rh.c

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/*
 * Wireless USB Host Controller
 * Root Hub operations
 *
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * We fake a root hub that has fake ports (as many as simultaneous
 * devices the Wireless USB Host Controller can deal with). For each
 * port we keep an state in @wusbhc->port[index] identical to the one
 * specified in the USB2.0[ch11] spec and some extra device
 * information that complements the one in 'struct usb_device' (as
 * this lacs a hcpriv pointer).
 *
 * Note this is common to WHCI and HWA host controllers.
 *
 * Through here we enable most of the state changes that the USB stack
 * will use to connect or disconnect devices. We need to do some
 * forced adaptation of Wireless USB device states vs. wired:
 *
 *        USB:                 WUSB:
 *
 * Port   Powered-off          port slot n/a
 *        Powered-on           port slot available
 *        Disconnected         port slot available
 *        Connected            port slot assigned device
 *                     device sent DN_Connect
 *                             device was authenticated
 *        Enabled              device is authenticated, transitioned
 *                             from unauth -> auth -> default address
 *                             -> enabled
 *        Reset                disconnect
 *        Disable              disconnect
 *
 * This maps the standard USB port states with the WUSB device states
 * so we can fake ports without having to modify the USB stack.
 *
 * FIXME: this process will change in the future
 *
 *
 * ENTRY POINTS
 *
 * Our entry points into here are, as in hcd.c, the USB stack root hub
 * ops defined in the usb_hcd struct:
 *
 * wusbhc_rh_status_data()  Provide hub and port status data bitmap
 *
 * wusbhc_rh_control()          Execution of all the major requests
 *                              you can do to a hub (Set|Clear
 *                              features, get descriptors, status, etc).
 *
 * wusbhc_rh_[suspend|resume]() That
 *
 * wusbhc_rh_start_port_reset() ??? unimplemented
 */
#include <linux/slab.h>
#include <linux/export.h>
#include "wusbhc.h"

/*
 * Reset a fake port
 *
 * Using a Reset Device IE is too heavyweight as it causes the device
 * to enter the UnConnected state and leave the cluster, this can mean
 * that when the device reconnects it is connected to a different fake
 * port.
 *
 * Instead, reset authenticated devices with a SetAddress(0), followed
 * by a SetAddresss(AuthAddr).
 *
 * For unauthenticated devices just pretend to reset but do nothing.
 * If the device initialization continues to fail it will eventually
 * time out after TrustTimeout and enter the UnConnected state.
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 *
 * Supposedly we are the only thread accesing @wusbhc->port; in any
 * case, maybe we should move the mutex locking from
 * wusbhc_devconnect_auth() to here.
 *
 * @port_idx refers to the wusbhc's port index, not the USB port number
 */
static int wusbhc_rh_port_reset(struct wusbhc *wusbhc, u8 port_idx)
{
    int result = 0;
    struct wusb_port *port = wusb_port_by_idx(wusbhc, port_idx);
    struct wusb_dev *wusb_dev = port->wusb_dev;

    if (wusb_dev == NULL)
        return -ENOTCONN;

    port->status |= USB_PORT_STAT_RESET;
    port->change |= USB_PORT_STAT_C_RESET;

    if (wusb_dev->addr & WUSB_DEV_ADDR_UNAUTH)
        result = 0;
    else
        result = wusb_dev_update_address(wusbhc, wusb_dev);

    port->status &= ~USB_PORT_STAT_RESET;
    port->status |= USB_PORT_STAT_ENABLE;
    port->change |= USB_PORT_STAT_C_RESET | USB_PORT_STAT_C_ENABLE; 

    return result;
}

/*
 * Return the hub change status bitmap
 *
 * The bits in the change status bitmap are cleared when a
 * ClearPortFeature request is issued (USB2.0[11.12.3,11.12.4].
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 *
 * WARNING!! This gets called from atomic context; we cannot get the
 *           mutex--the only race condition we can find is some bit
 *           changing just after we copy it, which shouldn't be too
 *           big of a problem [and we can't make it an spinlock
 *           because other parts need to take it and sleep] .
 *
 *           @usb_hcd is refcounted, so it won't disappear under us
 *           and before killing a host, the polling of the root hub
 *           would be stopped anyway.
 */
int wusbhc_rh_status_data(struct usb_hcd *usb_hcd, char *_buf)
{
    struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
    size_t cnt, size;
    unsigned long *buf = (unsigned long *) _buf;

    /* WE DON'T LOCK, see comment */
    size = wusbhc->ports_max + 1 /* hub bit */;
    size = (size + 8 - 1) / 8;  /* round to bytes */
    for (cnt = 0; cnt < wusbhc->ports_max; cnt++)
        if (wusb_port_by_idx(wusbhc, cnt)->change)
            set_bit(cnt + 1, buf);
        else
            clear_bit(cnt + 1, buf);
    return size;
}
EXPORT_SYMBOL_GPL(wusbhc_rh_status_data);

