4 * Copyright (C) 2012 Intel Corp
6 * Author: Lan Tianyu <tianyu.lan@intel.com>
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.
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
19 #include <linux/slab.h>
20 #include <linux/pm_qos.h>
24 static const struct attribute_group *port_dev_group[];
26 static ssize_t connect_type_show(struct device *dev,
27 struct device_attribute *attr, char *buf)
29 struct usb_port *port_dev = to_usb_port(dev);
32 switch (port_dev->connect_type) {
33 case USB_PORT_CONNECT_TYPE_HOT_PLUG:
36 case USB_PORT_CONNECT_TYPE_HARD_WIRED:
39 case USB_PORT_NOT_USED:
47 return sprintf(buf, "%s\n", result);
49 static DEVICE_ATTR_RO(connect_type);
51 static struct attribute *port_dev_attrs[] = {
52 &dev_attr_connect_type.attr,
56 static struct attribute_group port_dev_attr_grp = {
57 .attrs = port_dev_attrs,
60 static const struct attribute_group *port_dev_group[] = {
65 static void usb_port_device_release(struct device *dev)
67 struct usb_port *port_dev = to_usb_port(dev);
72 #ifdef CONFIG_PM_RUNTIME
73 static int usb_port_runtime_resume(struct device *dev)
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);
78 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
79 struct usb_device *udev = port_dev->child;
80 struct usb_port *peer = port_dev->peer;
81 int port1 = port_dev->portnum;
87 set_bit(port1, hub->power_bits);
92 * Power on our usb3 peer before this usb2 port to prevent a usb3
93 * device from degrading to its usb2 connection
95 if (!port_dev->is_superspeed && peer)
96 pm_runtime_get_sync(&peer->dev);
98 usb_autopm_get_interface(intf);
99 retval = usb_hub_set_port_power(hdev, hub, port1, true);
100 msleep(hub_power_on_good_delay(hub));
101 if (udev && !retval) {
103 * Attempt to wait for usb hub port to be reconnected in order
104 * to make the resume procedure successful. The device may have
105 * disconnected while the port was powered off, so ignore the
108 retval = hub_port_debounce_be_connected(hub, port1);
110 dev_dbg(&port_dev->dev, "can't get reconnection after setting port power on, status %d\n",
114 /* Force the child awake to revalidate after the power loss. */
115 if (!test_and_set_bit(port1, hub->child_usage_bits)) {
116 pm_runtime_get_noresume(&port_dev->dev);
117 pm_request_resume(&udev->dev);
121 usb_autopm_put_interface(intf);
126 static int usb_port_runtime_suspend(struct device *dev)
128 struct usb_port *port_dev = to_usb_port(dev);
129 struct usb_device *hdev = to_usb_device(dev->parent->parent);
130 struct usb_interface *intf = to_usb_interface(dev->parent);
131 struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
132 struct usb_port *peer = port_dev->peer;
133 int port1 = port_dev->portnum;
141 if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
145 usb_autopm_get_interface(intf);
146 retval = usb_hub_set_port_power(hdev, hub, port1, false);
147 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
148 if (!port_dev->is_superspeed)
149 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
150 usb_autopm_put_interface(intf);
153 * Our peer usb3 port may now be able to suspend, so
154 * asynchronously queue a suspend request to observe that this
155 * usb2 port is now off.
157 if (!port_dev->is_superspeed && peer)
158 pm_runtime_put(&peer->dev);
164 static const struct dev_pm_ops usb_port_pm_ops = {
165 #ifdef CONFIG_PM_RUNTIME
166 .runtime_suspend = usb_port_runtime_suspend,
167 .runtime_resume = usb_port_runtime_resume,
171 struct device_type usb_port_device_type = {
173 .release = usb_port_device_release,
174 .pm = &usb_port_pm_ops,
177 static struct device_driver usb_port_driver = {
179 .owner = THIS_MODULE,
182 static int link_peers(struct usb_port *left, struct usb_port *right)
184 struct usb_port *ss_port, *hs_port;
187 if (left->peer == right && right->peer == left)
190 if (left->peer || right->peer) {
191 struct usb_port *lpeer = left->peer;
192 struct usb_port *rpeer = right->peer;
194 WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n",
195 dev_name(&left->dev), dev_name(&right->dev),
196 dev_name(&left->dev), lpeer,
197 dev_name(&right->dev), rpeer);
201 rc = sysfs_create_link(&left->dev.kobj, &right->dev.kobj, "peer");
204 rc = sysfs_create_link(&right->dev.kobj, &left->dev.kobj, "peer");
206 sysfs_remove_link(&left->dev.kobj, "peer");
211 * We need to wake the HiSpeed port to make sure we don't race
212 * setting ->peer with usb_port_runtime_suspend(). Otherwise we
213 * may miss a suspend event for the SuperSpeed port.
215 if (left->is_superspeed) {
217 WARN_ON(right->is_superspeed);
221 WARN_ON(!right->is_superspeed);
224 pm_runtime_get_sync(&hs_port->dev);
230 * The SuperSpeed reference is dropped when the HiSpeed port in
231 * this relationship suspends, i.e. when it is safe to allow a
232 * SuperSpeed connection to drop since there is no risk of a
233 * device degrading to its powered-off HiSpeed connection.
