drivers/usb/core/port.c

   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
  19 #include <linux/slab.h>
  20 #include <linux/pm_qos.h>
  21
  22 #include "hub.h"
  23
  24 static const struct attribute_group *port_dev_group[];
  25
  26 static ssize_t connect_type_show(struct device *dev,
  27                                  struct device_attribute *attr, char *buf)
  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 }
  49 static DEVICE_ATTR_RO(connect_type);
  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
  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
  72 #ifdef CONFIG_PM_RUNTIME
  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);
  78         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
  79         int port1 = port_dev->portnum;
  80         int retval;
  81
  82         if (!hub)
  83                 return -EINVAL;
  84         if (hub->in_reset) {
  85                 port_dev->power_is_on = 1;
  86                 return 0;
  87         }
  88
  89         usb_autopm_get_interface(intf);
  90         set_bit(port1, hub->busy_bits);
  91
  92         retval = usb_hub_set_port_power(hdev, hub, port1, true);
  93         if (port_dev->child && !retval) {
  94                 /*
  95                  * Attempt to wait for usb hub port to be reconnected in order
  96                  * to make the resume procedure successful.  The device may have
  97                  * disconnected while the port was powered off, so ignore the
  98                  * return status.
  99                  */
 100                 retval = hub_port_debounce_be_connected(hub, port1);
 101                 if (retval < 0)
 102                         dev_dbg(&port_dev->dev, "can't get reconnection after setting port  power on, status %d\n",
 103                                         retval);
 104                 usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_ENABLE);
 105                 retval = 0;
 106         }
 107
 108         clear_bit(port1, hub->busy_bits);
 109         usb_autopm_put_interface(intf);
 110         return retval;
 111 }
 112
 113 static int usb_port_runtime_suspend(struct device *dev)
 114 {
 115         struct usb_port *port_dev = to_usb_port(dev);
 116         struct usb_device *hdev = to_usb_device(dev->parent->parent);
 117         struct usb_interface *intf = to_usb_interface(dev->parent);
 118         struct usb_hub *hub = usb_hub_to_struct_hub(hdev);
 119         int port1 = port_dev->portnum;
 120         int retval;
 121
 122         if (!hub)
 123                 return -EINVAL;
 124         if (hub->in_reset)
 125                 return -EBUSY;
 126
 127         if (dev_pm_qos_flags(&port_dev->dev, PM_QOS_FLAG_NO_POWER_OFF)
 128                         == PM_QOS_FLAGS_ALL)
 129                 return -EAGAIN;
 130
 131         usb_autopm_get_interface(intf);
 132         set_bit(port1, hub->busy_bits);
 133         retval = usb_hub_set_port_power(hdev, hub, port1, false);
 134         usb_clear_port_feature(hdev, port1, USB_PORT_FEAT_C_CONNECTION);
 135         usb_clear_port_feature(hdev, port1,     USB_PORT_FEAT_C_ENABLE);
 136         clear_bit(port1, hub->busy_bits);
 137         usb_autopm_put_interface(intf);
 138         return retval;
 139 }
 140 #endif
 141
 142 static const struct dev_pm_ops usb_port_pm_ops = {
 143 #ifdef CONFIG_PM_RUNTIME
 144         .runtime_suspend =      usb_port_runtime_suspend,
 145         .runtime_resume =       usb_port_runtime_resume,
 146 #endif
 147 };
 148
 149 struct device_type usb_port_device_type = {
 150         .name =         "usb_port",
 151         .release =      usb_port_device_release,
 152         .pm =           &usb_port_pm_ops,
 153 };
 154
 155 static struct device_driver usb_port_driver = {
 156         .name = "usb",
 157         .owner = THIS_MODULE,
 158 };
 159
 160 static void link_peers(struct usb_port *left, struct usb_port *right)
 161 {
 162         if (left->peer == right && right->peer == left)
 163                 return;
 164
 165         if (left->peer || right->peer) {
 166                 struct usb_port *lpeer = left->peer;
 167                 struct usb_port *rpeer = right->peer;
 168
 169                 WARN(1, "failed to peer %s and %s (%s -> %p) (%s -> %p)\n",
 170                         dev_name(&left->dev), dev_name(&right->dev),
 171                         dev_name(&left->dev), lpeer,
 172                         dev_name(&right->dev), rpeer);
 173                 return;
 174         }
 175
 176         left->peer = right;
 177         right->peer = left;
 178 }
 179
 180 static void unlink_peers(struct usb_port *left, struct usb_port *right)
 181 {
 182         WARN(right->peer != left || left->peer != right,
 183                         "%s and %s are not peers?\n",
 184                         dev_name(&left->dev), dev_name(&right->dev));
 185
 186         right->peer = NULL;
 187         left->peer = NULL;
 188 }
 189
 190 /*
 191  * For each usb hub device in the system check to see if it is in the
 192  * peer domain of the given port_dev, and if it is check to see if it
 193  * has a port that matches the given port by location
 194  */
 195 static int match_location(struct usb_device *peer_hdev, void *p)
 196 {
 197         int port1;
 198         struct usb_hcd *hcd, *peer_hcd;
 199         struct usb_port *port_dev = p, *peer;
 200         struct usb_hub *peer_hub = usb_hub_to_struct_hub(peer_hdev);
 201         struct usb_device *hdev = to_usb_device(port_dev->dev.parent->parent);
 202
 203         if (!peer_hub)
 204                 return 0;
 205
 206         hcd = bus_to_hcd(hdev->bus);
 207         peer_hcd = bus_to_hcd(peer_hdev->bus);
 208         /* peer_hcd is provisional until we verify it against the known peer */
 209         if (peer_hcd != hcd->shared_hcd)
 210                 return 0;
 211
 212         for (port1 = 1; port1 <= peer_hdev->maxchild; port1++) {
 213                 peer = peer_hub->ports[port1 - 1];
 214                 if (peer && peer->location == port_dev->location) {
 215                         link_peers(port_dev, peer);
 216                         return 1; /* done */
 217                 }
 218         }
 219
 220         return 0;
 221 }
 222
 223 /*
 224  * Find the peer port either via explicit platform firmware "location"
 225  * data, the peer hcd for root hubs, or the upstream peer relationship
 226  * for all other hubs.
