/*
 * Copyright 2019 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 */

#include "smuio/smuio_11_0_0_offset.h"
#include "smuio/smuio_11_0_0_sh_mask.h"

#include "smu_v11_0_i2c.h"
#include "amdgpu.h"
#include "soc15_common.h"
#include <drm/drm_fixed.h>
#include <drm/drm_drv.h>
#include "amdgpu_amdkfd.h"
#include <linux/i2c.h>
#include <linux/pci.h>

/* error codes */
#define I2C_OK                0
#define I2C_NAK_7B_ADDR_NOACK 1
#define I2C_NAK_TXDATA_NOACK  2
#define I2C_TIMEOUT           4
#define I2C_SW_TIMEOUT        8
#define I2C_ABORT             0x10

/* I2C transaction flags */
#define I2C_NO_STOP     1
#define I2C_RESTART     2

#define to_amdgpu_device(x) (container_of(x, struct amdgpu_device, pm.smu_i2c))

static void smu_v11_0_i2c_set_clock_gating(struct i2c_adapter *control, bool en)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t reg = RREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT);

        reg = REG_SET_FIELD(reg, SMUIO_PWRMGT, i2c_clk_gate_en, en ? 1 : 0);
        WREG32_SOC15(SMUIO, 0, mmSMUIO_PWRMGT, reg);
}


static void smu_v11_0_i2c_enable(struct i2c_adapter *control, bool enable)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);

        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, enable ? 1 : 0);
}

static void smu_v11_0_i2c_clear_status(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        /* do */
        {
                RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_INTR);

        } /* while (reg_CKSVII2C_ic_clr_intr == 0) */
}

static void smu_v11_0_i2c_configure(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t reg = 0;

        reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_SLAVE_DISABLE, 1);
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_RESTART_EN, 1);
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_MASTER, 0);
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_10BITADDR_SLAVE, 0);
        /* Standard mode */
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MAX_SPEED_MODE, 2);
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_CON, IC_MASTER_MODE, 1);

        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CON, reg);
}

static void smu_v11_0_i2c_set_clock(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);

        /*
         * Standard mode speed, These values are taken from SMUIO MAS,
         * but are different from what is given is
         * Synopsys spec. The values here are based on assumption
         * that refclock is 100MHz
         *
         * Configuration for standard mode; Speed = 100kbps
         * Scale linearly, for now only support standard speed clock
         * This will work only with 100M ref clock
         *
         * TBD:Change the calculation to take into account ref clock values also.
         */

        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_FS_SPKLEN, 2);
        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_HCNT, 120);
        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SS_SCL_LCNT, 130);
        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_SDA_HOLD, 20);
}

static void smu_v11_0_i2c_set_address(struct i2c_adapter *control, uint8_t address)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);

        /* Convert fromr 8-bit to 7-bit address */
        address >>= 1;
        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TAR, (address & 0xFF));
}

static uint32_t smu_v11_0_i2c_poll_tx_status(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t ret = I2C_OK;
        uint32_t reg, reg_c_tx_abrt_source;

        /*Check if transmission is completed */
        unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);

        do {
                if (time_after(jiffies, timeout_counter)) {
                        ret |= I2C_SW_TIMEOUT;
                        break;
                }

                reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);

        } while (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFE) == 0);

        if (ret != I2C_OK)
                return ret;

        /* This only checks if NAK is received and transaction got aborted */
        reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_INTR_STAT);

        if (REG_GET_FIELD(reg, CKSVII2C_IC_INTR_STAT, R_TX_ABRT) == 1) {
                reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);
                DRM_INFO("TX was terminated, IC_TX_ABRT_SOURCE val is:%x", reg_c_tx_abrt_source);

                /* Check for stop due to NACK */
                if (REG_GET_FIELD(reg_c_tx_abrt_source,
                                  CKSVII2C_IC_TX_ABRT_SOURCE,
                                  ABRT_TXDATA_NOACK) == 1) {

                        ret |= I2C_NAK_TXDATA_NOACK;

                } else if (REG_GET_FIELD(reg_c_tx_abrt_source,
                                         CKSVII2C_IC_TX_ABRT_SOURCE,
                                         ABRT_7B_ADDR_NOACK) == 1) {

