i2c: kona: Add Kona I2C driver

Add support for the Kona I2C controller found on Broadcom mobile SoCs.

Signed-off-by: Darwin Rambo <drambo@broadcom.com>
Reviewed-by: Steve Rae <srae@broadcom.com>
Reviewed-by: Tim Kryger <tkryger@linaro.org>

2 files changed, 731 insertions, 0 deletions

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index fa3a875..36d5e5f 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_SH_SH7734_I2C) += sh_sh7734_i2c.o
 obj-$(CONFIG_SYS_I2C) += i2c_core.o
 obj-$(CONFIG_SYS_I2C_FSL) += fsl_i2c.o
 obj-$(CONFIG_SYS_I2C_FTI2C010) += fti2c010.o
+obj-$(CONFIG_SYS_I2C_KONA) += kona_i2c.o
 obj-$(CONFIG_SYS_I2C_MXC) += mxc_i2c.o
 obj-$(CONFIG_SYS_I2C_OMAP24XX) += omap24xx_i2c.o
 obj-$(CONFIG_SYS_I2C_OMAP34XX) += omap24xx_i2c.o
diff --git a/drivers/i2c/kona_i2c.c b/drivers/i2c/kona_i2c.c
new file mode 100644
index 0000000..0b1715a
--- /dev/null
+++ b/drivers/i2c/kona_i2c.c
@@ -0,0 +1,730 @@
+/*
+ * Copyright 2013 Broadcom Corporation.
+ *
+ * SPDX-License-Identifier:      GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/errno.h>
+#include <asm/arch/sysmap.h>
+#include <asm/kona-common/clk.h>
+#include <i2c.h>
+
+/* Hardware register offsets and field defintions */
+#define CS_OFFSET				0x00000020
+#define CS_ACK_SHIFT				3
+#define CS_ACK_MASK				0x00000008
+#define CS_ACK_CMD_GEN_START			0x00000000
+#define CS_ACK_CMD_GEN_RESTART			0x00000001
+#define CS_CMD_SHIFT				1
+#define CS_CMD_CMD_NO_ACTION			0x00000000
+#define CS_CMD_CMD_START_RESTART		0x00000001
+#define CS_CMD_CMD_STOP				0x00000002
+#define CS_EN_SHIFT				0
+#define CS_EN_CMD_ENABLE_BSC			0x00000001
+
+#define TIM_OFFSET				0x00000024
+#define TIM_PRESCALE_SHIFT			6
+#define TIM_P_SHIFT				3
+#define TIM_NO_DIV_SHIFT			2
+#define TIM_DIV_SHIFT				0
+
+#define DAT_OFFSET				0x00000028
+
+#define TOUT_OFFSET				0x0000002c
+
+#define TXFCR_OFFSET				0x0000003c
+#define TXFCR_FIFO_FLUSH_MASK			0x00000080
+#define TXFCR_FIFO_EN_MASK			0x00000040
+
+#define IER_OFFSET				0x00000044
+#define IER_READ_COMPLETE_INT_MASK		0x00000010
+#define IER_I2C_INT_EN_MASK			0x00000008
+#define IER_FIFO_INT_EN_MASK			0x00000002
+#define IER_NOACK_EN_MASK			0x00000001
+
+#define ISR_OFFSET				0x00000048
+#define ISR_RESERVED_MASK			0xffffff60
+#define ISR_CMDBUSY_MASK			0x00000080
+#define ISR_READ_COMPLETE_MASK			0x00000010
+#define ISR_SES_DONE_MASK			0x00000008
+#define ISR_ERR_MASK				0x00000004
+#define ISR_TXFIFOEMPTY_MASK			0x00000002
+#define ISR_NOACK_MASK				0x00000001
+
+#define CLKEN_OFFSET				0x0000004c
+#define CLKEN_AUTOSENSE_OFF_MASK		0x00000080
+#define CLKEN_M_SHIFT				4
+#define CLKEN_N_SHIFT				1
+#define CLKEN_CLKEN_MASK			0x00000001
+
+#define FIFO_STATUS_OFFSET			0x00000054
+#define FIFO_STATUS_RXFIFO_EMPTY_MASK		0x00000004
+#define FIFO_STATUS_TXFIFO_EMPTY_MASK		0x00000010
+
+#define HSTIM_OFFSET				0x00000058
+#define HSTIM_HS_MODE_MASK			0x00008000
+#define HSTIM_HS_HOLD_SHIFT			10
+#define HSTIM_HS_HIGH_PHASE_SHIFT		5
+#define HSTIM_HS_SETUP_SHIFT			0
+
+#define PADCTL_OFFSET				0x0000005c
+#define PADCTL_PAD_OUT_EN_MASK			0x00000004
+
+#define RXFCR_OFFSET				0x00000068
+#define RXFCR_NACK_EN_SHIFT			7
+#define RXFCR_READ_COUNT_SHIFT			0
+#define RXFIFORDOUT_OFFSET			0x0000006c
+
+/* Locally used constants */
+#define MAX_RX_FIFO_SIZE		64U	/* bytes */
+#define MAX_TX_FIFO_SIZE		64U	/* bytes */
+
+#define I2C_TIMEOUT			100000	/* usecs */
+
+#define WAIT_INT_CHK			100	/* usecs */
+#if I2C_TIMEOUT % WAIT_INT_CHK
+#error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK
+#endif
+
+/* Operations that can be commanded to the controller */
+enum bcm_kona_cmd_t {
+	BCM_CMD_NOACTION = 0,
+	BCM_CMD_START,
+	BCM_CMD_RESTART,
+	BCM_CMD_STOP,
+};
+
+enum bus_speed_index {
+	BCM_SPD_100K = 0,
+	BCM_SPD_400K,
+	BCM_SPD_1MHZ,
+};
+
+/* Internal divider settings for standard mode, fast mode and fast mode plus */
