drivers/usb/typec/bus.c

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This source file includes following definitions.
typec_altmode_set_mux
typec_altmode_set_state
typec_altmode_notify
typec_altmode_enter
typec_altmode_exit
typec_altmode_attention
typec_altmode_vdm
typec_altmode_get_partner
typec_altmode_get_plug
typec_altmode_put_plug
__typec_altmode_register_driver
typec_altmode_unregister_driver
typec_match_altmode
description_show
typec_match
typec_uevent
typec_altmode_create_links
typec_altmode_remove_links
typec_probe
typec_remove
   1 // SPDX-License-Identifier: GPL-2.0
   2 /**
   3  * Bus for USB Type-C Alternate Modes
   4  *
   5  * Copyright (C) 2018 Intel Corporation
   6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
   7  */
   8 
   9 #include <linux/usb/pd_vdo.h>
  10 
  11 #include "bus.h"
  12 
  13 static inline int typec_altmode_set_mux(struct altmode *alt, u8 state)
  14 {
  15         return alt->mux ? alt->mux->set(alt->mux, state) : 0;
  16 }
  17 
  18 static int typec_altmode_set_state(struct typec_altmode *adev, int state)
  19 {
  20         bool is_port = is_typec_port(adev->dev.parent);
  21         struct altmode *port_altmode;
  22         int ret;
  23 
  24         port_altmode = is_port ? to_altmode(adev) : to_altmode(adev)->partner;
  25 
  26         ret = typec_altmode_set_mux(port_altmode, state);
  27         if (ret)
  28                 return ret;
  29 
  30         blocking_notifier_call_chain(&port_altmode->nh, state, NULL);
  31 
  32         return 0;
  33 }
  34 
  35 /* -------------------------------------------------------------------------- */
  36 /* Common API */
  37 
  38 /**
  39  * typec_altmode_notify - Communication between the OS and alternate mode driver
  40  * @adev: Handle to the alternate mode
  41  * @conf: Alternate mode specific configuration value
  42  * @data: Alternate mode specific data
  43  *
  44  * The primary purpose for this function is to allow the alternate mode drivers
  45  * to tell which pin configuration has been negotiated with the partner. That
  46  * information will then be used for example to configure the muxes.
  47  * Communication to the other direction is also possible, and low level device
  48  * drivers can also send notifications to the alternate mode drivers. The actual
  49  * communication will be specific for every SVID.
  50  */
  51 int typec_altmode_notify(struct typec_altmode *adev,
  52                          unsigned long conf, void *data)
  53 {
  54         bool is_port;
  55         struct altmode *altmode;
  56         struct altmode *partner;
  57         int ret;
  58 
  59         if (!adev)
  60                 return 0;
  61 
  62         altmode = to_altmode(adev);
  63 
  64         if (!altmode->partner)
  65                 return -ENODEV;
  66 
  67         is_port = is_typec_port(adev->dev.parent);
  68         partner = altmode->partner;
  69 
  70         ret = typec_altmode_set_mux(is_port ? altmode : partner, (u8)conf);
  71         if (ret)
  72                 return ret;
  73 
  74         blocking_notifier_call_chain(is_port ? &altmode->nh : &partner->nh,
  75                                      conf, data);
  76 
  77         if (partner->adev.ops && partner->adev.ops->notify)
  78                 return partner->adev.ops->notify(&partner->adev, conf, data);
  79 
  80         return 0;
  81 }
  82 EXPORT_SYMBOL_GPL(typec_altmode_notify);
  83 
  84 /**
  85  * typec_altmode_enter - Enter Mode
  86  * @adev: The alternate mode
  87  *
  88  * The alternate mode drivers use this function to enter mode. The port drivers
  89  * use this to inform the alternate mode drivers that the partner has initiated
  90  * Enter Mode command.
  91  */
  92 int typec_altmode_enter(struct typec_altmode *adev)
  93 {
  94         struct altmode *partner = to_altmode(adev)->partner;
  95         struct typec_altmode *pdev = &partner->adev;
  96         int ret;
  97 
  98         if (!adev || adev->active)
  99                 return 0;
 100 
 101         if (!pdev->ops || !pdev->ops->enter)
 102                 return -EOPNOTSUPP;
 103 
 104         /* Moving to USB Safe State */
 105         ret = typec_altmode_set_state(adev, TYPEC_STATE_SAFE);
 106         if (ret)
 107                 return ret;
 108 
 109         /* Enter Mode */
 110         return pdev->ops->enter(pdev);
 111 }
 112 EXPORT_SYMBOL_GPL(typec_altmode_enter);
 113 
 114 /**
 115  * typec_altmode_exit - Exit Mode
 116  * @adev: The alternate mode
 117  *
 118  * The partner of @adev has initiated Exit Mode command.