                        ret |= I2C_NAK_7B_ADDR_NOACK;
                } else {
                        ret |= I2C_ABORT;
                }

                smu_v11_0_i2c_clear_status(control);
        }

        return ret;
}

static uint32_t smu_v11_0_i2c_poll_rx_status(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t ret = I2C_OK;
        uint32_t reg_ic_status, reg_c_tx_abrt_source;

        reg_c_tx_abrt_source = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_TX_ABRT_SOURCE);

        /* If slave is not present */
        if (REG_GET_FIELD(reg_c_tx_abrt_source,
                          CKSVII2C_IC_TX_ABRT_SOURCE,
                          ABRT_7B_ADDR_NOACK) == 1) {
                ret |= I2C_NAK_7B_ADDR_NOACK;

                smu_v11_0_i2c_clear_status(control);
        } else {  /* wait till some data is there in RXFIFO */
                /* Poll for some byte in RXFIFO */
                unsigned long  timeout_counter = jiffies + msecs_to_jiffies(20);

                do {
                        if (time_after(jiffies, timeout_counter)) {
                                ret |= I2C_SW_TIMEOUT;
                                break;
                        }

                        reg_ic_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);

                } while (REG_GET_FIELD(reg_ic_status, CKSVII2C_IC_STATUS, RFNE) == 0);
        }

        return ret;
}




/**
 * smu_v11_0_i2c_transmit - Send a block of data over the I2C bus to a slave device.
 *
 * @control: I2C adapter reference
 * @address: The I2C address of the slave device.
 * @data: The data to transmit over the bus.
 * @numbytes: The amount of data to transmit.
 * @i2c_flag: Flags for transmission
 *
 * Returns 0 on success or error.
 */
static uint32_t smu_v11_0_i2c_transmit(struct i2c_adapter *control,
                                  uint8_t address, uint8_t *data,
                                  uint32_t numbytes, uint32_t i2c_flag)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t bytes_sent, reg, ret = 0;
        unsigned long  timeout_counter;

        bytes_sent = 0;

        DRM_DEBUG_DRIVER("I2C_Transmit(), address = %x, bytes = %d , data: ",
                 (uint16_t)address, numbytes);

        if (drm_debug_enabled(DRM_UT_DRIVER)) {
                print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
                               16, 1, data, numbytes, false);
        }

        /* Set the I2C slave address */
        smu_v11_0_i2c_set_address(control, address);
        /* Enable I2C */
        smu_v11_0_i2c_enable(control, true);

        /* Clear status bits */
        smu_v11_0_i2c_clear_status(control);


        timeout_counter = jiffies + msecs_to_jiffies(20);

        while (numbytes > 0) {
                reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);
                if (REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF)) {
                        do {
                                reg = 0;
                                /*
                                 * Prepare transaction, no need to set RESTART. I2C engine will send
                                 * START as soon as it sees data in TXFIFO
                                 */
                                if (bytes_sent == 0)
                                        reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
                                                            (i2c_flag & I2C_RESTART) ? 1 : 0);
                                reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, data[bytes_sent]);

                                /* determine if we need to send STOP bit or not */
                                if (numbytes == 1)
                                        /* Final transaction, so send stop unless I2C_NO_STOP */
                                        reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
                                                            (i2c_flag & I2C_NO_STOP) ? 0 : 1);
                                /* Write */
                                reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 0);
                                WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);

                                /* Record that the bytes were transmitted */
                                bytes_sent++;
                                numbytes--;

                                reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_STATUS);

                        } while (numbytes &&  REG_GET_FIELD(reg, CKSVII2C_IC_STATUS, TFNF));
                }

                /*
                 * We waited too long for the transmission FIFO to become not-full.
                 * Exit the loop with error.
                 */
                if (time_after(jiffies, timeout_counter)) {
                        ret |= I2C_SW_TIMEOUT;
                        goto Err;
                }
        }

        ret = smu_v11_0_i2c_poll_tx_status(control);

