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(alt->retimer, &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(alt->mux, &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(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(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, 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, 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(&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(&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->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->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, "%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, struct device_driver *driver)
451{
452	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		    (id->mode == TYPEC_ANY_MODE || id->mode == altmode->mode))
459			return 1;
460	return 0;
461}
462
463static int typec_uevent(const struct device *dev, struct kobj_uevent_env *env)
464{
465	const struct typec_altmode *altmode = to_typec_altmode(dev);
466
467	if (add_uevent_var(env, "SVID=%04X", altmode->svid))
468		return -ENOMEM;
469
470	if (add_uevent_var(env, "MODE=%u", altmode->mode))
471		return -ENOMEM;
472
473	return add_uevent_var(env, "MODALIAS=typec:id%04Xm%02X",
474			      altmode->svid, altmode->mode);
475}
476
477static int typec_altmode_create_links(struct altmode *alt)
478{
479	struct device *port_dev = &alt->partner->adev.dev;
480	struct device *dev = &alt->adev.dev;
481	int err;
482
483	err = sysfs_create_link(&dev->kobj, &port_dev->kobj, "port");
484	if (err)
485		return err;
486
487	err = sysfs_create_link(&port_dev->kobj, &dev->kobj, "partner");
488	if (err)
489		sysfs_remove_link(&dev->kobj, "port");
490
491	return err;
492}
493
494static void typec_altmode_remove_links(struct altmode *alt)
495{
496	sysfs_remove_link(&alt->partner->adev.dev.kobj, "partner");
497	sysfs_remove_link(&alt->adev.dev.kobj, "port");
498}
499
500static int typec_probe(struct device *dev)
501{
502	struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
503	struct typec_altmode *adev = to_typec_altmode(dev);
504	struct altmode *altmode = to_altmode(adev);
505	int ret;
506
507	/* Fail if the port does not support the alternate mode */
508	if (!altmode->partner)
509		return -ENODEV;
510
511	ret = typec_altmode_create_links(altmode);
512	if (ret) {
513		dev_warn(dev, "failed to create symlinks\n");
514		return ret;
515	}
516
517	ret = drv->probe(adev);
518	if (ret)
519		typec_altmode_remove_links(altmode);
520
521	return ret;
522}
523
524static void typec_remove(struct device *dev)
525{
526	struct typec_altmode_driver *drv = to_altmode_driver(dev->driver);
527	struct typec_altmode *adev = to_typec_altmode(dev);
528	struct altmode *altmode = to_altmode(adev);
529
530	typec_altmode_remove_links(altmode);
531
532	if (drv->remove)
533		drv->remove(to_typec_altmode(dev));
534
535	if (adev->active) {
536		WARN_ON(typec_altmode_set_state(adev, TYPEC_STATE_SAFE, NULL));
537		typec_altmode_update_active(adev, false);
538	}
539
540	adev->desc = NULL;
541	adev->ops = NULL;
542}
543
544const struct bus_type typec_bus = {
545	.name = "typec",
546	.dev_groups = typec_groups,
547	.match = typec_match,
548	.uevent = typec_uevent,
549	.probe = typec_probe,
550	.remove = typec_remove,
551};
552