Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 1447 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-cadence.c b/drivers/i2c/busses/i2c-cadence.c
new file mode 100644
index 0000000000..de3f58b60d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-cadence.c
@@ -0,0 +1,1447 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * I2C bus driver for the Cadence I2C controller.
+ *
+ * Copyright (C) 2009 - 2014 Xilinx, Inc.
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/reset.h>
+
+/* Register offsets for the I2C device. */
+#define CDNS_I2C_CR_OFFSET		0x00 /* Control Register, RW */
+#define CDNS_I2C_SR_OFFSET		0x04 /* Status Register, RO */
+#define CDNS_I2C_ADDR_OFFSET		0x08 /* I2C Address Register, RW */
+#define CDNS_I2C_DATA_OFFSET		0x0C /* I2C Data Register, RW */
+#define CDNS_I2C_ISR_OFFSET		0x10 /* IRQ Status Register, RW */
+#define CDNS_I2C_XFER_SIZE_OFFSET	0x14 /* Transfer Size Register, RW */
+#define CDNS_I2C_TIME_OUT_OFFSET	0x1C /* Time Out Register, RW */
+#define CDNS_I2C_IMR_OFFSET		0x20 /* IRQ Mask Register, RO */
+#define CDNS_I2C_IER_OFFSET		0x24 /* IRQ Enable Register, WO */
+#define CDNS_I2C_IDR_OFFSET		0x28 /* IRQ Disable Register, WO */
+
+/* Control Register Bit mask definitions */
+#define CDNS_I2C_CR_HOLD		BIT(4) /* Hold Bus bit */
+#define CDNS_I2C_CR_ACK_EN		BIT(3)
+#define CDNS_I2C_CR_NEA			BIT(2)
+#define CDNS_I2C_CR_MS			BIT(1)
+/* Read or Write Master transfer 0 = Transmitter, 1 = Receiver */
+#define CDNS_I2C_CR_RW			BIT(0)
+/* 1 = Auto init FIFO to zeroes */
+#define CDNS_I2C_CR_CLR_FIFO		BIT(6)
+#define CDNS_I2C_CR_DIVA_SHIFT		14
+#define CDNS_I2C_CR_DIVA_MASK		(3 << CDNS_I2C_CR_DIVA_SHIFT)
+#define CDNS_I2C_CR_DIVB_SHIFT		8
+#define CDNS_I2C_CR_DIVB_MASK		(0x3f << CDNS_I2C_CR_DIVB_SHIFT)
+
+#define CDNS_I2C_CR_MASTER_EN_MASK	(CDNS_I2C_CR_NEA | \
+					 CDNS_I2C_CR_ACK_EN | \
+					 CDNS_I2C_CR_MS)
+
+#define CDNS_I2C_CR_SLAVE_EN_MASK	~CDNS_I2C_CR_MASTER_EN_MASK
+
+/* Status Register Bit mask definitions */
+#define CDNS_I2C_SR_BA		BIT(8)
+#define CDNS_I2C_SR_TXDV	BIT(6)
+#define CDNS_I2C_SR_RXDV	BIT(5)
+#define CDNS_I2C_SR_RXRW	BIT(3)
+
+/*
+ * I2C Address Register Bit mask definitions
+ * Normal addressing mode uses [6:0] bits. Extended addressing mode uses [9:0]
+ * bits. A write access to this register always initiates a transfer if the I2C
+ * is in master mode.
+ */
+#define CDNS_I2C_ADDR_MASK	0x000003FF /* I2C Address Mask */
+
+/*
+ * I2C Interrupt Registers Bit mask definitions
+ * All the four interrupt registers (Status/Mask/Enable/Disable) have the same
+ * bit definitions.
+ */
+#define CDNS_I2C_IXR_ARB_LOST		BIT(9)
+#define CDNS_I2C_IXR_RX_UNF		BIT(7)
+#define CDNS_I2C_IXR_TX_OVF		BIT(6)
+#define CDNS_I2C_IXR_RX_OVF		BIT(5)
+#define CDNS_I2C_IXR_SLV_RDY		BIT(4)
+#define CDNS_I2C_IXR_TO			BIT(3)
+#define CDNS_I2C_IXR_NACK		BIT(2)
+#define CDNS_I2C_IXR_DATA		BIT(1)
+#define CDNS_I2C_IXR_COMP		BIT(0)
+
+#define CDNS_I2C_IXR_ALL_INTR_MASK	(CDNS_I2C_IXR_ARB_LOST | \
+					 CDNS_I2C_IXR_RX_UNF | \
+					 CDNS_I2C_IXR_TX_OVF | \
+					 CDNS_I2C_IXR_RX_OVF | \
+					 CDNS_I2C_IXR_SLV_RDY | \
+					 CDNS_I2C_IXR_TO | \
+					 CDNS_I2C_IXR_NACK | \
+					 CDNS_I2C_IXR_DATA | \
+					 CDNS_I2C_IXR_COMP)
+
+#define CDNS_I2C_IXR_ERR_INTR_MASK	(CDNS_I2C_IXR_ARB_LOST | \
+					 CDNS_I2C_IXR_RX_UNF | \
+					 CDNS_I2C_IXR_TX_OVF | \
+					 CDNS_I2C_IXR_RX_OVF | \
+					 CDNS_I2C_IXR_NACK)
+
+#define CDNS_I2C_ENABLED_INTR_MASK	(CDNS_I2C_IXR_ARB_LOST | \
+					 CDNS_I2C_IXR_RX_UNF | \
+					 CDNS_I2C_IXR_TX_OVF | \
+					 CDNS_I2C_IXR_RX_OVF | \
+					 CDNS_I2C_IXR_NACK | \
+					 CDNS_I2C_IXR_DATA | \
+					 CDNS_I2C_IXR_COMP)
+
+#define CDNS_I2C_IXR_SLAVE_INTR_MASK	(CDNS_I2C_IXR_RX_UNF | \
+					 CDNS_I2C_IXR_TX_OVF | \
+					 CDNS_I2C_IXR_RX_OVF | \
+					 CDNS_I2C_IXR_TO | \
+					 CDNS_I2C_IXR_NACK | \
+					 CDNS_I2C_IXR_DATA | \
+					 CDNS_I2C_IXR_COMP)
+
+#define CDNS_I2C_TIMEOUT		msecs_to_jiffies(1000)
+/* timeout for pm runtime autosuspend */
+#define CNDS_I2C_PM_TIMEOUT		1000	/* ms */
+
+#define CDNS_I2C_FIFO_DEPTH_DEFAULT	16
+#define CDNS_I2C_MAX_TRANSFER_SIZE	255
+/* Transfer size in multiples of data interrupt depth */
+#define CDNS_I2C_TRANSFER_SIZE(max)	((max) - 3)
+
+#define DRIVER_NAME		"cdns-i2c"
+
+#define CDNS_I2C_DIVA_MAX	4
+#define CDNS_I2C_DIVB_MAX	64
+
+#define CDNS_I2C_TIMEOUT_MAX	0xFF
+
+#define CDNS_I2C_BROKEN_HOLD_BIT	BIT(0)
+#define CDNS_I2C_POLL_US	100000
+#define CDNS_I2C_TIMEOUT_US	500000
+
+#define cdns_i2c_readreg(offset)       readl_relaxed(id->membase + offset)