 227  */
 228 static void find_and_link_peer(struct usb_hub *hub, int port1)
 229 {
 230         struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
 231         struct usb_device *hdev = hub->hdev;
 232         struct usb_device *peer_hdev;
 233         struct usb_hub *peer_hub;
 234
 235         /*
 236          * If location data is available then we can only peer this port
 237          * by a location match, not the default peer (lest we create a
 238          * situation where we need to go back and undo a default peering
 239          * when the port is later peered by location data)
 240          */
 241         if (port_dev->location) {
 242                 /* we link the peer in match_location() if found */
 243                 usb_for_each_dev(port_dev, match_location);
 244                 return;
 245         } else if (!hdev->parent) {
 246                 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
 247                 struct usb_hcd *peer_hcd = hcd->shared_hcd;
 248
 249                 if (!peer_hcd)
 250                         return;
 251
 252                 peer_hdev = peer_hcd->self.root_hub;
 253         } else {
 254                 struct usb_port *upstream;
 255                 struct usb_device *parent = hdev->parent;
 256                 struct usb_hub *parent_hub = usb_hub_to_struct_hub(parent);
 257
 258                 if (!parent_hub)
 259                         return;
 260
 261                 upstream = parent_hub->ports[hdev->portnum - 1];
 262                 if (!upstream || !upstream->peer)
 263                         return;
 264
 265                 peer_hdev = upstream->peer->child;
 266         }
 267
 268         peer_hub = usb_hub_to_struct_hub(peer_hdev);
 269         if (!peer_hub || port1 > peer_hdev->maxchild)
 270                 return;
 271
 272         /*
 273          * we found a valid default peer, last check is to make sure it
 274          * does not have location data
 275          */
 276         peer = peer_hub->ports[port1 - 1];
 277         if (peer && peer->location == 0)
 278                 link_peers(port_dev, peer);
 279 }
 280
 281 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 282 {
 283         struct usb_port *port_dev;
 284         int retval;
 285
 286         port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 287         if (!port_dev) {
 288                 retval = -ENOMEM;
 289                 goto exit;
 290         }
 291
 292         hub->ports[port1 - 1] = port_dev;
 293         port_dev->portnum = port1;
 294         port_dev->power_is_on = true;
 295         port_dev->dev.parent = hub->intfdev;
 296         port_dev->dev.groups = port_dev_group;
 297         port_dev->dev.type = &usb_port_device_type;
 298         port_dev->dev.driver = &usb_port_driver;
 299         dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
 300                         port1);
 301         retval = device_register(&port_dev->dev);
 302         if (retval)
 303                 goto error_register;
 304
 305         find_and_link_peer(hub, port1);
 306
 307         pm_runtime_set_active(&port_dev->dev);
 308
 309         /*
 310          * Do not enable port runtime pm if the hub does not support
 311          * power switching.  Also, userspace must have final say of
 312          * whether a port is permitted to power-off.  Do not enable
 313          * runtime pm if we fail to expose pm_qos_no_power_off.
 314          */
 315         if (hub_is_port_power_switchable(hub)
 316                         && dev_pm_qos_expose_flags(&port_dev->dev,
 317                         PM_QOS_FLAG_NO_POWER_OFF) == 0)
 318                 pm_runtime_enable(&port_dev->dev);
 319
 320         device_enable_async_suspend(&port_dev->dev);
 321         return 0;
 322
 323 error_register:
 324         put_device(&port_dev->dev);
 325 exit:
 326         return retval;
 327 }
 328
 329 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 330 {
 331         struct usb_port *port_dev = hub->ports[port1 - 1];
 332         struct usb_port *peer;
 333
 334         peer = port_dev->peer;
 335         if (peer)
 336                 unlink_peers(port_dev, peer);
 337         device_unregister(&port_dev->dev);
 338 }