235 * Also, drop the HiSpeed ref taken above.
237 pm_runtime_get_sync(&ss_port->dev);
238 pm_runtime_put(&hs_port->dev);
243 static void link_peers_report(struct usb_port *left, struct usb_port *right)
247 rc = link_peers(left, right);
249 dev_dbg(&left->dev, "peered to %s\n", dev_name(&right->dev));
251 dev_warn(&left->dev, "failed to peer to %s (%d)\n",
252 dev_name(&right->dev), rc);
253 pr_warn_once("usb: port power management may be unreliable\n");
257 static void unlink_peers(struct usb_port *left, struct usb_port *right)
259 struct usb_port *ss_port, *hs_port;
261 WARN(right->peer != left || left->peer != right,
262 "%s and %s are not peers?\n",
263 dev_name(&left->dev), dev_name(&right->dev));
266 * We wake the HiSpeed port to make sure we don't race its
267 * usb_port_runtime_resume() event which takes a SuperSpeed ref
268 * when ->peer is !NULL.
270 if (left->is_superspeed) {
278 pm_runtime_get_sync(&hs_port->dev);
280 sysfs_remove_link(&left->dev.kobj, "peer");
282 sysfs_remove_link(&right->dev.kobj, "peer");
285 /* Drop the SuperSpeed ref held on behalf of the active HiSpeed port */
286 pm_runtime_put(&ss_port->dev);
288 /* Drop the ref taken above */
289 pm_runtime_put(&hs_port->dev);
293 * For each usb hub device in the system check to see if it is in the
294 * peer domain of the given port_dev, and if it is check to see if it
295 * has a port that matches the given port by location
297 static int match_location(struct usb_device *peer_hdev, void *p)
300 struct usb_hcd *hcd, *peer_hcd;
301 struct usb_port *port_dev = p, *peer;
302 struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
303 struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
308 hcd = bus_to_hcd(hdev->bus);
309 peer_hcd = bus_to_hcd(peer_hdev->bus);
310 /* peer_hcd is provisional until we verify it against the known peer */
311 if (peer_hcd != hcd->shared_hcd)
314 for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
315 peer = peer_hub->ports[port1 - 1];
316 if (peer && peer->location == port_dev->location) {
317 link_peers_report(port_dev, peer);
326 * Find the peer port either via explicit platform firmware "location"
327 * data, the peer hcd for root hubs, or the upstream peer relationship
328 * for all other hubs.
330 static void find_and_link_peer(struct usb_hub *hub, int port1)
332 struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
333 struct usb_device *hdev = hub->hdev;
334 struct usb_device *peer_hdev;
335 struct usb_hub *peer_hub;
338 * If location data is available then we can only peer this port
339 * by a location match, not the default peer (lest we create a
340 * situation where we need to go back and undo a default peering
341 * when the port is later peered by location data)
343 if (port_dev->location) {
344 /* we link the peer in match_location() if found */
345 usb_for_each_dev(port_dev, match_location);
347 } else if (!hdev->parent) {
348 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
349 struct usb_hcd *peer_hcd = hcd->shared_hcd;
354 peer_hdev = peer_hcd->self.root_hub;
356 struct usb_port *upstream;
357 struct usb_device *parent = hdev->parent;
358 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
363 upstream = parent_hub->ports[hdev->portnum - 1];
364 if (!upstream || !upstream->peer)
367 peer_hdev = upstream->peer->child;
370 peer_hub = usb_hub_to_struct_hub(peer_hdev);
371 if (!peer_hub || port1 > peer_hdev->maxchild)
375 * we found a valid default peer, last check is to make sure it
376 * does not have location data
378 peer = peer_hub->ports[port1 - 1];
379 if (peer && peer->location == 0)
380 link_peers_report(port_dev, peer);
383 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
385 struct usb_port *port_dev;
388 port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
394 hub->ports[port1 - 1] = port_dev;
395 port_dev->portnum = port1;
396 set_bit(port1, hub->power_bits);
397 port_dev->dev.parent = hub->intfdev;
398 port_dev->dev.groups = port_dev_group;
399 port_dev->dev.type = &usb_port_device_type;
400 port_dev->dev.driver = &usb_port_driver;
401 if (hub_is_superspeed(hub->hdev))
402 port_dev->is_superspeed = 1;
403 dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
405 mutex_init(&port_dev->status_lock);
406 retval = device_register(&port_dev->dev);
410 find_and_link_peer(hub, port1);
412 pm_runtime_set_active(&port_dev->dev);
415 * Do not enable port runtime pm if the hub does not support
416 * power switching. Also, userspace must have final say of
417 * whether a port is permitted to power-off. Do not enable
418 * runtime pm if we fail to expose pm_qos_no_power_off.
420 if (hub_is_port_power_switchable(hub)
421 && dev_pm_qos_expose_flags(&port_dev->dev,
422 PM_QOS_FLAG_NO_POWER_OFF) == 0)
423 pm_runtime_enable(&port_dev->dev);
425 device_enable_async_suspend(&port_dev->dev);
429 put_device(&port_dev->dev);
434 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
436 struct usb_port *port_dev = hub->ports[port1 - 1];
437 struct usb_port *peer;
439 peer = port_dev->peer;
441 unlink_peers(port_dev, peer);
442 device_unregister(&port_dev->dev);