+#define cdns_i2c_writereg(val, offset) writel_relaxed(val, id->membase + offset)
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+/**
+ * enum cdns_i2c_mode - I2C Controller current operating mode
+ *
+ * @CDNS_I2C_MODE_SLAVE:       I2C controller operating in slave mode
+ * @CDNS_I2C_MODE_MASTER:      I2C Controller operating in master mode
+ */
+enum cdns_i2c_mode {
+	CDNS_I2C_MODE_SLAVE,
+	CDNS_I2C_MODE_MASTER,
+};
+
+/**
+ * enum cdns_i2c_slave_state - Slave state when I2C is operating in slave mode
+ *
+ * @CDNS_I2C_SLAVE_STATE_IDLE: I2C slave idle
+ * @CDNS_I2C_SLAVE_STATE_SEND: I2C slave sending data to master
+ * @CDNS_I2C_SLAVE_STATE_RECV: I2C slave receiving data from master
+ */
+enum cdns_i2c_slave_state {
+	CDNS_I2C_SLAVE_STATE_IDLE,
+	CDNS_I2C_SLAVE_STATE_SEND,
+	CDNS_I2C_SLAVE_STATE_RECV,
+};
+#endif
+
+/**
+ * struct cdns_i2c - I2C device private data structure
+ *
+ * @dev:		Pointer to device structure
+ * @membase:		Base address of the I2C device
+ * @adap:		I2C adapter instance
+ * @p_msg:		Message pointer
+ * @err_status:		Error status in Interrupt Status Register
+ * @xfer_done:		Transfer complete status
+ * @p_send_buf:		Pointer to transmit buffer
+ * @p_recv_buf:		Pointer to receive buffer
+ * @send_count:		Number of bytes still expected to send
+ * @recv_count:		Number of bytes still expected to receive
+ * @curr_recv_count:	Number of bytes to be received in current transfer
+ * @input_clk:		Input clock to I2C controller
+ * @i2c_clk:		Maximum I2C clock speed
+ * @bus_hold_flag:	Flag used in repeated start for clearing HOLD bit
+ * @clk:		Pointer to struct clk
+ * @clk_rate_change_nb:	Notifier block for clock rate changes
+ * @reset:		Reset control for the device
+ * @quirks:		flag for broken hold bit usage in r1p10
+ * @ctrl_reg:		Cached value of the control register.
+ * @rinfo:		I2C GPIO recovery information
+ * @ctrl_reg_diva_divb: value of fields DIV_A and DIV_B from CR register
+ * @slave:		Registered slave instance.
+ * @dev_mode:		I2C operating role(master/slave).
+ * @slave_state:	I2C Slave state(idle/read/write).
+ * @fifo_depth:		The depth of the transfer FIFO
+ * @transfer_size:	The maximum number of bytes in one transfer
+ */
+struct cdns_i2c {
+	struct device		*dev;
+	void __iomem *membase;
+	struct i2c_adapter adap;
+	struct i2c_msg *p_msg;
+	int err_status;
+	struct completion xfer_done;
+	unsigned char *p_send_buf;
+	unsigned char *p_recv_buf;
+	unsigned int send_count;
+	unsigned int recv_count;
+	unsigned int curr_recv_count;
+	unsigned long input_clk;
+	unsigned int i2c_clk;
+	unsigned int bus_hold_flag;
+	struct clk *clk;
+	struct notifier_block clk_rate_change_nb;
+	struct reset_control *reset;
+	u32 quirks;
+	u32 ctrl_reg;
+	struct i2c_bus_recovery_info rinfo;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	u16 ctrl_reg_diva_divb;
+	struct i2c_client *slave;
+	enum cdns_i2c_mode dev_mode;
+	enum cdns_i2c_slave_state slave_state;
+#endif
+	u32 fifo_depth;
+	unsigned int transfer_size;
+};
+
+struct cdns_platform_data {
+	u32 quirks;
+};
+
+#define to_cdns_i2c(_nb)	container_of(_nb, struct cdns_i2c, \
+					     clk_rate_change_nb)
+
+/**
+ * cdns_i2c_clear_bus_hold - Clear bus hold bit
+ * @id:	Pointer to driver data struct
+ *
+ * Helper to clear the controller's bus hold bit.
+ */
+static void cdns_i2c_clear_bus_hold(struct cdns_i2c *id)
+{
+	u32 reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+	if (reg & CDNS_I2C_CR_HOLD)
+		cdns_i2c_writereg(reg & ~CDNS_I2C_CR_HOLD, CDNS_I2C_CR_OFFSET);
+}
+
+static inline bool cdns_is_holdquirk(struct cdns_i2c *id, bool hold_wrkaround)
+{
+	return (hold_wrkaround &&
+		(id->curr_recv_count == id->fifo_depth + 1));
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static void cdns_i2c_set_mode(enum cdns_i2c_mode mode, struct cdns_i2c *id)
+{
+	/* Disable all interrupts */
+	cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK, CDNS_I2C_IDR_OFFSET);
+
+	/* Clear FIFO and transfer size */
+	cdns_i2c_writereg(CDNS_I2C_CR_CLR_FIFO, CDNS_I2C_CR_OFFSET);
+
+	/* Update device mode and state */
+	id->dev_mode = mode;
+	id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;
+
+	switch (mode) {
+	case CDNS_I2C_MODE_MASTER:
+		/* Enable i2c master */
+		cdns_i2c_writereg(id->ctrl_reg_diva_divb |
+				  CDNS_I2C_CR_MASTER_EN_MASK,
+				  CDNS_I2C_CR_OFFSET);
+		/*
+		 * This delay is needed to give the IP some time to switch to
+		 * the master mode. With lower values(like 110 us) i2cdetect
+		 * will not detect any slave and without this delay, the IP will
+		 * trigger a timeout interrupt.
