source: mainline/uspace/lib/usb/src/pipesinit.c@ ca56afa

/*
 * 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
 * Initialization of endpoint pipes.
 *
 */
#include <usb/usb.h>
#include <usb/pipes.h>
#include <usb/dp.h>
#include <errno.h>
#include <assert.h>


#define NESTING(parentname, childname) \
        { \
                .child = USB_DESCTYPE_##childname, \
                .parent = USB_DESCTYPE_##parentname, \
        }
#define LAST_NESTING { -1, -1 }

/** Nesting pairs of standard descriptors. */
static usb_dp_descriptor_nesting_t descriptor_nesting[] = {
        NESTING(CONFIGURATION, INTERFACE),
        NESTING(INTERFACE, ENDPOINT),
        NESTING(INTERFACE, HUB),
        NESTING(INTERFACE, HID),
        NESTING(HID, HID_REPORT),
        LAST_NESTING
};

/** Tells whether given descriptor is of endpoint type.
 *
 * @param descriptor Descriptor in question.
 * @return Whether the given descriptor is endpoint descriptor.
 */
static inline bool is_endpoint_descriptor(uint8_t *descriptor)
{
        return descriptor[1] == USB_DESCTYPE_ENDPOINT;
}

/** Tells whether found endpoint corresponds to endpoint described by user.
 *
 * @param wanted Endpoint description as entered by driver author.
 * @param found Endpoint description obtained from endpoint descriptor.
 * @return Whether the @p found descriptor fits the @p wanted descriptor.
 */
static bool endpoint_fits_description(const usb_endpoint_description_t *wanted,
    usb_endpoint_description_t *found)
{
#define _SAME(fieldname) ((wanted->fieldname) == (found->fieldname))

        if (!_SAME(direction)) {
                return false;
        }

        if (!_SAME(transfer_type)) {
                return false;
        }

        if ((wanted->interface_class >= 0) && !_SAME(interface_class)) {
                return false;
        }

        if ((wanted->interface_subclass >= 0) && !_SAME(interface_subclass)) {
                return false;
        }

        if ((wanted->interface_protocol >= 0) && !_SAME(interface_protocol)) {
                return false;
        }

#undef _SAME

        return true;
}

/** Find endpoint mapping for a found endpoint.
 *
 * @param mapping Endpoint mapping list.
 * @param mapping_count Number of endpoint mappings in @p mapping.
 * @param found_endpoint Description of found endpoint.
 * @param interface_number Number of currently processed interface.
 * @return Endpoint mapping corresponding to @p found_endpoint.
 * @retval NULL No corresponding endpoint found.
 */
static usb_endpoint_mapping_t *find_endpoint_mapping(
    usb_endpoint_mapping_t *mapping, size_t mapping_count,
    usb_endpoint_description_t *found_endpoint,
    int interface_number)
{
        while (mapping_count > 0) {
                bool interface_number_fits = (mapping->interface_no < 0)
                    || (mapping->interface_no == interface_number);

                bool endpoint_descriptions_fits = endpoint_fits_description(
                    mapping->description, found_endpoint);

                if (interface_number_fits && endpoint_descriptions_fits) {
                        return mapping;
                }

                mapping++;
                mapping_count--;
        }
        return NULL;
}

/** Process endpoint descriptor.
 *
 * @param mapping Endpoint mapping list.
 * @param mapping_count Number of endpoint mappings in @p mapping.
 * @param interface Interface descriptor under which belongs the @p endpoint.
 * @param endpoint Endpoint descriptor.
 * @param wire Connection backing the endpoint pipes.
 * @return Error code.
 */
static int process_endpoint(
    usb_endpoint_mapping_t *mapping, size_t mapping_count,
    usb_standard_interface_descriptor_t *interface,
    usb_standard_endpoint_descriptor_t *endpoint,
    usb_device_connection_t *wire)
{
        usb_endpoint_description_t description;

        /*
         * Get endpoint characteristics.
         */

        /* Actual endpoint number is in bits 0..3 */
        usb_endpoint_t ep_no = endpoint->endpoint_address & 0x0F;

        /* Endpoint direction is set by bit 7 */
        description.direction = (endpoint->endpoint_address & 128)
            ? USB_DIRECTION_IN : USB_DIRECTION_OUT;
        /* Transfer type is in bits 0..2 and the enum values corresponds 1:1 */
        description.transfer_type = endpoint->attributes & 3;

        /*
         * Get interface characteristics.
         */
        description.interface_class = interface->interface_class;
        description.interface_subclass = interface->interface_subclass;
        description.interface_protocol = interface->interface_protocol;

        /*
         * Find the most fitting mapping and initialize the pipe.
         */
        usb_endpoint_mapping_t *ep_mapping = find_endpoint_mapping(mapping,
            mapping_count, &description, interface->interface_number);
        if (ep_mapping == NULL) {
                return ENOENT;
        }

        if (ep_mapping->pipe == NULL) {
                return EBADMEM;
        }
        if (ep_mapping->present) {
                return EEXISTS;
        }

        int rc = usb_endpoint_pipe_initialize(ep_mapping->pipe, wire,
            ep_no, description.transfer_type, endpoint->max_packet_size,
            description.direction);
        if (rc != EOK) {
                return rc;
        }

        ep_mapping->present = true;
        ep_mapping->descriptor = endpoint;
        ep_mapping->interface = interface;

