/*
 * Copyright 2013 Broadcom Corporation.
 *
 * SPDX-License-Identifier:      GPL-2.0+
 *
 * NOTE: This driver should be converted to driver model before June 2017.
 * Please see doc/driver-model/i2c-howto.txt for instructions.
 */

#include <common.h>
#include <asm/io.h>
#include <linux/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 kona_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 kona_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 occurred */
        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 kona_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 kona_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 kona_i2c_msg msgs[], int num)
{
        struct kona_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 kona_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 kona_i2c_msg msg[1];
        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