[linux-2.6-block.git] / drivers / usb / core / port.c

/*
 * 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 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);
}

#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_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);
	set_bit(port1, hub->busy_bits);

	retval = usb_hub_set_port_power(hdev, hub, port1, true);
	msleep(hub_power_on_good_delay(hub));
	if (port_dev->child && !retval) {
		/*
		 * Attempt to wait for usb hub port to be reconnected in order
		 * to make the resume procedure successful.  The device may have
		 * disconnected while the port was powered off, so ignore the
		 * return status.
		 */
		retval = hub_port_debounce_be_connected(hub, port1);
		if (retval < 0)
			dev_dbg(&port_dev->dev, "can't get reconnection after setting port  power on, status %d\n",
					retval);
		retval = 0;
	}

	clear_bit(port1, hub->busy_bits);
	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;

	usb_autopm_get_interface(intf);
	set_bit(port1, hub->busy_bits);
	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);
	clear_bit(port1, hub->busy_bits);
	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;

		WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n",
			dev_name(&left->dev), dev_name(&right->dev),
			dev_name(&left->dev), lpeer,
			dev_name(&right->dev), rpeer);
		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;
}

static void link_peers_report(struct usb_port *left, struct usb_port *right)
{
	int rc;

	rc = link_peers(left, right);
	if (rc == 0) {
		dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
	} else {
		dev_warn(&left->dev, "failed to peer to %s (%d)\n",
				dev_name(&right->dev), rc);
		pr_warn_once("usb: port power management may be unreliable\n");
	}
}

static void unlink_peers(struct usb_port *left, struct usb_port *right)
{
	struct usb_port *ss_port, *hs_port;

	WARN(right->peer != left || left->peer != right,
			"%s and %s are not peers?\n",
			dev_name(&left->dev), dev_name(&right->dev));

	/*
	 * We wake the HiSpeed port to make sure we don't race its
	 * usb_port_runtime_resume() event which takes a SuperSpeed ref
	 * when ->peer is !NULL.
	 */
	if (left->is_superspeed) {
		ss_port = left;
		hs_port = right;
	} else {
		ss_port = right;
		hs_port = left;
	}

	pm_runtime_get_sync(&hs_port->dev);

	sysfs_remove_link(&left->dev.kobj, "peer");
	right->peer = NULL;
	sysfs_remove_link(&right->dev.kobj, "peer");
	left->peer = NULL;

	/* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
	pm_runtime_put(&ss_port->dev);

	/* Drop the ref taken above */
	pm_runtime_put(&hs_port->dev);
}

/*
 * For each usb hub device in the system check to see if it is in the
 * peer domain of the given port_dev, and if it is check to see if it
 * has a port that matches the given port by location
 */
static int match_location(struct usb_device *peer_hdev, void *p)
{
	int port1;
	struct usb_hcd *hcd, *peer_hcd;
	struct usb_port *port_dev = p, *peer;
	struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
	struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);

	if (!peer_hub)
		return 0;

	hcd = bus_to_hcd(hdev->bus);
	peer_hcd = bus_to_hcd(peer_hdev->bus);
	/* peer_hcd is provisional until we verify it against the known peer */
	if (peer_hcd != hcd->shared_hcd)
		return 0;

	for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
		peer = peer_hub->ports[port1 - 1];
		if (peer && peer->location == port_dev->location) {
			link_peers_report(port_dev, peer);
			return 1; /* done */
		}
	}

	return 0;
}

/*
 * Find the peer port either via explicit platform firmware "location"
 * data, the peer hcd for root hubs, or the upstream peer relationship
 * for all other hubs.
 */
static void find_and_link_peer(struct usb_hub *hub, int port1)
{
	struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
	struct usb_device *hdev = hub->hdev;
	struct usb_device *peer_hdev;
	struct usb_hub *peer_hub;