+		 */
+		usleep_range(115, 125);
+		break;
+	case CDNS_I2C_MODE_SLAVE:
+		/* Enable i2c slave */
+		cdns_i2c_writereg(id->ctrl_reg_diva_divb &
+				  CDNS_I2C_CR_SLAVE_EN_MASK,
+				  CDNS_I2C_CR_OFFSET);
+
+		/* Setting slave address */
+		cdns_i2c_writereg(id->slave->addr & CDNS_I2C_ADDR_MASK,
+				  CDNS_I2C_ADDR_OFFSET);
+
+		/* Enable slave send/receive interrupts */
+		cdns_i2c_writereg(CDNS_I2C_IXR_SLAVE_INTR_MASK,
+				  CDNS_I2C_IER_OFFSET);
+		break;
+	}
+}
+
+static void cdns_i2c_slave_rcv_data(struct cdns_i2c *id)
+{
+	u8 bytes;
+	unsigned char data;
+
+	/* Prepare backend for data reception */
+	if (id->slave_state == CDNS_I2C_SLAVE_STATE_IDLE) {
+		id->slave_state = CDNS_I2C_SLAVE_STATE_RECV;
+		i2c_slave_event(id->slave, I2C_SLAVE_WRITE_REQUESTED, NULL);
+	}
+
+	/* Fetch number of bytes to receive */
+	bytes = cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
+
+	/* Read data and send to backend */
+	while (bytes--) {
+		data = cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET);
+		i2c_slave_event(id->slave, I2C_SLAVE_WRITE_RECEIVED, &data);
+	}
+}
+
+static void cdns_i2c_slave_send_data(struct cdns_i2c *id)
+{
+	u8 data;
+
+	/* Prepare backend for data transmission */
+	if (id->slave_state == CDNS_I2C_SLAVE_STATE_IDLE) {
+		id->slave_state = CDNS_I2C_SLAVE_STATE_SEND;
+		i2c_slave_event(id->slave, I2C_SLAVE_READ_REQUESTED, &data);
+	} else {
+		i2c_slave_event(id->slave, I2C_SLAVE_READ_PROCESSED, &data);
+	}
+
+	/* Send data over bus */
+	cdns_i2c_writereg(data, CDNS_I2C_DATA_OFFSET);
+}
+
+/**
+ * cdns_i2c_slave_isr - Interrupt handler for the I2C device in slave role
+ * @ptr:       Pointer to I2C device private data
+ *
+ * This function handles the data interrupt and transfer complete interrupt of
+ * the I2C device in slave role.
+ *
+ * Return: IRQ_HANDLED always
+ */
+static irqreturn_t cdns_i2c_slave_isr(void *ptr)
+{
+	struct cdns_i2c *id = ptr;
+	unsigned int isr_status, i2c_status;
+
+	/* Fetch the interrupt status */
+	isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
+	cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
+
+	/* Ignore masked interrupts */
+	isr_status &= ~cdns_i2c_readreg(CDNS_I2C_IMR_OFFSET);
+
+	/* Fetch transfer mode (send/receive) */
+	i2c_status = cdns_i2c_readreg(CDNS_I2C_SR_OFFSET);
+
+	/* Handle data send/receive */
+	if (i2c_status & CDNS_I2C_SR_RXRW) {
+		/* Send data to master */
+		if (isr_status & CDNS_I2C_IXR_DATA)
+			cdns_i2c_slave_send_data(id);
+
+		if (isr_status & CDNS_I2C_IXR_COMP) {
+			id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;
+			i2c_slave_event(id->slave, I2C_SLAVE_STOP, NULL);
+		}
+	} else {
+		/* Receive data from master */
+		if (isr_status & CDNS_I2C_IXR_DATA)
+			cdns_i2c_slave_rcv_data(id);
+
+		if (isr_status & CDNS_I2C_IXR_COMP) {
+			cdns_i2c_slave_rcv_data(id);
+			id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;
+			i2c_slave_event(id->slave, I2C_SLAVE_STOP, NULL);
+		}
+	}
+
+	/* Master indicated xfer stop or fifo underflow/overflow */
+	if (isr_status & (CDNS_I2C_IXR_NACK | CDNS_I2C_IXR_RX_OVF |
+			  CDNS_I2C_IXR_RX_UNF | CDNS_I2C_IXR_TX_OVF)) {
+		id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;
+		i2c_slave_event(id->slave, I2C_SLAVE_STOP, NULL);
+		cdns_i2c_writereg(CDNS_I2C_CR_CLR_FIFO, CDNS_I2C_CR_OFFSET);
+	}
+
+	return IRQ_HANDLED;
+}
+#endif
+
+/**
+ * cdns_i2c_master_isr - Interrupt handler for the I2C device in master role
+ * @ptr:       Pointer to I2C device private data
+ *
+ * This function handles the data interrupt, transfer complete interrupt and
+ * the error interrupts of the I2C device in master role.
+ *
+ * Return: IRQ_HANDLED always
+ */
+static irqreturn_t cdns_i2c_master_isr(void *ptr)
+{
+	unsigned int isr_status, avail_bytes;
+	unsigned int bytes_to_send;
+	bool updatetx;
+	struct cdns_i2c *id = ptr;
+	/* Signal completion only after everything is updated */
+	int done_flag = 0;
+	irqreturn_t status = IRQ_NONE;
+
+	isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
+	cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
+	id->err_status = 0;
+
+	/* Handling nack and arbitration lost interrupt */
+	if (isr_status & (CDNS_I2C_IXR_NACK | CDNS_I2C_IXR_ARB_LOST)) {
+		done_flag = 1;
+		status = IRQ_HANDLED;
+	}
+
+	/*
+	 * Check if transfer size register needs to be updated again for a
+	 * large data receive operation.
+	 */
+	updatetx = id->recv_count > id->curr_recv_count;
+
+	/* When receiving, handle data interrupt and completion interrupt */
+	if (id->p_recv_buf &&
+	    ((isr_status & CDNS_I2C_IXR_COMP) ||
+	     (isr_status & CDNS_I2C_IXR_DATA))) {
+		/* Read data if receive data valid is set */
+		while (cdns_i2c_readreg(CDNS_I2C_SR_OFFSET) &
+		       CDNS_I2C_SR_RXDV) {
+			if (id->recv_count > 0) {
+				*(id->p_recv_buf)++ =
+					cdns_i2c_readreg(CDNS_I2C_DATA_OFFSET);
+				id->recv_count--;
+				id->curr_recv_count--;
+
+				/*
+				 * Clear hold bit that was set for FIFO control
+				 * if RX data left is less than or equal to
+				 * FIFO DEPTH unless repeated start is selected
+				 */
+				if (id->recv_count <= id->fifo_depth &&
+				    !id->bus_hold_flag)
+					cdns_i2c_clear_bus_hold(id);
+
+			} else {
+				dev_err(id->adap.dev.parent,
+					"xfer_size reg rollover. xfer aborted!\n");
+				id->err_status |= CDNS_I2C_IXR_TO;
+				break;
+			}
+
+			if (cdns_is_holdquirk(id, updatetx))
+				break;
+		}
+
+		/*
+		 * The controller sends NACK to the slave when transfer size
+		 * register reaches zero without considering the HOLD bit.
+		 * This workaround is implemented for large data transfers to
+		 * maintain transfer size non-zero while performing a large
+		 * receive operation.
+		 */
+		if (cdns_is_holdquirk(id, updatetx)) {
+			/* wait while fifo is full */
+			while (cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET) !=
+			       (id->curr_recv_count - id->fifo_depth))
+				;
+
+			/*
+			 * Check number of bytes to be received against maximum
+			 * transfer size and update register accordingly.
