xref: /linux/drivers/usb/typec/altmodes/displayport.c (revision 8a18f896e667df491331371b55d4ad644dc51d60)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB Typec-C DisplayPort Alternate Mode driver
4  *
5  * Copyright (C) 2018 Intel Corporation
6  * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
7  *
8  * DisplayPort is trademark of VESA (www.vesa.org)
9  */
10 
11 #include <linux/delay.h>
12 #include <linux/mutex.h>
13 #include <linux/module.h>
14 #include <linux/property.h>
15 #include <linux/usb/pd_vdo.h>
16 #include <linux/usb/typec_dp.h>
17 #include <drm/drm_connector.h>
18 #include "displayport.h"
19 
20 #define DP_HEADER(_dp, ver, cmd)	(VDO((_dp)->alt->svid, 1, ver, cmd)	\
21 					 | VDO_OPOS(USB_TYPEC_DP_MODE))
22 
23 enum {
24 	DP_CONF_USB,
25 	DP_CONF_DFP_D,
26 	DP_CONF_UFP_D,
27 	DP_CONF_DUAL_D,
28 };
29 
30 /* Pin assignments that use USB3.1 Gen2 signaling to carry DP protocol */
31 #define DP_PIN_ASSIGN_GEN2_BR_MASK	(BIT(DP_PIN_ASSIGN_A) | \
32 					 BIT(DP_PIN_ASSIGN_B))
33 
34 /* Pin assignments that use DP v1.3 signaling to carry DP protocol */
35 #define DP_PIN_ASSIGN_DP_BR_MASK	(BIT(DP_PIN_ASSIGN_C) | \
36 					 BIT(DP_PIN_ASSIGN_D) | \
37 					 BIT(DP_PIN_ASSIGN_E) | \
38 					 BIT(DP_PIN_ASSIGN_F))
39 
40 /* DP only pin assignments */
41 #define DP_PIN_ASSIGN_DP_ONLY_MASK	(BIT(DP_PIN_ASSIGN_A) | \
42 					 BIT(DP_PIN_ASSIGN_C) | \
43 					 BIT(DP_PIN_ASSIGN_E))
44 
45 /* Pin assignments where one channel is for USB */
46 #define DP_PIN_ASSIGN_MULTI_FUNC_MASK	(BIT(DP_PIN_ASSIGN_B) | \
47 					 BIT(DP_PIN_ASSIGN_D) | \
48 					 BIT(DP_PIN_ASSIGN_F))
49 
50 enum dp_state {
51 	DP_STATE_IDLE,
52 	DP_STATE_ENTER,
53 	DP_STATE_ENTER_PRIME,
54 	DP_STATE_UPDATE,
55 	DP_STATE_CONFIGURE,
56 	DP_STATE_CONFIGURE_PRIME,
57 	DP_STATE_EXIT,
58 	DP_STATE_EXIT_PRIME,
59 };
60 
61 struct dp_altmode {
62 	struct typec_displayport_data data;
63 	struct typec_displayport_data data_prime;
64 
65 	enum dp_state state;
66 	bool hpd;
67 	bool pending_hpd;
68 	u32 irq_hpd_count;
69 	/*
70 	 * hpd is mandatory for irq_hpd assertion, so irq_hpd also needs its own pending flag if
71 	 * both hpd and irq_hpd are asserted in the first Status Update before the pin assignment
72 	 * is configured.
