devices.c

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/*
 * devices.c
 * (C) Copyright 1999 Randy Dunlap.
 * (C) Copyright 1999,2000 Thomas Sailer <[email protected]>.
 *     (proc file per device)
 * (C) Copyright 1999 Deti Fliegl (new USB architecture)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 *************************************************************
 *
 * <mountpoint>/devices contains USB topology, device, config, class,
 * interface, & endpoint data.
 *
 * I considered using /proc/bus/usb/devices/device# for each device
 * as it is attached or detached, but I didn't like this for some
 * reason -- maybe it's just too deep of a directory structure.
 * I also don't like looking in multiple places to gather and view
 * the data.  Having only one file for ./devices also prevents race
 * conditions that could arise if a program was reading device info
 * for devices that are being removed (unplugged).  (That is, the
 * program may find a directory for devnum_12 then try to open it,
 * but it was just unplugged, so the directory is now deleted.
 * But programs would just have to be prepared for situations like
 * this in any plug-and-play environment.)
 *
 * 1999-12-16: Thomas Sailer <[email protected]>
 *   Converted the whole proc stuff to real
 *   read methods. Now not the whole device list needs to fit
 *   into one page, only the device list for one bus.
 *   Added a poll method to /proc/bus/usb/devices, to wake
 *   up an eventual usbd
 * 2000-01-04: Thomas Sailer <[email protected]>
 *   Turned into its own filesystem
 * 2000-07-05: Ashley Montanaro <[email protected]>
 *   Converted file reading routine to dump to buffer once
 *   per device, not per bus
 */

#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/gfp.h>
#include <linux/poll.h>
#include <linux/usb.h>
#include <linux/usbdevice_fs.h>
#include <linux/usb/hcd.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>

#include "usb.h"

/* Define ALLOW_SERIAL_NUMBER if you want to see the serial number of devices */
#define ALLOW_SERIAL_NUMBER

static const char format_topo[] =
/* T:  Bus=dd Lev=dd Prnt=dd Port=dd Cnt=dd Dev#=ddd Spd=dddd MxCh=dd */
"\nT:  Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%-4s MxCh=%2d\n";

static const char format_string_manufacturer[] =
/* S:  Manufacturer=xxxx */
  "S:  Manufacturer=%.100s\n";

static const char format_string_product[] =
/* S:  Product=xxxx */
  "S:  Product=%.100s\n";

#ifdef ALLOW_SERIAL_NUMBER
static const char format_string_serialnumber[] =
/* S:  SerialNumber=xxxx */
  "S:  SerialNumber=%.100s\n";
#endif

static const char format_bandwidth[] =
/* B:  Alloc=ddd/ddd us (xx%), #Int=ddd, #Iso=ddd */
  "B:  Alloc=%3d/%3d us (%2d%%), #Int=%3d, #Iso=%3d\n";

static const char format_device1[] =
/* D:  Ver=xx.xx Cls=xx(sssss) Sub=xx Prot=xx MxPS=dd #Cfgs=dd */
  "D:  Ver=%2x.%02x Cls=%02x(%-5s) Sub=%02x Prot=%02x MxPS=%2d #Cfgs=%3d\n";

static const char format_device2[] =
/* P:  Vendor=xxxx ProdID=xxxx Rev=xx.xx */
  "P:  Vendor=%04x ProdID=%04x Rev=%2x.%02x\n";

static const char format_config[] =
/* C:  #Ifs=dd Cfg#=dd Atr=xx MPwr=dddmA */
  "C:%c #Ifs=%2d Cfg#=%2d Atr=%02x MxPwr=%3dmA\n";

static const char format_iad[] =
/* A:  FirstIf#=dd IfCount=dd Cls=xx(sssss) Sub=xx Prot=xx */
  "A:  FirstIf#=%2d IfCount=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x\n";

static const char format_iface[] =
/* I:  If#=dd Alt=dd #EPs=dd Cls=xx(sssss) Sub=xx Prot=xx Driver=xxxx*/
  "I:%c If#=%2d Alt=%2d #EPs=%2d Cls=%02x(%-5s) Sub=%02x Prot=%02x Driver=%s\n";

static const char format_endpt[] =
/* E:  Ad=xx(s) Atr=xx(ssss) MxPS=dddd Ivl=D?s */
  "E:  Ad=%02x(%c) Atr=%02x(%-4s) MxPS=%4d Ivl=%d%cs\n";


