/*
 * Copyright 2013, Jérôme Duval, korli@users.berlios.de.
 * Distributed under the terms of the MIT License.
 */


#include "VirtioRNGPrivate.h"

#include <new>
#include <stdlib.h>
#include <string.h>


#define VIRTIO_RNG_CONTROLLER_PRETTY_NAME "Virtio RNG Device"

#define VIRTIO_RNG_DRIVER_MODULE_NAME "busses/random/virtio_rng/driver_v1"
#define VIRTIO_RNG_DEVICE_MODULE_NAME "busses/random/virtio_rng/device_v1"


device_manager_info *gDeviceManager;
random_for_controller_interface *gRandom;
dpc_module_info *gDPC;


//      #pragma mark -  Driver module interface


static float
virtio_rng_supports_device(device_node *parent)
{
        const char *bus;
        uint16 deviceType;

        // make sure parent is really the Virtio bus manager
        if (gDeviceManager->get_attr_string(parent, B_DEVICE_BUS, &bus, false))
                return -1;

        if (strcmp(bus, "virtio"))
                return 0.0;

        // check whether it's really a Virtio Entropy Device
        if (gDeviceManager->get_attr_uint16(parent, VIRTIO_DEVICE_TYPE_ITEM,
                        &deviceType, true) != B_OK || deviceType != VIRTIO_DEVICE_ID_ENTROPY)
                return 0.0;

        TRACE("Virtio RNG device found!\n");

        return 0.6f;
}


static status_t
virtio_rng_register_device(device_node *parent)
{
        CALLED();

        device_attr attrs[] = {
                { NULL }
        };

        return gDeviceManager->register_node(parent, VIRTIO_RNG_DRIVER_MODULE_NAME,
                attrs, NULL, NULL);
}


static status_t
virtio_rng_init_driver(device_node *node, void **_cookie)
{
        CALLED();
        VirtioRNGDevice *device =  new(std::nothrow) VirtioRNGDevice(node);
        if (device == NULL)
                return B_NO_MEMORY;
        status_t status = device->InitCheck();
        if (status < B_OK) {
                delete device;
                return status;
        }
        *_cookie = device;

        return B_OK;
}


static void
virtio_rng_uninit_driver(void *cookie)
{
        VirtioRNGDevice *device = (VirtioRNGDevice*)cookie;
        delete device;
}


static driver_module_info sVirtioRNGDriver = {
        {
                VIRTIO_RNG_DRIVER_MODULE_NAME,
                0,
                NULL
        },
        virtio_rng_supports_device,
        virtio_rng_register_device,
        virtio_rng_init_driver,
        virtio_rng_uninit_driver,
        NULL,
        NULL,   // rescan
        NULL,   // device_removed
};


module_dependency module_dependencies[] = {
        { B_DEVICE_MANAGER_MODULE_NAME, (module_info **)&gDeviceManager },
        { RANDOM_FOR_CONTROLLER_MODULE_NAME, (module_info **)&gRandom },
        { B_DPC_MODULE_NAME, (module_info **)&gDPC },
        {}
};


module_info *modules[] = {
        (module_info *)&sVirtioRNGDriver,
        NULL
};