73 	 */
74 	bool pending_irq_hpd;
75 
76 	struct mutex lock; /* device lock */
77 	struct work_struct work;
78 	struct typec_altmode *alt;
79 	const struct typec_altmode *port;
80 	struct fwnode_handle *connector_fwnode;
81 	struct typec_altmode *plug_prime;
82 };
83 
84 static int dp_altmode_notify(struct dp_altmode *dp)
85 {
86 	unsigned long conf;
87 	u8 state;
88 
89 	if (dp->data.conf) {
90 		state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
91 		conf = TYPEC_MODAL_STATE(state);
92 	} else {
93 		conf = TYPEC_STATE_USB;
94 	}
95 
96 	return typec_altmode_notify(dp->alt, conf, &dp->data);
97 }
98 
99 static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
100 {
101 	u8 pin_assign = 0;
102 	u32 conf;
103 	u32 signal;
104 
105 	/* DP Signalling */
106 	signal = DP_CAP_DP_SIGNALLING(dp->port->vdo) & DP_CAP_DP_SIGNALLING(dp->alt->vdo);
107 	if (dp->plug_prime)
108 		signal &= DP_CAP_DP_SIGNALLING(dp->plug_prime->vdo);
109 
110 	conf = signal << DP_CONF_SIGNALLING_SHIFT;
111 
112 	switch (con) {
113 	case DP_STATUS_CON_DISABLED:
114 		return 0;
115 	case DP_STATUS_CON_DFP_D:
116 		conf |= DP_CONF_UFP_U_AS_DFP_D;
117 		pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
118 			     DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
119 		/* Account for active cable capabilities */
120 		if (dp->plug_prime)
121 			pin_assign &= DP_CAP_DFP_D_PIN_ASSIGN(dp->plug_prime->vdo);
122 		break;
123 	case DP_STATUS_CON_UFP_D:
124 	case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
125 		conf |= DP_CONF_UFP_U_AS_UFP_D;
126 		pin_assign = DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo) &
127 				 DP_CAP_PIN_ASSIGN_DFP_D(dp->port->vdo);
128 		/* Account for active cable capabilities */
129 		if (dp->plug_prime)
130 			pin_assign &= DP_CAP_UFP_D_PIN_ASSIGN(dp->plug_prime->vdo);
131 		break;
132 	default:
133 		break;
134 	}
135 
136 	/* Determining the initial pin assignment. */
137 	if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
138 		/* Is USB together with DP preferred */
139 		if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
140 		    pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
141 			pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
142 		else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
143 			pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
144 			/* Default to pin assign C if available */
145 			if (pin_assign & BIT(DP_PIN_ASSIGN_C))
146 				pin_assign = BIT(DP_PIN_ASSIGN_C);
147 		}
148 
149 		if (!pin_assign)
150 			return -EINVAL;
151 
152 		conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
153 	}
154 
155 	dp->data.conf = conf;
156 	if (dp->plug_prime)
157 		dp->data_prime.conf = conf;
158 
159 	return 0;
160 }
161 
162 static int dp_altmode_status_update(struct dp_altmode *dp)
163 {
164 	bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
165 	bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
166 	bool irq_hpd = !!(dp->data.status & DP_STATUS_IRQ_HPD);
167 	u8 con = DP_STATUS_CONNECTION(dp->data.status);
168 	int ret = 0;
169 
170 	if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
171 		dp->data.conf = 0;
172 		dp->data_prime.conf = 0;
173 		dp->state = dp->plug_prime ? DP_STATE_CONFIGURE_PRIME :
174 					     DP_STATE_CONFIGURE;
175 	} else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
176 		dp->state = DP_STATE_EXIT;
177 	} else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
178 		ret = dp_altmode_configure(dp, con);
179 		if (!ret) {
180 			dp->state = dp->plug_prime ? DP_STATE_CONFIGURE_PRIME :
181 						     DP_STATE_CONFIGURE;
182 			if (dp->hpd != hpd) {
183 				dp->hpd = hpd;
184 				dp->pending_hpd = true;
185 			}
186 			if (dp->hpd && dp->pending_hpd && irq_hpd)
187 				dp->pending_irq_hpd = true;
188 		}
189 	} else {
190 		drm_connector_oob_hotplug_event(dp->connector_fwnode,
191 						hpd ? connector_status_connected :
192 						      connector_status_disconnected);
193 		dp->hpd = hpd;
194 		sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
195 		if (hpd && irq_hpd) {
196 			dp->irq_hpd_count++;
197 			sysfs_notify(&dp->alt->dev.kobj, "displayport", "irq_hpd");
198 		}
199 	}
200 
201 	return ret;
202 }
203 
204 static int dp_altmode_configured(struct dp_altmode *dp)
205 {
206 	sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
207 	sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
208 	/*
209 	 * If the DFP_D/UFP_D sends a change in HPD when first notifying the
210 	 * DisplayPort driver that it is connected, then we wait until
211 	 * configuration is complete to signal HPD.
