xilinx_hwicap.c

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/*****************************************************************************
 *
 *     Author: Xilinx, Inc.
 *
 *     This program is free software; you can redistribute it and/or modify it
 *     under the terms of the GNU General Public License as published by the
 *     Free Software Foundation; either version 2 of the License, or (at your
 *     option) any later version.
 *
 *     XILINX IS PROVIDING THIS DESIGN, CODE, OR INFORMATION "AS IS"
 *     AS A COURTESY TO YOU, SOLELY FOR USE IN DEVELOPING PROGRAMS AND
 *     SOLUTIONS FOR XILINX DEVICES.  BY PROVIDING THIS DESIGN, CODE,
 *     OR INFORMATION AS ONE POSSIBLE IMPLEMENTATION OF THIS FEATURE,
 *     APPLICATION OR STANDARD, XILINX IS MAKING NO REPRESENTATION
 *     THAT THIS IMPLEMENTATION IS FREE FROM ANY CLAIMS OF INFRINGEMENT,
 *     AND YOU ARE RESPONSIBLE FOR OBTAINING ANY RIGHTS YOU MAY REQUIRE
 *     FOR YOUR IMPLEMENTATION.  XILINX EXPRESSLY DISCLAIMS ANY
 *     WARRANTY WHATSOEVER WITH RESPECT TO THE ADEQUACY OF THE
 *     IMPLEMENTATION, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OR
 *     REPRESENTATIONS THAT THIS IMPLEMENTATION IS FREE FROM CLAIMS OF
 *     INFRINGEMENT, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 *     FOR A PARTICULAR PURPOSE.
 *
 *     (c) Copyright 2002 Xilinx Inc., Systems Engineering Group
 *     (c) Copyright 2004 Xilinx Inc., Systems Engineering Group
 *     (c) Copyright 2007-2008 Xilinx Inc.
 *     All rights reserved.
 *
 *     You should have received a copy of the GNU General Public License along
 *     with this program; if not, write to the Free Software Foundation, Inc.,
 *     675 Mass Ave, Cambridge, MA 02139, USA.
 *
 *****************************************************************************/

/*
 * This is the code behind /dev/icap* -- it allows a user-space
 * application to use the Xilinx ICAP subsystem.
 *
 * The following operations are possible:
 *
 * open         open the port and initialize for access.
 * release      release port
 * write        Write a bitstream to the configuration processor.
 * read         Read a data stream from the configuration processor.
 *
 * After being opened, the port is initialized and accessed to avoid a
 * corrupted first read which may occur with some hardware.  The port
 * is left in a desynched state, requiring that a synch sequence be
 * transmitted before any valid configuration data.  A user will have
 * exclusive access to the device while it remains open, and the state
 * of the ICAP cannot be guaranteed after the device is closed.  Note
 * that a complete reset of the core and the state of the ICAP cannot
 * be performed on many versions of the cores, hence users of this
 * device should avoid making inconsistent accesses to the device.  In
 * particular, accessing the read interface, without first generating
 * a write containing a readback packet can leave the ICAP in an
 * inaccessible state.
 *
 * Note that in order to use the read interface, it is first necessary
 * to write a request packet to the write interface.  i.e., it is not
 * possible to simply readback the bitstream (or any configuration
 * bits) from a device without specifically requesting them first.
 * The code to craft such packets is intended to be part of the
 * user-space application code that uses this device.  The simplest
 * way to use this interface is simply:
 *
 * cp foo.bit /dev/icap0
 *
 * Note that unless foo.bit is an appropriately constructed partial
 * bitstream, this has a high likelihood of overwriting the design
 * currently programmed in the FPGA.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>
#include <linux/mutex.h>
#include <linux/sysctl.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#ifdef CONFIG_OF
/* For open firmware. */
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#endif

#include "xilinx_hwicap.h"
#include "buffer_icap.h"
#include "fifo_icap.h"

#define DRIVER_NAME "icap"

#define HWICAP_REGS   (0x10000)

#define XHWICAP_MAJOR 259
#define XHWICAP_MINOR 0
#define HWICAP_DEVICES 1

/* An array, which is set to true when the device is registered. */
static DEFINE_MUTEX(hwicap_mutex);
static bool probed_devices[HWICAP_DEVICES];
static struct mutex icap_sem;

static struct class *icap_class;

