else {
+		rspi->rx_irq = ret;
+		ret = platform_get_irq_byname(pdev, "tx");
+		if (ret >= 0)
+			rspi->tx_irq = ret;
+	}
+
+	if (rspi->rx_irq == rspi->tx_irq) {
+		/* Single multiplexed interrupt */
+		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_mux,
+				       "mux", rspi);
+	} else {
+		/* Multi-interrupt mode, only SPRI and SPTI are used */
+		ret = rspi_request_irq(&pdev->dev, rspi->rx_irq, rspi_irq_rx,
+				       "rx", rspi);
+		if (!ret)
+			ret = rspi_request_irq(&pdev->dev, rspi->tx_irq,
+					       rspi_irq_tx, "tx", rspi);
+	}
+	if (ret < 0) {
+		dev_err(&pdev->dev, "request_irq error\n");
+		goto error2;
+	}
+
+	ret = rspi_request_dma(&pdev->dev, ctlr, res);
+	if (ret < 0)
+		dev_warn(&pdev->dev, "DMA not available, using PIO\n");
+
+	ret = devm_spi_register_controller(&pdev->dev, ctlr);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "devm_spi_register_controller error.\n");
+		goto error3;
+	}
+
+	dev_info(&pdev->dev, "probed\n");
+
+	return 0;
+
+error3:
+	rspi_release_dma(ctlr);
+error2:
+	pm_runtime_disable(&pdev->dev);
+error1:
+	spi_controller_put(ctlr);
+
+	return ret;
+}
+
+static const struct platform_device_id spi_driver_ids[] = {
+	{ "rspi",	(kernel_ulong_t)&rspi_ops },
+	{},
+};
+
+MODULE_DEVICE_TABLE(platform, spi_driver_ids);
+
+#ifdef CONFIG_PM_SLEEP
+static int rspi_suspend(struct device *dev)
+{
+	struct rspi_data *rspi = dev_get_drvdata(dev);
+
+	return spi_controller_suspend(rspi->ctlr);
+}
+
+static int rspi_resume(struct device *dev)
+{
+	struct rspi_data *rspi = dev_get_drvdata(dev);
+
+	return spi_controller_resume(rspi->ctlr);
+}
+
+static SIMPLE_DEV_PM_OPS(rspi_pm_ops, rspi_suspend, rspi_resume);
+#define DEV_PM_OPS	&rspi_pm_ops
+#else
+#define DEV_PM_OPS	NULL
+#endif /* CONFIG_PM_SLEEP */
+
+static struct platform_driver rspi_driver = {
+	.probe =	rspi_probe,
+	.remove =	rspi_remove,
+	.id_table =	spi_driver_ids,
+	.driver		= {
+		.name = "renesas_spi",
+		.pm = DEV_PM_OPS,
+		.of_match_table = of_match_ptr(rspi_of_match),
+	},
+};
+module_platform_driver(rspi_driver);
+
+MODULE_DESCRIPTION("Renesas RSPI bus driver");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Yoshihiro Shimoda");