+struct bus_speed_cfg {
+	uint8_t time_m;		/* Number of cycles for setup time */
+	uint8_t time_n;		/* Number of cycles for hold time */
+	uint8_t prescale;	/* Prescale divider */
+	uint8_t time_p;		/* Timing coefficient */
+	uint8_t no_div;		/* Disable clock divider */
+	uint8_t time_div;	/* Post-prescale divider */
+};
+
+static const struct bus_speed_cfg std_cfg_table[] = {
+	[BCM_SPD_100K] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02},
+	[BCM_SPD_400K] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02},
+	[BCM_SPD_1MHZ] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03},
+};
+
+struct bcm_kona_i2c_dev {
+	void *base;
+	uint speed;
+	const struct bus_speed_cfg *std_cfg;
+};
+
+/* Keep these two defines in sync */
+#define DEF_SPD 100000
+#define DEF_SPD_ENUM BCM_SPD_100K
+
+#define DEF_DEVICE(num) \
+{(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]}
+
+static struct bcm_kona_i2c_dev g_i2c_devs[CONFIG_SYS_MAX_I2C_BUS] = {
+#ifdef CONFIG_SYS_I2C_BASE0
+	DEF_DEVICE(0),
+#endif
+#ifdef CONFIG_SYS_I2C_BASE1
+	DEF_DEVICE(1),
+#endif
+#ifdef CONFIG_SYS_I2C_BASE2
+	DEF_DEVICE(2),
+#endif
+#ifdef CONFIG_SYS_I2C_BASE3
+	DEF_DEVICE(3),
+#endif
+#ifdef CONFIG_SYS_I2C_BASE4
+	DEF_DEVICE(4),
+#endif
+#ifdef CONFIG_SYS_I2C_BASE5
+	DEF_DEVICE(5),
+#endif
+};
+
+#define I2C_M_TEN	0x0010	/* ten bit address */
+#define I2C_M_RD	0x0001	/* read data */
+#define I2C_M_NOSTART	0x4000	/* no restart between msgs */
+
+struct i2c_msg {
+	uint16_t addr;
+	uint16_t flags;
+	uint16_t len;
+	uint8_t *buf;
+};
+
+static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev,
+					  enum bcm_kona_cmd_t cmd)
+{
+	debug("%s, %d\n", __func__, cmd);
+
+	switch (cmd) {
+	case BCM_CMD_NOACTION:
+		writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	case BCM_CMD_START:
+		writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) |
+		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	case BCM_CMD_RESTART:
+		writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) |
+		       (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	case BCM_CMD_STOP:
+		writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) |
+		       (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT),
+		       dev->base + CS_OFFSET);
+		break;
+
+	default:
+		printf("Unknown command %d\n", cmd);
+	}
+}
+
+static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+/* Wait until at least one of the mask bit(s) are set */
+static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev,
+					  unsigned long time_left,
+					  uint32_t mask)
+{
+	uint32_t status;
+
+	while (time_left) {
+		status = readl(dev->base + ISR_OFFSET);
+
+		if ((status & ~ISR_RESERVED_MASK) == 0) {
+			debug("Bogus I2C interrupt 0x%x\n", status);
+			continue;
+		}
+
+		/* Must flush the TX FIFO when NAK detected */
+		if (status & ISR_NOACK_MASK)
+			writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+			       dev->base + TXFCR_OFFSET);
+
+		writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET);
+
+		if (status & mask) {
+			/* We are done since one of the mask bits are set */
+			return time_left;
+		}
+		udelay(WAIT_INT_CHK);
+		time_left -= WAIT_INT_CHK;
+	}
+	return 0;
+}
+
+/* Send command to I2C bus */
+static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev,
+				 enum bcm_kona_cmd_t cmd)
+{
+	int rc = 0;
+	unsigned long time_left = I2C_TIMEOUT;
+
+	/* Send the command */
+	bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd);
+
+	/* Wait for transaction to finish or timeout */
+	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
+
+	if (!time_left) {
+		printf("controller timed out\n");
+		rc = -ETIMEDOUT;
+	}
+
+	/* Clear command */
+	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+	return rc;
+}
+
+/* Read a single RX FIFO worth of data from the i2c bus */