 119  */
 120 int typec_altmode_exit(struct typec_altmode *adev)
 121 {
 122         struct altmode *partner = to_altmode(adev)->partner;
 123         struct typec_altmode *pdev = &partner->adev;
 124         int ret;
 125 
 126         if (!adev || !adev->active)
 127                 return 0;
 128 
 129         if (!pdev->ops || !pdev->ops->enter)
 130                 return -EOPNOTSUPP;
 131 
 132         /* Moving to USB Safe State */
 133         ret = typec_altmode_set_state(adev, TYPEC_STATE_SAFE);
 134         if (ret)
 135                 return ret;
 136 
 137         /* Exit Mode command */
 138         return pdev->ops->exit(pdev);
 139 }
 140 EXPORT_SYMBOL_GPL(typec_altmode_exit);
 141 
 142 /**
 143  * typec_altmode_attention - Attention command
 144  * @adev: The alternate mode
 145  * @vdo: VDO for the Attention command
 146  *
 147  * Notifies the partner of @adev about Attention command.
 148  */
 149 void typec_altmode_attention(struct typec_altmode *adev, u32 vdo)
 150 {
 151         struct typec_altmode *pdev = &to_altmode(adev)->partner->adev;
 152 
 153         if (pdev->ops && pdev->ops->attention)
 154                 pdev->ops->attention(pdev, vdo);
 155 }
 156 EXPORT_SYMBOL_GPL(typec_altmode_attention);
 157 
 158 /**
 159  * typec_altmode_vdm - Send Vendor Defined Messages (VDM) to the partner
 160  * @adev: Alternate mode handle
 161  * @header: VDM Header
 162  * @vdo: Array of Vendor Defined Data Objects
 163  * @count: Number of Data Objects
 164  *
 165  * The alternate mode drivers use this function for SVID specific communication
 166  * with the partner. The port drivers use it to deliver the Structured VDMs
 167  * received from the partners to the alternate mode drivers.
 168  */
 169 int typec_altmode_vdm(struct typec_altmode *adev,
 170                       const u32 header, const u32 *vdo, int count)
 171 {
 172         struct typec_altmode *pdev;
 173         struct altmode *altmode;
 174 
 175         if (!adev)
 176                 return 0;
 177 
 178         altmode = to_altmode(adev);
 179 
 180         if (!altmode->partner)
 181                 return -ENODEV;
 182 
 183         pdev = &altmode->partner->adev;
 184 
 185         if (!pdev->ops || !pdev->ops->vdm)
 186                 return -EOPNOTSUPP;
 187 
 188         return pdev->ops->vdm(pdev, header, vdo, count);
 189 }
 190 EXPORT_SYMBOL_GPL(typec_altmode_vdm);
 191 
 192 const struct typec_altmode *
 193 typec_altmode_get_partner(struct typec_altmode *adev)
 194 {
 195         if (!adev || !to_altmode(adev)->partner)
 196                 return NULL;
 197 
 198         return &to_altmode(adev)->partner->adev;
 199 }
 200 EXPORT_SYMBOL_GPL(typec_altmode_get_partner);
 201 
 202 /* -------------------------------------------------------------------------- */
 203 /* API for the alternate mode drivers */
 204 
 205 /**
 206  * typec_altmode_get_plug - Find cable plug alternate mode
 207  * @adev: Handle to partner alternate mode
 208  * @index: Cable plug index
 209  *
 210  * Increment reference count for cable plug alternate mode device. Returns
 211  * handle to the cable plug alternate mode, or NULL if none is found.
 212  */
 213 struct typec_altmode *typec_altmode_get_plug(struct typec_altmode *adev,
 214                                              enum typec_plug_index index)
 215 {
 216         struct altmode *port = to_altmode(adev)->partner;
 217 
 218         if (port->plug[index]) {
 219                 get_device(&port->plug[index]->adev.dev);
 220                 return &port->plug[index]->adev;
 221         }
 222 
 223         return NULL;
 224 }
 225 EXPORT_SYMBOL_GPL(typec_altmode_get_plug);
 226 
 227 /**
 228  * typec_altmode_put_plug - Decrement cable plug alternate mode reference count
 229  * @plug: Handle to the cable plug alternate mode
 230  */
 231 void typec_altmode_put_plug(struct typec_altmode *plug)
 232 {
 233         if (plug)
 234                 put_device(&plug->dev);
 235 }
 236 EXPORT_SYMBOL_GPL(typec_altmode_put_plug);
 237 
 238 int __typec_altmode_register_driver(struct typec_altmode_driver *drv,
 239                                     struct module *module)
 240 {
 241         if (!drv->probe)
 242                 return -EINVAL;
 243 
 244         drv->driver.owner = module;
 245         drv->driver.bus = &typec_bus;
 246 
 247         return driver_register(&drv->driver);
 248 }
 249 EXPORT_SYMBOL_GPL(__typec_altmode_register_driver);
 250 
 251 void typec_altmode_unregister_driver(struct typec_altmode_driver *drv)
 252 {
 253         driver_unregister(&drv->driver);
 254 }
 255 EXPORT_SYMBOL_GPL(typec_altmode_unregister_driver);
 256 
 257 /* -------------------------------------------------------------------------- */
 258 /* API for the port drivers */
 259 
 260 /**
 261  * typec_match_altmode - Match SVID and mode to an array of alternate modes
 262  * @altmodes: Array of alternate modes
 263  * @n: Number of elements in the array, or -1 for NULL terminated arrays
 264  * @svid: Standard or Vendor ID to match with
 265  * @mode: Mode to match with
 266  *
 267  * Return pointer to an alternate mode with SVID matching @svid, or NULL when no
 268  * match is found.
