source: mainline/uspace/lib/usb/src/recognise.c@ a822cd8

/*
 * 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 Functions for recognising kind of attached devices.
 */
#include <usb/usbdrv.h>
#include <usb/classes/classes.h>
#include <stdio.h>
#include <errno.h>


#define BCD_INT(a) (((unsigned int)(a)) / 256)
#define BCD_FRAC(a) (((unsigned int)(a)) % 256)

#define BCD_FMT "%x.%x"
#define BCD_ARGS(a) BCD_INT((a)), BCD_FRAC((a))

/* FIXME: make this dynamic */
#define MATCH_STRING_MAX 256

/** Add formatted match id.
 *
 * @param matches List of match ids where to add to.
 * @param score Score of the match.
 * @param format Printf-like format
 * @return Error code.
 */
static int usb_add_match_id(match_id_list_t *matches, int score,
    const char *format, ...)
{
        char *match_str = NULL;
        match_id_t *match_id = NULL;
        int rc;
        
        match_str = malloc(MATCH_STRING_MAX + 1);
        if (match_str == NULL) {
                rc = ENOMEM;
                goto failure;
        }

        /*
         * FIXME: replace with dynamic allocation of exact size
         */
        va_list args;
        va_start(args, format   );
        vsnprintf(match_str, MATCH_STRING_MAX, format, args);
        match_str[MATCH_STRING_MAX] = 0;
        va_end(args);

        match_id = create_match_id();
        if (match_id == NULL) {
                rc = ENOMEM;
                goto failure;
        }

        match_id->id = match_str;
        match_id->score = score;
        add_match_id(matches, match_id);

        return EOK;
        
failure:
        if (match_str != NULL) {
                free(match_str);
        }
        if (match_id != NULL) {
                match_id->id = NULL;
                delete_match_id(match_id);
        }
        
        return rc;
}

/** Add match ids based on configuration descriptor.
 *
 * @param hc Open phone to host controller.
 * @param matches Match ids list to add matches to.
 * @param address USB address of the attached device.
 * @return Error code.
 */
static int usb_add_config_descriptor_match_ids(int hc,
    match_id_list_t *matches, usb_address_t address,
    int config_count)
{
        int final_rc = EOK;
        
        int config_index;
        for (config_index = 0; config_index < config_count; config_index++) {
                int rc;
                usb_standard_configuration_descriptor_t config_descriptor;
                rc = usb_drv_req_get_bare_configuration_descriptor(hc,
                    address,  config_index, &config_descriptor);
                if (rc != EOK) {
                        final_rc = rc;
                        continue;
                }

                size_t full_config_descriptor_size;
                void *full_config_descriptor
                    = malloc(config_descriptor.total_length);
                rc = usb_drv_req_get_full_configuration_descriptor(hc,
                    address, config_index,
                    full_config_descriptor, config_descriptor.total_length,
                    &full_config_descriptor_size);
                if (rc != EOK) {
                        final_rc = rc;
                        continue;
                }
                if (full_config_descriptor_size
                    != config_descriptor.total_length) {
                        final_rc = ERANGE;
                        continue;
                }

                /*
                 * Iterate through config descriptor to find the interface
                 * descriptors.
                 */
                size_t position = sizeof(config_descriptor);
                while (position + 1 < full_config_descriptor_size) {
                        uint8_t *current_descriptor
                            = ((uint8_t *) full_config_descriptor) + position;
                        uint8_t cur_descr_len = current_descriptor[0];
                        uint8_t cur_descr_type = current_descriptor[1];
                        
                        position += cur_descr_len;
                        
                        if (cur_descr_type != USB_DESCTYPE_INTERFACE) {
                                continue;
                        }
                        /*
                         * Finally, we found an interface descriptor.
                         */
                        usb_standard_interface_descriptor_t *interface
                            = (usb_standard_interface_descriptor_t *)
                            current_descriptor;
                        
                        rc = usb_add_match_id(matches, 50,
                            "usb&interface&class=%s",
                            usb_str_class(interface->interface_class));
                        if (rc != EOK) {
                                final_rc = rc;
                                break;
                        }
                }
        }
        
        return final_rc;
}

/** Create match ids describing attached device.
 *
 * @warning The list of match ids @p matches may change even when
 * function exits with error.
 *
 * @param hc Open phone to host controller.
 * @param matches Initialized list of match ids.
 * @param address USB address of the attached device.
 * @return Error code.
 */
int usb_drv_create_device_match_ids(int hc, match_id_list_t *matches,
    usb_address_t address)
{
        int rc;
        usb_standard_device_descriptor_t device_descriptor;

        rc = usb_drv_req_get_device_descriptor(hc, address,
            &device_descriptor);
        if (rc != EOK) {
                return rc;
        }

        /*
         * Unless the vendor id is 0, the pair idVendor-idProduct
         * quite uniquely describes the device.
         */
        if (device_descriptor.vendor_id != 0) {
                /* First, with release number. */
                rc = usb_add_match_id(matches, 100,
                    "usb&vendor=%d&product=%d&release=" BCD_FMT,
                    (int) device_descriptor.vendor_id,
                    (int) device_descriptor.product_id,
                    BCD_ARGS(device_descriptor.device_version));
                if (rc != EOK) {
                        return rc;
                }
                
                /* Next, without release number. */
                rc = usb_add_match_id(matches, 90, "usb&vendor=%d&product=%d",
                    (int) device_descriptor.vendor_id,
                    (int) device_descriptor.product_id);
                if (rc != EOK) {
                        return rc;
                }

        }       

        /*
         * If the device class points to interface we skip adding
         * class directly.
         */
        if (device_descriptor.device_class != USB_CLASS_USE_INTERFACE) {
                rc = usb_add_match_id(matches, 50, "usb&class=%s",
                    usb_str_class(device_descriptor.device_class));
                if (rc != EOK) {
                        return rc;
                }
        }
        /*
         * Go through all configurations and add matches
         * based on interface class.
         */
        rc = usb_add_config_descriptor_match_ids(hc, matches,
            address, device_descriptor.configuration_count);
        if (rc != EOK) {
                return rc;
        }

        /*
         * As a fallback, provide the simplest match id possible.
         */
        rc = usb_add_match_id(matches, 1, "usb&fallback");
        if (rc != EOK) {
                return rc;
        }

        return EOK;
}


/** Probe for device kind and register it in devman.
 *
 * @param hc Open phone to the host controller.
 * @param parent Parent device.
 * @param address Address of the (unknown) attached device.
 * @return Error code.
 */
int usb_drv_register_child_in_devman(int hc, device_t *parent,
    usb_address_t address, devman_handle_t *child_handle)
{
        device_t *child = NULL;
        char *child_name = NULL;
        int rc;

        child = create_device();
        if (child == NULL) {
                rc = ENOMEM;
                goto failure;
        }

        /*
         * TODO: some better child naming
         */
        rc = asprintf(&child_name, "usb%p", child);
        if (rc < 0) {
                goto failure;
        }
        child->name = child_name;
        
        rc = usb_drv_create_device_match_ids(hc, &child->match_ids, address);
        if (rc != EOK) {
                goto failure;
        }

        rc = child_device_register(child, parent);
        if (rc != EOK) {
                goto failure;
        }

        if (child_handle != NULL) {
                *child_handle = child->handle;
        }
        
        return EOK;

failure:
        if (child != NULL) {
                child->name = NULL;
                /* This takes care of match_id deallocation as well. */
                delete_device(child);
        }
        if (child_name != NULL) {
                free(child_name);
        }

        return rc;

}


/**
 * @}
 */