#define UNIMPLEMENTED 0xFFFF

static const struct config_registers v2_config_registers = {
    .CRC = 0,
    .FAR = 1,
    .FDRI = 2,
    .FDRO = 3,
    .CMD = 4,
    .CTL = 5,
    .MASK = 6,
    .STAT = 7,
    .LOUT = 8,
    .COR = 9,
    .MFWR = 10,
    .FLR = 11,
    .KEY = 12,
    .CBC = 13,
    .IDCODE = 14,
    .AXSS = UNIMPLEMENTED,
    .C0R_1 = UNIMPLEMENTED,
    .CSOB = UNIMPLEMENTED,
    .WBSTAR = UNIMPLEMENTED,
    .TIMER = UNIMPLEMENTED,
    .BOOTSTS = UNIMPLEMENTED,
    .CTL_1 = UNIMPLEMENTED,
};

static const struct config_registers v4_config_registers = {
    .CRC = 0,
    .FAR = 1,
    .FDRI = 2,
    .FDRO = 3,
    .CMD = 4,
    .CTL = 5,
    .MASK = 6,
    .STAT = 7,
    .LOUT = 8,
    .COR = 9,
    .MFWR = 10,
    .FLR = UNIMPLEMENTED,
    .KEY = UNIMPLEMENTED,
    .CBC = 11,
    .IDCODE = 12,
    .AXSS = 13,
    .C0R_1 = UNIMPLEMENTED,
    .CSOB = UNIMPLEMENTED,
    .WBSTAR = UNIMPLEMENTED,
    .TIMER = UNIMPLEMENTED,
    .BOOTSTS = UNIMPLEMENTED,
    .CTL_1 = UNIMPLEMENTED,
};

static const struct config_registers v5_config_registers = {
    .CRC = 0,
    .FAR = 1,
    .FDRI = 2,
    .FDRO = 3,
    .CMD = 4,
    .CTL = 5,
    .MASK = 6,
    .STAT = 7,
    .LOUT = 8,
    .COR = 9,
    .MFWR = 10,
    .FLR = UNIMPLEMENTED,
    .KEY = UNIMPLEMENTED,
    .CBC = 11,
    .IDCODE = 12,
    .AXSS = 13,
    .C0R_1 = 14,
    .CSOB = 15,
    .WBSTAR = 16,
    .TIMER = 17,
    .BOOTSTS = 18,
    .CTL_1 = 19,
};

static const struct config_registers v6_config_registers = {
    .CRC = 0,
    .FAR = 1,
    .FDRI = 2,
    .FDRO = 3,
    .CMD = 4,
    .CTL = 5,
    .MASK = 6,
    .STAT = 7,
    .LOUT = 8,
    .COR = 9,
    .MFWR = 10,
    .FLR = UNIMPLEMENTED,
    .KEY = UNIMPLEMENTED,
    .CBC = 11,
    .IDCODE = 12,
    .AXSS = 13,
    .C0R_1 = 14,
    .CSOB = 15,
    .WBSTAR = 16,
    .TIMER = 17,
    .BOOTSTS = 22,
    .CTL_1 = 24,
};

static int hwicap_command_desync(struct hwicap_drvdata *drvdata)
{
    u32 buffer[4];
    u32 index = 0;

    /*
     * Create the data to be written to the ICAP.
     */
    buffer[index++] = hwicap_type_1_write(drvdata->config_regs->CMD) | 1;
    buffer[index++] = XHI_CMD_DESYNCH;
    buffer[index++] = XHI_NOOP_PACKET;
    buffer[index++] = XHI_NOOP_PACKET;

    /*
     * Write the data to the FIFO and intiate the transfer of data present
     * in the FIFO to the ICAP device.
     */
    return drvdata->config->set_configuration(drvdata,
            &buffer[0], index);
}

static int hwicap_get_configuration_register(struct hwicap_drvdata *drvdata,
        u32 reg, u32 *reg_data)
{
    int status;
    u32 buffer[6];
    u32 index = 0;

    /*
     * Create the data to be written to the ICAP.
     */
    buffer[index++] = XHI_DUMMY_PACKET;
    buffer[index++] = XHI_NOOP_PACKET;
    buffer[index++] = XHI_SYNC_PACKET;
    buffer[index++] = XHI_NOOP_PACKET;
    buffer[index++] = XHI_NOOP_PACKET;

    /*
     * Write the data to the FIFO and initiate the transfer of data present
     * in the FIFO to the ICAP device.
     */
    status = drvdata->config->set_configuration(drvdata,
                            &buffer[0], index);
    if (status)
        return status;