212 	 */
213 	if (dp->pending_hpd) {
214 		drm_connector_oob_hotplug_event(dp->connector_fwnode,
215 						connector_status_connected);
216 		sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
217 		dp->pending_hpd = false;
218 		if (dp->pending_irq_hpd) {
219 			dp->irq_hpd_count++;
220 			sysfs_notify(&dp->alt->dev.kobj, "displayport", "irq_hpd");
221 			dp->pending_irq_hpd = false;
222 		}
223 	}
224 
225 	return dp_altmode_notify(dp);
226 }
227 
228 static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
229 {
230 	int svdm_version = typec_altmode_get_svdm_version(dp->alt);
231 	u32 header;
232 	int ret;
233 
234 	if (svdm_version < 0)
235 		return svdm_version;
236 
237 	header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
238 	ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
239 	if (ret) {
240 		dev_err(&dp->alt->dev,
241 			"unable to put to connector to safe mode\n");
242 		return ret;
243 	}
244 
245 	ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
246 	if (ret)
247 		dp_altmode_notify(dp);
248 
249 	return ret;
250 }
251 
252 static int dp_altmode_configure_vdm_cable(struct dp_altmode *dp, u32 conf)
253 {
254 	int svdm_version = typec_altmode_get_cable_svdm_version(dp->plug_prime);
255 	u32 header;
256 
257 	if (svdm_version < 0)
258 		return svdm_version;
259 
260 	header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
261 
262 	return typec_cable_altmode_vdm(dp->plug_prime, TYPEC_PLUG_SOP_P, header, &conf, 2);
263 }
264 
265 static void dp_altmode_work(struct work_struct *work)
266 {
267 	struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
268 	int svdm_version;
269 	u32 header;
270 	u32 vdo;
271 	int ret;
272 
273 	mutex_lock(&dp->lock);
274 
275 	switch (dp->state) {
276 	case DP_STATE_ENTER:
277 		ret = typec_altmode_enter(dp->alt, NULL);
278 		if (ret && ret != -EBUSY)
279 			dev_err(&dp->alt->dev, "failed to enter mode: %d\n", ret);
280 		break;
281 	case DP_STATE_ENTER_PRIME:
282 		ret = typec_cable_altmode_enter(dp->alt, TYPEC_PLUG_SOP_P, NULL);
283 		/*
284 		 * If we fail to enter Alt Mode on SOP', then we should drop the
285 		 * plug from the driver and attempt to run the driver without
286 		 * it.
287 		 */
288 		if (ret && ret != -EBUSY) {
289 			dev_err(&dp->alt->dev, "plug failed to enter mode\n");
290 			dp->state = DP_STATE_ENTER;
291 			goto disable_prime;
292 		}
293 		break;
294 	case DP_STATE_UPDATE:
295 		svdm_version = typec_altmode_get_svdm_version(dp->alt);
296 		if (svdm_version < 0)
297 			break;
298 		header = DP_HEADER(dp, svdm_version, DP_CMD_STATUS_UPDATE);
299 		vdo = 1;
300 		ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
301 		if (ret)
302 			dev_err(&dp->alt->dev,
303 				"unable to send Status Update command (%d)\n",
304 				ret);
305 		break;
306 	case DP_STATE_CONFIGURE:
307 		ret = dp_altmode_configure_vdm(dp, dp->data.conf);
308 		if (ret)
309 			dev_err(&dp->alt->dev,
310 				"unable to send Configure command (%d)\n", ret);
311 		break;
312 	case DP_STATE_CONFIGURE_PRIME:
313 		ret = dp_altmode_configure_vdm_cable(dp, dp->data_prime.conf);
314 		if (ret) {
315 			dev_err(&dp->plug_prime->dev,
316 				"unable to send Configure command (%d)\n",
317 				ret);
318 			dp->state = DP_STATE_CONFIGURE;
319 			goto disable_prime;
320 		}
321 		break;
322 	case DP_STATE_EXIT:
323 		if (typec_altmode_exit(dp->alt))
324 			dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
325 		break;
326 	case DP_STATE_EXIT_PRIME:
327 		if (typec_cable_altmode_exit(dp->plug_prime, TYPEC_PLUG_SOP_P))
328 			dev_err(&dp->plug_prime->dev, "Exit Mode Failed!\n");
329 		break;
330 	default:
331 		break;
332 	}
333 
334 	dp->state = DP_STATE_IDLE;
335 
336 	mutex_unlock(&dp->lock);