+static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev,
+					 uint8_t *buf, unsigned int len,
+					 unsigned int last_byte_nak)
+{
+	unsigned long time_left = I2C_TIMEOUT;
+
+	/* Start the RX FIFO */
+	writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) |
+	       (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET);
+
+	/* Wait for FIFO read to complete */
+	time_left =
+	    wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK);
+
+	if (!time_left) {
+		printf("RX FIFO time out\n");
+		return -EREMOTEIO;
+	}
+
+	/* Read data from FIFO */
+	for (; len > 0; len--, buf++)
+		*buf = readl(dev->base + RXFIFORDOUT_OFFSET);
+
+	return 0;
+}
+
+/* Read any amount of data using the RX FIFO from the i2c bus */
+static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev,
+				  struct i2c_msg *msg)
+{
+	unsigned int bytes_to_read = MAX_RX_FIFO_SIZE;
+	unsigned int last_byte_nak = 0;
+	unsigned int bytes_read = 0;
+	int rc;
+
+	uint8_t *tmp_buf = msg->buf;
+
+	while (bytes_read < msg->len) {
+		if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) {
+			last_byte_nak = 1;	/* NAK last byte of transfer */
+			bytes_to_read = msg->len - bytes_read;
+		}
+
+		rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read,
+						   last_byte_nak);
+		if (rc < 0)
+			return -EREMOTEIO;
+
+		bytes_read += bytes_to_read;
+		tmp_buf += bytes_to_read;
+	}
+
+	return 0;
+}
+
+/* Write a single byte of data to the i2c bus */
+static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data,
+				   unsigned int nak_expected)
+{
+	unsigned long time_left = I2C_TIMEOUT;
+	unsigned int nak_received;
+
+	/* Clear pending session done interrupt */
+	writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET);
+
+	/* Send one byte of data */
+	writel(data, dev->base + DAT_OFFSET);
+
+	time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK);
+
+	if (!time_left) {
+		debug("controller timed out\n");
+		return -ETIMEDOUT;
+	}
+
+	nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0;
+
+	if (nak_received ^ nak_expected) {
+		debug("unexpected NAK/ACK\n");
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+/* Write a single TX FIFO worth of data to the i2c bus */
+static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev,
+					  uint8_t *buf, unsigned int len)
+{
+	int k;
+	unsigned long time_left = I2C_TIMEOUT;
+	unsigned int fifo_status;
+
+	/* Write data into FIFO */
+	for (k = 0; k < len; k++)
+		writel(buf[k], (dev->base + DAT_OFFSET));
+
+	/* Wait for FIFO to empty */
+	do {
+		time_left =
+		    wait_for_int_timeout(dev, time_left,
+					 (IER_FIFO_INT_EN_MASK |
+					  IER_NOACK_EN_MASK));
+		fifo_status = readl(dev->base + FIFO_STATUS_OFFSET);
+	} while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK));
+
+	/* Check if there was a NAK */
+	if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) {
+		printf("unexpected NAK\n");
+		return -EREMOTEIO;
+	}
+
+	/* Check if a timeout occured */
+	if (!time_left) {
+		printf("completion timed out\n");
+		return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+/* Write any amount of data using TX FIFO to the i2c bus */
+static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev,
+				   struct i2c_msg *msg)
+{
+	unsigned int bytes_to_write = MAX_TX_FIFO_SIZE;
+	unsigned int bytes_written = 0;
+	int rc;
+
+	uint8_t *tmp_buf = msg->buf;
+
+	while (bytes_written < msg->len) {
+		if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE)
+			bytes_to_write = msg->len - bytes_written;
+
+		rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf,
+						    bytes_to_write);
+		if (rc < 0)
+			return -EREMOTEIO;
+
+		bytes_written += bytes_to_write;
+		tmp_buf += bytes_to_write;
+	}
+
+	return 0;
+}
+
+/* Send i2c address */
+static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev,
+				struct i2c_msg *msg)