Err:
        /* Any error, no point in proceeding */
        if (ret != I2C_OK) {
                if (ret & I2C_SW_TIMEOUT)
                        DRM_ERROR("TIMEOUT ERROR !!!");

                if (ret & I2C_NAK_7B_ADDR_NOACK)
                        DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");


                if (ret & I2C_NAK_TXDATA_NOACK)
                        DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");
        }

        return ret;
}


/**
 * smu_v11_0_i2c_receive - Receive a block of data over the I2C bus from a slave device.
 *
 * @control: I2C adapter reference
 * @address: The I2C address of the slave device.
 * @data: Placeholder to store received data.
 * @numbytes: The amount of data to transmit.
 * @i2c_flag: Flags for transmission
 *
 * Returns 0 on success or error.
 */
static uint32_t smu_v11_0_i2c_receive(struct i2c_adapter *control,
                                 uint8_t address, uint8_t *data,
                                 uint32_t numbytes, uint8_t i2c_flag)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t bytes_received, ret = I2C_OK;

        bytes_received = 0;

        /* Set the I2C slave address */
        smu_v11_0_i2c_set_address(control, address);

        /* Enable I2C */
        smu_v11_0_i2c_enable(control, true);

        while (numbytes > 0) {
                uint32_t reg = 0;

                smu_v11_0_i2c_clear_status(control);


                /* Prepare transaction */

                /* Each time we disable I2C, so this is not a restart */
                if (bytes_received == 0)
                        reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, RESTART,
                                            (i2c_flag & I2C_RESTART) ? 1 : 0);

                reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT, 0);
                /* Read */
                reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, CMD, 1);

                /* Transmitting last byte */
                if (numbytes == 1)
                        /* Final transaction, so send stop if requested */
                        reg = REG_SET_FIELD(reg, CKSVII2C_IC_DATA_CMD, STOP,
                                            (i2c_flag & I2C_NO_STOP) ? 0 : 1);

                WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD, reg);

                ret = smu_v11_0_i2c_poll_rx_status(control);

                /* Any error, no point in proceeding */
                if (ret != I2C_OK) {
                        if (ret & I2C_SW_TIMEOUT)
                                DRM_ERROR("TIMEOUT ERROR !!!");

                        if (ret & I2C_NAK_7B_ADDR_NOACK)
                                DRM_ERROR("Received I2C_NAK_7B_ADDR_NOACK !!!");

                        if (ret & I2C_NAK_TXDATA_NOACK)
                                DRM_ERROR("Received I2C_NAK_TXDATA_NOACK !!!");

                        break;
                }

                reg = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_DATA_CMD);
                data[bytes_received] = REG_GET_FIELD(reg, CKSVII2C_IC_DATA_CMD, DAT);

                /* Record that the bytes were received */
                bytes_received++;
                numbytes--;
        }

        DRM_DEBUG_DRIVER("I2C_Receive(), address = %x, bytes = %d, data :",
                  (uint16_t)address, bytes_received);

        if (drm_debug_enabled(DRM_UT_DRIVER)) {
                print_hex_dump(KERN_INFO, "data: ", DUMP_PREFIX_NONE,
                               16, 1, data, bytes_received, false);
        }

        return ret;
}

static void smu_v11_0_i2c_abort(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t reg = 0;

        /* Enable I2C engine; */
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ENABLE, 1);
        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);

        /* Abort previous transaction */
        reg = REG_SET_FIELD(reg, CKSVII2C_IC_ENABLE, ABORT, 1);
        WREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE, reg);

        DRM_DEBUG_DRIVER("I2C_Abort() Done.");
}


static bool smu_v11_0_i2c_activity_done(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);

        const uint32_t IDLE_TIMEOUT = 1024;
        uint32_t timeout_count = 0;
        uint32_t reg_ic_enable, reg_ic_enable_status, reg_ic_clr_activity;

        reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
        reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);


        if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
            (REG_GET_FIELD(reg_ic_enable_status, CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
                /*
                 * Nobody is using I2C engine, but engine remains active because
                 * someone missed to send STOP
                 */
                smu_v11_0_i2c_abort(control);
        } else if (REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) {
                /* Nobody is using I2C engine */
                return true;
        }

        /* Keep reading activity bit until it's cleared */
        do {
                reg_ic_clr_activity = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_CLR_ACTIVITY);

                if (REG_GET_FIELD(reg_ic_clr_activity,
                    CKSVII2C_IC_CLR_ACTIVITY, CLR_ACTIVITY) == 0)
                        return true;

