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linux-2.6/drivers/usb/core/sysfs.c
Alan Stern 69d42a78f9 USB: add "descriptors" binary sysfs attribute
This patch (as934) adds a new readonly binary sysfs attribute file
called "descriptors" for each USB device.  The attribute contains the
device descriptor followed by the raw descriptor entry (config plug
subsidiary descriptors) for the current configuration.

Having this information available in fixed-format binary makes life a
lot easier for user programs by avoiding the need to open, read, and
parse multiple sysfs text files.

The information in this attribute file is much like that in usbfs's
device file, but there are some significant differences:

	The 2-byte fields in the device descriptor are left in
	little-endian byte order, as they appear on the bus and
	in the kernel.

	Only one raw descriptor set is presented, that of the
	current configuration.

	Opening this file will not cause a suspended device to be
	autoresumed.

The last item in particular should be a big selling point for libusb,
which currently forces all USB devices to be resumed as it scans the
device tree.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Dave Mielke <dave@mielke.cc>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-19 17:46:04 -07:00

711 lines
18 KiB
C

/*
* drivers/usb/core/sysfs.c
*
* (C) Copyright 2002 David Brownell
* (C) Copyright 2002,2004 Greg Kroah-Hartman
* (C) Copyright 2002,2004 IBM Corp.
*
* All of the sysfs file attributes for usb devices and interfaces.
*
*/
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/usb.h>
#include "usb.h"
/* Active configuration fields */
#define usb_actconfig_show(field, multiplier, format_string) \
static ssize_t show_##field(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_device *udev; \
struct usb_host_config *actconfig; \
\
udev = to_usb_device(dev); \
actconfig = udev->actconfig; \
if (actconfig) \
return sprintf(buf, format_string, \
actconfig->desc.field * multiplier); \
else \
return 0; \
} \
#define usb_actconfig_attr(field, multiplier, format_string) \
usb_actconfig_show(field, multiplier, format_string) \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
usb_actconfig_attr(bmAttributes, 1, "%2x\n")
usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")
static ssize_t show_configuration_string(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
struct usb_host_config *actconfig;
udev = to_usb_device(dev);
actconfig = udev->actconfig;
if ((!actconfig) || (!actconfig->string))
return 0;
return sprintf(buf, "%s\n", actconfig->string);
}
static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
/* configuration value is always present, and r/w */
usb_actconfig_show(bConfigurationValue, 1, "%u\n");
static ssize_t
set_bConfigurationValue(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int config, value;
if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
return -EINVAL;
usb_lock_device(udev);
value = usb_set_configuration(udev, config);
usb_unlock_device(udev);
return (value < 0) ? value : count;
}
static DEVICE_ATTR(bConfigurationValue, S_IRUGO | S_IWUSR,
show_bConfigurationValue, set_bConfigurationValue);
/* String fields */
#define usb_string_attr(name) \
static ssize_t show_##name(struct device *dev, \
struct device_attribute *attr, char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, "%s\n", udev->name); \
} \
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
usb_string_attr(product);
usb_string_attr(manufacturer);
usb_string_attr(serial);
static ssize_t
show_speed(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
char *speed;
udev = to_usb_device(dev);
switch (udev->speed) {
case USB_SPEED_LOW:
speed = "1.5";
break;
case USB_SPEED_UNKNOWN:
case USB_SPEED_FULL:
speed = "12";
break;
case USB_SPEED_HIGH:
speed = "480";
break;
default:
speed = "unknown";
}
return sprintf(buf, "%s\n", speed);
}
static DEVICE_ATTR(speed, S_IRUGO, show_speed, NULL);
static ssize_t
show_busnum(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->bus->busnum);
}
static DEVICE_ATTR(busnum, S_IRUGO, show_busnum, NULL);
static ssize_t
show_devnum(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->devnum);
}
static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL);
static ssize_t
show_version(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
u16 bcdUSB;
udev = to_usb_device(dev);
bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
static ssize_t
show_maxchild(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->maxchild);
}
static DEVICE_ATTR(maxchild, S_IRUGO, show_maxchild, NULL);
static ssize_t
show_quirks(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev;
udev = to_usb_device(dev);
return sprintf(buf, "0x%x\n", udev->quirks);
}
static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);
#if defined(CONFIG_USB_PERSIST) || defined(CONFIG_USB_SUSPEND)
static const char power_group[] = "power";
#endif
#ifdef CONFIG_USB_PERSIST
static ssize_t
show_persist(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->persist_enabled);
}
static ssize_t
set_persist(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int value;
/* Hubs are always enabled for USB_PERSIST */
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
return -EPERM;
if (sscanf(buf, "%d", &value) != 1)
return -EINVAL;
usb_pm_lock(udev);
udev->persist_enabled = !!value;
usb_pm_unlock(udev);
return count;
}
static DEVICE_ATTR(persist, S_IRUGO | S_IWUSR, show_persist, set_persist);
static int add_persist_attributes(struct device *dev)
{
int rc = 0;
if (is_usb_device(dev)) {
struct usb_device *udev = to_usb_device(dev);
/* Hubs are automatically enabled for USB_PERSIST */
if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
udev->persist_enabled = 1;
rc = sysfs_add_file_to_group(&dev->kobj,
&dev_attr_persist.attr,
power_group);
}
return rc;
}
static void remove_persist_attributes(struct device *dev)
{
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_persist.attr,
power_group);
}
#else
#define add_persist_attributes(dev) 0
#define remove_persist_attributes(dev) do {} while (0)
#endif /* CONFIG_USB_PERSIST */
#ifdef CONFIG_USB_SUSPEND
static ssize_t
show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
return sprintf(buf, "%d\n", udev->autosuspend_delay / HZ);
}
static ssize_t
set_autosuspend(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int value;
if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/HZ ||
value <= - INT_MAX/HZ)
return -EINVAL;
value *= HZ;
udev->autosuspend_delay = value;
if (value >= 0)
usb_try_autosuspend_device(udev);
else {
if (usb_autoresume_device(udev) == 0)
usb_autosuspend_device(udev);
}
return count;
}
static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
show_autosuspend, set_autosuspend);
static const char on_string[] = "on";
static const char auto_string[] = "auto";
static const char suspend_string[] = "suspend";
static ssize_t
show_level(struct device *dev, struct device_attribute *attr, char *buf)
{
struct usb_device *udev = to_usb_device(dev);
const char *p = auto_string;
if (udev->state == USB_STATE_SUSPENDED) {
if (udev->autoresume_disabled)
p = suspend_string;
} else {
if (udev->autosuspend_disabled)
p = on_string;
}
return sprintf(buf, "%s\n", p);
}
static ssize_t
set_level(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct usb_device *udev = to_usb_device(dev);
int len = count;
char *cp;
int rc = 0;
int old_autosuspend_disabled, old_autoresume_disabled;
cp = memchr(buf, '\n', count);
if (cp)
len = cp - buf;
usb_lock_device(udev);
old_autosuspend_disabled = udev->autosuspend_disabled;
old_autoresume_disabled = udev->autoresume_disabled;
/* Setting the flags without calling usb_pm_lock is a subject to
* races, but who cares...
*/
if (len == sizeof on_string - 1 &&
strncmp(buf, on_string, len) == 0) {
udev->autosuspend_disabled = 1;
udev->autoresume_disabled = 0;
rc = usb_external_resume_device(udev);
} else if (len == sizeof auto_string - 1 &&
strncmp(buf, auto_string, len) == 0) {
udev->autosuspend_disabled = 0;
udev->autoresume_disabled = 0;
rc = usb_external_resume_device(udev);
} else if (len == sizeof suspend_string - 1 &&
strncmp(buf, suspend_string, len) == 0) {
udev->autosuspend_disabled = 0;
udev->autoresume_disabled = 1;
rc = usb_external_suspend_device(udev, PMSG_SUSPEND);
} else
rc = -EINVAL;
if (rc) {
udev->autosuspend_disabled = old_autosuspend_disabled;
udev->autoresume_disabled = old_autoresume_disabled;
}
usb_unlock_device(udev);
return (rc < 0 ? rc : count);
}
static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);
static int add_power_attributes(struct device *dev)
{
int rc = 0;
if (is_usb_device(dev)) {
rc = sysfs_add_file_to_group(&dev->kobj,
&dev_attr_autosuspend.attr,
power_group);
if (rc == 0)
rc = sysfs_add_file_to_group(&dev->kobj,
&dev_attr_level.attr,