337 	return;
338 
339 disable_prime:
340 	typec_altmode_put_plug(dp->plug_prime);
341 	dp->plug_prime = NULL;
342 	schedule_work(&dp->work);
343 	mutex_unlock(&dp->lock);
344 }
345 
346 static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
347 {
348 	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
349 	u8 old_state;
350 
351 	mutex_lock(&dp->lock);
352 
353 	old_state = dp->state;
354 	dp->data.status = vdo;
355 
356 	if (old_state != DP_STATE_IDLE)
357 		dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
358 			 old_state);
359 
360 	if (dp_altmode_status_update(dp))
361 		dev_warn(&alt->dev, "%s: status update failed\n", __func__);
362 
363 	if (dp_altmode_notify(dp))
364 		dev_err(&alt->dev, "%s: notification failed\n", __func__);
365 
366 	if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
367 		schedule_work(&dp->work);
368 
369 	mutex_unlock(&dp->lock);
370 }
371 
372 static int dp_altmode_vdm(struct typec_altmode *alt,
373 			  const u32 hdr, const u32 *vdo, int count)
374 {
375 	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
376 	int cmd_type = PD_VDO_CMDT(hdr);
377 	int cmd = PD_VDO_CMD(hdr);
378 	int ret = 0;
379 
380 	mutex_lock(&dp->lock);
381 
382 	if (dp->state != DP_STATE_IDLE) {
383 		ret = -EBUSY;
384 		goto err_unlock;
385 	}
386 
387 	switch (cmd_type) {
388 	case CMDT_RSP_ACK:
389 		switch (cmd) {
390 		case CMD_ENTER_MODE:
391 			typec_altmode_update_active(alt, true);
392 			dp->state = DP_STATE_UPDATE;
393 			break;
394 		case CMD_EXIT_MODE:
395 			typec_altmode_update_active(alt, false);
396 			dp->data.status = 0;
397 			dp->data.conf = 0;
398 			if (dp->hpd) {
399 				drm_connector_oob_hotplug_event(dp->connector_fwnode,
400 								connector_status_disconnected);
401 				dp->hpd = false;
402 				sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
403 			}
404 			if (dp->plug_prime)
405 				dp->state = DP_STATE_EXIT_PRIME;
406 			break;
407 		case DP_CMD_STATUS_UPDATE:
408 			if (count < 2)
409 				break;
410 			dp->data.status = *vdo;
411 			ret = dp_altmode_status_update(dp);
412 			break;
413 		case DP_CMD_CONFIGURE:
414 			ret = dp_altmode_configured(dp);
415 			break;
416 		default:
417 			break;
418 		}
419 		break;
420 	case CMDT_RSP_NAK:
421 		switch (cmd) {
422 		case DP_CMD_STATUS_UPDATE:
423 			dp->state = DP_STATE_EXIT;
424 			break;
425 		case DP_CMD_CONFIGURE:
426 			dp->data.conf = 0;
427 			ret = dp_altmode_configured(dp);
428 			break;
429 		default:
430 			break;
431 		}
432 		break;
433 	default:
434 		break;
435 	}
436 
437 	if (dp->state != DP_STATE_IDLE)
438 		schedule_work(&dp->work);
439 
440 err_unlock:
441 	mutex_unlock(&dp->lock);
442 	return ret;
443 }
444 
445 static int dp_cable_altmode_vdm(struct typec_altmode *alt, enum typec_plug_index sop,
446 				const u32 hdr, const u32 *vdo, int count)
447 {
448 	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
449 	int cmd_type = PD_VDO_CMDT(hdr);
450 	int cmd = PD_VDO_CMD(hdr);
451 	int ret = 0;
452 
453 	mutex_lock(&dp->lock);
454 
455 	if (dp->state != DP_STATE_IDLE) {
456 		ret = -EBUSY;
457 		goto err_unlock;
458 	}
459 
460 	switch (cmd_type) {
461 	case CMDT_RSP_ACK:
462 		switch (cmd) {
463 		case CMD_ENTER_MODE:
464 			typec_altmode_update_active(dp->plug_prime, true);
465 			dp->state = DP_STATE_ENTER;
466 			break;
467 		case CMD_EXIT_MODE:
468 			dp->data_prime.status = 0;
469 			dp->data_prime.conf = 0;
470 			typec_altmode_update_active(dp->plug_prime, false);
471 			break;
472 		case DP_CMD_CONFIGURE:
473 			dp->state = DP_STATE_CONFIGURE;
474 			break;
475 		default:
476 			break;
477 		}
478 		break;
479 	case CMDT_RSP_NAK:
480 		switch (cmd) {
481 		case DP_CMD_CONFIGURE:
482 			dp->data_prime.conf = 0;
