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|
/*
* usb port device code
*
* Copyright (C) 2012 Intel Corp
*
* Author: Lan Tianyu <tianyu.lan@intel.com>
*
* 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.
*
*/
#include <linux/slab.h>
#include <linux/pm_qos.h>
#include "hub.h"
static int usb_port_block_power_off;
static const struct attribute_group *port_dev_group[];
static ssize_t connect_type_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct usb_port *port_dev = to_usb_port(dev);
char *result;
switch (port_dev->connect_type) {
case USB_PORT_CONNECT_TYPE_HOT_PLUG:
result = "hotplug";
break;
case USB_PORT_CONNECT_TYPE_HARD_WIRED:
result = "hardwired";
break;
case USB_PORT_NOT_USED:
result = "not used";
break;
default:
result = "unknown";
break;
}
return sprintf(buf, "%s\n", result);
}
static DEVICE_ATTR_RO(connect_type);
static struct attribute *port_dev_attrs[] = {
&dev_attr_connect_type.attr,
NULL,
};
static struct attribute_group port_dev_attr_grp = {
.attrs = port_dev_attrs,
};
static const struct attribute_group *port_dev_group[] = {
&port_dev_attr_grp,
NULL,
};
static void usb_port_device_release(struct device *dev)
{
struct usb_port *port_dev = to_usb_port(dev);
kfree(port_dev->req);
kfree(port_dev);
}
#ifdef CONFIG_PM_RUNTIME
static int usb_port_runtime_resume(struct device *dev)
{
struct usb_port *port_dev = to_usb_port(dev);
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_interface *intf = to_usb_interface(dev->parent);
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
struct usb_device *udev = port_dev->child;
struct usb_port *peer = port_dev->peer;
int port1 = port_dev->portnum;
int retval;
if (!hub)
return -EINVAL;
if (hub->in_reset) {
set_bit(port1, hub->power_bits);
return 0;
}
/*
* Power on our usb3 peer before this usb2 port to prevent a usb3
* device from degrading to its usb2 connection
*/
if (!port_dev->is_superspeed && peer)
pm_runtime_get_sync(&peer->dev);
usb_autopm_get_interface(intf);
retval = usb_hub_set_port_power(hdev, hub, port1, true);
msleep(hub_power_on_good_delay(hub));
if (udev && !retval) {
/*
* Our preference is to simply wait for the port to reconnect,
* as that is the lowest latency method to restart the port.
* However, there are cases where toggling port power results in
* the host port and the device port getting out of sync causing
* a link training live lock. Upon timeout, flag the port as
* needing warm reset recovery (to be performed later by
* usb_port_resume() as requested via usb_wakeup_notification())
*/
if (hub_port_debounce_be_connected(hub, port1) < 0) {
dev_dbg(&port_dev->dev, "reconnect timeout\n");
if (hub_is_superspeed(hdev))
set_bit(port1, hub->warm_reset_bits);
}
/* Force the child awake to revalidate after the power loss. */
if (!test_and_set_bit(port1, hub->child_usage_bits)) {
pm_runtime_get_noresume(&port_dev->dev);
pm_request_resume(&udev->dev);
}
}
usb_autopm_put_interface(intf);
return retval;
}
static int usb_port_runtime_suspend(struct device *dev)
{
struct usb_port *port_dev = to_usb_port(dev);
struct usb_device *hdev = to_usb_device(dev->parent->parent);
struct usb_interface *intf = to_usb_interface(dev->parent);
struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
struct usb_port *peer = port_dev->peer;
int port1 = port_dev->portnum;
int retval;
if (!hub)
return -EINVAL;
if (hub->in_reset)
return -EBUSY;
if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
== PM_QOS_FLAGS_ALL)
return -EAGAIN;
if (usb_port_block_power_off)
return -EBUSY;
usb_autopm_get_interface(intf);
retval = usb_hub_set_port_power(hdev, hub, port1, false);
usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
if (!port_dev->is_superspeed)
usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
usb_autopm_put_interface(intf);
/*
* Our peer usb3 port may now be able to suspend, so
* asynchronously queue a suspend request to observe that this
* usb2 port is now off.
*/
if (!port_dev->is_superspeed && peer)
pm_runtime_put(&peer->dev);
return retval;
}
#endif
static const struct dev_pm_ops usb_port_pm_ops = {
#ifdef CONFIG_PM_RUNTIME
.runtime_suspend = usb_port_runtime_suspend,
.runtime_resume = usb_port_runtime_resume,
#endif
};
struct device_type usb_port_device_type = {
.name = "usb_port",
.release = usb_port_device_release,
.pm = &usb_port_pm_ops,
};
static struct device_driver usb_port_driver = {
.name = "usb",
.owner = THIS_MODULE,
};
static int link_peers(struct usb_port *left, struct usb_port *right)
{
struct usb_port *ss_port, *hs_port;
int rc;
if (left->peer == right && right->peer == left)
return 0;
if (left->peer || right->peer) {
struct usb_port *lpeer = left->peer;
struct usb_port *rpeer = right->peer;
char *method;
if (left->location && left->location == right->location)
method = "location";
else
method = "default";
pr_warn("usb: failed to peer %s and %s by %s (%s:%s) (%s:%s)\n",
dev_name(&left->dev), dev_name(&right->dev), method,
dev_name(&left->dev),
lpeer ? dev_name(&lpeer->dev) : "none",
dev_name(&right->dev),
rpeer ? dev_name(&rpeer->dev) : "none");
return -EBUSY;
}
rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
if (rc)
return rc;
rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
if (rc) {
sysfs_remove_link(&left->dev.kobj, "peer");
return rc;
}
/*
* We need to wake the HiSpeed port to make sure we don't race
* setting ->peer with usb_port_runtime_suspend(). Otherwise we
* may miss a suspend event for the SuperSpeed port.
*/
if (left->is_superspeed) {
ss_port = left;
WARN_ON(right->is_superspeed);
hs_port = right;
} else {
ss_port = right;
WARN_ON(!right->is_superspeed);
hs_port = left;
}
pm_runtime_get_sync(&hs_port->dev);
left->peer = right;
right->peer = left;
/*
* The SuperSpeed reference is dropped when the HiSpeed port in
* this relationship suspends, i.e. when it is safe to allow a
* SuperSpeed connection to drop since there is no risk of a
* device degrading to its powered-off HiSpeed connection.
*
* Also, drop the HiSpeed ref taken above.
*/
pm_runtime_get_sync(&ss_port->dev);
pm_runtime_put(&hs_port->dev);
return 0;
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