/*
 * Return the hub's descriptor
 *
 * NOTE: almost cut and paste from ehci-hub.c
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked
 */
static int wusbhc_rh_get_hub_descr(struct wusbhc *wusbhc, u16 wValue,
                   u16 wIndex,
                   struct usb_hub_descriptor *descr,
                   u16 wLength)
{
    u16 temp = 1 + (wusbhc->ports_max / 8);
    u8 length = 7 + 2 * temp;

    if (wLength < length)
        return -ENOSPC;
    descr->bDescLength = 7 + 2 * temp;
    descr->bDescriptorType = 0x29;  /* HUB type */
    descr->bNbrPorts = wusbhc->ports_max;
    descr->wHubCharacteristics = cpu_to_le16(
        0x00            /* All ports power at once */
        | 0x00          /* not part of compound device */
        | 0x10          /* No overcurrent protection */
        | 0x00          /* 8 FS think time FIXME ?? */
        | 0x00);        /* No port indicators */
    descr->bPwrOn2PwrGood = 0;
    descr->bHubContrCurrent = 0;
    /* two bitmaps:  ports removable, and usb 1.0 legacy PortPwrCtrlMask */
    memset(&descr->u.hs.DeviceRemovable[0], 0, temp);
    memset(&descr->u.hs.DeviceRemovable[temp], 0xff, temp);
    return 0;
}

/*
 * Clear a hub feature
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 *
 * Nothing to do, so no locking needed ;)
 */
static int wusbhc_rh_clear_hub_feat(struct wusbhc *wusbhc, u16 feature)
{
    int result;

    switch (feature) {
    case C_HUB_LOCAL_POWER:
        /* FIXME: maybe plug bit 0 to the power input status,
         * if any?
         * see wusbhc_rh_get_hub_status() */
    case C_HUB_OVER_CURRENT:
        result = 0;
        break;
    default:
        result = -EPIPE;
    }
    return result;
}

/*
 * Return hub status (it is always zero...)
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 *
 * Nothing to do, so no locking needed ;)
 */
static int wusbhc_rh_get_hub_status(struct wusbhc *wusbhc, u32 *buf,
                    u16 wLength)
{
    /* FIXME: maybe plug bit 0 to the power input status (if any)? */
    *buf = 0;
    return 0;
}

/*
 * Set a port feature
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 */
static int wusbhc_rh_set_port_feat(struct wusbhc *wusbhc, u16 feature,
                   u8 selector, u8 port_idx)
{
    struct device *dev = wusbhc->dev;

    if (port_idx > wusbhc->ports_max)
        return -EINVAL;

    switch (feature) {
        /* According to USB2.0[11.24.2.13]p2, these features
         * are not required to be implemented. */
    case USB_PORT_FEAT_C_OVER_CURRENT:
    case USB_PORT_FEAT_C_ENABLE:
    case USB_PORT_FEAT_C_SUSPEND:
    case USB_PORT_FEAT_C_CONNECTION:
    case USB_PORT_FEAT_C_RESET:
        return 0;
    case USB_PORT_FEAT_POWER:
        /* No such thing, but we fake it works */
        mutex_lock(&wusbhc->mutex);
        wusb_port_by_idx(wusbhc, port_idx)->status |= USB_PORT_STAT_POWER;
        mutex_unlock(&wusbhc->mutex);
        return 0;
    case USB_PORT_FEAT_RESET:
        return wusbhc_rh_port_reset(wusbhc, port_idx);
    case USB_PORT_FEAT_ENABLE:
    case USB_PORT_FEAT_SUSPEND:
        dev_err(dev, "(port_idx %d) set feat %d/%d UNIMPLEMENTED\n",
            port_idx, feature, selector);
        return -ENOSYS;
    default:
        dev_err(dev, "(port_idx %d) set feat %d/%d UNKNOWN\n",
            port_idx, feature, selector);
        return -EPIPE;
    }

    return 0;
}

/*
 * Clear a port feature...
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 */
static int wusbhc_rh_clear_port_feat(struct wusbhc *wusbhc, u16 feature,
                     u8 selector, u8 port_idx)
{
    int result = 0;
    struct device *dev = wusbhc->dev;

    if (port_idx > wusbhc->ports_max)
        return -EINVAL;

    mutex_lock(&wusbhc->mutex);
    switch (feature) {
    case USB_PORT_FEAT_POWER:   /* fake port always on */
        /* According to USB2.0[11.24.2.7.1.4], no need to implement? */
    case USB_PORT_FEAT_C_OVER_CURRENT:
        break;
    case USB_PORT_FEAT_C_RESET:
        wusb_port_by_idx(wusbhc, port_idx)->change &= ~USB_PORT_STAT_C_RESET;
        break;
    case USB_PORT_FEAT_C_CONNECTION:
        wusb_port_by_idx(wusbhc, port_idx)->change &= ~USB_PORT_STAT_C_CONNECTION;
        break;
    case USB_PORT_FEAT_ENABLE:
        __wusbhc_dev_disable(wusbhc, port_idx);
        break;
    case USB_PORT_FEAT_C_ENABLE:
        wusb_port_by_idx(wusbhc, port_idx)->change &= ~USB_PORT_STAT_C_ENABLE;
        break;
    case USB_PORT_FEAT_SUSPEND:
    case USB_PORT_FEAT_C_SUSPEND:
        dev_err(dev, "(port_idx %d) Clear feat %d/%d UNIMPLEMENTED\n",
            port_idx, feature, selector);
        result = -ENOSYS;
        break;
    default:
        dev_err(dev, "(port_idx %d) Clear feat %d/%d UNKNOWN\n",
            port_idx, feature, selector);
        result = -EPIPE;
        break;
    }
    mutex_unlock(&wusbhc->mutex);

