source: mainline/uspace/drv/uhci/callback.c@ d1984e0

#include <errno.h>
#include <mem.h>

#include "callback.h"
int callback_init(callback_t *instance, device_t *dev,
  void *buffer, size_t size, usbhc_iface_transfer_in_callback_t func_in,
  usbhc_iface_transfer_out_callback_t func_out, void *arg)
{
        assert(instance);
        assert(func_in == NULL || func_out == NULL);
        instance->new_buffer = malloc32(size);
        if (!instance->new_buffer) {
                uhci_print_error("Failed to allocate device acessible buffer.\n");
                return ENOMEM;
        }

        if (func_out)
                memcpy(instance->new_buffer, buffer, size);

        instance->callback_out = func_out;
        instance->callback_in = func_in;
        instance->old_buffer = buffer;
        instance->buffer_size = size;
        instance->dev = dev;
        return EOK;
}
/*----------------------------------------------------------------------------*/
void callback_run(
callback_t *instance, usb_transaction_outcome_t outcome, size_t act_size)
{
        assert(instance);

        /* update the old buffer */
        if (instance->new_buffer) {
                memcpy(instance->new_buffer, instance->old_buffer, instance->buffer_size);
                free32(instance->new_buffer);
                instance->new_buffer = NULL;
        }

        if (instance->callback_in) {
                assert(instance->callback_out == NULL);
                instance->callback_in(
                  instance->dev, act_size, outcome, instance->arg);
        }
}