                ++timeout_count;

        } while (timeout_count < IDLE_TIMEOUT);

        return false;
}

static void smu_v11_0_i2c_init(struct i2c_adapter *control)
{
        /* Disable clock gating */
        smu_v11_0_i2c_set_clock_gating(control, false);

        if (!smu_v11_0_i2c_activity_done(control))
                DRM_WARN("I2C busy !");

        /* Disable I2C */
        smu_v11_0_i2c_enable(control, false);

        /* Configure I2C to operate as master and in standard mode */
        smu_v11_0_i2c_configure(control);

        /* Initialize the clock to 50 kHz default */
        smu_v11_0_i2c_set_clock(control);

}

static void smu_v11_0_i2c_fini(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        uint32_t reg_ic_enable_status, reg_ic_enable;

        smu_v11_0_i2c_enable(control, false);

        /* Double check if disabled, else force abort */
        reg_ic_enable_status = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE_STATUS);
        reg_ic_enable = RREG32_SOC15(SMUIO, 0, mmCKSVII2C_IC_ENABLE);

        if ((REG_GET_FIELD(reg_ic_enable, CKSVII2C_IC_ENABLE, ENABLE) == 0) &&
            (REG_GET_FIELD(reg_ic_enable_status,
                           CKSVII2C_IC_ENABLE_STATUS, IC_EN) == 1)) {
                /*
                 * Nobody is using I2C engine, but engine remains active because
                 * someone missed to send STOP
                 */
                smu_v11_0_i2c_abort(control);
        }

        /* Restore clock gating */

        /*
         * TODO Reenabling clock gating seems to break subsequent SMU operation
         *      on the I2C bus. My guess is that SMU doesn't disable clock gating like
         *      we do here before working with the bus. So for now just don't restore
         *      it but later work with SMU to see if they have this issue and can
         *      update their code appropriately
         */
        /* smu_v11_0_i2c_set_clock_gating(control, true); */

}

static bool smu_v11_0_i2c_bus_lock(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);

        /* Send  PPSMC_MSG_RequestI2CBus */
        if (!amdgpu_dpm_smu_i2c_bus_access(adev, true))
                return true;

        return false;
}

static bool smu_v11_0_i2c_bus_unlock(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);

        /* Send  PPSMC_MSG_ReleaseI2CBus */
        if (!amdgpu_dpm_smu_i2c_bus_access(adev, false))
                return true;

        return false;
}

/***************************** I2C GLUE ****************************/

static uint32_t smu_v11_0_i2c_read_data(struct i2c_adapter *control,
                                        uint8_t address,
                                        uint8_t *data,
                                        uint32_t numbytes)
{
        uint32_t  ret = 0;

        /* First 2 bytes are dummy write to set EEPROM address */
        ret = smu_v11_0_i2c_transmit(control, address, data, 2, I2C_NO_STOP);
        if (ret != I2C_OK)
                goto Fail;

        /* Now read data starting with that address */
        ret = smu_v11_0_i2c_receive(control, address, data + 2, numbytes - 2,
                                    I2C_RESTART);

Fail:
        if (ret != I2C_OK)
                DRM_ERROR("ReadData() - I2C error occurred :%x", ret);

        return ret;
}

static uint32_t smu_v11_0_i2c_write_data(struct i2c_adapter *control,
                                         uint8_t address,
                                         uint8_t *data,
                                         uint32_t numbytes)
{
        uint32_t  ret;

        ret = smu_v11_0_i2c_transmit(control, address, data, numbytes, 0);

        if (ret != I2C_OK)
                DRM_ERROR("WriteI2CData() - I2C error occurred :%x", ret);
        else
                /*
                 * According to EEPROM spec there is a MAX of 10 ms required for
                 * EEPROM to flush internal RX buffer after STOP was issued at the
                 * end of write transaction. During this time the EEPROM will not be
                 * responsive to any more commands - so wait a bit more.
                 *
                 * TODO Improve to wait for first ACK for slave address after
                 * internal write cycle done.
                 */
                msleep(10);

        return ret;