	/*
	 * If location data is available then we can only peer this port
	 * by a location match, not the default peer (lest we create a
	 * situation where we need to go back and undo a default peering
	 * when the port is later peered by location data)
	 */
	if (port_dev->location) {
		/* we link the peer in match_location() if found */
		usb_for_each_dev(port_dev, match_location);
		return;
	} else if (!hdev->parent) {
		struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
		struct usb_hcd *peer_hcd = hcd->shared_hcd;

		if (!peer_hcd)
			return;

		peer_hdev = peer_hcd->self.root_hub;
	} else {
		struct usb_port *upstream;
		struct usb_device *parent = hdev->parent;
		struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);

		if (!parent_hub)
			return;

		upstream = parent_hub->ports[hdev->portnum - 1];
		if (!upstream || !upstream->peer)
			return;

		peer_hdev = upstream->peer->child;
	}

	peer_hub = usb_hub_to_struct_hub(peer_hdev);
	if (!peer_hub || port1 > peer_hdev->maxchild)
		return;

	/*
	 * we found a valid default peer, last check is to make sure it
	 * does not have location data
	 */
	peer = peer_hub->ports[port1 - 1];
	if (peer && peer->location == 0)
		link_peers_report(port_dev, peer);
}

int usb_hub_create_port_device(struct usb_hub *hub, int port1)
{
	struct usb_port *port_dev;
	int retval;

	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
	if (!port_dev) {
		retval = -ENOMEM;
		goto exit;
	}

	hub->ports[port1 - 1] = port_dev;
	port_dev->portnum = port1;
	set_bit(port1, hub->power_bits);
	port_dev->dev.parent = hub->intfdev;
	port_dev->dev.groups = port_dev_group;
	port_dev->dev.type = &usb_port_device_type;
	port_dev->dev.driver = &usb_port_driver;
	if (hub_is_superspeed(hub->hdev))
		port_dev->is_superspeed = 1;
	dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
			port1);
	retval = device_register(&port_dev->dev);
	if (retval)
		goto error_register;

	find_and_link_peer(hub, port1);

	pm_runtime_set_active(&port_dev->dev);

	/*
	 * Do not enable port runtime pm if the hub does not support
	 * power switching.  Also, userspace must have final say of
	 * whether a port is permitted to power-off.  Do not enable
	 * runtime pm if we fail to expose pm_qos_no_power_off.
	 */
	if (hub_is_port_power_switchable(hub)
			&& dev_pm_qos_expose_flags(&port_dev->dev,
			PM_QOS_FLAG_NO_POWER_OFF) == 0)
		pm_runtime_enable(&port_dev->dev);

	device_enable_async_suspend(&port_dev->dev);
	return 0;

error_register:
	put_device(&port_dev->dev);
exit:
	return retval;
}

void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
{
	struct usb_port *port_dev = hub->ports[port1 - 1];
	struct usb_port *peer;

