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 /* set the default peer port for root hubs */
 191 static void find_and_link_peer(struct usb_hub *hub, int port1)
 192 {
 193         struct usb_port *port_dev = hub->ports[port1 - 1], *peer;
 194         struct usb_device *hdev = hub->hdev;
 195
 196         if (!hdev->parent) {
 197                 struct usb_hub *peer_hub;
 198                 struct usb_device *peer_hdev;
 199                 struct usb_hcd *hcd = bus_to_hcd(hdev->bus);
 200                 struct usb_hcd *peer_hcd = hcd->shared_hcd;
 201
 202                 if (!peer_hcd)
 203                         return;
 204
 205                 peer_hdev = peer_hcd->self.root_hub;
 206                 peer_hub = usb_hub_to_struct_hub(peer_hdev);
 207                 if (!peer_hub || port1 > peer_hdev->maxchild)
 208                         return;
 209
 210                 peer = peer_hub->ports[port1 - 1];
 211
 212                 if (peer)
 213                         link_peers(port_dev, peer);
 214         }
 215 }
 216
 217 int usb_hub_create_port_device(struct usb_hub *hub, int port1)
 218 {
 219         struct usb_port *port_dev;
 220         int retval;
 221
 222         port_dev = kzalloc(sizeof(*port_dev), GFP_KERNEL);
 223         if (!port_dev) {
 224                 retval = -ENOMEM;
 225                 goto exit;
 226         }
 227
 228         hub->ports[port1 - 1] = port_dev;
 229         port_dev->portnum = port1;
 230         port_dev->power_is_on = true;
 231         port_dev->dev.parent = hub->intfdev;
 232         port_dev->dev.groups = port_dev_group;
 233         port_dev->dev.type = &usb_port_device_type;
 234         port_dev->dev.driver = &usb_port_driver;
 235         dev_set_name(&port_dev->dev, "%s-port%d", dev_name(&hub->hdev->dev),
 236                         port1);
 237         retval = device_register(&port_dev->dev);
 238         if (retval)
 239                 goto error_register;
 240
 241         find_and_link_peer(hub, port1);
 242
 243         pm_runtime_set_active(&port_dev->dev);
 244
 245         /*
 246          * Do not enable port runtime pm if the hub does not support
 247          * power switching.  Also, userspace must have final say of
 248          * whether a port is permitted to power-off.  Do not enable
 249          * runtime pm if we fail to expose pm_qos_no_power_off.
 250          */
 251         if (hub_is_port_power_switchable(hub)
 252                         && dev_pm_qos_expose_flags(&port_dev->dev,
 253                         PM_QOS_FLAG_NO_POWER_OFF) == 0)
 254                 pm_runtime_enable(&port_dev->dev);
 255
 256         device_enable_async_suspend(&port_dev->dev);
 257         return 0;
 258
 259 error_register:
 260         put_device(&port_dev->dev);
 261 exit:
 262         return retval;
 263 }
 264
 265 void usb_hub_remove_port_device(struct usb_hub *hub, int port1)
 266 {
 267         struct usb_port *port_dev = hub->ports[port1 - 1];
 268         struct usb_port *peer;
 269
 270         peer = port_dev->peer;
 271         if (peer)
 272                 unlink_peers(port_dev, peer);
 273         device_unregister(&port_dev->dev);
 274 }