483 			/* Attempt to configure on SOP, drop plug */
484 			typec_altmode_put_plug(dp->plug_prime);
485 			dp->plug_prime = NULL;
486 			dp->state = DP_STATE_CONFIGURE;
487 			break;
488 		default:
489 			break;
490 		}
491 		break;
492 	default:
493 		break;
494 	}
495 
496 	if (dp->state != DP_STATE_IDLE)
497 		schedule_work(&dp->work);
498 
499 err_unlock:
500 	mutex_unlock(&dp->lock);
501 	return ret;
502 }
503 
504 static int dp_altmode_activate(struct typec_altmode *alt, int activate)
505 {
506 	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
507 	int ret;
508 
509 	if (activate) {
510 		if (dp->plug_prime) {
511 			ret = typec_cable_altmode_enter(alt, TYPEC_PLUG_SOP_P, NULL);
512 			if (ret < 0) {
513 				typec_altmode_put_plug(dp->plug_prime);
514 				dp->plug_prime = NULL;
515 			} else {
516 				return ret;
517 			}
518 		}
519 		return typec_altmode_enter(alt, NULL);
520 	} else {
521 		return typec_altmode_exit(alt);
522 	}
523 }
524 
525 static const struct typec_altmode_ops dp_altmode_ops = {
526 	.attention = dp_altmode_attention,
527 	.vdm = dp_altmode_vdm,
528 	.activate = dp_altmode_activate,
529 };
530 
531 static const struct typec_cable_ops dp_cable_ops = {
532 	.vdm = dp_cable_altmode_vdm,
533 };
534 
535 static const char * const configurations[] = {
536 	[DP_CONF_USB]	= "USB",
537 	[DP_CONF_DFP_D]	= "source",
538 	[DP_CONF_UFP_D]	= "sink",
539 };
540 
541 static ssize_t
542 configuration_store(struct device *dev, struct device_attribute *attr,
543 		    const char *buf, size_t size)
544 {
545 	struct dp_altmode *dp = dev_get_drvdata(dev);
546 	u32 conf;
547 	u32 cap;
548 	int con;
549 	int ret = 0;
550 
551 	con = sysfs_match_string(configurations, buf);
552 	if (con < 0)
553 		return con;
554 
555 	mutex_lock(&dp->lock);
556 
557 	if (dp->state != DP_STATE_IDLE) {
558 		ret = -EBUSY;
559 		goto err_unlock;
560 	}
561 
562 	cap = DP_CAP_CAPABILITY(dp->alt->vdo);
563 
564 	if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
565 	    (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
566 		ret = -EINVAL;
567 		goto err_unlock;
568 	}
569 
570 	conf = dp->data.conf & ~DP_CONF_DUAL_D;
571 	conf |= con;
572 
573 	if (dp->alt->active) {
574 		ret = dp_altmode_configure_vdm(dp, conf);
575 		if (ret)
576 			goto err_unlock;
577 	}
578 
579 	dp->data.conf = conf;
580 
581 err_unlock:
582 	mutex_unlock(&dp->lock);
583 
584 	return ret ? ret : size;
585 }
586 
587 static ssize_t configuration_show(struct device *dev,
588 				  struct device_attribute *attr, char *buf)
589 {
590 	struct dp_altmode *dp = dev_get_drvdata(dev);
591 	int len;
592 	u8 cap;
593 	u8 cur;
594 	int i;
595 
596 	mutex_lock(&dp->lock);
597 
598 	cap = DP_CAP_CAPABILITY(dp->alt->vdo);
599 	cur = DP_CONF_CURRENTLY(dp->data.conf);
600 
601 	len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
602 
603 	for (i = 1; i < ARRAY_SIZE(configurations); i++) {
604 		if (i == cur)
605 			len += sprintf(buf + len, "[%s] ", configurations[i]);
606 		else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
607 			 (i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
608 			len += sprintf(buf + len, "%s ", configurations[i]);
609 	}
610 
611 	mutex_unlock(&dp->lock);
612 
613 	buf[len - 1] = '\n';
614 	return len;
615 }
616 static DEVICE_ATTR_RW(configuration);
617 
618 static const char * const pin_assignments[] = {
619 	[DP_PIN_ASSIGN_A] = "A",
620 	[DP_PIN_ASSIGN_B] = "B",
621 	[DP_PIN_ASSIGN_C] = "C",
622 	[DP_PIN_ASSIGN_D] = "D",
623 	[DP_PIN_ASSIGN_E] = "E",
624 	[DP_PIN_ASSIGN_F] = "F",
625 };
626 
627 /*
628  * Helper function to extract a peripheral's currently supported
629  * Pin Assignments from its DisplayPort alternate mode state.
