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
16static inline int
17typec_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(retimer: alt->retimer, state: &state);
29}
30
31static inline int
32typec_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(mux: alt->mux, state: &state);
44}
45
46/* Wrapper to set various Type-C port switches together. */
47static inline int
48typec_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
59static 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(alt: 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 */
86int 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(alt: 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}
114EXPORT_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 */
126int 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, conf: TYPEC_STATE_SAFE, NULL);
143 if (ret)
144 return ret;
145
146 /* Enter Mode */
147 return pdev->ops->enter(pdev, vdo);
148}
149EXPORT_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 */
157int 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, conf: TYPEC_STATE_SAFE, NULL);
171 if (ret)
172 return ret;
173
174 /* Exit Mode command */
175 return pdev->ops->exit(pdev);
176}
177EXPORT_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 */
186int typec_altmode_attention(struct typec_altmode *adev, u32 vdo)
187{
188 struct altmode *partner = to_altmode(adev)->partner;
189 struct typec_altmode *pdev;
190
191 if (!partner)
192 return -ENODEV;
193
194 pdev = &partner->adev;
195
196 if (pdev->ops && pdev->ops->attention)
197 pdev->ops->attention(pdev, vdo);
198
199 return 0;
200}
201EXPORT_SYMBOL_GPL(typec_altmode_attention);
202
203/**
204 * typec_altmode_vdm - Send Vendor Defined Messages (VDM) to the partner
205 * @adev: Alternate mode handle
206 * @header: VDM Header
207 * @vdo: Array of Vendor Defined Data Objects
208 * @count: Number of Data Objects
209 *
210 * The alternate mode drivers use this function for SVID specific communication
211 * with the partner. The port drivers use it to deliver the Structured VDMs
212 * received from the partners to the alternate mode drivers.
213 */
214int typec_altmode_vdm(struct typec_altmode *adev,
215 const u32 header, const u32 *vdo, int count)
216{
217 struct typec_altmode *pdev;
218 struct altmode *altmode;
219
220 if (!adev)
221 return 0;
222
223 altmode = to_altmode(adev);
224
225 if (!altmode->partner)
226 return -ENODEV;
227
228 pdev = &altmode->partner->adev;
229
230 if (!pdev->ops || !pdev->ops->vdm)
231 return -EOPNOTSUPP;
232
233 return pdev->ops->vdm(pdev, header, vdo, count);
234}
235EXPORT_SYMBOL_GPL(typec_altmode_vdm);
236
237const struct typec_altmode *
238typec_altmode_get_partner(struct typec_altmode *adev)
239{
240 if (!adev || !to_altmode(adev)->partner)
241 return NULL;
242
243 return &to_altmode(adev)->partner->adev;
244}
245EXPORT_SYMBOL_GPL(typec_altmode_get_partner);
246
247/* -------------------------------------------------------------------------- */
248/* API for cable alternate modes */
249
250/**
251 * typec_cable_altmode_enter - Enter Mode
252 * @adev: The alternate mode
253 * @sop: Cable plug target for Enter Mode command
254 * @vdo: VDO for the Enter Mode command
255 *
256 * Alternate mode drivers use this function to enter mode on the cable plug.
257 * If the alternate mode does not require VDO, @vdo must be NULL.
258 */
259int typec_cable_altmode_enter(struct typec_altmode *adev, enum typec_plug_index sop, u32 *vdo)
260{
261 struct altmode *partner = to_altmode(adev)->partner;
262 struct typec_altmode *pdev;
263
264 if (!adev || adev->active)
265 return 0;
266
267 if (!partner)
268 return -ENODEV;
269
270 pdev = &partner->adev;
271
272 if (!pdev->active)
273 return -EPERM;
274
275 if (!pdev->cable_ops || !pdev->cable_ops->enter)
276 return -EOPNOTSUPP;
277
278 return pdev->cable_ops->enter(pdev, sop, vdo);
279}
280EXPORT_SYMBOL_GPL(typec_cable_altmode_enter);
281
282/**
283 * typec_cable_altmode_exit - Exit Mode
284 * @adev: The alternate mode
285 * @sop: Cable plug target for Exit Mode command
286 *
287 * The alternate mode drivers use this function to exit mode on the cable plug.