    /* If the syncword was not found, then we need to start over. */
    status = drvdata->config->get_status(drvdata);
    if ((status & XHI_SR_DALIGN_MASK) != XHI_SR_DALIGN_MASK)
        return -EIO;

    index = 0;
    buffer[index++] = hwicap_type_1_read(reg) | 1;
    buffer[index++] = XHI_NOOP_PACKET;
    buffer[index++] = XHI_NOOP_PACKET;

    /*
     * Write the data to the FIFO and intiate the transfer of data present
     * in the FIFO to the ICAP device.
     */
    status = drvdata->config->set_configuration(drvdata,
            &buffer[0], index);
    if (status)
        return status;

    /*
     * Read the configuration register
     */
    status = drvdata->config->get_configuration(drvdata, reg_data, 1);
    if (status)
        return status;

    return 0;
}

static int hwicap_initialize_hwicap(struct hwicap_drvdata *drvdata)
{
    int status;
    u32 idcode;

    dev_dbg(drvdata->dev, "initializing\n");

    /* Abort any current transaction, to make sure we have the
     * ICAP in a good state. */
    dev_dbg(drvdata->dev, "Reset...\n");
    drvdata->config->reset(drvdata);

    dev_dbg(drvdata->dev, "Desync...\n");
    status = hwicap_command_desync(drvdata);
    if (status)
        return status;

    /* Attempt to read the IDCODE from ICAP.  This
     * may not be returned correctly, due to the design of the
     * hardware.
     */
    dev_dbg(drvdata->dev, "Reading IDCODE...\n");
    status = hwicap_get_configuration_register(
            drvdata, drvdata->config_regs->IDCODE, &idcode);
    dev_dbg(drvdata->dev, "IDCODE = %x\n", idcode);
    if (status)
        return status;

    dev_dbg(drvdata->dev, "Desync...\n");
    status = hwicap_command_desync(drvdata);
    if (status)
        return status;

    return 0;
}

static ssize_t
hwicap_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
{
    struct hwicap_drvdata *drvdata = file->private_data;
    ssize_t bytes_to_read = 0;
    u32 *kbuf;
    u32 words;
    u32 bytes_remaining;
    int status;

    status = mutex_lock_interruptible(&drvdata->sem);
    if (status)
        return status;

    if (drvdata->read_buffer_in_use) {
        /* If there are leftover bytes in the buffer, just */
        /* return them and don't try to read more from the */
        /* ICAP device. */
        bytes_to_read =
            (count < drvdata->read_buffer_in_use) ? count :
            drvdata->read_buffer_in_use;

        /* Return the data currently in the read buffer. */
        if (copy_to_user(buf, drvdata->read_buffer, bytes_to_read)) {
            status = -EFAULT;
            goto error;
        }
        drvdata->read_buffer_in_use -= bytes_to_read;
        memmove(drvdata->read_buffer,
               drvdata->read_buffer + bytes_to_read,
               4 - bytes_to_read);
    } else {
        /* Get new data from the ICAP, and return was was requested. */
        kbuf = (u32 *) get_zeroed_page(GFP_KERNEL);
        if (!kbuf) {
            status = -ENOMEM;
            goto error;
        }

        /* The ICAP device is only able to read complete */
        /* words.  If a number of bytes that do not correspond */
        /* to complete words is requested, then we read enough */
        /* words to get the required number of bytes, and then */
        /* save the remaining bytes for the next read. */

        /* Determine the number of words to read, rounding up */
        /* if necessary. */
        words = ((count + 3) >> 2);
        bytes_to_read = words << 2;

        if (bytes_to_read > PAGE_SIZE)
            bytes_to_read = PAGE_SIZE;

        /* Ensure we only read a complete number of words. */
        bytes_remaining = bytes_to_read & 3;
        bytes_to_read &= ~3;
        words = bytes_to_read >> 2;

        status = drvdata->config->get_configuration(drvdata,
                kbuf, words);

        /* If we didn't read correctly, then bail out. */
        if (status) {
            free_page((unsigned long)kbuf);
            goto error;
        }