+			 */
+			if (((int)(id->recv_count) - id->fifo_depth) >
+			    id->transfer_size) {
+				cdns_i2c_writereg(id->transfer_size,
+						  CDNS_I2C_XFER_SIZE_OFFSET);
+				id->curr_recv_count = id->transfer_size +
+						      id->fifo_depth;
+			} else {
+				cdns_i2c_writereg(id->recv_count -
+						  id->fifo_depth,
+						  CDNS_I2C_XFER_SIZE_OFFSET);
+				id->curr_recv_count = id->recv_count;
+			}
+		}
+
+		/* Clear hold (if not repeated start) and signal completion */
+		if ((isr_status & CDNS_I2C_IXR_COMP) && !id->recv_count) {
+			if (!id->bus_hold_flag)
+				cdns_i2c_clear_bus_hold(id);
+			done_flag = 1;
+		}
+
+		status = IRQ_HANDLED;
+	}
+
+	/* When sending, handle transfer complete interrupt */
+	if ((isr_status & CDNS_I2C_IXR_COMP) && !id->p_recv_buf) {
+		/*
+		 * If there is more data to be sent, calculate the
+		 * space available in FIFO and fill with that many bytes.
+		 */
+		if (id->send_count) {
+			avail_bytes = id->fifo_depth -
+			    cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
+			if (id->send_count > avail_bytes)
+				bytes_to_send = avail_bytes;
+			else
+				bytes_to_send = id->send_count;
+
+			while (bytes_to_send--) {
+				cdns_i2c_writereg(
+					(*(id->p_send_buf)++),
+					 CDNS_I2C_DATA_OFFSET);
+				id->send_count--;
+			}
+		} else {
+			/*
+			 * Signal the completion of transaction and
+			 * clear the hold bus bit if there are no
+			 * further messages to be processed.
+			 */
+			done_flag = 1;
+		}
+		if (!id->send_count && !id->bus_hold_flag)
+			cdns_i2c_clear_bus_hold(id);
+
+		status = IRQ_HANDLED;
+	}
+
+	/* Update the status for errors */
+	id->err_status |= isr_status & CDNS_I2C_IXR_ERR_INTR_MASK;
+	if (id->err_status)
+		status = IRQ_HANDLED;
+
+	if (done_flag)
+		complete(&id->xfer_done);
+
+	return status;
+}
+
+/**
+ * cdns_i2c_isr - Interrupt handler for the I2C device
+ * @irq:	irq number for the I2C device
+ * @ptr:	void pointer to cdns_i2c structure
+ *
+ * This function passes the control to slave/master based on current role of
+ * i2c controller.
+ *
+ * Return: IRQ_HANDLED always
+ */
+static irqreturn_t cdns_i2c_isr(int irq, void *ptr)
+{
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	struct cdns_i2c *id = ptr;
+
+	if (id->dev_mode == CDNS_I2C_MODE_SLAVE)
+		return cdns_i2c_slave_isr(ptr);
+#endif
+	return cdns_i2c_master_isr(ptr);
+}
+
+/**
+ * cdns_i2c_mrecv - Prepare and start a master receive operation
+ * @id:		pointer to the i2c device structure
+ */
+static void cdns_i2c_mrecv(struct cdns_i2c *id)
+{
+	unsigned int ctrl_reg;
+	unsigned int isr_status;
+	unsigned long flags;
+	bool hold_clear = false;
+	bool irq_save = false;
+
+	u32 addr;
+
+	id->p_recv_buf = id->p_msg->buf;
+	id->recv_count = id->p_msg->len;
+
+	/* Put the controller in master receive mode and clear the FIFO */
+	ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+	ctrl_reg |= CDNS_I2C_CR_RW | CDNS_I2C_CR_CLR_FIFO;
+
+	/*
+	 * Receive up to I2C_SMBUS_BLOCK_MAX data bytes, plus one message length
+	 * byte, plus one checksum byte if PEC is enabled. p_msg->len will be 2 if
+	 * PEC is enabled, otherwise 1.
+	 */
+	if (id->p_msg->flags & I2C_M_RECV_LEN)
+		id->recv_count = I2C_SMBUS_BLOCK_MAX + id->p_msg->len;
+
+	id->curr_recv_count = id->recv_count;
+
+	/*
+	 * Check for the message size against FIFO depth and set the
+	 * 'hold bus' bit if it is greater than FIFO depth.
+	 */
+	if (id->recv_count > id->fifo_depth)
+		ctrl_reg |= CDNS_I2C_CR_HOLD;
+
+	cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
+
+	/* Clear the interrupts in interrupt status register */
+	isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
+	cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
+
+	/*
+	 * The no. of bytes to receive is checked against the limit of
+	 * max transfer size. Set transfer size register with no of bytes
+	 * receive if it is less than transfer size and transfer size if
+	 * it is more. Enable the interrupts.
+	 */
+	if (id->recv_count > id->transfer_size) {
+		cdns_i2c_writereg(id->transfer_size,
+				  CDNS_I2C_XFER_SIZE_OFFSET);
+		id->curr_recv_count = id->transfer_size;
+	} else {
+		cdns_i2c_writereg(id->recv_count, CDNS_I2C_XFER_SIZE_OFFSET);
+	}
+
+	/* Determine hold_clear based on number of bytes to receive and hold flag */
+	if (!id->bus_hold_flag && id->recv_count <= id->fifo_depth) {
+		if (ctrl_reg & CDNS_I2C_CR_HOLD) {
+			hold_clear = true;
+			if (id->quirks & CDNS_I2C_BROKEN_HOLD_BIT)
+				irq_save = true;
+		}
+	}
+
+	addr = id->p_msg->addr;
+	addr &= CDNS_I2C_ADDR_MASK;
+
+	if (hold_clear) {
+		ctrl_reg &= ~CDNS_I2C_CR_HOLD;
+		/*
+		 * In case of Xilinx Zynq SOC, clear the HOLD bit before transfer size
+		 * register reaches '0'. This is an IP bug which causes transfer size
+		 * register overflow to 0xFF. To satisfy this timing requirement,
+		 * disable the interrupts on current processor core between register
+		 * writes to slave address register and control register.
+		 */
+		if (irq_save)
+			local_irq_save(flags);
+
+		cdns_i2c_writereg(addr, CDNS_I2C_ADDR_OFFSET);
+		cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
+		/* Read it back to avoid bufferring and make sure write happens */
+		cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+
+		if (irq_save)
+			local_irq_restore(flags);
+	} else {
+		cdns_i2c_writereg(addr, CDNS_I2C_ADDR_OFFSET);
+	}
+
+	cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
+}
+
+/**
+ * cdns_i2c_msend - Prepare and start a master send operation
+ * @id:		pointer to the i2c device
+ */
+static void cdns_i2c_msend(struct cdns_i2c *id)
+{
+	unsigned int avail_bytes;
+	unsigned int bytes_to_send;
+	unsigned int ctrl_reg;
+	unsigned int isr_status;
+
+	id->p_recv_buf = NULL;
+	id->p_send_buf = id->p_msg->buf;
+	id->send_count = id->p_msg->len;
+
+	/* Set the controller in Master transmit mode and clear the FIFO. */
+	ctrl_reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+	ctrl_reg &= ~CDNS_I2C_CR_RW;
+	ctrl_reg |= CDNS_I2C_CR_CLR_FIFO;
+
+	/*
+	 * Check for the message size against FIFO depth and set the
+	 * 'hold bus' bit if it is greater than FIFO depth.