	peer = port_dev->peer;
	if (peer)
		unlink_peers(port_dev, peer);
	device_unregister(&port_dev->dev);
}
Commit	Line	Data
6e30d7cb LT	1	/*
	2	* usb port device code
	3	*
	4	* Copyright (C) 2012 Intel Corp
	5	*
	6	* Author: Lan Tianyu <tianyu.lan@intel.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	* This program is distributed in the hope that it will be useful, but
	13	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
	14	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	15	* for more details.
	16	*
	17	*/
	18
9f7344fb	19	#include <linux/slab.h>
971fcd49	20	#include <linux/pm_qos.h>
9f7344fb	21
6e30d7cb LT	22	#include "hub.h"
6e30d7cb LT	23
cef7468c LT	24	static const struct attribute_group *port_dev_group[];
cef7468c LT	25
d03f254f GKH	26	static ssize_t connect_type_show(struct device *dev,
d03f254f GKH	27	struct device_attribute attr, char buf)
cef7468c LT	28	{
	29	struct usb_port *port_dev = to_usb_port(dev);
	30	char *result;
	31
	32	switch (port_dev->connect_type) {
	33	case USB_PORT_CONNECT_TYPE_HOT_PLUG:
	34	result = "hotplug";
	35	break;
	36	case USB_PORT_CONNECT_TYPE_HARD_WIRED:
	37	result = "hardwired";
	38	break;
	39	case USB_PORT_NOT_USED:
	40	result = "not used";
	41	break;
	42	default:
	43	result = "unknown";
	44	break;
	45	}
	46
	47	return sprintf(buf, "%s\n", result);
	48	}
d03f254f	49	static DEVICE_ATTR_RO(connect_type);
cef7468c LT	50
	51	static struct attribute *port_dev_attrs[] = {
	52	&dev_attr_connect_type.attr,
	53	NULL,
	54	};
	55
	56	static struct attribute_group port_dev_attr_grp = {
	57	.attrs = port_dev_attrs,
	58	};
	59
	60	static const struct attribute_group *port_dev_group[] = {
	61	&port_dev_attr_grp,
	62	NULL,
	63	};
	64
6e30d7cb LT	65	static void usb_port_device_release(struct device *dev)
	66	{
	67	struct usb_port *port_dev = to_usb_port(dev);
	68
	69	kfree(port_dev);
	70	}
	71
84ebc102	72	#ifdef CONFIG_PM_RUNTIME
971fcd49 LT	73	static int usb_port_runtime_resume(struct device *dev)
	74	{
	75	struct usb_port *port_dev = to_usb_port(dev);
	76	struct usb_device *hdev = to_usb_device(dev->parent->parent);
	77	struct usb_interface *intf = to_usb_interface(dev->parent);
ad493e5e	78	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
7ad3c470	79	struct usb_port *peer = port_dev->peer;
ad493e5e	80	int port1 = port_dev->portnum;
971fcd49 LT	81	int retval;
971fcd49 LT	82
ad493e5e LT	83	if (!hub)
ad493e5e LT	84	return -EINVAL;
600856c2	85	if (hub->in_reset) {
d5c3834e	86	set_bit(port1, hub->power_bits);
600856c2 AS	87	return 0;
600856c2 AS	88	}
ad493e5e	89
7ad3c470 DW	90	/*
	91	* Power on our usb3 peer before this usb2 port to prevent a usb3
	92	* device from degrading to its usb2 connection
	93	*/
	94	if (!port_dev->is_superspeed && peer)
	95	pm_runtime_get_sync(&peer->dev);
	96
971fcd49	97	usb_autopm_get_interface(intf);
ad493e5e LT	98	set_bit(port1, hub->busy_bits);
ad493e5e LT	99
41341261	100	retval = usb_hub_set_port_power(hdev, hub, port1, true);
7ad3c470	101	msleep(hub_power_on_good_delay(hub));
ad493e5e LT	102	if (port_dev->child && !retval) {
ad493e5e LT	103	/*
d49dad3e SS	104	* Attempt to wait for usb hub port to be reconnected in order
	105	* to make the resume procedure successful. The device may have
	106	* disconnected while the port was powered off, so ignore the
	107	* return status.
ad493e5e LT	108	*/
ad493e5e LT	109	retval = hub_port_debounce_be_connected(hub, port1);
d49dad3e	110	if (retval < 0)
ad493e5e LT	111	dev_dbg(&port_dev->dev, "can't get reconnection after setting port power on, status %d\n",
ad493e5e LT	112	retval);
ad493e5e LT	113	retval = 0;
	114	}
	115
