text: /*
   * devices.c
   * (C) Copyright 1999 Randy Dunlap.
   * (C) Copyright 1999,2000 Thomas Sailer <sailer@ife.ee.ethz.ch>. (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 <sailer@ife.ee.ethz.ch>
   *   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 <sailer@ife.ee.ethz.ch>
   *   Turned into its own filesystem
   * 2000-07-05: Ashley Montanaro <ashley@compsoc.man.ac.uk>
   *   Converted file reading routine to dump to buffer once
   *   per device, not per bus
   */
  
  #include <linux/fs.h>
  #include <linux/mm.h>
  #include <linux/slab.h>
  #include <linux/poll.h>
  #include <linux/usb.h>
  #include <linux/smp_lock.h>
  #include <linux/usbdevice_fs.h>
  #include <linux/mutex.h>
  #include <asm/uaccess.h>
  
  #include "usb.h"
  #include "hcd.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=ddd MxCh=dd */
  "\nT:  Bus=%2.2d Lev=%2.2d Prnt=%2.2d Port=%2.2d Cnt=%2.2d Dev#=%3d Spd=%3s 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.
   */
  
  static DECLARE_WAIT_QUEUE_HEAD(deviceconndiscwq);
  static unsigned int conndiscevcnt;
  
  /* this struct stores the poll state for <mountpoint>/devices pollers */
  struct usb_device_status {
  	unsigned int lastev;
  };
  
  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)
  {
  	conndiscevcnt++;
  	wake_up(&deviceconndiscwq);
  }
  
  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 (le16_to_cpu(desc->wMaxPacketSize) & (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)
  			interval = 1 << (desc->bInterval - 1);
  		else
  			interval = desc->bInterval;
  		break;
  	default:	/* "can't happen" */
  		return start;
  	}
  	interval *= (speed == USB_SPEED_HIGH) ? 125 : 1000;
  	if (interval % 1000)
  		unit = 'u';
  	else {
  		unit = 'm';
  		interval /= 1000;
  	}
  
  	start += sprintf(start, format_endpt, desc->bEndpointAddress, dir,
  			 desc->bmAttributes, type,
  			 (le16_to_cpu(desc->wMaxPacketSize) & 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;
  
  	/* 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_HIGH:
  		speed = "480"; 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;
  
  		/* high speed reserves 80%, full/low reserves 90% */
  		if (usbdev->speed == USB_SPEED_HIGH)
  			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. */
  	for (chix = 0; chix < usbdev->maxchild; chix++) {
  		struct usb_device *childdev = usbdev->children[chix];
  
  		if (childdev) {
  			usb_lock_device(childdev);
  			ret = usb_device_dump(buffer, nbytes, skip_bytes,
  					      file_offset, childdev, bus,
  					      level + 1, chix, ++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->root_hub)
  			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)
  {
  	struct usb_device_status *st = file->private_data;
  	unsigned int mask = 0;
  
  	lock_kernel();
  	if (!st) {
  		st = kmalloc(sizeof(struct usb_device_status), GFP_KERNEL);
  
  		/* we may have dropped BKL -
  		 * need to check for having lost the race */
  		if (file->private_data) {
  			kfree(st);
  			st = file->private_data;
  			goto lost_race;
  		}
  		/* we haven't lost - check for allocation failure now */
  		if (!st) {
  			unlock_kernel();
  			return POLLIN;
  		}
  
  		/*
  		 * need to prevent the module from being unloaded, since
  		 * proc_unregister does not call the release method and
  		 * we would have a memory leak
  		 */
  		st->lastev = conndiscevcnt;
  		file->private_data = st;
  		mask = POLLIN;
  	}
  lost_race:
  	if (file->f_mode & FMODE_READ)
  		poll_wait(file, &deviceconndiscwq, wait);
  	if (st->lastev != conndiscevcnt)
  		mask |= POLLIN;
  	st->lastev = conndiscevcnt;
  	unlock_kernel();
  	return mask;
  }
  
  static int usb_device_open(struct inode *inode, struct file *file)
  {
  	file->private_data = NULL;
  	return 0;
  }
  
  static int usb_device_release(struct inode *inode, struct file *file)
  {
  	kfree(file->private_data);
  	file->private_data = NULL;
  	return 0;
  }
  
  static loff_t usb_device_lseek(struct file *file, loff_t offset, int orig)
  {
  	loff_t ret;
  
  	lock_kernel();
  
  	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;
  	}
  
  	unlock_kernel();
  	return ret;
  }
  
  const struct file_operations usbfs_devices_fops = {
  	.llseek =	usb_device_lseek,
  	.read =		usb_device_read,
  	.poll =		usb_device_poll,
  	.open =		usb_device_open,
  	.release =	usb_device_release,
  };
  