power_group);
}
return rc;
}
static void remove_power_attributes(struct device *dev)
{
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_level.attr,
power_group);
sysfs_remove_file_from_group(&dev->kobj,
&dev_attr_autosuspend.attr,
power_group);
}
#else
#define add_power_attributes(dev) 0
#define remove_power_attributes(dev) do {} while (0)
#endif /* CONFIG_USB_SUSPEND */
/* Descriptor fields */
#define usb_descriptor_attr_le16(field, format_string) \
static ssize_t \
show_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, format_string, \
le16_to_cpu(udev->descriptor.field)); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_descriptor_attr_le16(idVendor, "%04x\n")
usb_descriptor_attr_le16(idProduct, "%04x\n")
usb_descriptor_attr_le16(bcdDevice, "%04x\n")
#define usb_descriptor_attr(field, format_string) \
static ssize_t \
show_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_device *udev; \
\
udev = to_usb_device(dev); \
return sprintf(buf, format_string, udev->descriptor.field); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_descriptor_attr(bDeviceClass, "%02x\n")
usb_descriptor_attr(bDeviceSubClass, "%02x\n")
usb_descriptor_attr(bDeviceProtocol, "%02x\n")
usb_descriptor_attr(bNumConfigurations, "%d\n")
usb_descriptor_attr(bMaxPacketSize0, "%d\n")
static struct attribute *dev_attrs[] = {
/* current configuration's attributes */
&dev_attr_configuration.attr,
&dev_attr_bNumInterfaces.attr,
&dev_attr_bConfigurationValue.attr,
&dev_attr_bmAttributes.attr,
&dev_attr_bMaxPower.attr,
/* device attributes */
&dev_attr_idVendor.attr,
&dev_attr_idProduct.attr,
&dev_attr_bcdDevice.attr,
&dev_attr_bDeviceClass.attr,
&dev_attr_bDeviceSubClass.attr,
&dev_attr_bDeviceProtocol.attr,
&dev_attr_bNumConfigurations.attr,
&dev_attr_bMaxPacketSize0.attr,
&dev_attr_speed.attr,
&dev_attr_busnum.attr,
&dev_attr_devnum.attr,
&dev_attr_version.attr,
&dev_attr_maxchild.attr,
&dev_attr_quirks.attr,
NULL,
};
static struct attribute_group dev_attr_grp = {
.attrs = dev_attrs,
};
/* Binary descriptors */
static ssize_t
read_descriptors(struct kobject *kobj, struct bin_attribute *attr,
char *buf, loff_t off, size_t count)
{
struct usb_device *udev = to_usb_device(
container_of(kobj, struct device, kobj));
size_t nleft = count;
size_t srclen, n;
usb_lock_device(udev);
/* The binary attribute begins with the device descriptor */
srclen = sizeof(struct usb_device_descriptor);
if (off < srclen) {
n = min_t(size_t, nleft, srclen - off);
memcpy(buf, off + (char *) &udev->descriptor, n);
nleft -= n;
buf += n;
off = 0;
} else {
off -= srclen;
}
/* Then follows the raw descriptor entry for the current
* configuration (config plus subsidiary descriptors).
*/
if (udev->actconfig) {
int cfgno = udev->actconfig - udev->config;
srclen = __le16_to_cpu(udev->actconfig->desc.wTotalLength);
if (off < srclen) {
n = min_t(size_t, nleft, srclen - off);
memcpy(buf, off + udev->rawdescriptors[cfgno], n);
nleft -= n;
}
}
usb_unlock_device(udev);
return count - nleft;
}
static struct bin_attribute dev_bin_attr_descriptors = {
.attr = {.name = "descriptors", .mode = 0444},
.read = read_descriptors,
.size = 18 + 65535, /* dev descr + max-size raw descriptor */
};
int usb_create_sysfs_dev_files(struct usb_device *udev)
{
struct device *dev = &udev->dev;
int retval;
retval = sysfs_create_group(&dev->kobj, &dev_attr_grp);
if (retval)
return retval;
retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
if (retval)
goto error;
retval = add_persist_attributes(dev);
if (retval)
goto error;
retval = add_power_attributes(dev);
if (retval)
goto error;
if (udev->manufacturer) {
retval = device_create_file(dev, &dev_attr_manufacturer);
if (retval)
goto error;
}
if (udev->product) {
retval = device_create_file(dev, &dev_attr_product);
if (retval)
goto error;
}
if (udev->serial) {
retval = device_create_file(dev, &dev_attr_serial);
if (retval)
goto error;
}
retval = usb_create_ep_files(dev, &udev->ep0, udev);
if (retval)
goto error;
return 0;
error:
usb_remove_sysfs_dev_files(udev);
return retval;
}
void usb_remove_sysfs_dev_files(struct usb_device *udev)
{
struct device *dev = &udev->dev;
usb_remove_ep_files(&udev->ep0);
device_remove_file(dev, &dev_attr_manufacturer);
device_remove_file(dev, &dev_attr_product);
device_remove_file(dev, &dev_attr_serial);
remove_power_attributes(dev);
remove_persist_attributes(dev);
device_remove_bin_file(dev, &dev_bin_attr_descriptors);
