Archipelago » qemu

/*

 * QEMU USB emulation

 *

 * Copyright (c) 2005 Fabrice Bellard

 *

 * 2008 Generic packet handler rewrite by Max Krasnyansky

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "qemu-common.h"

#include "usb.h"

void usb_attach(USBPort *port, USBDevice *dev)

{

    if (dev != NULL) {

        /* attach */

        if (port->dev) {

            usb_attach(port, NULL);

        }

        dev->port = port;

        port->dev = dev;

        port->ops->attach(port);

        usb_send_msg(dev, USB_MSG_ATTACH);

    } else {

        /* detach */

        dev = port->dev;

        assert(dev);

        port->ops->detach(port);

        usb_send_msg(dev, USB_MSG_DETACH);

        dev->port = NULL;

        port->dev = NULL;

    }

}

void usb_wakeup(USBDevice *dev)

{

    if (dev->remote_wakeup && dev->port && dev->port->ops->wakeup) {

        dev->port->ops->wakeup(dev->port);

    }

}

/**********************/

/* generic USB device helpers (you are not forced to use them when

   writing your USB device driver, but they help handling the

   protocol)

*/

#define SETUP_STATE_IDLE  0

#define SETUP_STATE_SETUP 1

#define SETUP_STATE_DATA  2

#define SETUP_STATE_ACK   3

static int do_token_setup(USBDevice *s, USBPacket *p)

{

    int request, value, index;

    int ret = 0;

    if (p->len != 8)

        return USB_RET_STALL;

    memcpy(s->setup_buf, p->data, 8);

    s->setup_len   = (s->setup_buf[7] << 8) | s->setup_buf[6];

    s->setup_index = 0;

    request = (s->setup_buf[0] << 8) | s->setup_buf[1];

    value   = (s->setup_buf[3] << 8) | s->setup_buf[2];

    index   = (s->setup_buf[5] << 8) | s->setup_buf[4];

    if (s->setup_buf[0] & USB_DIR_IN) {

        ret = s->info->handle_control(s, p, request, value, index,

                                      s->setup_len, s->data_buf);

        if (ret == USB_RET_ASYNC) {

             s->setup_state = SETUP_STATE_SETUP;

             return USB_RET_ASYNC;

        }

        if (ret < 0)

            return ret;

        if (ret < s->setup_len)

            s->setup_len = ret;

        s->setup_state = SETUP_STATE_DATA;

    } else {

        if (s->setup_len > sizeof(s->data_buf)) {

            fprintf(stderr,

                "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n",

                s->setup_len, sizeof(s->data_buf));

            return USB_RET_STALL;

        }

        if (s->setup_len == 0)

            s->setup_state = SETUP_STATE_ACK;

        else

            s->setup_state = SETUP_STATE_DATA;

    }

    return ret;

}

static int do_token_in(USBDevice *s, USBPacket *p)

{

    int request, value, index;

    int ret = 0;

    if (p->devep != 0)

        return s->info->handle_data(s, p);

    request = (s->setup_buf[0] << 8) | s->setup_buf[1];

    value   = (s->setup_buf[3] << 8) | s->setup_buf[2];

    index   = (s->setup_buf[5] << 8) | s->setup_buf[4];

    switch(s->setup_state) {

    case SETUP_STATE_ACK:

        if (!(s->setup_buf[0] & USB_DIR_IN)) {

            ret = s->info->handle_control(s, p, request, value, index,

                                          s->setup_len, s->data_buf);

            if (ret == USB_RET_ASYNC) {

                return USB_RET_ASYNC;

            }

            s->setup_state = SETUP_STATE_IDLE;

            if (ret > 0)

                return 0;

            return ret;

        }

        /* return 0 byte */

        return 0;

    case SETUP_STATE_DATA:

        if (s->setup_buf[0] & USB_DIR_IN) {

            int len = s->setup_len - s->setup_index;

            if (len > p->len)

                len = p->len;

            memcpy(p->data, s->data_buf + s->setup_index, len);

            s->setup_index += len;

            if (s->setup_index >= s->setup_len)

                s->setup_state = SETUP_STATE_ACK;

            return len;

        }

        s->setup_state = SETUP_STATE_IDLE;

        return USB_RET_STALL;

    default:

        return USB_RET_STALL;

    }

}

static int do_token_out(USBDevice *s, USBPacket *p)

{

    if (p->devep != 0)

        return s->info->handle_data(s, p);

    switch(s->setup_state) {

    case SETUP_STATE_ACK:

        if (s->setup_buf[0] & USB_DIR_IN) {

            s->setup_state = SETUP_STATE_IDLE;

            /* transfer OK */

        } else {

            /* ignore additional output */

        }

        return 0;

    case SETUP_STATE_DATA:

        if (!(s->setup_buf[0] & USB_DIR_IN)) {

            int len = s->setup_len - s->setup_index;

            if (len > p->len)

                len = p->len;

            memcpy(s->data_buf + s->setup_index, p->data, len);

            s->setup_index += len;

            if (s->setup_index >= s->setup_len)

                s->setup_state = SETUP_STATE_ACK;

            return len;

        }

        s->setup_state = SETUP_STATE_IDLE;

        return USB_RET_STALL;

    default:

        return USB_RET_STALL;

    }

}

/*

 * Generic packet handler.