288 */
289int typec_cable_altmode_exit(struct typec_altmode *adev, enum typec_plug_index sop)
290{
291 struct altmode *partner = to_altmode(adev)->partner;
292 struct typec_altmode *pdev;
293
294 if (!adev || !adev->active)
295 return 0;
296
297 if (!partner)
298 return -ENODEV;
299
300 pdev = &partner->adev;
301
302 if (!pdev->cable_ops || !pdev->cable_ops->exit)
303 return -EOPNOTSUPP;
304
305 return pdev->cable_ops->exit(pdev, sop);
306}
307EXPORT_SYMBOL_GPL(typec_cable_altmode_exit);
308
309/**
310 * typec_cable_altmode_vdm - Send Vendor Defined Messages (VDM) between the cable plug and port.
311 * @adev: Alternate mode handle
312 * @sop: Cable plug target for VDM
313 * @header: VDM Header
314 * @vdo: Array of Vendor Defined Data Objects
315 * @count: Number of Data Objects
316 *
317 * The alternate mode drivers use this function for SVID specific communication
318 * with the cable plugs. The port drivers use it to deliver the Structured VDMs
319 * received from the cable plugs to the alternate mode drivers.
320 */
321int typec_cable_altmode_vdm(struct typec_altmode *adev, enum typec_plug_index sop,
322 const u32 header, const u32 *vdo, int count)
323{
324 struct altmode *altmode;
325 struct typec_altmode *pdev;
326
327 if (!adev)
328 return 0;
329
330 altmode = to_altmode(adev);
331
332 if (is_typec_plug(adev->dev.parent)) {
333 if (!altmode->partner)
334 return -ENODEV;
335 pdev = &altmode->partner->adev;
336 } else {
337 if (!altmode->plug[sop])
338 return -ENODEV;
339 pdev = &altmode->plug[sop]->adev;
340 }
341
342 if (!pdev->cable_ops || !pdev->cable_ops->vdm)
343 return -EOPNOTSUPP;
344
345 return pdev->cable_ops->vdm(pdev, sop, header, vdo, count);
346}
347EXPORT_SYMBOL_GPL(typec_cable_altmode_vdm);
348
349/* -------------------------------------------------------------------------- */
350/* API for the alternate mode drivers */
351
352/**
353 * typec_altmode_get_plug - Find cable plug alternate mode
354 * @adev: Handle to partner alternate mode
355 * @index: Cable plug index
356 *
357 * Increment reference count for cable plug alternate mode device. Returns
358 * handle to the cable plug alternate mode, or NULL if none is found.
359 */
360struct typec_altmode *typec_altmode_get_plug(struct typec_altmode *adev,
361 enum typec_plug_index index)
362{
363 struct altmode *port = to_altmode(adev)->partner;
364
365 if (port->plug[index]) {
366 get_device(dev: &port->plug[index]->adev.dev);
367 return &port->plug[index]->adev;
368 }
369
370 return NULL;
371}
372EXPORT_SYMBOL_GPL(typec_altmode_get_plug);
373
374/**
375 * typec_altmode_put_plug - Decrement cable plug alternate mode reference count
376 * @plug: Handle to the cable plug alternate mode
377 */
378void typec_altmode_put_plug(struct typec_altmode *plug)
379{
380 if (plug)
381 put_device(dev: &plug->dev);
382}
383EXPORT_SYMBOL_GPL(typec_altmode_put_plug);
384
385int __typec_altmode_register_driver(struct typec_altmode_driver *drv,
386 struct module *module)
387{
388 if (!drv->probe)
389 return -EINVAL;
390
391 drv->driver.owner = module;
392 drv->driver.bus = &typec_bus;
393
394 return driver_register(drv: &drv->driver);
395}
396EXPORT_SYMBOL_GPL(__typec_altmode_register_driver);
397
398void typec_altmode_unregister_driver(struct typec_altmode_driver *drv)
399{
400 driver_unregister(drv: &drv->driver);
401}
402EXPORT_SYMBOL_GPL(typec_altmode_unregister_driver);
403
404/* -------------------------------------------------------------------------- */
405/* API for the port drivers */
406
407/**
408 * typec_match_altmode - Match SVID and mode to an array of alternate modes
409 * @altmodes: Array of alternate modes
410 * @n: Number of elements in the array, or -1 for NULL terminated arrays
411 * @svid: Standard or Vendor ID to match with
412 * @mode: Mode to match with
413 *
414 * Return pointer to an alternate mode with SVID matching @svid, or NULL when no
415 * match is found.