+	 */
+	if (id->send_count > id->fifo_depth)
+		ctrl_reg |= CDNS_I2C_CR_HOLD;
+	cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
+
+	/* Clear the interrupts in interrupt status register. */
+	isr_status = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
+	cdns_i2c_writereg(isr_status, CDNS_I2C_ISR_OFFSET);
+
+	/*
+	 * Calculate the space available in FIFO. Check the message length
+	 * against the space available, and fill the FIFO accordingly.
+	 * Enable the interrupts.
+	 */
+	avail_bytes = id->fifo_depth -
+				cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
+
+	if (id->send_count > avail_bytes)
+		bytes_to_send = avail_bytes;
+	else
+		bytes_to_send = id->send_count;
+
+	while (bytes_to_send--) {
+		cdns_i2c_writereg((*(id->p_send_buf)++), CDNS_I2C_DATA_OFFSET);
+		id->send_count--;
+	}
+
+	/*
+	 * Clear the bus hold flag if there is no more data
+	 * and if it is the last message.
+	 */
+	if (!id->bus_hold_flag && !id->send_count)
+		cdns_i2c_clear_bus_hold(id);
+	/* Set the slave address in address register - triggers operation. */
+	cdns_i2c_writereg(id->p_msg->addr & CDNS_I2C_ADDR_MASK,
+						CDNS_I2C_ADDR_OFFSET);
+
+	cdns_i2c_writereg(CDNS_I2C_ENABLED_INTR_MASK, CDNS_I2C_IER_OFFSET);
+}
+
+/**
+ * cdns_i2c_master_reset - Reset the interface
+ * @adap:	pointer to the i2c adapter driver instance
+ *
+ * This function cleanup the fifos, clear the hold bit and status
+ * and disable the interrupts.
+ */
+static void cdns_i2c_master_reset(struct i2c_adapter *adap)
+{
+	struct cdns_i2c *id = adap->algo_data;
+	u32 regval;
+
+	/* Disable the interrupts */
+	cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK, CDNS_I2C_IDR_OFFSET);
+	/* Clear the hold bit and fifos */
+	regval = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+	regval &= ~CDNS_I2C_CR_HOLD;
+	regval |= CDNS_I2C_CR_CLR_FIFO;
+	cdns_i2c_writereg(regval, CDNS_I2C_CR_OFFSET);
+	/* Update the transfercount register to zero */
+	cdns_i2c_writereg(0, CDNS_I2C_XFER_SIZE_OFFSET);
+	/* Clear the interrupt status register */
+	regval = cdns_i2c_readreg(CDNS_I2C_ISR_OFFSET);
+	cdns_i2c_writereg(regval, CDNS_I2C_ISR_OFFSET);
+	/* Clear the status register */
+	regval = cdns_i2c_readreg(CDNS_I2C_SR_OFFSET);
+	cdns_i2c_writereg(regval, CDNS_I2C_SR_OFFSET);
+}
+
+static int cdns_i2c_process_msg(struct cdns_i2c *id, struct i2c_msg *msg,
+		struct i2c_adapter *adap)
+{
+	unsigned long time_left, msg_timeout;
+	u32 reg;
+
+	id->p_msg = msg;
+	id->err_status = 0;
+	reinit_completion(&id->xfer_done);
+
+	/* Check for the TEN Bit mode on each msg */
+	reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+	if (msg->flags & I2C_M_TEN) {
+		if (reg & CDNS_I2C_CR_NEA)
+			cdns_i2c_writereg(reg & ~CDNS_I2C_CR_NEA,
+					CDNS_I2C_CR_OFFSET);
+	} else {
+		if (!(reg & CDNS_I2C_CR_NEA))
+			cdns_i2c_writereg(reg | CDNS_I2C_CR_NEA,
+					CDNS_I2C_CR_OFFSET);
+	}
+
+	/* Check for the R/W flag on each msg */
+	if (msg->flags & I2C_M_RD)
+		cdns_i2c_mrecv(id);
+	else
+		cdns_i2c_msend(id);
+
+	/* Minimal time to execute this message */
+	msg_timeout = msecs_to_jiffies((1000 * msg->len * BITS_PER_BYTE) / id->i2c_clk);
+	/* Plus some wiggle room */
+	msg_timeout += msecs_to_jiffies(500);
+
+	if (msg_timeout < adap->timeout)
+		msg_timeout = adap->timeout;
+
+	/* Wait for the signal of completion */
+	time_left = wait_for_completion_timeout(&id->xfer_done, msg_timeout);
+	if (time_left == 0) {
+		cdns_i2c_master_reset(adap);
+		dev_err(id->adap.dev.parent,
+				"timeout waiting on completion\n");
+		return -ETIMEDOUT;
+	}
+
+	cdns_i2c_writereg(CDNS_I2C_IXR_ALL_INTR_MASK,
+			  CDNS_I2C_IDR_OFFSET);
+
+	/* If it is bus arbitration error, try again */
+	if (id->err_status & CDNS_I2C_IXR_ARB_LOST)
+		return -EAGAIN;
+
+	if (msg->flags & I2C_M_RECV_LEN)
+		msg->len += min_t(unsigned int, msg->buf[0], I2C_SMBUS_BLOCK_MAX);
+
+	return 0;
+}
+
+/**
+ * cdns_i2c_master_xfer - The main i2c transfer function
+ * @adap:	pointer to the i2c adapter driver instance
+ * @msgs:	pointer to the i2c message structure
+ * @num:	the number of messages to transfer
+ *
+ * Initiates the send/recv activity based on the transfer message received.
+ *
+ * Return: number of msgs processed on success, negative error otherwise
+ */
+static int cdns_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+				int num)
+{
+	int ret, count;
+	u32 reg;
+	struct cdns_i2c *id = adap->algo_data;
+	bool hold_quirk;
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	bool change_role = false;
+#endif
+
+	ret = pm_runtime_resume_and_get(id->dev);
+	if (ret < 0)
+		return ret;
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	/* Check i2c operating mode and switch if possible */
+	if (id->dev_mode == CDNS_I2C_MODE_SLAVE) {
+		if (id->slave_state != CDNS_I2C_SLAVE_STATE_IDLE) {
+			ret = -EAGAIN;
+			goto out;
+		}
+
+		/* Set mode to master */
+		cdns_i2c_set_mode(CDNS_I2C_MODE_MASTER, id);
+
+		/* Mark flag to change role once xfer is completed */
+		change_role = true;
+	}
+#endif
+
+	/* Check if the bus is free */
+
+	ret = readl_relaxed_poll_timeout(id->membase + CDNS_I2C_SR_OFFSET,
+					 reg,
+					 !(reg & CDNS_I2C_SR_BA),
+					 CDNS_I2C_POLL_US, CDNS_I2C_TIMEOUT_US);
+	if (ret) {
+		ret = -EAGAIN;
+		if (id->adap.bus_recovery_info)
+			i2c_recover_bus(adap);
+		goto out;
+	}
+
+	hold_quirk = !!(id->quirks & CDNS_I2C_BROKEN_HOLD_BIT);
+	/*
+	 * Set the flag to one when multiple messages are to be
+	 * processed with a repeated start.
