source: mainline/uspace/lib/usb/src/hidiface.c@ 27b85d9

/*
 * 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
 * Client functions for accessing USB HID interface (implementation).
 */
#include <dev_iface.h>
#include <usbhid_iface.h>
#include <usb/classes/hid/iface.h>
#include <errno.h>
#include <str_error.h>
#include <async.h>
#include <assert.h>

/** Ask for event array length.
 *
 * @param dev_phone Opened phone to DDF device providing USB HID interface.
 * @return Number of usages returned or negative error code.
 */
int usbhid_dev_get_event_length(int dev_phone)
{
        if (dev_phone < 0) {
                return EINVAL;
        }

        sysarg_t len;
        int rc = async_req_1_1(dev_phone, DEV_IFACE_ID(USBHID_DEV_IFACE),
            IPC_M_USBHID_GET_EVENT_LENGTH, &len);
        if (rc == EOK) {
                return (int) len;
        } else {
                return rc;
        }
}

/** Request for next event from HID device.
 *
 * @param[in] dev_phone Opened phone to DDF device providing USB HID interface.
 * @param[out] usage_pages Where to store usage pages.
 * @param[out] usages Where to store usages (actual data).
 * @param[in] usage_count Length of @p usage_pages and @p usages buffer
 *      (in items, not bytes).
 * @param[out] actual_usage_count Number of usages actually returned by the
 *      device driver.
 * @param[in] flags Flags (see USBHID_IFACE_FLAG_*).
 * @return Error code.
 */
int usbhid_dev_get_event(int dev_phone, uint16_t *usage_pages, uint16_t *usages,
    size_t usage_count, size_t *actual_usage_count, unsigned int flags)
{
        if (dev_phone < 0) {
                return EINVAL;
        }
        if ((usage_pages == NULL) || (usages == NULL)) {
                return ENOMEM;
        }
        if (usage_count == 0) {
                return EINVAL;
        }

        size_t buffer_size = sizeof(uint16_t) * usage_count * 2;
        uint16_t *buffer = malloc(buffer_size);
        if (buffer == NULL) {
                return ENOMEM;
        }

        aid_t opening_request = async_send_2(dev_phone,
            DEV_IFACE_ID(USBHID_DEV_IFACE), IPC_M_USBHID_GET_EVENT,
            flags, NULL);
        if (opening_request == 0) {
                free(buffer);
                return ENOMEM;
        }

        ipc_call_t data_request_call;
        aid_t data_request = async_data_read(dev_phone, buffer, buffer_size,
            &data_request_call);
        if (data_request == 0) {
                async_wait_for(opening_request, NULL);
                free(buffer);
                return ENOMEM;
        }

        sysarg_t data_request_rc;
        sysarg_t opening_request_rc;
        async_wait_for(data_request, &data_request_rc);
        async_wait_for(opening_request, &opening_request_rc);

        if (data_request_rc != EOK) {
                /* Prefer return code of the opening request. */
                if (opening_request_rc != EOK) {
                        return (int) opening_request_rc;
                } else {
                        return (int) data_request_rc;
                }
        }

        if (opening_request_rc != EOK) {
                return (int) opening_request_rc;
        }

        size_t actual_size = IPC_GET_ARG2(data_request_call);
        size_t items = actual_size / 2;

        /* Copy the individual items. */
        memcpy(usage_pages, buffer, items * sizeof(uint16_t));
        memcpy(usages, buffer + items, items * sizeof(uint16_t));

        if (actual_usage_count != NULL) {
                *actual_usage_count = items;
        }

        return EOK;
}

/**
 * @}
 */