/*
 * Need access to the driver and USB bus lists.
 * extern struct list_head usb_bus_list;
 * However, these will come from functions that return ptrs to each of them.
 */

/*
 * Wait for an connect/disconnect event to happen. We initialize
 * the event counter with an odd number, and each event will increment
 * the event counter by two, so it will always _stay_ odd. That means
 * that it will never be zero, so "event 0" will never match a current
 * event, and thus 'poll' will always trigger as readable for the first
 * time it gets called.
 */
static struct device_connect_event {
    atomic_t count;
    wait_queue_head_t wait;
} device_event = {
    .count = ATOMIC_INIT(1),
    .wait = __WAIT_QUEUE_HEAD_INITIALIZER(device_event.wait)
};

struct class_info {
    int class;
    char *class_name;
};

static const struct class_info clas_info[] = {
    /* max. 5 chars. per name string */
    {USB_CLASS_PER_INTERFACE,   ">ifc"},
    {USB_CLASS_AUDIO,       "audio"},
    {USB_CLASS_COMM,        "comm."},
    {USB_CLASS_HID,         "HID"},
    {USB_CLASS_PHYSICAL,        "PID"},
    {USB_CLASS_STILL_IMAGE,     "still"},
    {USB_CLASS_PRINTER,     "print"},
    {USB_CLASS_MASS_STORAGE,    "stor."},
    {USB_CLASS_HUB,         "hub"},
    {USB_CLASS_CDC_DATA,        "data"},
    {USB_CLASS_CSCID,       "scard"},
    {USB_CLASS_CONTENT_SEC,     "c-sec"},
    {USB_CLASS_VIDEO,       "video"},
    {USB_CLASS_WIRELESS_CONTROLLER, "wlcon"},
    {USB_CLASS_MISC,        "misc"},
    {USB_CLASS_APP_SPEC,        "app."},
    {USB_CLASS_VENDOR_SPEC,     "vend."},
    {-1,                "unk."}     /* leave as last */
};

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

void usbfs_conn_disc_event(void)
{
    atomic_add(2, &device_event.count);
    wake_up(&device_event.wait);
}

static const char *class_decode(const int class)
{
    int ix;

    for (ix = 0; clas_info[ix].class != -1; ix++)
        if (clas_info[ix].class == class)
            break;
    return clas_info[ix].class_name;
}

static char *usb_dump_endpoint_descriptor(int speed, char *start, char *end,
                const struct usb_endpoint_descriptor *desc)
{
    char dir, unit, *type;
    unsigned interval, bandwidth = 1;

    if (start > end)
        return start;

    dir = usb_endpoint_dir_in(desc) ? 'I' : 'O';

    if (speed == USB_SPEED_HIGH) {
        switch (usb_endpoint_maxp(desc) & (0x03 << 11)) {
        case 1 << 11:
            bandwidth = 2; break;
        case 2 << 11:
            bandwidth = 3; break;
        }
    }

    /* this isn't checking for illegal values */
    switch (usb_endpoint_type(desc)) {
    case USB_ENDPOINT_XFER_CONTROL:
        type = "Ctrl";
        if (speed == USB_SPEED_HIGH)    /* uframes per NAK */
            interval = desc->bInterval;
        else
            interval = 0;
        dir = 'B';          /* ctrl is bidirectional */
        break;
    case USB_ENDPOINT_XFER_ISOC:
        type = "Isoc";
        interval = 1 << (desc->bInterval - 1);
        break;
    case USB_ENDPOINT_XFER_BULK:
        type = "Bulk";
        if (speed == USB_SPEED_HIGH && dir == 'O') /* uframes per NAK */
            interval = desc->bInterval;
        else
            interval = 0;
        break;
    case USB_ENDPOINT_XFER_INT:
        type = "Int.";
        if (speed == USB_SPEED_HIGH || speed == USB_SPEED_SUPER)
            interval = 1 << (desc->bInterval - 1);
        else
            interval = desc->bInterval;
        break;
    default:    /* "can't happen" */
        return start;
    }
    interval *= (speed == USB_SPEED_HIGH ||
             speed == USB_SPEED_SUPER) ? 125 : 1000;
    if (interval % 1000)
        unit = 'u';
    else {
        unit = 'm';
        interval /= 1000;
    }

    start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
             desc->bmAttributes, type,
             (usb_endpoint_maxp(desc) & 0x07ff) *
             bandwidth,
             interval, unit);
    return start;
}