+{
+	unsigned char addr;
+
+	if (msg->flags & I2C_M_TEN) {
+		/* First byte is 11110XX0 where XX is upper 2 bits */
+		addr = 0xf0 | ((msg->addr & 0x300) >> 7);
+		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+			return -EREMOTEIO;
+
+		/* Second byte is the remaining 8 bits */
+		addr = msg->addr & 0xff;
+		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+			return -EREMOTEIO;
+
+		if (msg->flags & I2C_M_RD) {
+			/* For read, send restart command */
+			if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0)
+				return -EREMOTEIO;
+
+			/* Then re-send the first byte with the read bit set */
+			addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01;
+			if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+				return -EREMOTEIO;
+		}
+	} else {
+		addr = msg->addr << 1;
+
+		if (msg->flags & I2C_M_RD)
+			addr |= 1;
+
+		if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0)
+			return -EREMOTEIO;
+	}
+
+	return 0;
+}
+
+static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK,
+	       dev->base + CLKEN_OFFSET);
+}
+
+static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev)
+{
+	writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK,
+	       dev->base + HSTIM_OFFSET);
+
+	writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) |
+	       (dev->std_cfg->time_p << TIM_P_SHIFT) |
+	       (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) |
+	       (dev->std_cfg->time_div << TIM_DIV_SHIFT),
+	       dev->base + TIM_OFFSET);
+
+	writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) |
+	       (dev->std_cfg->time_n << CLKEN_N_SHIFT) |
+	       CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET);
+}
+
+/* Master transfer function */
+static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev,
+			     struct i2c_msg msgs[], int num)
+{
+	struct i2c_msg *pmsg;
+	int rc = 0;
+	int i;
+
+	/* Enable pad output */
+	writel(0, dev->base + PADCTL_OFFSET);
+
+	/* Enable internal clocks */
+	bcm_kona_i2c_enable_clock(dev);
+
+	/* Send start command */
+	rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START);
+	if (rc < 0) {
+		printf("Start command failed rc = %d\n", rc);
+		goto xfer_disable_pad;
+	}
+
+	/* Loop through all messages */
+	for (i = 0; i < num; i++) {
+		pmsg = &msgs[i];
+
+		/* Send restart for subsequent messages */
+		if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) {
+			rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART);
+			if (rc < 0) {
+				printf("restart cmd failed rc = %d\n", rc);
+				goto xfer_send_stop;
+			}
+		}
+
+		/* Send slave address */
+		if (!(pmsg->flags & I2C_M_NOSTART)) {
+			rc = bcm_kona_i2c_do_addr(dev, pmsg);
+			if (rc < 0) {
+				debug("NAK from addr %2.2x msg#%d rc = %d\n",
+				      pmsg->addr, i, rc);
+				goto xfer_send_stop;
+			}
+		}
+
+		/* Perform data transfer */
+		if (pmsg->flags & I2C_M_RD) {
+			rc = bcm_kona_i2c_read_fifo(dev, pmsg);
+			if (rc < 0) {
+				printf("read failure\n");
+				goto xfer_send_stop;
+			}
+		} else {
+			rc = bcm_kona_i2c_write_fifo(dev, pmsg);
+			if (rc < 0) {
+				printf("write failure");
+				goto xfer_send_stop;
+			}
+		}
+	}
+
+	rc = num;
+
+xfer_send_stop:
+	/* Send a STOP command */
+	bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP);
+
+xfer_disable_pad:
+	/* Disable pad output */
+	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+
+	/* Stop internal clock */
+	bcm_kona_i2c_disable_clock(dev);
+
+	return rc;
+}
+
+static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev,
+					  uint speed)
+{
+	switch (speed) {
+	case 100000:
+		dev->std_cfg = &std_cfg_table[BCM_SPD_100K];
+		break;
+	case 400000:
+		dev->std_cfg = &std_cfg_table[BCM_SPD_400K];
+		break;
+	case 1000000:
+		dev->std_cfg = &std_cfg_table[BCM_SPD_1MHZ];
+		break;
+	default:
+		printf("%d hz bus speed not supported\n", speed);