}

static void lock_bus(struct i2c_adapter *i2c, unsigned int flags)
{
        struct amdgpu_device *adev = to_amdgpu_device(i2c);

        if (!smu_v11_0_i2c_bus_lock(i2c)) {
                DRM_ERROR("Failed to lock the bus from SMU");
                return;
        }

        adev->pm.bus_locked = true;
}

static int trylock_bus(struct i2c_adapter *i2c, unsigned int flags)
{
        WARN_ONCE(1, "This operation not supposed to run in atomic context!");
        return false;
}

static void unlock_bus(struct i2c_adapter *i2c, unsigned int flags)
{
        struct amdgpu_device *adev = to_amdgpu_device(i2c);

        if (!smu_v11_0_i2c_bus_unlock(i2c)) {
                DRM_ERROR("Failed to unlock the bus from SMU");
                return;
        }

        adev->pm.bus_locked = false;
}

static const struct i2c_lock_operations smu_v11_0_i2c_i2c_lock_ops = {
        .lock_bus = lock_bus,
        .trylock_bus = trylock_bus,
        .unlock_bus = unlock_bus,
};

static int smu_v11_0_i2c_xfer(struct i2c_adapter *i2c_adap,
                              struct i2c_msg *msgs, int num)
{
        int i, ret;
        struct amdgpu_device *adev = to_amdgpu_device(i2c_adap);

        if (!adev->pm.bus_locked) {
                DRM_ERROR("I2C bus unlocked, stopping transaction!");
                return -EIO;
        }

        smu_v11_0_i2c_init(i2c_adap);

        for (i = 0; i < num; i++) {
                if (msgs[i].flags & I2C_M_RD)
                        ret = smu_v11_0_i2c_read_data(i2c_adap,
                                                      (uint8_t)msgs[i].addr,
                                                      msgs[i].buf, msgs[i].len);
                else
                        ret = smu_v11_0_i2c_write_data(i2c_adap,
                                                       (uint8_t)msgs[i].addr,
                                                       msgs[i].buf, msgs[i].len);

                if (ret != I2C_OK) {
                        num = -EIO;
                        break;
                }
        }

        smu_v11_0_i2c_fini(i2c_adap);
        return num;
}

static u32 smu_v11_0_i2c_func(struct i2c_adapter *adap)
{
        return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
}


static const struct i2c_algorithm smu_v11_0_i2c_algo = {
        .master_xfer = smu_v11_0_i2c_xfer,
        .functionality = smu_v11_0_i2c_func,
};

int smu_v11_0_i2c_control_init(struct i2c_adapter *control)
{
        struct amdgpu_device *adev = to_amdgpu_device(control);
        int res;

        control->owner = THIS_MODULE;
        control->class = I2C_CLASS_SPD;
        control->dev.parent = &adev->pdev->dev;
        control->algo = &smu_v11_0_i2c_algo;
        snprintf(control->name, sizeof(control->name), "AMDGPU SMU");
        control->lock_ops = &smu_v11_0_i2c_i2c_lock_ops;

        res = i2c_add_adapter(control);
        if (res)
                DRM_ERROR("Failed to register hw i2c, err: %d\n", res);

        return res;
}

void smu_v11_0_i2c_control_fini(struct i2c_adapter *control)
{
        i2c_del_adapter(control);
}

/*
 * Keep this for future unit test if bugs arise
 */
#if 0
#define I2C_TARGET_ADDR 0xA0

bool smu_v11_0_i2c_test_bus(struct i2c_adapter *control)
{

        uint32_t ret = I2C_OK;
        uint8_t data[6] = {0xf, 0, 0xde, 0xad, 0xbe, 0xef};


        DRM_INFO("Begin");

        if (!smu_v11_0_i2c_bus_lock(control)) {
                DRM_ERROR("Failed to lock the bus!.");
                return false;
        }

        smu_v11_0_i2c_init(control);

        /* Write 0xde to address 0x0000 on the EEPROM */
        ret = smu_v11_0_i2c_write_data(control, I2C_TARGET_ADDR, data, 6);

        ret = smu_v11_0_i2c_read_data(control, I2C_TARGET_ADDR, data, 6);

        smu_v11_0_i2c_fini(control);

        smu_v11_0_i2c_bus_unlock(control);


        DRM_INFO("End");
        return true;
}
#endif