 * Called by the HC (host controller).

 *

 * Returns length of the transaction or one of the USB_RET_XXX codes.

 */

int usb_generic_handle_packet(USBDevice *s, USBPacket *p)

{

    switch(p->pid) {

    case USB_MSG_ATTACH:

        s->state = USB_STATE_ATTACHED;

        if (s->info->handle_attach) {

            s->info->handle_attach(s);

        }

        return 0;

    case USB_MSG_DETACH:

        s->state = USB_STATE_NOTATTACHED;

        return 0;

    case USB_MSG_RESET:

        s->remote_wakeup = 0;

        s->addr = 0;

        s->state = USB_STATE_DEFAULT;

        if (s->info->handle_reset) {

            s->info->handle_reset(s);

        }

        return 0;

    }

    /* Rest of the PIDs must match our address */

    if (s->state < USB_STATE_DEFAULT || p->devaddr != s->addr)

        return USB_RET_NODEV;

    switch (p->pid) {

    case USB_TOKEN_SETUP:

        return do_token_setup(s, p);

    case USB_TOKEN_IN:

        return do_token_in(s, p);

    case USB_TOKEN_OUT:

        return do_token_out(s, p);

    default:

        return USB_RET_STALL;

    }

}

/* ctrl complete function for devices which use usb_generic_handle_packet and

   may return USB_RET_ASYNC from their handle_control callback. Device code

   which does this *must* call this function instead of the normal

   usb_packet_complete to complete their async control packets. */

void usb_generic_async_ctrl_complete(USBDevice *s, USBPacket *p)

{

    if (p->len < 0) {

        s->setup_state = SETUP_STATE_IDLE;

    }

    switch (s->setup_state) {

    case SETUP_STATE_SETUP:

        if (p->len < s->setup_len) {

            s->setup_len = p->len;

        }

        s->setup_state = SETUP_STATE_DATA;

        p->len = 8;

        break;

    case SETUP_STATE_ACK:

        s->setup_state = SETUP_STATE_IDLE;

        p->len = 0;

        break;

    default:

        break;

    }

    usb_packet_complete(s, p);

}

/* XXX: fix overflow */

int set_usb_string(uint8_t *buf, const char *str)

{

    int len, i;

    uint8_t *q;

    q = buf;

    len = strlen(str);

    *q++ = 2 * len + 2;

    *q++ = 3;

    for(i = 0; i < len; i++) {

        *q++ = str[i];

        *q++ = 0;

    }

    return q - buf;

}

/* Send an internal message to a USB device.  */

void usb_send_msg(USBDevice *dev, int msg)

{

    USBPacket p;

    int ret;

    memset(&p, 0, sizeof(p));

    p.pid = msg;

    ret = usb_handle_packet(dev, &p);

    /* This _must_ be synchronous */

    assert(ret != USB_RET_ASYNC);

}

/* Hand over a packet to a device for processing.  Return value

   USB_RET_ASYNC indicates the processing isn't finished yet, the

   driver will call usb_packet_complete() when done processing it. */

int usb_handle_packet(USBDevice *dev, USBPacket *p)

{

    int ret;

    assert(p->owner == NULL);

    ret = dev->info->handle_packet(dev, p);

    if (ret == USB_RET_ASYNC) {

        if (p->owner == NULL) {

            p->owner = dev;

        } else {

            /* We'll end up here when usb_handle_packet is called

             * recursively due to a hub being in the chain.  Nothing

             * to do.  Leave p->owner pointing to the device, not the

             * hub. */;

        }

    }

    return ret;

}

/* Notify the controller that an async packet is complete.  This should only

   be called for packets previously deferred by returning USB_RET_ASYNC from

   handle_packet. */

void usb_packet_complete(USBDevice *dev, USBPacket *p)

{

    /* Note: p->owner != dev is possible in case dev is a hub */

    assert(p->owner != NULL);

    dev->port->ops->complete(dev->port, p);

    p->owner = NULL;

}

/* Cancel an active packet.  The packed must have been deferred by

   returning USB_RET_ASYNC from handle_packet, and not yet

   completed.  */

void usb_cancel_packet(USBPacket * p)

{

    assert(p->owner != NULL);

    p->owner->info->cancel_packet(p->owner, p);

    p->owner = NULL;

}