source: mainline/uspace/lib/usb/virtdev.c@ bc9a629

/*
 * Copyright (c) 2010 Vojtech Horky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup libusb usb
 * @{
 */
/** @file
 * @brief Virtual USB device (implementation).
 */
#include "virtdev.h"
#include <devmap.h>
#include <fcntl.h>
#include <vfs/vfs.h>
#include <errno.h>
#include <stdlib.h>

#define NAMESPACE "usb"

static usb_virtdev_on_data_from_host_t on_data_from_host = NULL;

static void handle_data_to_device(ipc_callid_t iid, ipc_call_t icall)
{
        usb_endpoint_t endpoint = IPC_GET_ARG1(icall);
        
        size_t len;
        void * buffer;
        int rc = async_data_write_accept(&buffer, false,
            1, USB_MAX_PAYLOAD_SIZE,
            0, &len);
        
        if (rc != EOK) {
                ipc_answer_0(iid, rc);
                return;
        }
        
        on_data_from_host(endpoint, buffer, len);
        
        free(buffer);
        
        ipc_answer_0(iid, EOK);
}

static void callback_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        ipc_answer_0(iid, EOK);
        
        while (true) {
                ipc_callid_t callid; 
                ipc_call_t call; 
                
                callid = async_get_call(&call);
                switch (IPC_GET_METHOD(call)) {
                        case IPC_M_PHONE_HUNGUP:
                                ipc_answer_0(callid, EOK);
                                return;
                        
                        case IPC_M_USB_VIRTDEV_DATA_TO_DEVICE:
                                handle_data_to_device(callid, call);
                                break;
                        
                        default:
                                ipc_answer_0(callid, EINVAL);
                                break;
                }
        }
}

/** Create necessary phones for comunication with virtual HCD.
 * This function wraps following calls:
 * -# open <code>/dev/usb/<i>hcd_path</i></code> for reading
 * -# access phone of file opened in previous step
 * -# create callback through just opened phone
 * -# create handler for calling on data from host to function
 * -# return the (outgoing) phone
 *
 * @warning This function is wrapper for several actions and therefore
 * it is not possible - in case of error - to determine at which point
 * error occured.
 *
 * @param hcd_path HCD identification under devfs
 *     (without <code>/dev/usb/</code>).
 * @param device_id Internal device identification (used by HCD).
 * @param callback Handler for callbacks from HCD.
 * @return Phone for comunicating with HCD or error code from errno.h.
 */
int usb_virtdev_connect(const char *hcd_path, int device_id,
    usb_virtdev_on_data_from_host_t callback)
{
        char dev_path[DEVMAP_NAME_MAXLEN + 1];
        snprintf(dev_path, DEVMAP_NAME_MAXLEN,
            "/dev/%s/%s", NAMESPACE, hcd_path);
        
        int fd = open(dev_path, O_RDONLY);
        if (fd < 0) {
                return fd;
        }
        
        int hcd_phone = fd_phone(fd);
        
        if (hcd_phone < 0) {
                return hcd_phone;
        }
        
        ipcarg_t phonehash;
        int rc = ipc_connect_to_me(hcd_phone, 1, device_id, 0, &phonehash);
        if (rc != EOK) {
                return rc;
        }
        on_data_from_host = callback;
        async_new_connection(phonehash, 0, NULL, callback_connection);
        
        return hcd_phone;
}

int usb_virtdev_data_to_host(int phone,
    usb_endpoint_t endpoint,
    void * buffer, size_t size)
{
        if (phone < 0) {
                return EINVAL;
        }
        if ((buffer == NULL) || (size == 0)) {
                return EINVAL;
        }

        ipc_call_t answer_data;
        ipcarg_t answer_rc;
        aid_t req;
        int rc;
        
        req = async_send_1(phone,
            IPC_M_USB_VIRTDEV_DATA_FROM_DEVICE,
            endpoint,
            &answer_data);
        
        rc = async_data_write_start(phone, buffer, size);
        if (rc != EOK) {
                async_wait_for(req, NULL);
                return rc;
        }
        
        async_wait_for(req, &answer_rc);
        rc = (int)answer_rc;
        if (rc != EOK) {
                return rc;
        }
        
        return EOK;
}

/**
 * @}
 */