static char *usb_dump_interface_descriptor(char *start, char *end,
                    const struct usb_interface_cache *intfc,
                    const struct usb_interface *iface,
                    int setno)
{
    const struct usb_interface_descriptor *desc;
    const char *driver_name = "";
    int active = 0;

    if (start > end)
        return start;
    desc = &intfc->altsetting[setno].desc;
    if (iface) {
        driver_name = (iface->dev.driver
                ? iface->dev.driver->name
                : "(none)");
        active = (desc == &iface->cur_altsetting->desc);
    }
    start += sprintf(start, format_iface,
             active ? '*' : ' ',    /* mark active altsetting */
             desc->bInterfaceNumber,
             desc->bAlternateSetting,
             desc->bNumEndpoints,
             desc->bInterfaceClass,
             class_decode(desc->bInterfaceClass),
             desc->bInterfaceSubClass,
             desc->bInterfaceProtocol,
             driver_name);
    return start;
}

static char *usb_dump_interface(int speed, char *start, char *end,
                const struct usb_interface_cache *intfc,
                const struct usb_interface *iface, int setno)
{
    const struct usb_host_interface *desc = &intfc->altsetting[setno];
    int i;

    start = usb_dump_interface_descriptor(start, end, intfc, iface, setno);
    for (i = 0; i < desc->desc.bNumEndpoints; i++) {
        if (start > end)
            return start;
        start = usb_dump_endpoint_descriptor(speed,
                start, end, &desc->endpoint[i].desc);
    }
    return start;
}

static char *usb_dump_iad_descriptor(char *start, char *end,
            const struct usb_interface_assoc_descriptor *iad)
{
    if (start > end)
        return start;
    start += sprintf(start, format_iad,
             iad->bFirstInterface,
             iad->bInterfaceCount,
             iad->bFunctionClass,
             class_decode(iad->bFunctionClass),
             iad->bFunctionSubClass,
             iad->bFunctionProtocol);
    return start;
}

/* TBD:
 * 0. TBDs
 * 1. marking active interface altsettings (code lists all, but should mark
 *    which ones are active, if any)
 */
static char *usb_dump_config_descriptor(char *start, char *end,
                const struct usb_config_descriptor *desc,
                int active)
{
    if (start > end)
        return start;
    start += sprintf(start, format_config,
             /* mark active/actual/current cfg. */
             active ? '*' : ' ',
             desc->bNumInterfaces,
             desc->bConfigurationValue,
             desc->bmAttributes,
             desc->bMaxPower * 2);
    return start;
}

static char *usb_dump_config(int speed, char *start, char *end,
                 const struct usb_host_config *config, int active)
{
    int i, j;
    struct usb_interface_cache *intfc;
    struct usb_interface *interface;

    if (start > end)
        return start;
    if (!config)
        /* getting these some in 2.3.7; none in 2.3.6 */
        return start + sprintf(start, "(null Cfg. desc.)\n");
    start = usb_dump_config_descriptor(start, end, &config->desc, active);
    for (i = 0; i < USB_MAXIADS; i++) {
        if (config->intf_assoc[i] == NULL)
            break;
        start = usb_dump_iad_descriptor(start, end,
                    config->intf_assoc[i]);
    }
    for (i = 0; i < config->desc.bNumInterfaces; i++) {
        intfc = config->intf_cache[i];
        interface = config->interface[i];
        for (j = 0; j < intfc->num_altsetting; j++) {
            if (start > end)
                return start;
            start = usb_dump_interface(speed,
                start, end, intfc, interface, j);
        }
    }
    return start;
}

/*
 * Dump the different USB descriptors.
 */
static char *usb_dump_device_descriptor(char *start, char *end,
                const struct usb_device_descriptor *desc)
{
    u16 bcdUSB = le16_to_cpu(desc->bcdUSB);
    u16 bcdDevice = le16_to_cpu(desc->bcdDevice);

    if (start > end)
        return start;
    start += sprintf(start, format_device1,
              bcdUSB >> 8, bcdUSB & 0xff,
              desc->bDeviceClass,
              class_decode(desc->bDeviceClass),
              desc->bDeviceSubClass,
              desc->bDeviceProtocol,
              desc->bMaxPacketSize0,
              desc->bNumConfigurations);
    if (start > end)
        return start;
    start += sprintf(start, format_device2,
             le16_to_cpu(desc->idVendor),
             le16_to_cpu(desc->idProduct),
             bcdDevice >> 8, bcdDevice & 0xff);
    return start;
}