ad493e5e	116	clear_bit(port1, hub->busy_bits);
971fcd49	117	usb_autopm_put_interface(intf);
7ad3c470	118
971fcd49 LT	119	return retval;
	120	}
	121
	122	static int usb_port_runtime_suspend(struct device *dev)
	123	{
	124	struct usb_port *port_dev = to_usb_port(dev);
	125	struct usb_device *hdev = to_usb_device(dev->parent->parent);
	126	struct usb_interface *intf = to_usb_interface(dev->parent);
ad493e5e	127	struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
7ad3c470	128	struct usb_port *peer = port_dev->peer;
ad493e5e	129	int port1 = port_dev->portnum;
971fcd49 LT	130	int retval;
971fcd49 LT	131
ad493e5e LT	132	if (!hub)
ad493e5e LT	133	return -EINVAL;
600856c2 AS	134	if (hub->in_reset)
600856c2 AS	135	return -EBUSY;
ad493e5e	136
971fcd49 LT	137	if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
	138	== PM_QOS_FLAGS_ALL)
	139	return -EAGAIN;
	140
	141	usb_autopm_get_interface(intf);
ad493e5e	142	set_bit(port1, hub->busy_bits);
41341261	143	retval = usb_hub_set_port_power(hdev, hub, port1, false);
ad493e5e	144	usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
69080584 DW	145	if (!port_dev->is_superspeed)
69080584 DW	146	usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
ad493e5e	147	clear_bit(port1, hub->busy_bits);
971fcd49	148	usb_autopm_put_interface(intf);
7ad3c470 DW	149
	150	/*
	151	* Our peer usb3 port may now be able to suspend, so
	152	* asynchronously queue a suspend request to observe that this
	153	* usb2 port is now off.
	154	*/
	155	if (!port_dev->is_superspeed && peer)
	156	pm_runtime_put(&peer->dev);
	157
971fcd49 LT	158	return retval;
	159	}
	160	#endif
	161
	162	static const struct dev_pm_ops usb_port_pm_ops = {
84ebc102	163	#ifdef CONFIG_PM_RUNTIME
971fcd49 LT	164	.runtime_suspend = usb_port_runtime_suspend,
971fcd49 LT	165	.runtime_resume = usb_port_runtime_resume,
971fcd49 LT	166	#endif
	167	};
	168
6e30d7cb LT	169	struct device_type usb_port_device_type = {
	170	.name = "usb_port",
	171	.release = usb_port_device_release,
971fcd49	172	.pm = &usb_port_pm_ops,
6e30d7cb LT	173	};
6e30d7cb LT	174
d99f6b41 DW	175	static struct device_driver usb_port_driver = {
	176	.name = "usb",
	177	.owner = THIS_MODULE,
	178	};
	179
b7e38eac	180	static int link_peers(struct usb_port left, struct usb_port right)
d8521afe	181	{
7ad3c470	182	struct usb_port ss_port, hs_port;
b7e38eac DW	183	int rc;
b7e38eac DW	184
d8521afe	185	if (left->peer == right && right->peer == left)
b7e38eac	186	return 0;
d8521afe DW	187
	188	if (left->peer \|\| right->peer) {
	189	struct usb_port *lpeer = left->peer;
	190	struct usb_port *rpeer = right->peer;
	191
	192	WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n",
	193	dev_name(&left->dev), dev_name(&right->dev),
	194	dev_name(&left->dev), lpeer,
	195	dev_name(&right->dev), rpeer);
b7e38eac DW	196	return -EBUSY;
	197	}
	198
	199	rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
	200	if (rc)
	201	return rc;
	202	rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
	203	if (rc) {
	204	sysfs_remove_link(&left->dev.kobj, "peer");
	205	return rc;
d8521afe DW	206	}
d8521afe DW	207
7ad3c470 DW	208	/*
	209	* We need to wake the HiSpeed port to make sure we don't race
	210	* setting ->peer with usb_port_runtime_suspend(). Otherwise we
	211	* may miss a suspend event for the SuperSpeed port.
	212	*/
	213	if (left->is_superspeed) {
	214	ss_port = left;
	215	WARN_ON(right->is_superspeed);
	216	hs_port = right;
	217	} else {
	218	ss_port = right;
	219	WARN_ON(!right->is_superspeed);
	220	hs_port = left;
	221	}
	222	pm_runtime_get_sync(&hs_port->dev);
	223
d8521afe DW	224	left->peer = right;