+	 */
+	if (num > 1) {
+		/*
+		 * This controller does not give completion interrupt after a
+		 * master receive message if HOLD bit is set (repeated start),
+		 * resulting in SW timeout. Hence, if a receive message is
+		 * followed by any other message, an error is returned
+		 * indicating that this sequence is not supported.
+		 */
+		for (count = 0; (count < num - 1 && hold_quirk); count++) {
+			if (msgs[count].flags & I2C_M_RD) {
+				dev_warn(adap->dev.parent,
+					 "Can't do repeated start after a receive message\n");
+				ret = -EOPNOTSUPP;
+				goto out;
+			}
+		}
+		id->bus_hold_flag = 1;
+		reg = cdns_i2c_readreg(CDNS_I2C_CR_OFFSET);
+		reg |= CDNS_I2C_CR_HOLD;
+		cdns_i2c_writereg(reg, CDNS_I2C_CR_OFFSET);
+	} else {
+		id->bus_hold_flag = 0;
+	}
+
+	/* Process the msg one by one */
+	for (count = 0; count < num; count++, msgs++) {
+		if (count == (num - 1))
+			id->bus_hold_flag = 0;
+
+		ret = cdns_i2c_process_msg(id, msgs, adap);
+		if (ret)
+			goto out;
+
+		/* Report the other error interrupts to application */
+		if (id->err_status) {
+			cdns_i2c_master_reset(adap);
+
+			if (id->err_status & CDNS_I2C_IXR_NACK) {
+				ret = -ENXIO;
+				goto out;
+			}
+			ret = -EIO;
+			goto out;
+		}
+	}
+
+	ret = num;
+
+out:
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	/* Switch i2c mode to slave */
+	if (change_role)
+		cdns_i2c_set_mode(CDNS_I2C_MODE_SLAVE, id);
+#endif
+
+	pm_runtime_mark_last_busy(id->dev);
+	pm_runtime_put_autosuspend(id->dev);
+	return ret;
+}
+
+/**
+ * cdns_i2c_func - Returns the supported features of the I2C driver
+ * @adap:	pointer to the i2c adapter structure
+ *
+ * Return: 32 bit value, each bit corresponding to a feature
+ */
+static u32 cdns_i2c_func(struct i2c_adapter *adap)
+{
+	u32 func = I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR |
+			(I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) |
+			I2C_FUNC_SMBUS_BLOCK_DATA;
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	func |= I2C_FUNC_SLAVE;
+#endif
+
+	return func;
+}
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+static int cdns_reg_slave(struct i2c_client *slave)
+{
+	int ret;
+	struct cdns_i2c *id = container_of(slave->adapter, struct cdns_i2c,
+									adap);
+
+	if (id->slave)
+		return -EBUSY;
+
+	if (slave->flags & I2C_CLIENT_TEN)
+		return -EAFNOSUPPORT;
+
+	ret = pm_runtime_resume_and_get(id->dev);
+	if (ret < 0)
+		return ret;
+
+	/* Store slave information */
+	id->slave = slave;
+
+	/* Enable I2C slave */
+	cdns_i2c_set_mode(CDNS_I2C_MODE_SLAVE, id);
+
+	return 0;
+}
+
+static int cdns_unreg_slave(struct i2c_client *slave)
+{
+	struct cdns_i2c *id = container_of(slave->adapter, struct cdns_i2c,
+									adap);
+
+	pm_runtime_put(id->dev);
+
+	/* Remove slave information */
+	id->slave = NULL;
+
+	/* Enable I2C master */
+	cdns_i2c_set_mode(CDNS_I2C_MODE_MASTER, id);
+
+	return 0;
+}
+#endif
+
+static const struct i2c_algorithm cdns_i2c_algo = {
+	.master_xfer	= cdns_i2c_master_xfer,
+	.functionality	= cdns_i2c_func,
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	.reg_slave	= cdns_reg_slave,
+	.unreg_slave	= cdns_unreg_slave,
+#endif
+};
+
+/**
+ * cdns_i2c_calc_divs - Calculate clock dividers
+ * @f:		I2C clock frequency
+ * @input_clk:	Input clock frequency
+ * @a:		First divider (return value)
+ * @b:		Second divider (return value)
+ *
+ * f is used as input and output variable. As input it is used as target I2C
+ * frequency. On function exit f holds the actually resulting I2C frequency.
+ *
+ * Return: 0 on success, negative errno otherwise.
+ */
+static int cdns_i2c_calc_divs(unsigned long *f, unsigned long input_clk,
+		unsigned int *a, unsigned int *b)
+{
+	unsigned long fscl = *f, best_fscl = *f, actual_fscl, temp;
+	unsigned int div_a, div_b, calc_div_a = 0, calc_div_b = 0;
+	unsigned int last_error, current_error;
+
+	/* calculate (divisor_a+1) x (divisor_b+1) */
+	temp = input_clk / (22 * fscl);
+
+	/*
+	 * If the calculated value is negative or 0, the fscl input is out of
+	 * range. Return error.
+	 */
+	if (!temp || (temp > (CDNS_I2C_DIVA_MAX * CDNS_I2C_DIVB_MAX)))
+		return -EINVAL;
+
+	last_error = -1;
+	for (div_a = 0; div_a < CDNS_I2C_DIVA_MAX; div_a++) {
+		div_b = DIV_ROUND_UP(input_clk, 22 * fscl * (div_a + 1));
+
+		if ((div_b < 1) || (div_b > CDNS_I2C_DIVB_MAX))
+			continue;
+		div_b--;
+
+		actual_fscl = input_clk / (22 * (div_a + 1) * (div_b + 1));
+
+		if (actual_fscl > fscl)
+			continue;
+
+		current_error = fscl - actual_fscl;
+
+		if (last_error > current_error) {
+			calc_div_a = div_a;
+			calc_div_b = div_b;
+			best_fscl = actual_fscl;
+			last_error = current_error;
+		}
+	}
+
+	*a = calc_div_a;
+	*b = calc_div_b;
+	*f = best_fscl;
+
+	return 0;
+}
+
+/**
+ * cdns_i2c_setclk - This function sets the serial clock rate for the I2C device
+ * @clk_in:	I2C clock input frequency in Hz
+ * @id:		Pointer to the I2C device structure
+ *
+ * The device must be idle rather than busy transferring data before setting
+ * these device options.
+ * The data rate is set by values in the control register.
+ * The formula for determining the correct register values is
+ *	Fscl = Fpclk/(22 x (divisor_a+1) x (divisor_b+1))
+ * See the hardware data sheet for a full explanation of setting the serial
+ * clock rate. The clock can not be faster than the input clock divide by 22.
+ * The two most common clock rates are 100KHz and 400KHz.