        /* If we fail to return the data to the user, then bail out. */
        if (copy_to_user(buf, kbuf, bytes_to_read)) {
            free_page((unsigned long)kbuf);
            status = -EFAULT;
            goto error;
        }
        memcpy(drvdata->read_buffer,
               kbuf,
               bytes_remaining);
        drvdata->read_buffer_in_use = bytes_remaining;
        free_page((unsigned long)kbuf);
    }
    status = bytes_to_read;
 error:
    mutex_unlock(&drvdata->sem);
    return status;
}

static ssize_t
hwicap_write(struct file *file, const char __user *buf,
        size_t count, loff_t *ppos)
{
    struct hwicap_drvdata *drvdata = file->private_data;
    ssize_t written = 0;
    ssize_t left = count;
    u32 *kbuf;
    ssize_t len;
    ssize_t status;

    status = mutex_lock_interruptible(&drvdata->sem);
    if (status)
        return status;

    left += drvdata->write_buffer_in_use;

    /* Only write multiples of 4 bytes. */
    if (left < 4) {
        status = 0;
        goto error;
    }

    kbuf = (u32 *) __get_free_page(GFP_KERNEL);
    if (!kbuf) {
        status = -ENOMEM;
        goto error;
    }

    while (left > 3) {
        /* only write multiples of 4 bytes, so there might */
        /* be as many as 3 bytes left (at the end). */
        len = left;

        if (len > PAGE_SIZE)
            len = PAGE_SIZE;
        len &= ~3;

        if (drvdata->write_buffer_in_use) {
            memcpy(kbuf, drvdata->write_buffer,
                    drvdata->write_buffer_in_use);
            if (copy_from_user(
                (((char *)kbuf) + drvdata->write_buffer_in_use),
                buf + written,
                len - (drvdata->write_buffer_in_use))) {
                free_page((unsigned long)kbuf);
                status = -EFAULT;
                goto error;
            }
        } else {
            if (copy_from_user(kbuf, buf + written, len)) {
                free_page((unsigned long)kbuf);
                status = -EFAULT;
                goto error;
            }
        }

        status = drvdata->config->set_configuration(drvdata,
                kbuf, len >> 2);

        if (status) {
            free_page((unsigned long)kbuf);
            status = -EFAULT;
            goto error;
        }
        if (drvdata->write_buffer_in_use) {
            len -= drvdata->write_buffer_in_use;
            left -= drvdata->write_buffer_in_use;
            drvdata->write_buffer_in_use = 0;
        }
        written += len;
        left -= len;
    }
    if ((left > 0) && (left < 4)) {
        if (!copy_from_user(drvdata->write_buffer,
                        buf + written, left)) {
            drvdata->write_buffer_in_use = left;
            written += left;
            left = 0;
        }
    }

    free_page((unsigned long)kbuf);
    status = written;
 error:
    mutex_unlock(&drvdata->sem);
    return status;
}

static int hwicap_open(struct inode *inode, struct file *file)
{
    struct hwicap_drvdata *drvdata;
    int status;

    mutex_lock(&hwicap_mutex);
    drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);

    status = mutex_lock_interruptible(&drvdata->sem);
    if (status)
        goto out;

    if (drvdata->is_open) {
        status = -EBUSY;
        goto error;
    }

    status = hwicap_initialize_hwicap(drvdata);
    if (status) {
        dev_err(drvdata->dev, "Failed to open file");
        goto error;
    }

    file->private_data = drvdata;
    drvdata->write_buffer_in_use = 0;
    drvdata->read_buffer_in_use = 0;
    drvdata->is_open = 1;

 error:
    mutex_unlock(&drvdata->sem);
 out:
    mutex_unlock(&hwicap_mutex);
    return status;
}

static int hwicap_release(struct inode *inode, struct file *file)
{
    struct hwicap_drvdata *drvdata = file->private_data;
    int i;
    int status = 0;

    mutex_lock(&drvdata->sem);

    if (drvdata->write_buffer_in_use) {
        /* Flush write buffer. */
        for (i = drvdata->write_buffer_in_use; i < 4; i++)
            drvdata->write_buffer[i] = 0;

        status = drvdata->config->set_configuration(drvdata,
                (u32 *) drvdata->write_buffer, 1);
        if (status)
            goto error;
    }

    status = hwicap_command_desync(drvdata);
    if (status)
        goto error;

 error:
    drvdata->is_open = 0;
    mutex_unlock(&drvdata->sem);
    return status;
}

static const struct file_operations hwicap_fops = {
    .owner = THIS_MODULE,
    .write = hwicap_write,
    .read = hwicap_read,
    .open = hwicap_open,
    .release = hwicap_release,
    .llseek = noop_llseek,
};

static int __devinit hwicap_setup(struct device *dev, int id,
        const struct resource *regs_res,
        const struct hwicap_driver_config *config,
        const struct config_registers *config_regs)
{
    dev_t devt;
    struct hwicap_drvdata *drvdata = NULL;
    int retval = 0;

