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/******************************************************************************

**

** (C) Copyright 2013 DFC Design, s.r.o., Brno, Czech Republic

** Author: Marek Kvas (m.kvas@dspfpga.com)

**

****************************************************************************

**

** This file is part of Xenia Ethernet Example project.

**

** Xenia Ethernet Example project is free software: you can

** redistribute it and/or modify it under the terms of

** the GNU Lesser General Public License as published by the Free

** Software Foundation, either version 3 of the License, or

** (at your option) any later version.

**

** Xenia Ethernet Example project is distributed in the hope that

** it will be useful, but WITHOUT ANY WARRANTY; without even

** the implied warranty of MERCHANTABILITY or FITNESS FOR A

** PARTICULAR PURPOSE.  See the GNU Lesser General Public License

** for more details.

**

** You should have received a copy of the GNU Lesser General Public

** License along with Xenia Ethernet Example project.  If not,

** see <http://www.gnu.org/licenses/>.

*******************************************************************************

**

** This is a wrapper for Xilinx IIC driver in interrupt mode.

**

*******************************************************************************

*/

#include "iic_wrap.h"

#include "timers.h"

static void RecvHandler(void *CallbackRef, int ByteCount)

{

        struct iic_wrap_dev *dev = (struct iic_wrap_dev *)CallbackRef;

        dev->hi.unprocessed_bytes = ByteCount;

        dev->hi.finished = 1;

        dev->hi.rcv_stat++;

}

static void SendHandler(void *CallbackRef, int ByteCount)

{

        struct iic_wrap_dev *dev = (struct iic_wrap_dev *)CallbackRef;

        dev->hi.unprocessed_bytes = ByteCount;

        dev->hi.finished = 1;

        dev->hi.snd_star++;

}

static void StatusHandler(void *CallbackRef, int Status)

{

        struct iic_wrap_dev *dev = (struct iic_wrap_dev *)CallbackRef;

        /* As we are single master, when this is called, it is always wrong */

        dev->hi.error = Status;

        dev->hi.finished = 1;

        dev->hi.stat_stat++;

}

/*

 * Initialize underlying iic controller and wrapper structures.

 */

int iic_wrap_init(struct iic_wrap_dev *dev, u16 IicDeviceId)

{

        int Status;

        XIic_Config *ConfigPtr; /* Pointer to configuration data */

        /* Clear the device structure */

        memset(dev, 0, sizeof(*dev));

        /*

         * Initialize the IIC driver so that it is ready to use.

         */

        ConfigPtr = XIic_LookupConfig(IicDeviceId);

        if (ConfigPtr == NULL) {

                return -1;

        }

        Status = XIic_CfgInitialize(&dev->iic, ConfigPtr,

                                        ConfigPtr->BaseAddress);

        if (Status != XST_SUCCESS) {

                return -1;

        }

        /*

         * Setup handler to process the asynchronous events which occur,

         * the driver is only interrupt driven such that this must be

         * done prior to starting the device.

         */

        XIic_SetRecvHandler(&dev->iic, (void *)dev, RecvHandler);

        XIic_SetSendHandler(&dev->iic, (void *)dev, SendHandler);

        XIic_SetStatusHandler(&dev->iic, (void *)dev, StatusHandler);

        return 0;

}

/*

 * Send message on I2C bus with timeout.

 * Returns 0 on success, negative number otherwise.

 */

int iic_wrap_send_timeout(struct iic_wrap_dev *dev, u8 addr, u8 *tx_msg, int length, int timeout_ms)

{

        int ret;

        /* If device is not started, do it */

        if (!dev->started) {

                dev->started = 1;

                XIic_Start(&dev->iic);

        }

        dev->hi.error = 0;

        dev->hi.finished = 0;

        dev->hi.op_started = 1;

        dev->hi.end_tstmp = timers_ms_now() + timeout_ms;

        XIic_SetAddress(&dev->iic, XII_ADDR_TO_SEND_TYPE, addr);

        /* If busy, retry until timeout */

        /* TODO: There is a bug xilinx driver in busy signaling. Make fix part of project */

        do {

                ret = XIic_DynMasterSend(&dev->iic, tx_msg, length);

        } while ((ret != XST_SUCCESS) && (timers_ms_now() < dev->hi.end_tstmp));

        while (!dev->hi.finished) {

                if (timers_ms_now() > dev->hi.end_tstmp) {

                        dev->hi.op_started = 0;

                        return -1;

                }

        }

        /* check for errors */

        if(dev->hi.error || dev->hi.unprocessed_bytes) {

                dev->hi.op_started = 0;

                return -1;

        }

        /* Success */

        dev->hi.op_started = 0;

        return 0;

}

/*

 * Receive message on I2C bus with timeout.

 * Returns 0 on success, negative number otherwise.

 */

int iic_wrap_recv_timeout(struct iic_wrap_dev *dev, u8 addr, u8 *rx_msg, int length, int timeout_ms)

{

        int ret;

        /* If device is not started, do it */

        if (!dev->started) {

                dev->started = 1;

                XIic_Start(&dev->iic);

        }

        dev->hi.error = 0;

        dev->hi.finished = 0;

        dev->hi.op_started = 1;

        dev->hi.end_tstmp = timers_ms_now() + timeout_ms;

        XIic_SetAddress(&dev->iic, XII_ADDR_TO_SEND_TYPE, addr);

        do {

                ret = XIic_DynMasterRecv(&dev->iic, rx_msg, length);

        } while ((ret != XST_SUCCESS) && (timers_ms_now() < dev->hi.end_tstmp));

        while (!dev->hi.finished) {

                if (timers_ms_now() > dev->hi.end_tstmp) {

                        dev->hi.op_started = 0;

                        return -1;

                }

        }

        /* check for errors */

        if(dev->hi.error || dev->hi.unprocessed_bytes) {

                dev->hi.op_started = 0;

                return -1;

        }

        /* Success */

        dev->hi.op_started = 0;

        return 0;

}