d8521afe DW	225	right->peer = left;
b7e38eac	226
7ad3c470 DW	227	/*
	228	* The SuperSpeed reference is dropped when the HiSpeed port in
	229	* this relationship suspends, i.e. when it is safe to allow a
	230	* SuperSpeed connection to drop since there is no risk of a
	231	* device degrading to its powered-off HiSpeed connection.
	232	*
	233	* Also, drop the HiSpeed ref taken above.
	234	*/
	235	pm_runtime_get_sync(&ss_port->dev);
	236	pm_runtime_put(&hs_port->dev);
	237
b7e38eac DW	238	return 0;
	239	}
	240
	241	static void link_peers_report(struct usb_port left, struct usb_port right)
	242	{
	243	int rc;
	244
	245	rc = link_peers(left, right);
	246	if (rc == 0) {
	247	dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
	248	} else {
	249	dev_warn(&left->dev, "failed to peer to %s (%d)\n",
	250	dev_name(&right->dev), rc);
	251	pr_warn_once("usb: port power management may be unreliable\n");
	252	}
d8521afe DW	253	}
	254
	255	static void unlink_peers(struct usb_port left, struct usb_port right)
	256	{
7ad3c470 DW	257	struct usb_port ss_port, hs_port;
7ad3c470 DW	258
d8521afe DW	259	WARN(right->peer != left \|\| left->peer != right,
	260	"%s and %s are not peers?\n",
	261	dev_name(&left->dev), dev_name(&right->dev));
	262
7ad3c470 DW	263	/*
	264	* We wake the HiSpeed port to make sure we don't race its
	265	* usb_port_runtime_resume() event which takes a SuperSpeed ref
	266	* when ->peer is !NULL.
	267	*/
	268	if (left->is_superspeed) {
	269	ss_port = left;
	270	hs_port = right;
	271	} else {
	272	ss_port = right;
	273	hs_port = left;
	274	}
	275
	276	pm_runtime_get_sync(&hs_port->dev);
	277
b7e38eac	278	sysfs_remove_link(&left->dev.kobj, "peer");
d8521afe	279	right->peer = NULL;
b7e38eac	280	sysfs_remove_link(&right->dev.kobj, "peer");
d8521afe	281	left->peer = NULL;
7ad3c470 DW	282
	283	/* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
	284	pm_runtime_put(&ss_port->dev);
	285
	286	/* Drop the ref taken above */
	287	pm_runtime_put(&hs_port->dev);
d8521afe DW	288	}
d8521afe DW	289
8b1ba80c	290	/*
3bfd659b DW	291	* For each usb hub device in the system check to see if it is in the
	292	* peer domain of the given port_dev, and if it is check to see if it
	293	* has a port that matches the given port by location
	294	*/
	295	static int match_location(struct usb_device peer_hdev, void p)
	296	{
	297	int port1;
	298	struct usb_hcd hcd, peer_hcd;
	299	struct usb_port port_dev = p, peer;
	300	struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
	301	struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
	302
	303	if (!peer_hub)
	304	return 0;
	305
	306	hcd = bus_to_hcd(hdev->bus);
	307	peer_hcd = bus_to_hcd(peer_hdev->bus);
	308	/* peer_hcd is provisional until we verify it against the known peer */
	309	if (peer_hcd != hcd->shared_hcd)
	310	return 0;
	311
	312	for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
	313	peer = peer_hub->ports[port1 - 1];
	314	if (peer && peer->location == port_dev->location) {
b7e38eac	315	link_peers_report(port_dev, peer);
3bfd659b DW	316	return 1; /* done */
	317	}
	318	}
	319
	320	return 0;
	321	}
	322
	323	/*
	324	* Find the peer port either via explicit platform firmware "location"
	325	* data, the peer hcd for root hubs, or the upstream peer relationship
	326	* for all other hubs.
8b1ba80c	327	*/
d8521afe DW	328	static void find_and_link_peer(struct usb_hub *hub, int port1)
	329	{
	330	struct usb_port port_dev = hub->ports[port1 - 1], peer;
	331	struct usb_device *hdev = hub->hdev;
8b1ba80c DW	332	struct usb_device *peer_hdev;
8b1ba80c DW	333	struct usb_hub *peer_hub;
d8521afe	334
3bfd659b DW	335	/*
