--- /dev/null
+/*
+ * 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
+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_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;
+}
+
+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");
+ usb_port_block_power_off = 1;
+ }
+}
+
+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)
+ return -ENOMEM;
+
+ port_dev->req = kzalloc(sizeof(*(port_dev->req)), GFP_KERNEL);
+ if (!port_dev->req) {
+ kfree(port_dev);
+ return -ENOMEM;
+ }
+
+ 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);
+ mutex_init(&port_dev->status_lock);
+ retval = device_register(&port_dev->dev);
+ if (retval) {
+ put_device(&port_dev->dev);
+ return retval;
+ }
+
+ /* Set default policy of port-poweroff disabled. */
+ retval = dev_pm_qos_add_request(&port_dev->dev, port_dev->req,
+ DEV_PM_QOS_FLAGS, PM_QOS_FLAG_NO_POWER_OFF);
+ if (retval < 0) {
+ device_unregister(&port_dev->dev);
+ return retval;
+ }
+
+ find_and_link_peer(hub, port1);
+
+ /*
+ * Enable runtime pm and hold a refernce that hub_configure()
+ * will drop once the PM_QOS_NO_POWER_OFF flag state has been set
+ * and the hub has been fully registered (hdev->maxchild set).
+ */
+ pm_runtime_set_active(&port_dev->dev);
+ pm_runtime_get_noresume(&port_dev->dev);
+ pm_runtime_enable(&port_dev->dev);
+ device_enable_async_suspend(&port_dev->dev);
+
+ /*
+ * Keep hidden the ability to enable port-poweroff if the hub
+ * does not support power switching.
+ */
+ if (!hub_is_port_power_switchable(hub))
+ return 0;
+
+ /* Attempt to let userspace take over the policy. */
+ retval = dev_pm_qos_expose_flags(&port_dev->dev,
+ PM_QOS_FLAG_NO_POWER_OFF);
+ if (retval < 0) {
+ dev_warn(&port_dev->dev, "failed to expose pm_qos_no_poweroff\n");
+ return 0;
+ }
+
+ /* Userspace owns the policy, drop the kernel 'no_poweroff' request. */
+ retval = dev_pm_qos_remove_request(port_dev->req);
+ if (retval >= 0) {
+ kfree(port_dev->req);
+ port_dev->req = NULL;
+ }
+ return 0;
+}
+
+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);
+}
Code Review / kvmfornfv.git / blobdiff