sysfs_remove_group(&dev->kobj, &dev_attr_grp);
}
/* Interface Accociation Descriptor fields */
#define usb_intf_assoc_attr(field, format_string) \
static ssize_t \
show_iad_##field (struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_interface *intf = to_usb_interface (dev); \
\
return sprintf (buf, format_string, \
intf->intf_assoc->field); \
} \
static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);
usb_intf_assoc_attr (bFirstInterface, "%02x\n")
usb_intf_assoc_attr (bInterfaceCount, "%02d\n")
usb_intf_assoc_attr (bFunctionClass, "%02x\n")
usb_intf_assoc_attr (bFunctionSubClass, "%02x\n")
usb_intf_assoc_attr (bFunctionProtocol, "%02x\n")
/* Interface fields */
#define usb_intf_attr(field, format_string) \
static ssize_t \
show_##field(struct device *dev, struct device_attribute *attr, \
char *buf) \
{ \
struct usb_interface *intf = to_usb_interface(dev); \
\
return sprintf(buf, format_string, \
intf->cur_altsetting->desc.field); \
} \
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
usb_intf_attr(bInterfaceNumber, "%02x\n")
usb_intf_attr(bAlternateSetting, "%2d\n")
usb_intf_attr(bNumEndpoints, "%02x\n")
usb_intf_attr(bInterfaceClass, "%02x\n")
usb_intf_attr(bInterfaceSubClass, "%02x\n")
usb_intf_attr(bInterfaceProtocol, "%02x\n")
static ssize_t show_interface_string(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf;
struct usb_device *udev;
int len;
intf = to_usb_interface(dev);
udev = interface_to_usbdev(intf);
len = snprintf(buf, 256, "%s", intf->cur_altsetting->string);
if (len < 0)
return 0;
buf[len] = '\n';
buf[len+1] = 0;
return len+1;
}
static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);
static ssize_t show_modalias(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf;
struct usb_device *udev;
struct usb_host_interface *alt;
intf = to_usb_interface(dev);
udev = interface_to_usbdev(intf);
alt = intf->cur_altsetting;
return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
"ic%02Xisc%02Xip%02X\n",
le16_to_cpu(udev->descriptor.idVendor),
le16_to_cpu(udev->descriptor.idProduct),
le16_to_cpu(udev->descriptor.bcdDevice),
udev->descriptor.bDeviceClass,
udev->descriptor.bDeviceSubClass,
udev->descriptor.bDeviceProtocol,
alt->desc.bInterfaceClass,
alt->desc.bInterfaceSubClass,
alt->desc.bInterfaceProtocol);
}
static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
static struct attribute *intf_assoc_attrs[] = {
&dev_attr_iad_bFirstInterface.attr,
&dev_attr_iad_bInterfaceCount.attr,
&dev_attr_iad_bFunctionClass.attr,
&dev_attr_iad_bFunctionSubClass.attr,
&dev_attr_iad_bFunctionProtocol.attr,
NULL,
};
static struct attribute_group intf_assoc_attr_grp = {
.attrs = intf_assoc_attrs,
};
static struct attribute *intf_attrs[] = {
&dev_attr_bInterfaceNumber.attr,
&dev_attr_bAlternateSetting.attr,
&dev_attr_bNumEndpoints.attr,
&dev_attr_bInterfaceClass.attr,
&dev_attr_bInterfaceSubClass.attr,
&dev_attr_bInterfaceProtocol.attr,
&dev_attr_modalias.attr,
NULL,
};
static struct attribute_group intf_attr_grp = {
.attrs = intf_attrs,
};
static inline void usb_create_intf_ep_files(struct usb_interface *intf,
struct usb_device *udev)
{
struct usb_host_interface *iface_desc;
int i;
iface_desc = intf->cur_altsetting;
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
usb_create_ep_files(&intf->dev, &iface_desc->endpoint[i],
udev);
}
static inline void usb_remove_intf_ep_files(struct usb_interface *intf)
{
struct usb_host_interface *iface_desc;
int i;
iface_desc = intf->cur_altsetting;
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
usb_remove_ep_files(&iface_desc->endpoint[i]);
}
int usb_create_sysfs_intf_files(struct usb_interface *intf)
{
struct device *dev = &intf->dev;
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *alt = intf->cur_altsetting;
int retval;
retval = sysfs_create_group(&dev->kobj, &intf_attr_grp);
if (retval)
return retval;
if (alt->string == NULL)
alt->string = usb_cache_string(udev, alt->desc.iInterface);
if (alt->string)
retval = device_create_file(dev, &dev_attr_interface);
if (intf->intf_assoc)
retval = sysfs_create_group(&dev->kobj, &intf_assoc_attr_grp);
usb_create_intf_ep_files(intf, udev);
return 0;
}
void usb_remove_sysfs_intf_files(struct usb_interface *intf)
{
struct device *dev = &intf->dev;
usb_remove_intf_ep_files(intf);
device_remove_file(dev, &dev_attr_interface);
sysfs_remove_group(&dev->kobj, &intf_attr_grp);
sysfs_remove_group(&intf->dev.kobj, &intf_assoc_attr_grp);
}