source: mainline/uspace/drv/usbmid/explore.c@ c7fbb90

/*
 * 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 drvusbmid
 * @{
 */
/**
 * @file
 * Exploration of available interfaces in the USB device.
 */
#include <errno.h>
#include <str_error.h>
#include <stdlib.h>
#include <usb/classes/classes.h>
#include <usb/request.h>
#include <usb/dp.h>
#include <usb/ddfiface.h>
#include "usbmid.h"

/** Operations of the device itself. */
static ddf_dev_ops_t mid_device_ops = {
        .interfaces[USB_DEV_IFACE] = &usb_iface_hub_impl
};

/** Tell whether given interface is already in the list.
 *
 * @param list List of usbmid_interface_t members to be searched.
 * @param interface_no Interface number caller is looking for.
 * @return Interface @p interface_no is already present in the list.
 */
static bool interface_in_list(link_t *list, int interface_no)
{
        link_t *l;
        for (l = list->next; l != list; l = l->next) {
                usbmid_interface_t *iface
                    = list_get_instance(l, usbmid_interface_t, link);
                if (iface->interface_no == interface_no) {
                        return true;
                }
        }

        return false;
}

/** Create list of interfaces from configuration descriptor.
 *
 * @param config_descriptor Configuration descriptor.
 * @param config_descriptor_size Size of configuration descriptor in bytes.
 * @param list List where to add the interfaces.
 */
static void create_interfaces(uint8_t *config_descriptor,
    size_t config_descriptor_size, link_t *list)
{
        usb_dp_parser_data_t data = {
                .data = config_descriptor,
                .size = config_descriptor_size,
                .arg = NULL
        };

        usb_dp_parser_t parser = {
                .nesting = usb_dp_standard_descriptor_nesting
        };

        uint8_t *interface_ptr = usb_dp_get_nested_descriptor(&parser, &data,
            data.data);
        if (interface_ptr == NULL) {
                return;
        }

        do {
                if (interface_ptr[1] != USB_DESCTYPE_INTERFACE) {
                        goto next_descriptor;
                }

                usb_standard_interface_descriptor_t *interface
                    = (usb_standard_interface_descriptor_t *) interface_ptr;

                /* Skip alternate interfaces. */
                if (!interface_in_list(list, interface->interface_number)) {
                        usbmid_interface_t *iface
                            = malloc(sizeof(usbmid_interface_t));
                        if (iface == NULL) {
                                break;
                        }
                        link_initialize(&iface->link);
                        iface->fun = NULL;
                        iface->interface_no = interface->interface_number;
                        iface->interface = interface;

                        list_append(&iface->link, list);
                }

                /* TODO: add the alternatives and create match ids from them
                 * as well.
                 */

next_descriptor:
                interface_ptr = usb_dp_get_sibling_descriptor(&parser, &data,
                    data.data, interface_ptr);

        } while (interface_ptr != NULL);

}

/** Explore MID device.
 *
 * We expect that @p dev is initialized and session on control pipe is
 * started.
 *
 * @param dev Device to be explored.
 * @return Whether to accept this device from devman.
 */
bool usbmid_explore_device(usb_device_t *dev)
{
        int rc;

        int dev_class = dev->descriptors.device.device_class;
        if (dev_class != USB_CLASS_USE_INTERFACE) {
                usb_log_warning(
                    "Device class: %d (%s), but expected class 0.\n",
                    dev_class, usb_str_class(dev_class));
                usb_log_error("Not multi interface device, refusing.\n");
                return false;
        }

        /* Short cuts to save on typing ;-). */
        uint8_t *config_descriptor_raw = dev->descriptors.configuration;
        size_t config_descriptor_size = dev->descriptors.configuration_size;
        usb_standard_configuration_descriptor_t *config_descriptor =
            (usb_standard_configuration_descriptor_t *) config_descriptor_raw;

        /* Select the first configuration */
        rc = usb_request_set_configuration(&dev->ctrl_pipe,
            config_descriptor->configuration_number);
        if (rc != EOK) {
                usb_log_error("Failed to set device configuration: %s.\n",
                    str_error(rc));
                return false;
        }

        /* Create control function */
        ddf_fun_t *ctl_fun = ddf_fun_create(dev->ddf_dev, fun_exposed, "ctl");
        if (ctl_fun == NULL) {
                usb_log_error("Failed to create control function.\n");
                return false;
        }

        ctl_fun->ops = &mid_device_ops;

        rc = ddf_fun_bind(ctl_fun);
        if (rc != EOK) {
                usb_log_error("Failed to bind control function: %s.\n",
                    str_error(rc));
                return false;
        }

        /* Create interface children. */
        link_t interface_list;
        list_initialize(&interface_list);
        create_interfaces(config_descriptor_raw, config_descriptor_size,
            &interface_list);

        link_t *link;
        for (link = interface_list.next; link != &interface_list;
            link = link->next) {
                usbmid_interface_t *iface = list_get_instance(link,
                    usbmid_interface_t, link);

                usb_log_info("Creating child for interface %d (%s).\n",
                    (int) iface->interface_no,
                    usb_str_class(iface->interface->interface_class));

                rc = usbmid_spawn_interface_child(dev, iface,
                    &dev->descriptors.device, iface->interface);
                if (rc != EOK) {
                        usb_log_error("Failed to create interface child: %s.\n",
                            str_error(rc));
                }
        }

        return true;
}

/**
 * @}
 */