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 #include "class.h" 13 #include "mux.h" 14 #include "retimer.h" 15 16 static inline int 17 typec_altmode_set_retimer(struct altmode *alt, unsigned long conf, void *data) 18 { 19 struct typec_retimer_state state; 20 21 if (!alt->retimer) 22 return 0; 23 24 state.alt = &alt->adev; 25 state.mode = conf; 26 state.data = data; 27 28 return typec_retimer_set(alt->retimer, &state); 29 } 30 31 static inline int 32 typec_altmode_set_mux(struct altmode *alt, unsigned long conf, void *data) 33 { 34 struct typec_mux_state state; 35 36 if (!alt->mux) 37 return 0; 38 39 state.alt = &alt->adev; 40 state.mode = conf; 41 state.data = data; 42 43 return typec_mux_set(alt->mux, &state); 44 } 45 46 /* Wrapper to set various Type-C port switches together. */ 47 static inline int 48 typec_altmode_set_switches(struct altmode *alt, unsigned long conf, void *data) 49 { 50 int ret; 51 52 ret = typec_altmode_set_retimer(alt, conf, data); 53 if (ret) 54 return ret; 55 56 return typec_altmode_set_mux(alt, conf, data); 57 } 58 59 static int typec_altmode_set_state(struct typec_altmode *adev, 60 unsigned long conf, void *data) 61 { 62 bool is_port = is_typec_port(adev->dev.parent); 63 struct altmode *port_altmode; 64 65 port_altmode = is_port ? to_altmode(adev) : to_altmode(adev)->partner; 66 67 return typec_altmode_set_switches(port_altmode, conf, data); 68 } 69 70 /* -------------------------------------------------------------------------- */ 71 /* Common API */ 72 73 /** 74 * typec_altmode_notify - Communication between the OS and alternate mode driver 75 * @adev: Handle to the alternate mode 76 * @conf: Alternate mode specific configuration value 77 * @data: Alternate mode specific data 78 * 79 * The primary purpose for this function is to allow the alternate mode drivers 80 * to tell which pin configuration has been negotiated with the partner. That 81 * information will then be used for example to configure the muxes. 82 * Communication to the other direction is also possible, and low level device 83 * drivers can also send notifications to the alternate mode drivers. The actual 84 * communication will be specific for every SVID. 85 */ 86 int typec_altmode_notify(struct typec_altmode *adev, 87 unsigned long conf, void *data) 88 { 89 bool is_port; 90 struct altmode *altmode; 91 struct altmode *partner; 92 int ret; 93 94 if (!adev) 95 return 0; 96 97 altmode = to_altmode(adev); 98 99 if (!altmode->partner) 100 return -ENODEV; 101 102 is_port = is_typec_port(adev->dev.parent); 103 partner = altmode->partner; 104 105 ret = typec_altmode_set_switches(is_port ? altmode : partner, conf, data); 106 if (ret) 107 return ret; 108 109 if (partner->adev.ops && partner->adev.ops->notify) 110 return partner->adev.ops->notify(&partner->adev, conf, data); 111 112 return 0; 113 } 114 EXPORT_SYMBOL_GPL(typec_altmode_notify); 115 116 /** 117 * typec_altmode_enter - Enter Mode 118 * @adev: The alternate mode 119 * @vdo: VDO for the Enter Mode command 120 * 121 * The alternate mode drivers use this function to enter mode. The port drivers 122 * use this to inform the alternate mode drivers that the partner has initiated 123 * Enter Mode command. If the alternate mode does not require VDO, @vdo must be 124 * NULL. 125 */ 126 int typec_altmode_enter(struct typec_altmode *adev, u32 *vdo) 127 { 128 struct altmode *partner = to_altmode(adev)->partner; 129 struct typec_altmode *pdev = &partner->adev; 130 int ret; 131 132 if (!adev || adev->active) 133 return 0; 134 135 if (!pdev->ops || !pdev->ops->enter) 136 return -EOPNOTSUPP; 137 138 if (is_typec_port(pdev->dev.parent) && !pdev->active) 139 return -EPERM; 140 141 /* Moving to USB Safe State */ 142 ret = typec_altmode_set_state(adev, TYPEC_STATE_SAFE, NULL); 143 if (ret) 144 return ret; 145 146 /* Enter Mode */ 147 return pdev->ops->enter(pdev, vdo); 148 } 149 EXPORT_SYMBOL_GPL(typec_altmode_enter); 150 151 /** 152 * typec_altmode_exit - Exit Mode 153 * @adev: The alternate mode 154 * 155 * The partner of @adev has initiated Exit Mode command. 