416 */
417struct typec_altmode *typec_match_altmode(struct typec_altmode **altmodes,
418 size_t n, u16 svid, u8 mode)
419{
420 int i;
421
422 for (i = 0; i < n; i++) {
423 if (!altmodes[i])
424 break;
425 if (altmodes[i]->svid == svid && altmodes[i]->mode == mode)
426 return altmodes[i];
427 }
428
429 return NULL;
430}
431EXPORT_SYMBOL_GPL(typec_match_altmode);
432
433/* -------------------------------------------------------------------------- */
434
435static ssize_t
436description_show(struct device *dev, struct device_attribute *attr, char *buf)
437{
438 struct typec_altmode *alt = to_typec_altmode(dev);
439
440 return sprintf(buf, fmt: "%s\n", alt->desc ? alt->desc : "");
441}
442static DEVICE_ATTR_RO(description);
443
444static struct attribute *typec_attrs[] = {
445 &dev_attr_description.attr,
446 NULL
447};
448ATTRIBUTE_GROUPS(typec);
449
450static int typec_match(struct device *dev, const struct device_driver *driver)
451{
452 const struct typec_altmode_driver *drv = to_altmode_driver(driver);
453 struct typec_altmode *altmode = to_typec_altmode(dev);
454 const struct typec_device_id *id;
455
456 for (id = drv->id_table; id->svid; id++)
457 if (id->svid == altmode->svid)
458 return 1;
459 return 0;
460}
461
462static int typec_uevent(const struct device *dev, struct kobj_uevent_env *env)
463{
464 const struct typec_altmode *altmode = to_typec_altmode(dev);
465
466 if (add_uevent_var(env, format: "SVID=%04X", altmode->svid))
467 return -ENOMEM;
468
469 if (add_uevent_var(env, format: "MODE=%u", altmode->mode))
470 return -ENOMEM;
471
472 return add_uevent_var(env, format: "MODALIAS=typec:id%04X", altmode->svid);
473}
474
475static int typec_altmode_create_links(struct altmode *alt)
476{
477 struct device *port_dev = &alt->partner->adev.dev;
478 struct device *dev = &alt->adev.dev;
479 int err;
480
481 err = sysfs_create_link(kobj: &dev->kobj, target: &port_dev->kobj, name: "port");
482 if (err)
483 return err;
484
485 err = sysfs_create_link(kobj: &port_dev->kobj, target: &dev->kobj, name: "partner");
486 if (err)
487 sysfs_remove_link(kobj: &dev->kobj, name: "port");
488
489 return err;
490}
491
492static void typec_altmode_remove_links(struct altmode *alt)
493{
494 sysfs_remove_link(kobj: &alt->partner->adev.dev.kobj, name: "partner");
495 sysfs_remove_link(kobj: &alt->adev.dev.kobj, name: "port");
496}
497
498static int typec_probe(struct device *dev)
499{
500 struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
501 struct typec_altmode *adev = to_typec_altmode(dev);
502 struct altmode *altmode = to_altmode(adev);
503 int ret;
504
505 /* Fail if the port does not support the alternate mode */
506 if (!altmode->partner)
507 return -ENODEV;
508
509 ret = typec_altmode_create_links(alt: altmode);
510 if (ret) {
511 dev_warn(dev, "failed to create symlinks\n");
512 return ret;
513 }
514
515 ret = drv->probe(adev);
516 if (ret)
517 typec_altmode_remove_links(alt: altmode);
518
519 return ret;
520}
521
522static void typec_remove(struct device *dev)
523{
524 struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
525 struct typec_altmode *adev = to_typec_altmode(dev);
526 struct altmode *altmode = to_altmode(adev);
527
528 typec_altmode_remove_links(alt: altmode);
529
530 if (drv->remove)
531 drv->remove(to_typec_altmode(dev));
532
533 if (adev->active) {
534 WARN_ON(typec_altmode_set_state(adev, TYPEC_STATE_SAFE, NULL));
535 typec_altmode_update_active(alt: adev, active: false);
536 }
537
538 adev->desc = NULL;
539 adev->ops = NULL;
540}
541
542const struct bus_type typec_bus = {
543 .name = "typec",
544 .dev_groups = typec_groups,
545 .match = typec_match,
546 .uevent = typec_uevent,
547 .probe = typec_probe,
548 .remove = typec_remove,
549};
550

source code of linux/drivers/usb/typec/bus.c