630  */
631 static u8 get_current_pin_assignments(struct dp_altmode *dp)
632 {
633 	if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_UFP_U_AS_DFP_D)
634 		return DP_CAP_PIN_ASSIGN_DFP_D(dp->alt->vdo);
635 	else
636 		return DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo);
637 }
638 
639 static ssize_t
640 pin_assignment_store(struct device *dev, struct device_attribute *attr,
641 		     const char *buf, size_t size)
642 {
643 	struct dp_altmode *dp = dev_get_drvdata(dev);
644 	u8 assignments;
645 	u32 conf;
646 	int ret;
647 
648 	ret = sysfs_match_string(pin_assignments, buf);
649 	if (ret < 0)
650 		return ret;
651 
652 	conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
653 	ret = 0;
654 
655 	mutex_lock(&dp->lock);
656 
657 	if (conf & dp->data.conf)
658 		goto out_unlock;
659 
660 	if (dp->state != DP_STATE_IDLE) {
661 		ret = -EBUSY;
662 		goto out_unlock;
663 	}
664 
665 	assignments = get_current_pin_assignments(dp);
666 
667 	if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
668 		ret = -EINVAL;
669 		goto out_unlock;
670 	}
671 
672 	conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
673 
674 	/* Only send Configure command if a configuration has been set */
675 	if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
676 		/* todo: send manual configure over SOP'*/
677 		ret = dp_altmode_configure_vdm(dp, conf);
678 		if (ret)
679 			goto out_unlock;
680 	}
681 
682 	dp->data.conf = conf;
683 
684 out_unlock:
685 	mutex_unlock(&dp->lock);
686 
687 	return ret ? ret : size;
688 }
689 
690 static ssize_t pin_assignment_show(struct device *dev,
691 				   struct device_attribute *attr, char *buf)
692 {
693 	struct dp_altmode *dp = dev_get_drvdata(dev);
694 	u8 assignments;
695 	int len = 0;
696 	u8 cur;
697 	int i;
698 
699 	mutex_lock(&dp->lock);
700 
701 	cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
702 
703 	assignments = get_current_pin_assignments(dp);
704 
705 	for (i = 0; assignments && i < DP_PIN_ASSIGN_MAX; assignments >>= 1, i++) {
706 		if (assignments & 1) {
707 			if (i == cur)
708 				len += sprintf(buf + len, "[%s] ",
709 					       pin_assignments[i]);
710 			else
711 				len += sprintf(buf + len, "%s ",
712 					       pin_assignments[i]);
713 		}
714 	}
715 
716 	mutex_unlock(&dp->lock);
717 
718 	/* get_current_pin_assignments can return 0 when no matching pin assignments are found */
719 	if (len == 0)
720 		len++;
721 
722 	buf[len - 1] = '\n';
723 	return len;
724 }
725 static DEVICE_ATTR_RW(pin_assignment);
726 
727 static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
728 {
729 	struct dp_altmode *dp = dev_get_drvdata(dev);
730 
731 	return sysfs_emit(buf, "%d\n", dp->hpd);
732 }
733 static DEVICE_ATTR_RO(hpd);
734 
735 static ssize_t irq_hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
736 {
737 	struct dp_altmode *dp = dev_get_drvdata(dev);
738 
739 	return sysfs_emit(buf, "%d\n", dp->irq_hpd_count);
740 }
741 static DEVICE_ATTR_RO(irq_hpd);
742 
743 static struct attribute *displayport_attrs[] = {
744 	&dev_attr_configuration.attr,
745 	&dev_attr_pin_assignment.attr,
746 	&dev_attr_hpd.attr,
747 	&dev_attr_irq_hpd.attr,
748 	NULL
749 };
750 
751 static const struct attribute_group displayport_group = {
