source: mainline/uspace/lib/usbdev/src/pipes.c@ 2c202c5

/*
 * Copyright (c) 2011 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 libusbdev
 * @{
 */
/** @file
 * USB endpoint pipes miscellaneous functions.
 */
#include <usb/usb.h>
#include <usb/dev/pipes.h>
#include <usb/debug.h>
#include <usb/hc.h>
#include <usbhc_iface.h>
#include <usb_iface.h>
#include <devman.h>
#include <errno.h>
#include <assert.h>
#include "pipepriv.h"

#define IPC_AGAIN_DELAY (1000 * 2) /* 2ms */

/** Tell USB address assigned to given device.
 *
 * @param sess Session to parent device.
 * @param dev Device in question.
 * @return USB address or error code.
 */
static usb_address_t get_my_address(async_sess_t *sess, const ddf_dev_t *dev)
{
        assert(sess);
        async_exch_t *exch = async_exchange_begin(sess);
        if (!exch)
                return ENOMEM;

        usb_address_t address;
        const int ret = usb_get_my_address(exch, &address);

        async_exchange_end(exch);

        return (ret == EOK) ? address : ret;
}

/** Tell USB interface assigned to given device.
 *
 * @param device Device in question.
 * @return Error code (ENOTSUP means any).
 */
int usb_device_get_assigned_interface(const ddf_dev_t *device)
{
        assert(device);
        async_sess_t *parent_sess =
            devman_parent_device_connect(EXCHANGE_ATOMIC, device->handle,
            IPC_FLAG_BLOCKING);
        if (!parent_sess)
                return ENOMEM;

        async_exch_t *exch = async_exchange_begin(parent_sess);
        if (!exch) {
                async_hangup(parent_sess);
                return ENOMEM;
        }

        int iface_no;
        const int ret = usb_get_my_interface(exch, &iface_no);

        return ret == EOK ? iface_no : ret;
}

/** Initialize connection to USB device.
 *
 * @param connection Connection structure to be initialized.
 * @param dev Generic device backing the USB device.
 * @return Error code.
 */
int usb_device_connection_initialize_from_device(
    usb_device_connection_t *connection, const ddf_dev_t *dev)
{
        assert(connection);
        assert(dev);
        
        int rc;
        devman_handle_t hc_handle;
        usb_address_t my_address;
        
        rc = usb_hc_find(dev->handle, &hc_handle);
        if (rc != EOK)
                return rc;
        
        async_sess_t *parent_sess =
            devman_parent_device_connect(EXCHANGE_ATOMIC, dev->handle,
            IPC_FLAG_BLOCKING);
        if (!parent_sess)
                return ENOMEM;
        
        /*
         * Asking for "my" address may require several attempts.
         * That is because following scenario may happen:
         *  - parent driver (i.e. driver of parent device) announces new device
         *    and devman launches current driver
         *  - parent driver is preempted and thus does not send address-handle
         *    binding to HC driver
         *  - this driver gets here and wants the binding
         *  - the HC does not know the binding yet and thus it answers ENOENT
         *  So, we need to wait for the HC to learn the binding.
         */
        
        do {
                my_address = get_my_address(parent_sess, dev);
                
                if (my_address == ENOENT) {
                        /* Be nice, let other fibrils run and try again. */
                        async_usleep(IPC_AGAIN_DELAY);
                } else if (my_address < 0) {
                        /* Some other problem, no sense trying again. */
                        rc = my_address;
                        goto leave;
                }
        
        } while (my_address < 0);
        
        rc = usb_device_connection_initialize(connection,
            hc_handle, my_address);
        
leave:
        async_hangup(parent_sess);
        return rc;
}

/** Initialize connection to USB device.
 *
 * @param connection Connection structure to be initialized.
 * @param host_controller_handle Devman handle of host controller device is
 *      connected to.
 * @param device_address Device USB address.
 * @return Error code.
 */
int usb_device_connection_initialize(usb_device_connection_t *connection,
    devman_handle_t host_controller_handle, usb_address_t device_address)
{
        assert(connection);

        if ((device_address < 0) || (device_address >= USB11_ADDRESS_MAX)) {
                return EINVAL;
        }

        connection->hc_handle = host_controller_handle;
        connection->address = device_address;

        return EOK;
}

/** Initialize connection to USB device on default address.
 *
 * @param dev_connection Device connection structure to be initialized.
 * @param hc_connection Initialized connection to host controller.
 * @return Error code.
 */
int usb_device_connection_initialize_on_default_address(
    usb_device_connection_t *dev_connection,
    usb_hc_connection_t *hc_connection)
{
        assert(dev_connection);

        if (hc_connection == NULL) {
                return EBADMEM;
        }

        return usb_device_connection_initialize(dev_connection,
            hc_connection->hc_handle, (usb_address_t) 0);
}

/** Prepare pipe for a long transfer.
 *
 * By a long transfer is mean transfer consisting of several
 * requests to the HC.
 * Calling such function is optional and it has positive effect of
 * improved performance because IPC session is initiated only once.
 *
 * @param pipe Pipe over which the transfer will happen.
 * @return Error code.
 */
void usb_pipe_start_long_transfer(usb_pipe_t *pipe)
{
        (void) pipe_add_ref(pipe, true);
}

/** Terminate a long transfer on a pipe.
 *
 * @see usb_pipe_start_long_transfer
 *
 * @param pipe Pipe where to end the long transfer.
 */
void usb_pipe_end_long_transfer(usb_pipe_t *pipe)
{
        pipe_drop_ref(pipe);
}

/**
 * @}
 */