/*
 * Dump the different strings that this device holds.
 */
static char *usb_dump_device_strings(char *start, char *end,
                     struct usb_device *dev)
{
    if (start > end)
        return start;
    if (dev->manufacturer)
        start += sprintf(start, format_string_manufacturer,
                 dev->manufacturer);
    if (start > end)
        goto out;
    if (dev->product)
        start += sprintf(start, format_string_product, dev->product);
    if (start > end)
        goto out;
#ifdef ALLOW_SERIAL_NUMBER
    if (dev->serial)
        start += sprintf(start, format_string_serialnumber,
                 dev->serial);
#endif
 out:
    return start;
}

static char *usb_dump_desc(char *start, char *end, struct usb_device *dev)
{
    int i;

    if (start > end)
        return start;

    start = usb_dump_device_descriptor(start, end, &dev->descriptor);

    if (start > end)
        return start;

    start = usb_dump_device_strings(start, end, dev);

    for (i = 0; i < dev->descriptor.bNumConfigurations; i++) {
        if (start > end)
            return start;
        start = usb_dump_config(dev->speed,
                start, end, dev->config + i,
                /* active ? */
                (dev->config + i) == dev->actconfig);
    }
    return start;
}


#ifdef PROC_EXTRA /* TBD: may want to add this code later */

static char *usb_dump_hub_descriptor(char *start, char *end,
                     const struct usb_hub_descriptor *desc)
{
    int leng = USB_DT_HUB_NONVAR_SIZE;
    unsigned char *ptr = (unsigned char *)desc;

    if (start > end)
        return start;
    start += sprintf(start, "Interface:");
    while (leng && start <= end) {
        start += sprintf(start, " %02x", *ptr);
        ptr++; leng--;
    }
    *start++ = '\n';
    return start;
}

static char *usb_dump_string(char *start, char *end,
                 const struct usb_device *dev, char *id, int index)
{
    if (start > end)
        return start;
    start += sprintf(start, "Interface:");
    if (index <= dev->maxstring && dev->stringindex &&
        dev->stringindex[index])
        start += sprintf(start, "%s: %.100s ", id,
                 dev->stringindex[index]);
    return start;
}

#endif /* PROC_EXTRA */

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

/* This is a recursive function. Parameters:
 * buffer - the user-space buffer to write data into
 * nbytes - the maximum number of bytes to write
 * skip_bytes - the number of bytes to skip before writing anything
 * file_offset - the offset into the devices file on completion
 * The caller must own the device lock.
 */
static ssize_t usb_device_dump(char __user **buffer, size_t *nbytes,
                   loff_t *skip_bytes, loff_t *file_offset,
                   struct usb_device *usbdev, struct usb_bus *bus,
                   int level, int index, int count)
{
    int chix;
    int ret, cnt = 0;
    int parent_devnum = 0;
    char *pages_start, *data_end, *speed;
    unsigned int length;
    ssize_t total_written = 0;
    struct usb_device *childdev = NULL;

    /* don't bother with anything else if we're not writing any data */
    if (*nbytes <= 0)
        return 0;

    if (level > MAX_TOPO_LEVEL)
        return 0;
    /* allocate 2^1 pages = 8K (on i386);
     * should be more than enough for one device */
    pages_start = (char *)__get_free_pages(GFP_NOIO, 1);
    if (!pages_start)
        return -ENOMEM;

    if (usbdev->parent && usbdev->parent->devnum != -1)
        parent_devnum = usbdev->parent->devnum;
    /*
     * So the root hub's parent is 0 and any device that is
     * plugged into the root hub has a parent of 0.
     */
    switch (usbdev->speed) {
    case USB_SPEED_LOW:
        speed = "1.5"; break;
    case USB_SPEED_UNKNOWN:     /* usb 1.1 root hub code */
    case USB_SPEED_FULL:
        speed = "12"; break;
    case USB_SPEED_WIRELESS:    /* Wireless has no real fixed speed */
    case USB_SPEED_HIGH:
        speed = "480"; break;
    case USB_SPEED_SUPER:
        speed = "5000"; break;
    default:
        speed = "??";
    }
    data_end = pages_start + sprintf(pages_start, format_topo,
            bus->busnum, level, parent_devnum,
            index, count, usbdev->devnum,
            speed, usbdev->maxchild);
    /*
     * level = topology-tier level;
     * parent_devnum = parent device number;
     * index = parent's connector number;
     * count = device count at this level
     */
    /* If this is the root hub, display the bandwidth information */
    if (level == 0) {
        int max;