+		return -EINVAL;
+	}
+	dev->speed = speed;
+	return 0;
+}
+
+static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev)
+{
+	/* Parse bus speed */
+	bcm_kona_i2c_assign_bus_speed(dev, dev->speed);
+
+	/* Enable internal clocks */
+	bcm_kona_i2c_enable_clock(dev);
+
+	/* Configure internal dividers */
+	bcm_kona_i2c_config_timing(dev);
+
+	/* Disable timeout */
+	writel(0, dev->base + TOUT_OFFSET);
+
+	/* Enable autosense */
+	bcm_kona_i2c_enable_autosense(dev);
+
+	/* Enable TX FIFO */
+	writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK,
+	       dev->base + TXFCR_OFFSET);
+
+	/* Mask all interrupts */
+	writel(0, dev->base + IER_OFFSET);
+
+	/* Clear all pending interrupts */
+	writel(ISR_CMDBUSY_MASK |
+	       ISR_READ_COMPLETE_MASK |
+	       ISR_SES_DONE_MASK |
+	       ISR_ERR_MASK |
+	       ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET);
+
+	/* Enable the controller but leave it idle */
+	bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION);
+
+	/* Disable pad output */
+	writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET);
+}
+
+/*
+ * uboot layer
+ */
+struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap)
+{
+	return &g_i2c_devs[adap->hwadapnr];
+}
+
+static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
+{
+	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
+
+	if (clk_bsc_enable(dev->base))
+		return;
+
+	bcm_kona_i2c_init(dev);
+}
+
+static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
+			 int alen, uchar *buffer, int len)
+{
+	/* msg[0] writes the addr, msg[1] reads the data */
+	struct i2c_msg msg[2];
+	unsigned char msgbuf0[64];
+	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
+
+	msg[0].addr = chip;
+	msg[0].flags = 0;
+	msg[0].len = 1;
+	msg[0].buf = msgbuf0;	/* msgbuf0 contains incrementing reg addr */
+
+	msg[1].addr = chip;
+	msg[1].flags = I2C_M_RD;
+	/* msg[1].buf dest ptr increments each read */
+
+	msgbuf0[0] = (unsigned char)addr;
+	msg[1].buf = buffer;
+	msg[1].len = len;
+	if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) {
+		/* Sending 2 i2c messages */
+		kona_i2c_init(adap, adap->speed, adap->slaveaddr);
+		debug("I2C read: I/O error\n");
+		return -EIO;
+	}
+	return 0;
+}
+
+static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
+			  int alen, uchar *buffer, int len)
+{
+	struct i2c_msg msg[0];
+	unsigned char msgbuf0[64];
+	unsigned int i;
+	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
+
+	msg[0].addr = chip;
+	msg[0].flags = 0;
+	msg[0].len = 2;		/* addr byte plus data */
+	msg[0].buf = msgbuf0;
+
+	for (i = 0; i < len; i++) {
+		msgbuf0[0] = addr++;
+		msgbuf0[1] = buffer[i];
+		if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) {
+			kona_i2c_init(adap, adap->speed, adap->slaveaddr);
+			debug("I2C write: I/O error\n");
+			return -EIO;
+		}
+	}
+	return 0;
+}
+
+static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip)
+{
+	uchar tmp;
+
+	/*
+	 * read addr 0x0 of the given chip.
+	 */
+	return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1);
+}
+
+static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed)
+{
+	struct bcm_kona_i2c_dev *dev = kona_get_dev(adap);
+	return bcm_kona_i2c_assign_bus_speed(dev, speed);
+}
+
+/*
+ * Register kona i2c adapters. Keep the order below so
+ * that the bus number matches the adapter number.
+ */
+#define DEF_ADAPTER(num) \
+U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \
+			 kona_i2c_read, kona_i2c_write, \
+			 kona_i2c_set_bus_speed, DEF_SPD, 0x00, num)
+
+#ifdef CONFIG_SYS_I2C_BASE0
+	DEF_ADAPTER(0)
+#endif
+#ifdef CONFIG_SYS_I2C_BASE1
+	DEF_ADAPTER(1)
+#endif
+#ifdef CONFIG_SYS_I2C_BASE2
+	DEF_ADAPTER(2)
+#endif
+#ifdef CONFIG_SYS_I2C_BASE3
+	DEF_ADAPTER(3)
+#endif
+#ifdef CONFIG_SYS_I2C_BASE4
+	DEF_ADAPTER(4)
+#endif
+#ifdef CONFIG_SYS_I2C_BASE5
+	DEF_ADAPTER(5)
+#endif