+ *
+ * Return: 0 on success, negative error otherwise
+ */
+static int cdns_i2c_setclk(unsigned long clk_in, struct cdns_i2c *id)
+{
+	unsigned int div_a, div_b;
+	unsigned int ctrl_reg;
+	int ret = 0;
+	unsigned long fscl = id->i2c_clk;
+
+	ret = cdns_i2c_calc_divs(&fscl, clk_in, &div_a, &div_b);
+	if (ret)
+		return ret;
+
+	ctrl_reg = id->ctrl_reg;
+	ctrl_reg &= ~(CDNS_I2C_CR_DIVA_MASK | CDNS_I2C_CR_DIVB_MASK);
+	ctrl_reg |= ((div_a << CDNS_I2C_CR_DIVA_SHIFT) |
+			(div_b << CDNS_I2C_CR_DIVB_SHIFT));
+	id->ctrl_reg = ctrl_reg;
+	cdns_i2c_writereg(ctrl_reg, CDNS_I2C_CR_OFFSET);
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	id->ctrl_reg_diva_divb = ctrl_reg & (CDNS_I2C_CR_DIVA_MASK |
+				 CDNS_I2C_CR_DIVB_MASK);
+#endif
+	return 0;
+}
+
+/**
+ * cdns_i2c_clk_notifier_cb - Clock rate change callback
+ * @nb:		Pointer to notifier block
+ * @event:	Notification reason
+ * @data:	Pointer to notification data object
+ *
+ * This function is called when the cdns_i2c input clock frequency changes.
+ * The callback checks whether a valid bus frequency can be generated after the
+ * change. If so, the change is acknowledged, otherwise the change is aborted.
+ * New dividers are written to the HW in the pre- or post change notification
+ * depending on the scaling direction.
+ *
+ * Return:	NOTIFY_STOP if the rate change should be aborted, NOTIFY_OK
+ *		to acknowledge the change, NOTIFY_DONE if the notification is
+ *		considered irrelevant.
+ */
+static int cdns_i2c_clk_notifier_cb(struct notifier_block *nb, unsigned long
+		event, void *data)
+{
+	struct clk_notifier_data *ndata = data;
+	struct cdns_i2c *id = to_cdns_i2c(nb);
+
+	if (pm_runtime_suspended(id->dev))
+		return NOTIFY_OK;
+
+	switch (event) {
+	case PRE_RATE_CHANGE:
+	{
+		unsigned long input_clk = ndata->new_rate;
+		unsigned long fscl = id->i2c_clk;
+		unsigned int div_a, div_b;
+		int ret;
+
+		ret = cdns_i2c_calc_divs(&fscl, input_clk, &div_a, &div_b);
+		if (ret) {
+			dev_warn(id->adap.dev.parent,
+					"clock rate change rejected\n");
+			return NOTIFY_STOP;
+		}
+
+		/* scale up */
+		if (ndata->new_rate > ndata->old_rate)
+			cdns_i2c_setclk(ndata->new_rate, id);
+
+		return NOTIFY_OK;
+	}
+	case POST_RATE_CHANGE:
+		id->input_clk = ndata->new_rate;
+		/* scale down */
+		if (ndata->new_rate < ndata->old_rate)
+			cdns_i2c_setclk(ndata->new_rate, id);
+		return NOTIFY_OK;
+	case ABORT_RATE_CHANGE:
+		/* scale up */
+		if (ndata->new_rate > ndata->old_rate)
+			cdns_i2c_setclk(ndata->old_rate, id);
+		return NOTIFY_OK;
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+/**
+ * cdns_i2c_runtime_suspend -  Runtime suspend method for the driver
+ * @dev:	Address of the platform_device structure
+ *
+ * Put the driver into low power mode.
+ *
+ * Return: 0 always
+ */
+static int __maybe_unused cdns_i2c_runtime_suspend(struct device *dev)
+{
+	struct cdns_i2c *xi2c = dev_get_drvdata(dev);
+
+	clk_disable(xi2c->clk);
+
+	return 0;
+}
+
+/**
+ * cdns_i2c_init -  Controller initialisation
+ * @id:		Device private data structure
+ *
+ * Initialise the i2c controller.
+ *
+ */
+static void cdns_i2c_init(struct cdns_i2c *id)
+{
+	cdns_i2c_writereg(id->ctrl_reg, CDNS_I2C_CR_OFFSET);
+	/*
+	 * Cadence I2C controller has a bug wherein it generates
+	 * invalid read transaction after HW timeout in master receiver mode.
+	 * HW timeout is not used by this driver and the interrupt is disabled.
+	 * But the feature itself cannot be disabled. Hence maximum value
+	 * is written to this register to reduce the chances of error.
+	 */
+	cdns_i2c_writereg(CDNS_I2C_TIMEOUT_MAX, CDNS_I2C_TIME_OUT_OFFSET);
+}
+
+/**
+ * cdns_i2c_runtime_resume - Runtime resume
+ * @dev:	Address of the platform_device structure
+ *
+ * Runtime resume callback.
+ *
+ * Return: 0 on success and error value on error
+ */
+static int __maybe_unused cdns_i2c_runtime_resume(struct device *dev)
+{
+	struct cdns_i2c *xi2c = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_enable(xi2c->clk);
+	if (ret) {
+		dev_err(dev, "Cannot enable clock.\n");
+		return ret;
+	}
+	cdns_i2c_init(xi2c);
+
+	return 0;
+}
+
+static const struct dev_pm_ops cdns_i2c_dev_pm_ops = {
+	SET_RUNTIME_PM_OPS(cdns_i2c_runtime_suspend,
+			   cdns_i2c_runtime_resume, NULL)
+};
+
+static const struct cdns_platform_data r1p10_i2c_def = {
+	.quirks = CDNS_I2C_BROKEN_HOLD_BIT,
+};
+
+static const struct of_device_id cdns_i2c_of_match[] = {
+	{ .compatible = "cdns,i2c-r1p10", .data = &r1p10_i2c_def },
+	{ .compatible = "cdns,i2c-r1p14",},
+	{ /* end of table */ }
+};
+MODULE_DEVICE_TABLE(of, cdns_i2c_of_match);
+
+/**
+ * cdns_i2c_detect_transfer_size - Detect the maximum transfer size supported
+ * @id: Device private data structure
+ *
+ * Detect the maximum transfer size that is supported by this instance of the
+ * Cadence I2C controller.
+ */
+static void cdns_i2c_detect_transfer_size(struct cdns_i2c *id)
+{
+	u32 val;
+
+	/*
+	 * Writing to the transfer size register is only possible if these two bits
+	 * are set in the control register.
+	 */
+	cdns_i2c_writereg(CDNS_I2C_CR_MS | CDNS_I2C_CR_RW, CDNS_I2C_CR_OFFSET);
+
+	/*
+	 * The number of writable bits of the transfer size register can be between
+	 * 4 and 8. This is a controlled through a synthesis parameter of the IP
+	 * core and can vary from instance to instance. The unused MSBs always read
+	 * back as 0. Writing 0xff and then reading the value back will report the
+	 * maximum supported transfer size.