        /* super/high speed reserves 80%, full/low reserves 90% */
        if (usbdev->speed == USB_SPEED_HIGH ||
            usbdev->speed == USB_SPEED_SUPER)
            max = 800;
        else
            max = FRAME_TIME_MAX_USECS_ALLOC;

        /* report "average" periodic allocation over a microsecond.
         * the schedules are actually bursty, HCDs need to deal with
         * that and just compute/report this average.
         */
        data_end += sprintf(data_end, format_bandwidth,
                bus->bandwidth_allocated, max,
                (100 * bus->bandwidth_allocated + max / 2)
                    / max,
                bus->bandwidth_int_reqs,
                bus->bandwidth_isoc_reqs);

    }
    data_end = usb_dump_desc(data_end, pages_start + (2 * PAGE_SIZE) - 256,
                 usbdev);

    if (data_end > (pages_start + (2 * PAGE_SIZE) - 256))
        data_end += sprintf(data_end, "(truncated)\n");

    length = data_end - pages_start;
    /* if we can start copying some data to the user */
    if (length > *skip_bytes) {
        length -= *skip_bytes;
        if (length > *nbytes)
            length = *nbytes;
        if (copy_to_user(*buffer, pages_start + *skip_bytes, length)) {
            free_pages((unsigned long)pages_start, 1);
            return -EFAULT;
        }
        *nbytes -= length;
        *file_offset += length;
        total_written += length;
        *buffer += length;
        *skip_bytes = 0;
    } else
        *skip_bytes -= length;

    free_pages((unsigned long)pages_start, 1);

    /* Now look at all of this device's children. */
    usb_hub_for_each_child(usbdev, chix, childdev) {
        if (childdev) {
            usb_lock_device(childdev);
            ret = usb_device_dump(buffer, nbytes, skip_bytes,
                          file_offset, childdev, bus,
                          level + 1, chix - 1, ++cnt);
            usb_unlock_device(childdev);
            if (ret == -EFAULT)
                return total_written;
            total_written += ret;
        }
    }
    return total_written;
}

static ssize_t usb_device_read(struct file *file, char __user *buf,
                   size_t nbytes, loff_t *ppos)
{
    struct usb_bus *bus;
    ssize_t ret, total_written = 0;
    loff_t skip_bytes = *ppos;

    if (*ppos < 0)
        return -EINVAL;
    if (nbytes <= 0)
        return 0;
    if (!access_ok(VERIFY_WRITE, buf, nbytes))
        return -EFAULT;

    mutex_lock(&usb_bus_list_lock);
    /* print devices for all busses */
    list_for_each_entry(bus, &usb_bus_list, bus_list) {
        /* recurse through all children of the root hub */
        if (!bus_to_hcd(bus)->rh_registered)
            continue;
        usb_lock_device(bus->root_hub);
        ret = usb_device_dump(&buf, &nbytes, &skip_bytes, ppos,
                      bus->root_hub, bus, 0, 0, 0);
        usb_unlock_device(bus->root_hub);
        if (ret < 0) {
            mutex_unlock(&usb_bus_list_lock);
            return ret;
        }
        total_written += ret;
    }
    mutex_unlock(&usb_bus_list_lock);
    return total_written;
}

/* Kernel lock for "lastev" protection */
static unsigned int usb_device_poll(struct file *file,
                    struct poll_table_struct *wait)
{
    unsigned int event_count;

    poll_wait(file, &device_event.wait, wait);

    event_count = atomic_read(&device_event.count);
    if (file->f_version != event_count) {
        file->f_version = event_count;
        return POLLIN | POLLRDNORM;
    }

    return 0;
}

static loff_t usb_device_lseek(struct file *file, loff_t offset, int orig)
{
    loff_t ret;

    mutex_lock(&file->f_dentry->d_inode->i_mutex);

    switch (orig) {
    case 0:
        file->f_pos = offset;
        ret = file->f_pos;
        break;
    case 1:
        file->f_pos += offset;
        ret = file->f_pos;
        break;
    case 2:
    default:
        ret = -EINVAL;
    }

    mutex_unlock(&file->f_dentry->d_inode->i_mutex);
    return ret;
}

const struct file_operations usbfs_devices_fops = {
    .llseek =   usb_device_lseek,
    .read =     usb_device_read,
    .poll =     usb_device_poll,
};