    dev_info(dev, "Xilinx icap port driver\n");

    mutex_lock(&icap_sem);

    if (id < 0) {
        for (id = 0; id < HWICAP_DEVICES; id++)
            if (!probed_devices[id])
                break;
    }
    if (id < 0 || id >= HWICAP_DEVICES) {
        mutex_unlock(&icap_sem);
        dev_err(dev, "%s%i too large\n", DRIVER_NAME, id);
        return -EINVAL;
    }
    if (probed_devices[id]) {
        mutex_unlock(&icap_sem);
        dev_err(dev, "cannot assign to %s%i; it is already in use\n",
            DRIVER_NAME, id);
        return -EBUSY;
    }

    probed_devices[id] = 1;
    mutex_unlock(&icap_sem);

    devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR + id);

    drvdata = kzalloc(sizeof(struct hwicap_drvdata), GFP_KERNEL);
    if (!drvdata) {
        dev_err(dev, "Couldn't allocate device private record\n");
        retval = -ENOMEM;
        goto failed0;
    }
    dev_set_drvdata(dev, (void *)drvdata);

    if (!regs_res) {
        dev_err(dev, "Couldn't get registers resource\n");
        retval = -EFAULT;
        goto failed1;
    }

    drvdata->mem_start = regs_res->start;
    drvdata->mem_end = regs_res->end;
    drvdata->mem_size = resource_size(regs_res);

    if (!request_mem_region(drvdata->mem_start,
                    drvdata->mem_size, DRIVER_NAME)) {
        dev_err(dev, "Couldn't lock memory region at %Lx\n",
            (unsigned long long) regs_res->start);
        retval = -EBUSY;
        goto failed1;
    }

    drvdata->devt = devt;
    drvdata->dev = dev;
    drvdata->base_address = ioremap(drvdata->mem_start, drvdata->mem_size);
    if (!drvdata->base_address) {
        dev_err(dev, "ioremap() failed\n");
        goto failed2;
    }

    drvdata->config = config;
    drvdata->config_regs = config_regs;

    mutex_init(&drvdata->sem);
    drvdata->is_open = 0;

    dev_info(dev, "ioremap %llx to %p with size %llx\n",
         (unsigned long long) drvdata->mem_start,
         drvdata->base_address,
         (unsigned long long) drvdata->mem_size);

    cdev_init(&drvdata->cdev, &hwicap_fops);
    drvdata->cdev.owner = THIS_MODULE;
    retval = cdev_add(&drvdata->cdev, devt, 1);
    if (retval) {
        dev_err(dev, "cdev_add() failed\n");
        goto failed3;
    }

    device_create(icap_class, dev, devt, NULL, "%s%d", DRIVER_NAME, id);
    return 0;       /* success */

 failed3:
    iounmap(drvdata->base_address);

 failed2:
    release_mem_region(regs_res->start, drvdata->mem_size);

 failed1:
    kfree(drvdata);

 failed0:
    mutex_lock(&icap_sem);
    probed_devices[id] = 0;
    mutex_unlock(&icap_sem);

    return retval;
}

static struct hwicap_driver_config buffer_icap_config = {
    .get_configuration = buffer_icap_get_configuration,
    .set_configuration = buffer_icap_set_configuration,
    .get_status = buffer_icap_get_status,
    .reset = buffer_icap_reset,
};

static struct hwicap_driver_config fifo_icap_config = {
    .get_configuration = fifo_icap_get_configuration,
    .set_configuration = fifo_icap_set_configuration,
    .get_status = fifo_icap_get_status,
    .reset = fifo_icap_reset,
};

static int __devexit hwicap_remove(struct device *dev)
{
    struct hwicap_drvdata *drvdata;

    drvdata = (struct hwicap_drvdata *)dev_get_drvdata(dev);

    if (!drvdata)
        return 0;

    device_destroy(icap_class, drvdata->devt);
    cdev_del(&drvdata->cdev);
    iounmap(drvdata->base_address);
    release_mem_region(drvdata->mem_start, drvdata->mem_size);
    kfree(drvdata);
    dev_set_drvdata(dev, NULL);

    mutex_lock(&icap_sem);
    probed_devices[MINOR(dev->devt)-XHWICAP_MINOR] = 0;
    mutex_unlock(&icap_sem);
    return 0;       /* success */
}