+	 */
+	cdns_i2c_writereg(CDNS_I2C_MAX_TRANSFER_SIZE, CDNS_I2C_XFER_SIZE_OFFSET);
+	val = cdns_i2c_readreg(CDNS_I2C_XFER_SIZE_OFFSET);
+	id->transfer_size = CDNS_I2C_TRANSFER_SIZE(val);
+	cdns_i2c_writereg(0, CDNS_I2C_XFER_SIZE_OFFSET);
+	cdns_i2c_writereg(0, CDNS_I2C_CR_OFFSET);
+}
+
+/**
+ * cdns_i2c_probe - Platform registration call
+ * @pdev:	Handle to the platform device structure
+ *
+ * This function does all the memory allocation and registration for the i2c
+ * device. User can modify the address mode to 10 bit address mode using the
+ * ioctl call with option I2C_TENBIT.
+ *
+ * Return: 0 on success, negative error otherwise
+ */
+static int cdns_i2c_probe(struct platform_device *pdev)
+{
+	struct resource *r_mem;
+	struct cdns_i2c *id;
+	int ret, irq;
+	const struct of_device_id *match;
+
+	id = devm_kzalloc(&pdev->dev, sizeof(*id), GFP_KERNEL);
+	if (!id)
+		return -ENOMEM;
+
+	id->dev = &pdev->dev;
+	platform_set_drvdata(pdev, id);
+
+	match = of_match_node(cdns_i2c_of_match, pdev->dev.of_node);
+	if (match && match->data) {
+		const struct cdns_platform_data *data = match->data;
+		id->quirks = data->quirks;
+	}
+
+	id->rinfo.pinctrl = devm_pinctrl_get(&pdev->dev);
+	if (IS_ERR(id->rinfo.pinctrl)) {
+		int err = PTR_ERR(id->rinfo.pinctrl);
+
+		dev_info(&pdev->dev, "can't get pinctrl, bus recovery not supported\n");
+		if (err != -ENODEV)
+			return err;
+	} else {
+		id->adap.bus_recovery_info = &id->rinfo;
+	}
+
+	id->membase = devm_platform_get_and_ioremap_resource(pdev, 0, &r_mem);
+	if (IS_ERR(id->membase))
+		return PTR_ERR(id->membase);
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0)
+		return irq;
+
+	id->adap.owner = THIS_MODULE;
+	id->adap.dev.of_node = pdev->dev.of_node;
+	id->adap.algo = &cdns_i2c_algo;
+	id->adap.timeout = CDNS_I2C_TIMEOUT;
+	id->adap.retries = 3;		/* Default retry value. */
+	id->adap.algo_data = id;
+	id->adap.dev.parent = &pdev->dev;
+	init_completion(&id->xfer_done);
+	snprintf(id->adap.name, sizeof(id->adap.name),
+		 "Cadence I2C at %08lx", (unsigned long)r_mem->start);
+
+	id->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(id->clk))
+		return dev_err_probe(&pdev->dev, PTR_ERR(id->clk),
+				     "input clock not found.\n");
+
+	id->reset = devm_reset_control_get_optional_shared(&pdev->dev, NULL);
+	if (IS_ERR(id->reset))
+		return dev_err_probe(&pdev->dev, PTR_ERR(id->reset),
+				     "Failed to request reset.\n");
+
+	ret = clk_prepare_enable(id->clk);
+	if (ret)
+		dev_err(&pdev->dev, "Unable to enable clock.\n");
+
+	ret = reset_control_deassert(id->reset);
+	if (ret) {
+		dev_err_probe(&pdev->dev, ret,
+			      "Failed to de-assert reset.\n");
+		goto err_clk_dis;
+	}
+
+	pm_runtime_set_autosuspend_delay(id->dev, CNDS_I2C_PM_TIMEOUT);
+	pm_runtime_use_autosuspend(id->dev);
+	pm_runtime_set_active(id->dev);
+	pm_runtime_enable(id->dev);
+
+	id->clk_rate_change_nb.notifier_call = cdns_i2c_clk_notifier_cb;
+	if (clk_notifier_register(id->clk, &id->clk_rate_change_nb))
+		dev_warn(&pdev->dev, "Unable to register clock notifier.\n");
+	id->input_clk = clk_get_rate(id->clk);
+
+	ret = of_property_read_u32(pdev->dev.of_node, "clock-frequency",
+			&id->i2c_clk);
+	if (ret || (id->i2c_clk > I2C_MAX_FAST_MODE_FREQ))
+		id->i2c_clk = I2C_MAX_STANDARD_MODE_FREQ;
+
+#if IS_ENABLED(CONFIG_I2C_SLAVE)
+	/* Set initial mode to master */
+	id->dev_mode = CDNS_I2C_MODE_MASTER;
+	id->slave_state = CDNS_I2C_SLAVE_STATE_IDLE;
+#endif
+	id->ctrl_reg = CDNS_I2C_CR_ACK_EN | CDNS_I2C_CR_NEA | CDNS_I2C_CR_MS;
+
+	id->fifo_depth = CDNS_I2C_FIFO_DEPTH_DEFAULT;
+	of_property_read_u32(pdev->dev.of_node, "fifo-depth", &id->fifo_depth);
+
+	cdns_i2c_detect_transfer_size(id);
+
+	ret = cdns_i2c_setclk(id->input_clk, id);
+	if (ret) {
+		dev_err(&pdev->dev, "invalid SCL clock: %u Hz\n", id->i2c_clk);
+		ret = -EINVAL;
+		goto err_clk_notifier_unregister;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, cdns_i2c_isr, 0,
+				 DRIVER_NAME, id);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot get irq %d\n", irq);
+		goto err_clk_notifier_unregister;
+	}
+	cdns_i2c_init(id);
+
+	ret = i2c_add_adapter(&id->adap);
+	if (ret < 0)
+		goto err_clk_notifier_unregister;
+
+	dev_info(&pdev->dev, "%u kHz mmio %08lx irq %d\n",
+		 id->i2c_clk / 1000, (unsigned long)r_mem->start, irq);
+
+	return 0;
+
+err_clk_notifier_unregister:
+	clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);
+	reset_control_assert(id->reset);
+err_clk_dis:
+	clk_disable_unprepare(id->clk);
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	return ret;
+}
+
+/**
+ * cdns_i2c_remove - Unregister the device after releasing the resources
+ * @pdev:	Handle to the platform device structure
+ *
+ * This function frees all the resources allocated to the device.
+ *
+ * Return: 0 always
+ */
+static void cdns_i2c_remove(struct platform_device *pdev)
+{
+	struct cdns_i2c *id = platform_get_drvdata(pdev);
+
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
+
+	i2c_del_adapter(&id->adap);
+	clk_notifier_unregister(id->clk, &id->clk_rate_change_nb);
+	reset_control_assert(id->reset);
+	clk_disable_unprepare(id->clk);
+}
+
+static struct platform_driver cdns_i2c_drv = {
+	.driver = {
+		.name  = DRIVER_NAME,
+		.of_match_table = cdns_i2c_of_match,
+		.pm = &cdns_i2c_dev_pm_ops,
+	},
+	.probe  = cdns_i2c_probe,
+	.remove_new = cdns_i2c_remove,
+};
+
+module_platform_driver(cdns_i2c_drv);
+
+MODULE_AUTHOR("Xilinx Inc.");
+MODULE_DESCRIPTION("Cadence I2C bus driver");
+MODULE_LICENSE("GPL");