752 	.name = "displayport",
753 	.attrs = displayport_attrs,
754 };
755 
756 static const struct attribute_group *displayport_groups[] = {
757 	&displayport_group,
758 	NULL,
759 };
760 
761 int dp_altmode_probe(struct typec_altmode *alt)
762 {
763 	const struct typec_altmode *port = typec_altmode_get_partner(alt);
764 	struct typec_altmode *plug = typec_altmode_get_plug(alt, TYPEC_PLUG_SOP_P);
765 	struct fwnode_handle *fwnode;
766 	struct dp_altmode *dp;
767 
768 	/* Port can only be DFP_U. */
769 	if (typec_altmode_get_data_role(alt) != TYPEC_HOST)
770 		return -EPROTO;
771 
772 	/* Make sure we have compatible pin configurations */
773 	if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
774 	      DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
775 	    !(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
776 	      DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo))) {
777 		typec_altmode_put_plug(plug);
778 		return -ENODEV;
779 	}
780 
781 	dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
782 	if (!dp) {
783 		typec_altmode_put_plug(plug);
784 		return -ENOMEM;
785 	}
786 
787 	INIT_WORK(&dp->work, dp_altmode_work);
788 	mutex_init(&dp->lock);
789 	dp->port = port;
790 	dp->alt = alt;
791 
792 	alt->desc = "DisplayPort";
793 	typec_altmode_set_ops(alt, &dp_altmode_ops);
794 
795 	if (plug) {
796 		plug->desc = "Displayport";
797 		plug->cable_ops = &dp_cable_ops;
798 	}
799 
800 	dp->plug_prime = plug;
801 
802 	fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
803 	if (fwnode_property_present(fwnode, "displayport"))
804 		dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
805 	else
806 		dp->connector_fwnode = fwnode_handle_get(fwnode); /* embedded DP */
807 	if (IS_ERR(dp->connector_fwnode))
808 		dp->connector_fwnode = NULL;
809 
810 	typec_altmode_set_drvdata(alt, dp);
811 	if (plug)
812 		typec_altmode_set_drvdata(plug, dp);
813 
814 	if (!alt->mode_selection) {
815 		dp->state = plug ? DP_STATE_ENTER_PRIME : DP_STATE_ENTER;
816 		schedule_work(&dp->work);
817 	}
818 
819 	return 0;
820 }
821 EXPORT_SYMBOL_GPL(dp_altmode_probe);
822 
823 void dp_altmode_remove(struct typec_altmode *alt)
824 {
825 	struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
826 
827 	cancel_work_sync(&dp->work);
828 	typec_altmode_put_plug(dp->plug_prime);
829 
830 	if (dp->connector_fwnode) {
831 		drm_connector_oob_hotplug_event(dp->connector_fwnode,
832 						connector_status_disconnected);
833 
834 		fwnode_handle_put(dp->connector_fwnode);
835 	}
836 }
837 EXPORT_SYMBOL_GPL(dp_altmode_remove);
838 
839 static const struct typec_device_id dp_typec_id[] = {
840 	{ USB_TYPEC_DP_SID },
841 	{ },
842 };
843 MODULE_DEVICE_TABLE(typec, dp_typec_id);
844 
845 static struct typec_altmode_driver dp_altmode_driver = {
846 	.id_table = dp_typec_id,
847 	.probe = dp_altmode_probe,
848 	.remove = dp_altmode_remove,
849 	.driver = {
850 		.name = "typec_displayport",
851 		.dev_groups = displayport_groups,
852 	},
853 };
854 module_typec_altmode_driver(dp_altmode_driver);
855 
856 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
857 MODULE_LICENSE("GPL v2");
858 MODULE_DESCRIPTION("DisplayPort Alternate Mode");
859