source: mainline/uspace/lib/usb/src/resolve.c@ a9ab7f47

/*
 * 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 libusb
 * @{
 */
/** @file
 *
 */
#include <inttypes.h>
#include <usb/driver.h>
#include <usb/hc.h>
#include <devman.h>
#include <errno.h>
#include <str.h>
#include <stdio.h>

#define MAX_DEVICE_PATH 1024

static bool try_parse_bus_and_address(const char *path,
    char **func_start,
    devman_handle_t *out_hc_handle, usb_address_t *out_device_address)
{
        size_t class_index;
        size_t address;
        int rc;
        char *ptr;

        rc = str_size_t(path, &ptr, 10, false, &class_index);
        if (rc != EOK) {
                return false;
        }
        if ((*ptr == ':') || (*ptr == '.')) {
                ptr++;
        } else {
                return false;
        }
        rc = str_size_t(ptr, func_start, 10, false, &address);
        if (rc != EOK) {
                return false;
        }
        rc = usb_ddf_get_hc_handle_by_class(class_index, out_hc_handle);
        if (rc != EOK) {
                return false;
        }
        if (out_device_address != NULL) {
                *out_device_address = (usb_address_t) address;
        }
        return true;
}

static int get_device_handle_by_address(devman_handle_t hc_handle, int addr,
    devman_handle_t *dev_handle)
{
        int rc;
        usb_hc_connection_t conn;

        usb_hc_connection_initialize(&conn, hc_handle);
        rc = usb_hc_connection_open(&conn);
        if (rc != EOK) {
                return rc;
        }

        rc = usb_hc_get_handle_by_address(&conn, addr, dev_handle);

        usb_hc_connection_close(&conn);

        return rc;
}

/** Resolve handle and address of USB device from its path.
 *
 * This is a wrapper working on best effort principle.
 * If the resolving fails, if will not give much details about what
 * is wrong.
 * Typically, error from this function would be reported to the user
 * as "bad device specification" or "device does not exist".
 *
 * The path can be specified in following format:
 *  - devman path (e.g. /hw/pci0/.../usb01_a5
 *  - bus number and device address (e.g. 5.1)
 *  - bus number, device address and device function (e.g. 2.1/HID0/keyboard)
 *
 * @param[in] dev_path Path to the device.
 * @param[out] out_hc_handle Where to store handle of a parent host controller.
 * @param[out] out_dev_addr Where to store device (USB) address.
 * @param[out] out_dev_handle Where to store device handle.
 * @return Error code.
 */
int usb_resolve_device_handle(const char *dev_path, devman_handle_t *out_hc_handle,
    usb_address_t *out_dev_addr, devman_handle_t *out_dev_handle)
{
        if (dev_path == NULL) {
                return EBADMEM;
        }

        bool found_hc = false;
        bool found_addr = false;
        devman_handle_t hc_handle, dev_handle;
        usb_address_t dev_addr = -1;
        int rc;
        bool is_bus_addr;
        char *func_start = NULL;
        char *path = NULL;

        /* First try the BUS.ADDR format. */
        is_bus_addr = try_parse_bus_and_address(dev_path, &func_start,
            &hc_handle, &dev_addr);
        if (is_bus_addr) {
                found_hc = true;
                found_addr = true;
                /*
                 * Now get the handle of the device. We will need that
                 * in both cases. If there is only BUS.ADDR, it will
                 * be the handle to be returned to the caller, otherwise
                 * we will need it to resolve the path to which the
                 * suffix would be appended.
                 */
                /* If there is nothing behind the BUS.ADDR, we will
                 * get the device handle from the host controller.
                 * Otherwise, we will
                 */
                rc = get_device_handle_by_address(hc_handle, dev_addr,
                    &dev_handle);
                if (rc != EOK) {
                        return rc;
                }
                if (str_length(func_start) > 0) {
                        char tmp_path[MAX_DEVICE_PATH ];
                        rc = devman_get_device_path(dev_handle,
                            tmp_path, MAX_DEVICE_PATH);
                        if (rc != EOK) {
                                return rc;
                        }
                        rc = asprintf(&path, "%s%s", tmp_path, func_start);
                        if (rc < 0) {
                                return ENOMEM;
                        }
                } else {
                        /* Everything is resolved. Get out of here. */
                        goto copy_out;
                }
        } else {
                path = str_dup(dev_path);
                if (path == NULL) {
                        return ENOMEM;
                }
        }

        /* First try to get the device handle. */
        rc = devman_device_get_handle(path, &dev_handle, 0);
        if (rc != EOK) {
                free(path);
                /* Invalid path altogether. */
                return rc;
        }

        /* Remove suffixes and hope that we will encounter device node. */
        while (str_length(path) > 0) {
                /* Get device handle first. */
                devman_handle_t tmp_handle;
                rc = devman_device_get_handle(path, &tmp_handle, 0);
                if (rc != EOK) {
                        free(path);
                        return rc;
                }

                /* Try to find its host controller. */
                if (!found_hc) {
                        rc = usb_hc_find(tmp_handle, &hc_handle);
                        if (rc == EOK) {
                                found_hc = true;
                        }
                }

                /* Try to get its address. */
                if (!found_addr) {
                        dev_addr = usb_hc_get_address_by_handle(tmp_handle);
                        if (dev_addr >= 0) {
                                found_addr = true;
                        }
                }

                /* Speed-up. */
                if (found_hc && found_addr) {
                        break;
                }

                /* Remove the last suffix. */
                char *slash_pos = str_rchr(path, '/');
                if (slash_pos != NULL) {
                        *slash_pos = 0;
                }
        }

        free(path);

        if (!found_addr || !found_hc) {
                return ENOENT;
        }

copy_out:
        if (out_dev_addr != NULL) {
                *out_dev_addr = dev_addr;
        }
        if (out_hc_handle != NULL) {
                *out_hc_handle = hc_handle;
        }
        if (out_dev_handle != NULL) {
                *out_dev_handle = dev_handle;
        }

        return EOK;
}


/**
 * @}
 */