linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * FPGA Region - Device Tree support for FPGA programming under Linux

 *

 *  Copyright (C) 2013-2016 Altera Corporation

 *  Copyright (C) 2017 Intel Corporation

 */

#include <linux/fpga/fpga-bridge.h>

#include <linux/fpga/fpga-mgr.h>

#include <linux/fpga/fpga-region.h>

#include <linux/idr.h>

#include <linux/kernel.h>

#include <linux/list.h>

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/spinlock.h>

​

static DEFINE_IDA(fpga_region_ida);

static struct class *fpga_region_class;

​

struct fpga_region *fpga_region_class_find(

    struct device *start, const void *data,

    int (*match)(struct device *, const void *))

{

    struct device *dev;

​

    dev = class_find_device(fpga_region_class, start, data, match);

    if (!dev)

        return NULL;

​

    return to_fpga_region(dev);

}

EXPORT_SYMBOL_GPL(fpga_region_class_find);

​

/**

 * fpga_region_get - get an exclusive reference to a fpga region

 * @region: FPGA Region struct

 *

 * Caller should call fpga_region_put() when done with region.

 *

 * Return fpga_region struct if successful.

 * Return -EBUSY if someone already has a reference to the region.

 * Return -ENODEV if @np is not a FPGA Region.

 */

static struct fpga_region *fpga_region_get(struct fpga_region *region)

{

    struct device *dev = &region->dev;

​

    if (!mutex_trylock(&region->mutex)) {

        dev_dbg(dev, "%s: FPGA Region already in use\n", __func__);

        return ERR_PTR(-EBUSY);

    }

​

    get_device(dev);

    if (!try_module_get(dev->parent->driver->owner)) {

        put_device(dev);

        mutex_unlock(&region->mutex);

        return ERR_PTR(-ENODEV);

    }

​

    dev_dbg(dev, "get\n");

​

    return region;