linux/drivers/usb/core/sysfs.c
Alan Stern b41a60eca8 USB: add power/persist device attribute
This patch (as920) adds an extra level of protection to the
USB-Persist facility.  Now it will apply by default only to hubs; for
all other devices the user must enable it explicitly by setting the
power/persist device attribute.

The disconnect_all_children() routine in hub.c has been removed and
its code placed inline.  This is the way it was originally as part of
hub_pre_reset(); the revised usage in hub_reset_resume() is
sufficiently different that the code can no longer be shared.
Likewise, mark_children_for_reset() is now inline as part of
hub_reset_resume().  The end result looks much cleaner than before.

The sysfs interface is updated to add the new attribute file, and
there are corresponding documentation updates.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-07-12 16:34:30 -07:00

624 lines
16 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,
};
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 = 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);
sysfs_remove_group(&dev->kobj, &dev_attr_grp);
}
/* 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_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);
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);
}