 269  */
 270 struct typec_altmode *typec_match_altmode(struct typec_altmode **altmodes,
 271                                           size_t n, u16 svid, u8 mode)
 272 {
 273         int i;
 274 
 275         for (i = 0; i < n; i++) {
 276                 if (!altmodes[i])
 277                         break;
 278                 if (altmodes[i]->svid == svid && altmodes[i]->mode == mode)
 279                         return altmodes[i];
 280         }
 281 
 282         return NULL;
 283 }
 284 EXPORT_SYMBOL_GPL(typec_match_altmode);
 285 
 286 /* -------------------------------------------------------------------------- */
 287 
 288 static ssize_t
 289 description_show(struct device *dev, struct device_attribute *attr, char *buf)
 290 {
 291         struct typec_altmode *alt = to_typec_altmode(dev);
 292 
 293         return sprintf(buf, "%s\n", alt->desc ? alt->desc : "");
 294 }
 295 static DEVICE_ATTR_RO(description);
 296 
 297 static struct attribute *typec_attrs[] = {
 298         &dev_attr_description.attr,
 299         NULL
 300 };
 301 ATTRIBUTE_GROUPS(typec);
 302 
 303 static int typec_match(struct device *dev, struct device_driver *driver)
 304 {
 305         struct typec_altmode_driver *drv = to_altmode_driver(driver);
 306         struct typec_altmode *altmode = to_typec_altmode(dev);
 307         const struct typec_device_id *id;
 308 
 309         for (id = drv->id_table; id->svid; id++)
 310                 if (id->svid == altmode->svid &&
 311                     (id->mode == TYPEC_ANY_MODE || id->mode == altmode->mode))
 312                         return 1;
 313         return 0;
 314 }
 315 
 316 static int typec_uevent(struct device *dev, struct kobj_uevent_env *env)
 317 {
 318         struct typec_altmode *altmode = to_typec_altmode(dev);
 319 
 320         if (add_uevent_var(env, "SVID=%04X", altmode->svid))
 321                 return -ENOMEM;
 322 
 323         if (add_uevent_var(env, "MODE=%u", altmode->mode))
 324                 return -ENOMEM;
 325 
 326         return add_uevent_var(env, "MODALIAS=typec:id%04Xm%02X",
 327                               altmode->svid, altmode->mode);
 328 }
 329 
 330 static int typec_altmode_create_links(struct altmode *alt)
 331 {
 332         struct device *port_dev = &alt->partner->adev.dev;
 333         struct device *dev = &alt->adev.dev;
 334         int err;
 335 
 336         err = sysfs_create_link(&dev->kobj, &port_dev->kobj, "port");
 337         if (err)
 338                 return err;
 339 
 340         err = sysfs_create_link(&port_dev->kobj, &dev->kobj, "partner");
 341         if (err)
 342                 sysfs_remove_link(&dev->kobj, "port");
 343 
 344         return err;
 345 }
 346 
 347 static void typec_altmode_remove_links(struct altmode *alt)
 348 {
 349         sysfs_remove_link(&alt->partner->adev.dev.kobj, "partner");
 350         sysfs_remove_link(&alt->adev.dev.kobj, "port");
 351 }
 352 
 353 static int typec_probe(struct device *dev)
 354 {
 355         struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
 356         struct typec_altmode *adev = to_typec_altmode(dev);
 357         struct altmode *altmode = to_altmode(adev);
 358         int ret;
 359 
 360         /* Fail if the port does not support the alternate mode */
 361         if (!altmode->partner)
 362                 return -ENODEV;
 363 
 364         ret = typec_altmode_create_links(altmode);
 365         if (ret) {
 366                 dev_warn(dev, "failed to create symlinks\n");
 367                 return ret;
 368         }
 369 
 370         ret = drv->probe(adev);
 371         if (ret)
 372                 typec_altmode_remove_links(altmode);
 373 
 374         return ret;
 375 }
 376 
 377 static int typec_remove(struct device *dev)
 378 {
 379         struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
 380         struct typec_altmode *adev = to_typec_altmode(dev);
 381         struct altmode *altmode = to_altmode(adev);
 382 
 383         typec_altmode_remove_links(altmode);
 384 
 385         if (drv->remove)
 386                 drv->remove(to_typec_altmode(dev));
 387 
 388         if (adev->active) {
 389                 WARN_ON(typec_altmode_set_state(adev, TYPEC_STATE_SAFE));
 390                 typec_altmode_update_active(adev, false);
 391         }
 392 
 393         adev->desc = NULL;
 394         adev->ops = NULL;
 395 
 396         return 0;
 397 }
 398 
 399 struct bus_type typec_bus = {
 400         .name = "typec",
 401         .dev_groups = typec_groups,
 402         .match = typec_match,
 403         .uevent = typec_uevent,
 404         .probe = typec_probe,
 405         .remove = typec_remove,
 406 };
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/usb/typec/bus.c

DEFINITIONS