	336	* If location data is available then we can only peer this port
	337	* by a location match, not the default peer (lest we create a
	338	* situation where we need to go back and undo a default peering
	339	* when the port is later peered by location data)
	340	*/
	341	if (port_dev->location) {
	342	/* we link the peer in match_location() if found */
	343	usb_for_each_dev(port_dev, match_location);
	344	return;
	345	} else if (!hdev->parent) {
d8521afe DW	346	struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
	347	struct usb_hcd *peer_hcd = hcd->shared_hcd;
	348
	349	if (!peer_hcd)
	350	return;
	351
	352	peer_hdev = peer_hcd->self.root_hub;
8b1ba80c DW	353	} else {
	354	struct usb_port *upstream;
	355	struct usb_device *parent = hdev->parent;
	356	struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
	357
	358	if (!parent_hub)
d8521afe DW	359	return;
d8521afe DW	360
8b1ba80c DW	361	upstream = parent_hub->ports[hdev->portnum - 1];
	362	if (!upstream \|\| !upstream->peer)
	363	return;
d8521afe	364
8b1ba80c	365	peer_hdev = upstream->peer->child;
d8521afe	366	}
8b1ba80c DW	367
	368	peer_hub = usb_hub_to_struct_hub(peer_hdev);
	369	if (!peer_hub \|\| port1 > peer_hdev->maxchild)
	370	return;
	371
3bfd659b DW	372	/*
	373	* we found a valid default peer, last check is to make sure it
	374	* does not have location data
	375	*/
8b1ba80c	376	peer = peer_hub->ports[port1 - 1];
3bfd659b	377	if (peer && peer->location == 0)
b7e38eac	378	link_peers_report(port_dev, peer);
d8521afe DW	379	}
d8521afe DW	380
6e30d7cb LT	381	int usb_hub_create_port_device(struct usb_hub *hub, int port1)
6e30d7cb LT	382	{
d8521afe	383	struct usb_port *port_dev;
6e30d7cb LT	384	int retval;
	385
	386	port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
	387	if (!port_dev) {
	388	retval = -ENOMEM;
	389	goto exit;
	390	}
	391
	392	hub->ports[port1 - 1] = port_dev;
971fcd49	393	port_dev->portnum = port1;
d5c3834e	394	set_bit(port1, hub->power_bits);
6e30d7cb	395	port_dev->dev.parent = hub->intfdev;
cef7468c	396	port_dev->dev.groups = port_dev_group;
6e30d7cb	397	port_dev->dev.type = &usb_port_device_type;
d99f6b41	398	port_dev->dev.driver = &usb_port_driver;
7ad3c470 DW	399	if (hub_is_superspeed(hub->hdev))
7ad3c470 DW	400	port_dev->is_superspeed = 1;
d99f6b41 DW	401	dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
d99f6b41 DW	402	port1);
6e30d7cb LT	403	retval = device_register(&port_dev->dev);
	404	if (retval)
	405	goto error_register;
	406
d8521afe DW	407	find_and_link_peer(hub, port1);
d8521afe DW	408
971fcd49	409	pm_runtime_set_active(&port_dev->dev);
f6cced1a	410
9262c19d DW	411	/*
	412	* Do not enable port runtime pm if the hub does not support
	413	* power switching. Also, userspace must have final say of
	414	* whether a port is permitted to power-off. Do not enable
	415	* runtime pm if we fail to expose pm_qos_no_power_off.
f6cced1a	416	*/
9262c19d DW	417	if (hub_is_port_power_switchable(hub)
	418	&& dev_pm_qos_expose_flags(&port_dev->dev,
	419	PM_QOS_FLAG_NO_POWER_OFF) == 0)
f6cced1a LT	420	pm_runtime_enable(&port_dev->dev);
f6cced1a LT	421
192fef18	422	device_enable_async_suspend(&port_dev->dev);
6e30d7cb LT	423	return 0;
	424
	425	error_register:
	426	put_device(&port_dev->dev);
	427	exit:
	428	return retval;
	429	}
	430
d8521afe	431	void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
6e30d7cb	432	{
d8521afe DW	433	struct usb_port *port_dev = hub->ports[port1 - 1];
d8521afe DW	434	struct usb_port *peer;
6e30d7cb	435
d8521afe DW	436	peer = port_dev->peer;
	437	if (peer)
	438	unlink_peers(port_dev, peer);
	439	device_unregister(&port_dev->dev);
	440	}