156 */ 157 int typec_altmode_exit(struct typec_altmode *adev) 158 { 159 struct altmode *partner = to_altmode(adev)->partner; 160 struct typec_altmode *pdev = &partner->adev; 161 int ret; 162 163 if (!adev || !adev->active) 164 return 0; 165 166 if (!pdev->ops || !pdev->ops->exit) 167 return -EOPNOTSUPP; 168 169 /* Moving to USB Safe State */ 170 ret = typec_altmode_set_state(adev, TYPEC_STATE_SAFE, NULL); 171 if (ret) 172 return ret; 173 174 /* Exit Mode command */ 175 return pdev->ops->exit(pdev); 176 } 177 EXPORT_SYMBOL_GPL(typec_altmode_exit); 178 179 /** 180 * typec_altmode_attention - Attention command 181 * @adev: The alternate mode 182 * @vdo: VDO for the Attention command 183 * 184 * Notifies the partner of @adev about Attention command. 185 */ 186 void typec_altmode_attention(struct typec_altmode *adev, u32 vdo) 187 { 188 struct typec_altmode *pdev = &to_altmode(adev)->partner->adev; 189 190 if (pdev->ops && pdev->ops->attention) 191 pdev->ops->attention(pdev, vdo); 192 } 193 EXPORT_SYMBOL_GPL(typec_altmode_attention); 194 195 /** 196 * typec_altmode_vdm - Send Vendor Defined Messages (VDM) to the partner 197 * @adev: Alternate mode handle 198 * @header: VDM Header 199 * @vdo: Array of Vendor Defined Data Objects 200 * @count: Number of Data Objects 201 * 202 * The alternate mode drivers use this function for SVID specific communication 203 * with the partner. The port drivers use it to deliver the Structured VDMs 204 * received from the partners to the alternate mode drivers. 205 */ 206 int typec_altmode_vdm(struct typec_altmode *adev, 207 const u32 header, const u32 *vdo, int count) 208 { 209 struct typec_altmode *pdev; 210 struct altmode *altmode; 211 212 if (!adev) 213 return 0; 214 215 altmode = to_altmode(adev); 216 217 if (!altmode->partner) 218 return -ENODEV; 219 220 pdev = &altmode->partner->adev; 221 222 if (!pdev->ops || !pdev->ops->vdm) 223 return -EOPNOTSUPP; 224 225 return pdev->ops->vdm(pdev, header, vdo, count); 226 } 227 EXPORT_SYMBOL_GPL(typec_altmode_vdm); 228 229 const struct typec_altmode * 230 typec_altmode_get_partner(struct typec_altmode *adev) 231 { 232 if (!adev || !to_altmode(adev)->partner) 233 return NULL; 234 235 return &to_altmode(adev)->partner->adev; 236 } 237 EXPORT_SYMBOL_GPL(typec_altmode_get_partner); 238 239 /* -------------------------------------------------------------------------- */ 240 /* API for the alternate mode drivers */ 241 242 /** 243 * typec_altmode_get_plug - Find cable plug alternate mode 244 * @adev: Handle to partner alternate mode 245 * @index: Cable plug index 246 * 247 * Increment reference count for cable plug alternate mode device. Returns 248 * handle to the cable plug alternate mode, or NULL if none is found. 249 */ 250 struct typec_altmode *typec_altmode_get_plug(struct typec_altmode *adev, 251 enum typec_plug_index index) 252 { 253 struct altmode *port = to_altmode(adev)->partner; 254 255 if (port->plug[index]) { 256 get_device(&port->plug[index]->adev.dev); 257 return &port->plug[index]->adev; 258 } 259 260 return NULL; 261 } 262 EXPORT_SYMBOL_GPL(typec_altmode_get_plug); 263 264 /** 265 * typec_altmode_put_plug - Decrement cable plug alternate mode reference count 266 * @plug: Handle to the cable plug alternate mode 267 */ 268 void typec_altmode_put_plug(struct typec_altmode *plug) 269 { 270 if (plug) 271 put_device(&plug->dev); 272 } 273 EXPORT_SYMBOL_GPL(typec_altmode_put_plug); 274 275 int __typec_altmode_register_driver(struct typec_altmode_driver *drv, 276 struct module *module) 277 { 278 if (!drv->probe) 279 return -EINVAL; 280 281 drv->driver.owner = module; 282 drv->driver.bus = &typec_bus; 283 284 return driver_register(&drv->driver); 285 } 286 EXPORT_SYMBOL_GPL(__typec_altmode_register_driver); 287 288 void typec_altmode_unregister_driver(struct typec_altmode_driver *drv) 289 { 290 driver_unregister(&drv->driver); 291 } 292 EXPORT_SYMBOL_GPL(typec_altmode_unregister_driver); 293 294 /* -------------------------------------------------------------------------- */ 295 /* API for the port drivers */ 296 297 /** 298 * typec_match_altmode - Match SVID and mode to an array of alternate modes 299 * @altmodes: Array of alternate modes 300 * @n: Number of elements in the array, or -1 for NULL terminated arrays 301 * @svid: Standard or Vendor ID to match with 302 * @mode: Mode to match with 303 * 304 * Return pointer to an alternate mode with SVID matching @svid, or NULL when no 305 * match is found. 