source: mainline/uspace/drv/bus/usb/usbmid/explore.c@ e8d6ce2

/*
 * 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/dev/request.h>
#include <usb/dev/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(const list_t *list, int interface_no)
{
        list_foreach(*list, l) {
                usbmid_interface_t *iface = usbmid_interface_from_link(l);
                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(const uint8_t *config_descriptor,
    size_t config_descriptor_size, list_t *list)
{
        const usb_dp_parser_data_t data = {
                .data = config_descriptor,
                .size = config_descriptor_size,
                .arg = NULL
        };

        static const usb_dp_parser_t parser = {
                .nesting = usb_dp_standard_descriptor_nesting
        };

        const uint8_t *interface_ptr =
            usb_dp_get_nested_descriptor(&parser, &data, config_descriptor);

        /* Walk all descriptors nested in the current configuration decriptor;
         * i.e. all interface descriptors. */
        for (;interface_ptr != NULL;
            interface_ptr = usb_dp_get_sibling_descriptor(
                &parser, &data, config_descriptor, interface_ptr))
        {
                /* The second byte is DESCTYPE byte in all desriptors. */
                if (interface_ptr[1] != USB_DESCTYPE_INTERFACE)
                        continue;

                const usb_standard_interface_descriptor_t *interface
                    = (usb_standard_interface_descriptor_t *) interface_ptr;

                /* Skip alternate interfaces. */
                if (interface_in_list(list, interface->interface_number)) {
                        /* TODO: add the alternatives and create match ids
                         * for them. */
                        continue;
                }
                usbmid_interface_t *iface = malloc(sizeof(usbmid_interface_t));
                if (iface == NULL) {
                        //TODO: Do something about that failure.
                        break;
                }

                link_initialize(&iface->link);
                iface->fun = NULL;
                iface->interface_no = interface->interface_number;
                iface->interface = interface;

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

/** 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;

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

        /* Shortcuts to save on typing ;-). */
        const void *config_descriptor_raw = dev->descriptors.configuration;
        size_t config_descriptor_size = dev->descriptors.configuration_size;
        const usb_standard_configuration_descriptor_t *config_descriptor =
            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 driver soft-state. */
        usb_mid_t *usb_mid = usb_device_data_alloc(dev, sizeof(usb_mid_t));
        if (!usb_mid) {
                usb_log_error("Failed to create USB MID structure.\n");
                return false;
        }

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

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


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

        /* Start child function for every interface. */
        list_foreach(usb_mid->interface_list, link) {
                usbmid_interface_t *iface = usbmid_interface_from_link(link);

                usb_log_info("Creating child for interface %d (%s).\n",
                    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;
}

/**
 * @}
 */