    return result;
}

/*
 * Return the port's status
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 */
static int wusbhc_rh_get_port_status(struct wusbhc *wusbhc, u16 port_idx,
                     u32 *_buf, u16 wLength)
{
    __le16 *buf = (__le16 *)_buf;

    if (port_idx > wusbhc->ports_max)
        return -EINVAL;

    mutex_lock(&wusbhc->mutex);
    buf[0] = cpu_to_le16(wusb_port_by_idx(wusbhc, port_idx)->status);
    buf[1] = cpu_to_le16(wusb_port_by_idx(wusbhc, port_idx)->change);
    mutex_unlock(&wusbhc->mutex);

    return 0;
}

/*
 * Entry point for Root Hub operations
 *
 * @wusbhc is assumed referenced and @wusbhc->mutex unlocked.
 */
int wusbhc_rh_control(struct usb_hcd *usb_hcd, u16 reqntype, u16 wValue,
              u16 wIndex, char *buf, u16 wLength)
{
    int result = -ENOSYS;
    struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);

    switch (reqntype) {
    case GetHubDescriptor:
        result = wusbhc_rh_get_hub_descr(
            wusbhc, wValue, wIndex,
            (struct usb_hub_descriptor *) buf, wLength);
        break;
    case ClearHubFeature:
        result = wusbhc_rh_clear_hub_feat(wusbhc, wValue);
        break;
    case GetHubStatus:
        result = wusbhc_rh_get_hub_status(wusbhc, (u32 *)buf, wLength);
        break;

    case SetPortFeature:
        result = wusbhc_rh_set_port_feat(wusbhc, wValue, wIndex >> 8,
                         (wIndex & 0xff) - 1);
        break;
    case ClearPortFeature:
        result = wusbhc_rh_clear_port_feat(wusbhc, wValue, wIndex >> 8,
                           (wIndex & 0xff) - 1);
        break;
    case GetPortStatus:
        result = wusbhc_rh_get_port_status(wusbhc, wIndex - 1,
                           (u32 *)buf, wLength);
        break;

    case SetHubFeature:
    default:
        dev_err(wusbhc->dev, "%s (%p [%p], %x, %x, %x, %p, %x) "
            "UNIMPLEMENTED\n", __func__, usb_hcd, wusbhc, reqntype,
            wValue, wIndex, buf, wLength);
        /* dump_stack(); */
        result = -ENOSYS;
    }
    return result;
}
EXPORT_SYMBOL_GPL(wusbhc_rh_control);

int wusbhc_rh_suspend(struct usb_hcd *usb_hcd)
{
    struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
    dev_err(wusbhc->dev, "%s (%p [%p]) UNIMPLEMENTED\n", __func__,
        usb_hcd, wusbhc);
    /* dump_stack(); */
    return -ENOSYS;
}
EXPORT_SYMBOL_GPL(wusbhc_rh_suspend);

int wusbhc_rh_resume(struct usb_hcd *usb_hcd)
{
    struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
    dev_err(wusbhc->dev, "%s (%p [%p]) UNIMPLEMENTED\n", __func__,
        usb_hcd, wusbhc);
    /* dump_stack(); */
    return -ENOSYS;
}
EXPORT_SYMBOL_GPL(wusbhc_rh_resume);

int wusbhc_rh_start_port_reset(struct usb_hcd *usb_hcd, unsigned port_idx)
{
    struct wusbhc *wusbhc = usb_hcd_to_wusbhc(usb_hcd);
    dev_err(wusbhc->dev, "%s (%p [%p], port_idx %u) UNIMPLEMENTED\n",
        __func__, usb_hcd, wusbhc, port_idx);
    WARN_ON(1);
    return -ENOSYS;
}
EXPORT_SYMBOL_GPL(wusbhc_rh_start_port_reset);

static void wusb_port_init(struct wusb_port *port)
{
    port->status |= USB_PORT_STAT_HIGH_SPEED;
}

/*
 * Alloc fake port specific fields and status.
 */
int wusbhc_rh_create(struct wusbhc *wusbhc)
{
    int result = -ENOMEM;
    size_t port_size, itr;
    port_size = wusbhc->ports_max * sizeof(wusbhc->port[0]);
    wusbhc->port = kzalloc(port_size, GFP_KERNEL);
    if (wusbhc->port == NULL)
        goto error_port_alloc;
    for (itr = 0; itr < wusbhc->ports_max; itr++)
        wusb_port_init(&wusbhc->port[itr]);
    result = 0;
error_port_alloc:
    return result;
}

void wusbhc_rh_destroy(struct wusbhc *wusbhc)
{
    kfree(wusbhc->port);
}