306 */ 307 struct typec_altmode *typec_match_altmode(struct typec_altmode **altmodes, 308 size_t n, u16 svid, u8 mode) 309 { 310 int i; 311 312 for (i = 0; i < n; i++) { 313 if (!altmodes[i]) 314 break; 315 if (altmodes[i]->svid == svid && altmodes[i]->mode == mode) 316 return altmodes[i]; 317 } 318 319 return NULL; 320 } 321 EXPORT_SYMBOL_GPL(typec_match_altmode); 322 323 /* -------------------------------------------------------------------------- */ 324 325 static ssize_t 326 description_show(struct device *dev, struct device_attribute *attr, char *buf) 327 { 328 struct typec_altmode *alt = to_typec_altmode(dev); 329 330 return sprintf(buf, "%s\n", alt->desc ? alt->desc : ""); 331 } 332 static DEVICE_ATTR_RO(description); 333 334 static struct attribute *typec_attrs[] = { 335 &dev_attr_description.attr, 336 NULL 337 }; 338 ATTRIBUTE_GROUPS(typec); 339 340 static int typec_match(struct device *dev, struct device_driver *driver) 341 { 342 struct typec_altmode_driver *drv = to_altmode_driver(driver); 343 struct typec_altmode *altmode = to_typec_altmode(dev); 344 const struct typec_device_id *id; 345 346 for (id = drv->id_table; id->svid; id++) 347 if (id->svid == altmode->svid && 348 (id->mode == TYPEC_ANY_MODE || id->mode == altmode->mode)) 349 return 1; 350 return 0; 351 } 352 353 static int typec_uevent(const struct device *dev, struct kobj_uevent_env *env) 354 { 355 const struct typec_altmode *altmode = to_typec_altmode(dev); 356 357 if (add_uevent_var(env, "SVID=%04X", altmode->svid)) 358 return -ENOMEM; 359 360 if (add_uevent_var(env, "MODE=%u", altmode->mode)) 361 return -ENOMEM; 362 363 return add_uevent_var(env, "MODALIAS=typec:id%04Xm%02X", 364 altmode->svid, altmode->mode); 365 } 366 367 static int typec_altmode_create_links(struct altmode *alt) 368 { 369 struct device *port_dev = &alt->partner->adev.dev; 370 struct device *dev = &alt->adev.dev; 371 int err; 372 373 err = sysfs_create_link(&dev->kobj, &port_dev->kobj, "port"); 374 if (err) 375 return err; 376 377 err = sysfs_create_link(&port_dev->kobj, &dev->kobj, "partner"); 378 if (err) 379 sysfs_remove_link(&dev->kobj, "port"); 380 381 return err; 382 } 383 384 static void typec_altmode_remove_links(struct altmode *alt) 385 { 386 sysfs_remove_link(&alt->partner->adev.dev.kobj, "partner"); 387 sysfs_remove_link(&alt->adev.dev.kobj, "port"); 388 } 389 390 static int typec_probe(struct device *dev) 391 { 392 struct typec_altmode_driver *drv = to_altmode_driver(dev->driver); 393 struct typec_altmode *adev = to_typec_altmode(dev); 394 struct altmode *altmode = to_altmode(adev); 395 int ret; 396 397 /* Fail if the port does not support the alternate mode */ 398 if (!altmode->partner) 399 return -ENODEV; 400 401 ret = typec_altmode_create_links(altmode); 402 if (ret) { 403 dev_warn(dev, "failed to create symlinks\n"); 404 return ret; 405 } 406 407 ret = drv->probe(adev); 408 if (ret) 409 typec_altmode_remove_links(altmode); 410 411 return ret; 412 } 413 414 static void typec_remove(struct device *dev) 415 { 416 struct typec_altmode_driver *drv = to_altmode_driver(dev->driver); 417 struct typec_altmode *adev = to_typec_altmode(dev); 418 struct altmode *altmode = to_altmode(adev); 419 420 typec_altmode_remove_links(altmode); 421 422 if (drv->remove) 423 drv->remove(to_typec_altmode(dev)); 424 425 if (adev->active) { 426 WARN_ON(typec_altmode_set_state(adev, TYPEC_STATE_SAFE, NULL)); 427 typec_altmode_update_active(adev, false); 428 } 429 430 adev->desc = NULL; 431 adev->ops = NULL; 432 } 433 434 const struct bus_type typec_bus = { 435 .name = "typec", 436 .dev_groups = typec_groups, 437 .match = typec_match, 438 .uevent = typec_uevent, 439 .probe = typec_probe, 440 .remove = typec_remove, 441 }; 442