        return EOK;
}

/** Process whole USB interface.
 *
 * @param mapping Endpoint mapping list.
 * @param mapping_count Number of endpoint mappings in @p mapping.
 * @param parser Descriptor parser.
 * @param parser_data Descriptor parser data.
 * @param interface_descriptor Interface descriptor.
 * @return Error code.
 */
static int process_interface(
    usb_endpoint_mapping_t *mapping, size_t mapping_count,
    usb_dp_parser_t *parser, usb_dp_parser_data_t *parser_data,
    uint8_t *interface_descriptor)
{
        uint8_t *descriptor = usb_dp_get_nested_descriptor(parser,
            parser_data, interface_descriptor);

        if (descriptor == NULL) {
                return ENOENT;
        }

        do {
                if (is_endpoint_descriptor(descriptor)) {
                        (void) process_endpoint(mapping, mapping_count,
                            (usb_standard_interface_descriptor_t *)
                                interface_descriptor,
                            (usb_standard_endpoint_descriptor_t *)
                                descriptor,
                            (usb_device_connection_t *) parser_data->arg);
                }

                descriptor = usb_dp_get_sibling_descriptor(parser, parser_data,
                    interface_descriptor, descriptor);
        } while (descriptor != NULL);

        return EOK;
}

/** Initialize endpoint pipes from configuration descriptor.
 *
 * The mapping array is expected to conform to following rules:
 * - @c pipe must point to already allocated structure with uninitialized pipe
 * - @c description must point to prepared endpoint description
 * - @c descriptor does not need to be initialized (will be overwritten)
 * - @c interface does not need to be initialized (will be overwritten)
 * - @c present does not need to be initialized (will be overwritten)
 *
 * After processing the configuration descriptor, the mapping is updated
 * in the following fashion:
 * - @c present will be set to @c true when the endpoint was found in the
 *   configuration
 * - @c descriptor will point inside the configuration descriptor to endpoint
 *   corresponding to given description (or NULL for not found descriptor)
 * - @c interface will point inside the configuration descriptor to interface
 *   descriptor the endpoint @c descriptor belongs to (or NULL for not found
 *   descriptor)
 * - @c pipe will be initialized when found, otherwise left untouched
 * - @c description will be untouched under all circumstances
 *
 * @param mapping Endpoint mapping list.
 * @param mapping_count Number of endpoint mappings in @p mapping.
 * @param configuration_descriptor Full configuration descriptor (is expected
 *      to be in USB endianness: i.e. as-is after being retrieved from
 *      the device).
 * @param configuration_descriptor_size Size of @p configuration_descriptor
 *      in bytes.
 * @param connection Connection backing the endpoint pipes.
 * @return Error code.
 */
int usb_endpoint_pipe_initialize_from_configuration(
    usb_endpoint_mapping_t *mapping, size_t mapping_count,
    uint8_t *configuration_descriptor, size_t configuration_descriptor_size,
    usb_device_connection_t *connection)
{
        assert(connection);

        if (configuration_descriptor == NULL) {
                return EBADMEM;
        }
        if (configuration_descriptor_size
            < sizeof(usb_standard_configuration_descriptor_t)) {
                return ERANGE;
        }

        /*
         * Go through the mapping and set all endpoints to not present.
         */
        size_t i;
        for (i = 0; i < mapping_count; i++) {
                mapping[i].present = false;
                mapping[i].descriptor = NULL;
                mapping[i].interface = NULL;
        }

        /*
         * Prepare the descriptor parser.
         */
        usb_dp_parser_t dp_parser = {
                .nesting = descriptor_nesting
        };
        usb_dp_parser_data_t dp_data = {
                .data = configuration_descriptor,
                .size = configuration_descriptor_size,
                .arg = connection
        };

        /*
         * Iterate through all interfaces.
         */
        uint8_t *interface = usb_dp_get_nested_descriptor(&dp_parser,
            &dp_data, configuration_descriptor);
        if (interface == NULL) {
                return ENOENT;
        }
        do {
                (void) process_interface(mapping, mapping_count,
                    &dp_parser, &dp_data,
                    interface);
                interface = usb_dp_get_sibling_descriptor(&dp_parser, &dp_data,
                    configuration_descriptor, interface);
        } while (interface != NULL);

        return EOK;
}

/** Initialize USB endpoint pipe.
 *
 * @param pipe Endpoint pipe to be initialized.
 * @param connection Connection to the USB device backing this pipe (the wire).
 * @param endpoint_no Endpoint number (in USB 1.1 in range 0 to 15).
 * @param transfer_type Transfer type (e.g. interrupt or bulk).
 * @param max_packet_size Maximum packet size in bytes.
 * @param direction Endpoint direction (in/out).
 * @return Error code.
 */
int usb_endpoint_pipe_initialize(usb_endpoint_pipe_t *pipe,
    usb_device_connection_t *connection, usb_endpoint_t endpoint_no,
    usb_transfer_type_t transfer_type, size_t max_packet_size,
    usb_direction_t direction)
{
        assert(pipe);
        assert(connection);

        pipe->wire = connection;
        pipe->hc_phone = -1;
        pipe->endpoint_no = endpoint_no;
        pipe->transfer_type = transfer_type;
        pipe->max_packet_size = max_packet_size;
        pipe->direction = direction;

        return EOK;
}


/** Initialize USB endpoint pipe as the default zero control pipe.
 *
 * @param pipe Endpoint pipe to be initialized.
 * @param connection Connection to the USB device backing this pipe (the wire).
 * @return Error code.
 */
int usb_endpoint_pipe_initialize_default_control(usb_endpoint_pipe_t *pipe,
    usb_device_connection_t *connection)
{
        assert(pipe);
        assert(connection);

        int rc = usb_endpoint_pipe_initialize(pipe, connection,
            0, USB_TRANSFER_CONTROL, 8, USB_DIRECTION_BOTH);

        return rc;
}

/**
 * @}
 */