#ifdef CONFIG_OF
static int __devinit hwicap_of_probe(struct platform_device *op,
                     const struct hwicap_driver_config *config)
{
    struct resource res;
    const unsigned int *id;
    const char *family;
    int rc;
    const struct config_registers *regs;


    rc = of_address_to_resource(op->dev.of_node, 0, &res);
    if (rc) {
        dev_err(&op->dev, "invalid address\n");
        return rc;
    }

    id = of_get_property(op->dev.of_node, "port-number", NULL);

    /* It's most likely that we're using V4, if the family is not
       specified */
    regs = &v4_config_registers;
    family = of_get_property(op->dev.of_node, "xlnx,family", NULL);

    if (family) {
        if (!strcmp(family, "virtex2p")) {
            regs = &v2_config_registers;
        } else if (!strcmp(family, "virtex4")) {
            regs = &v4_config_registers;
        } else if (!strcmp(family, "virtex5")) {
            regs = &v5_config_registers;
        } else if (!strcmp(family, "virtex6")) {
            regs = &v6_config_registers;
        }
    }
    return hwicap_setup(&op->dev, id ? *id : -1, &res, config,
            regs);
}
#else
static inline int hwicap_of_probe(struct platform_device *op,
                  const struct hwicap_driver_config *config)
{
    return -EINVAL;
}
#endif /* CONFIG_OF */

static const struct of_device_id __devinitconst hwicap_of_match[];
static int __devinit hwicap_drv_probe(struct platform_device *pdev)
{
    const struct of_device_id *match;
    struct resource *res;
    const struct config_registers *regs;
    const char *family;

    match = of_match_device(hwicap_of_match, &pdev->dev);
    if (match)
        return hwicap_of_probe(pdev, match->data);

    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (!res)
        return -ENODEV;

    /* It's most likely that we're using V4, if the family is not
       specified */
    regs = &v4_config_registers;
    family = pdev->dev.platform_data;

    if (family) {
        if (!strcmp(family, "virtex2p")) {
            regs = &v2_config_registers;
        } else if (!strcmp(family, "virtex4")) {
            regs = &v4_config_registers;
        } else if (!strcmp(family, "virtex5")) {
            regs = &v5_config_registers;
        } else if (!strcmp(family, "virtex6")) {
            regs = &v6_config_registers;
        }
    }

    return hwicap_setup(&pdev->dev, pdev->id, res,
            &buffer_icap_config, regs);
}

static int __devexit hwicap_drv_remove(struct platform_device *pdev)
{
    return hwicap_remove(&pdev->dev);
}

#ifdef CONFIG_OF
/* Match table for device tree binding */
static const struct of_device_id __devinitconst hwicap_of_match[] = {
    { .compatible = "xlnx,opb-hwicap-1.00.b", .data = &buffer_icap_config},
    { .compatible = "xlnx,xps-hwicap-1.00.a", .data = &fifo_icap_config},
    {},
};
MODULE_DEVICE_TABLE(of, hwicap_of_match);
#else
#define hwicap_of_match NULL
#endif

static struct platform_driver hwicap_platform_driver = {
    .probe = hwicap_drv_probe,
    .remove = hwicap_drv_remove,
    .driver = {
        .owner = THIS_MODULE,
        .name = DRIVER_NAME,
        .of_match_table = hwicap_of_match,
    },
};

static int __init hwicap_module_init(void)
{
    dev_t devt;
    int retval;

    icap_class = class_create(THIS_MODULE, "xilinx_config");
    mutex_init(&icap_sem);

    devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);
    retval = register_chrdev_region(devt,
                    HWICAP_DEVICES,
                    DRIVER_NAME);
    if (retval < 0)
        return retval;

    retval = platform_driver_register(&hwicap_platform_driver);
    if (retval)
        goto failed;

    return retval;

 failed:
    unregister_chrdev_region(devt, HWICAP_DEVICES);

    return retval;
}

static void __exit hwicap_module_cleanup(void)
{
    dev_t devt = MKDEV(XHWICAP_MAJOR, XHWICAP_MINOR);

    class_destroy(icap_class);

    platform_driver_unregister(&hwicap_platform_driver);

    unregister_chrdev_region(devt, HWICAP_DEVICES);
}

module_init(hwicap_module_init);
module_exit(hwicap_module_cleanup);

MODULE_AUTHOR("Xilinx, Inc; Xilinx Research Labs Group");
MODULE_DESCRIPTION("Xilinx ICAP Port Driver");
MODULE_LICENSE("GPL");