usb_util.c

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/* $FreeBSD$ */
/*-
 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
 *
 * Copyright (c) 2008-2022 Hans Petter Selasky
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
 */
 
#ifdef USB_GLOBAL_INCLUDE_FILE
#include USB_GLOBAL_INCLUDE_FILE
#else
#include <sys/stdint.h>
#include <sys/stddef.h>
#include <sys/param.h>
#include <sys/queue.h>
#include <sys/types.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/bus.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/condvar.h>
#include <sys/sysctl.h>
#include <sys/sx.h>
#include <sys/unistd.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/priv.h>
 
#include <dev/usb/usb.h>
#include <dev/usb/usbdi.h>
#include <dev/usb/usbdi_util.h>
 
#include <dev/usb/usb_core.h>
#include <dev/usb/usb_util.h>
#include <dev/usb/usb_process.h>
#include <dev/usb/usb_device.h>
#include <dev/usb/usb_request.h>
#include <dev/usb/usb_busdma.h>
 
#include <dev/usb/usb_controller.h>
#include <dev/usb/usb_bus.h>
#endif                  /* USB_GLOBAL_INCLUDE_FILE */
 
/*------------------------------------------------------------------------*
 *      device_set_usb_desc
 *
 * This function can be called at probe or attach to set the USB
 * device supplied textual description for the given device.
 *------------------------------------------------------------------------*/
void
device_set_usb_desc(device_t dev)
{
        struct usb_attach_arg *uaa;
        struct usb_device *udev;
        struct usb_interface *iface;
        char *temp_p;
        usb_error_t err;
        uint8_t do_unlock;
 
        if (dev == NULL) {
                /* should not happen */
                return;
        }
        uaa = device_get_ivars(dev);
        if (uaa == NULL) {
                /* can happen if called at the wrong time */
                return;
        }
        udev = uaa->device;
        iface = uaa->iface;
 
        if ((iface == NULL) ||
            (iface->idesc == NULL) ||
            (iface->idesc->iInterface == 0)) {
                err = USB_ERR_INVAL;
        } else {
                err = 0;
        }
 
        /* Protect scratch area */
        do_unlock = usbd_ctrl_lock(udev);
 
        temp_p = (char *)udev->scratch.data;
 
        if (err == 0) {
                /* try to get the interface string ! */
                err = usbd_req_get_string_any(udev, NULL, temp_p,
                    sizeof(udev->scratch.data),
                    iface->idesc->iInterface);
        }
        if (err != 0) {
                /* use default description */
                usb_devinfo(udev, temp_p,
                    sizeof(udev->scratch.data));
        }
 
        if (do_unlock)
                usbd_ctrl_unlock(udev);
 
        device_set_desc_copy(dev, temp_p);
        device_printf(dev, "<%s> on %s\n", temp_p,
            device_get_nameunit(udev->bus->bdev));
}
 
/*------------------------------------------------------------------------*
 *       usb_pause_mtx - factored out code
 *
 * This function will delay the code by the passed number of system
 * ticks. The passed mutex "mtx" will be dropped while waiting, if
 * "mtx" is different from NULL.
 *------------------------------------------------------------------------*/
void
usb_pause_mtx(struct mtx *mtx, int timo)
{
        if (mtx != NULL)
                mtx_unlock(mtx);
 
        /*
         * Add one tick to the timeout so that we don't return too
         * early! Note that pause() will assert that the passed
         * timeout is positive and non-zero!
         */
        pause("USBWAIT", timo + 1);
 
        if (mtx != NULL)
                mtx_lock(mtx);
}
 
/*------------------------------------------------------------------------*
 *      usb_printbcd
 *
 * This function will print the version number "bcd" to the string
 * pointed to by "p" having a maximum length of "p_len" bytes
 * including the terminating zero.
 *------------------------------------------------------------------------*/
void
usb_printbcd(char *p, uint16_t p_len, uint16_t bcd)
{
        if (snprintf(p, p_len, "%x.%02x", bcd >> 8, bcd & 0xff)) {
                /* ignore any errors */
        }
}
 
/*------------------------------------------------------------------------*
 *      usb_trim_spaces
 *
 * This function removes spaces at the beginning and the end of the string
 * pointed to by the "p" argument.
 *------------------------------------------------------------------------*/
void
usb_trim_spaces(char *p)
{
        char *q;
        char *e;
 
        if (p == NULL)
                return;
        q = e = p;
        while (*q == ' ')               /* skip leading spaces */
                q++;
        while ((*p = *q++))             /* copy string */
                if (*p++ != ' ')        /* remember last non-space */
                        e = p;
        *e = 0;                         /* kill trailing spaces */
}
 
/*------------------------------------------------------------------------*
 *      usb_make_str_desc - convert an ASCII string into a UNICODE string
 *------------------------------------------------------------------------*/
uint8_t
usb_make_str_desc(void *ptr, uint16_t max_len, const char *s)
{
        struct usb_string_descriptor *p = ptr;
        uint8_t totlen;
        int j;
 
        if (max_len < 2) {
                /* invalid length */
                return (0);
        }
        max_len = ((max_len / 2) - 1);
 
        j = strlen(s);
 
        if (j < 0) {
                j = 0;
        }
        if (j > 126) {
                j = 126;
        }
        if (max_len > j) {
                max_len = j;
        }
        totlen = (max_len + 1) * 2;
 
        p->bLength = totlen;
        p->bDescriptorType = UDESC_STRING;
 
        while (max_len--) {
                USETW2(p->bString[max_len], 0, s[max_len]);
        }
        return (totlen);
}
 
/*------------------------------------------------------------------------*
 *      usb_check_request - prevent damaging USB requests
 *
 * Return values:
 * 0: Access allowed
 * Else: No access
 *------------------------------------------------------------------------*/
#if USB_HAVE_UGEN
int
usb_check_request(struct usb_device *udev, struct usb_device_request *req)
{
        struct usb_endpoint *ep;
        int error;
 
        /*
         * Avoid requests that would damage the bus integrity:
         */
        if (((req->bmRequestType == UT_WRITE_DEVICE) &&
            (req->bRequest == UR_SET_ADDRESS)) ||
            ((req->bmRequestType == UT_WRITE_DEVICE) &&
            (req->bRequest == UR_SET_CONFIG)) ||
            ((req->bmRequestType == UT_WRITE_INTERFACE) &&
            (req->bRequest == UR_SET_INTERFACE))) {
                /*
                 * These requests can be useful for testing USB drivers.
                 */
                error = priv_check(curthread, PRIV_DRIVER);
                if (error)
                        return (error);
        }
 
        /*
         * Special case - handle clearing of stall
         */
        if (req->bmRequestType == UT_WRITE_ENDPOINT) {
                ep = usbd_get_ep_by_addr(udev, req->wIndex[0]);
                if (ep == NULL)
                        return (EINVAL);
                if ((req->bRequest == UR_CLEAR_FEATURE) &&
                    (UGETW(req->wValue) == UF_ENDPOINT_HALT))
                        usbd_clear_data_toggle(udev, ep);
        }
 
        /* TODO: add more checks to verify the interface index */
 
        return (0);
}
#endif