1 // SPDX-License-Identifier: GPL-2.0
3 * USB Typec-C DisplayPort Alternate Mode driver
5 * Copyright (C) 2018 Intel Corporation
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
8 * DisplayPort is trademark of VESA (www.vesa.org)
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"
20 #define DP_HEADER(_dp, ver, cmd) (VDO((_dp)->alt->svid, 1, ver, cmd) \
21 | VDO_OPOS(USB_TYPEC_DP_MODE))
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) | \
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) | \
40 /* DP only pin assignments */
41 #define DP_PIN_ASSIGN_DP_ONLY_MASK (BIT(DP_PIN_ASSIGN_A) | \
42 BIT(DP_PIN_ASSIGN_C) | \
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) | \
59 struct typec_displayport_data data;
64 struct mutex lock; /* device lock */
65 struct work_struct work;
66 struct typec_altmode *alt;
67 const struct typec_altmode *port;
68 struct fwnode_handle *connector_fwnode;
71 static int dp_altmode_notify(struct dp_altmode *dp)
77 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
78 conf = TYPEC_MODAL_STATE(state);
80 conf = TYPEC_STATE_USB;
83 return typec_altmode_notify(dp->alt, conf, &dp->data);
86 static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
88 u32 conf = DP_CONF_SIGNALING_DP; /* Only DP signaling supported */
92 case DP_STATUS_CON_DISABLED:
94 case DP_STATUS_CON_DFP_D:
95 conf |= DP_CONF_UFP_U_AS_DFP_D;
96 pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
97 DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
99 case DP_STATUS_CON_UFP_D:
100 case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
101 conf |= DP_CONF_UFP_U_AS_UFP_D;
102 pin_assign = DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo) &
103 DP_CAP_PIN_ASSIGN_DFP_D(dp->port->vdo);
109 /* Determining the initial pin assignment. */
110 if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
111 /* Is USB together with DP preferred */
112 if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
113 pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
114 pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
115 else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
116 pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
117 /* Default to pin assign C if available */
118 if (pin_assign & BIT(DP_PIN_ASSIGN_C))
119 pin_assign = BIT(DP_PIN_ASSIGN_C);
125 conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
128 dp->data.conf = conf;
133 static int dp_altmode_status_update(struct dp_altmode *dp)
135 bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
136 bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
137 u8 con = DP_STATUS_CONNECTION(dp->data.status);
140 if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
142 dp->state = DP_STATE_CONFIGURE;
143 } else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
144 dp->state = DP_STATE_EXIT;
145 } else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
146 ret = dp_altmode_configure(dp, con);
148 dp->state = DP_STATE_CONFIGURE;
150 if (dp->hpd != hpd) {
151 drm_connector_oob_hotplug_event(dp->connector_fwnode);
153 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
160 static int dp_altmode_configured(struct dp_altmode *dp)
162 sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
163 sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
165 return dp_altmode_notify(dp);
168 static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
170 int svdm_version = typec_altmode_get_svdm_version(dp->alt);
174 if (svdm_version < 0)
177 header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
178 ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
180 dev_err(&dp->alt->dev,
181 "unable to put to connector to safe mode\n");
185 ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
187 dp_altmode_notify(dp);
192 static void dp_altmode_work(struct work_struct *work)
194 struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
200 mutex_lock(&dp->lock);
204 ret = typec_altmode_enter(dp->alt, NULL);
205 if (ret && ret != -EBUSY)
206 dev_err(&dp->alt->dev, "failed to enter mode\n");
208 case DP_STATE_UPDATE:
209 svdm_version = typec_altmode_get_svdm_version(dp->alt);
210 if (svdm_version < 0)
212 header = DP_HEADER(dp, svdm_version, DP_CMD_STATUS_UPDATE);
214 ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
216 dev_err(&dp->alt->dev,
217 "unable to send Status Update command (%d)\n",
220 case DP_STATE_CONFIGURE:
221 ret = dp_altmode_configure_vdm(dp, dp->data.conf);
223 dev_err(&dp->alt->dev,
224 "unable to send Configure command (%d)\n", ret);
227 if (typec_altmode_exit(dp->alt))
228 dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
234 dp->state = DP_STATE_IDLE;
236 mutex_unlock(&dp->lock);
239 static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
241 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
244 mutex_lock(&dp->lock);
246 old_state = dp->state;
247 dp->data.status = vdo;
249 if (old_state != DP_STATE_IDLE)
250 dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
253 if (dp_altmode_status_update(dp))
254 dev_warn(&alt->dev, "%s: status update failed\n", __func__);
256 if (dp_altmode_notify(dp))
257 dev_err(&alt->dev, "%s: notification failed\n", __func__);
259 if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
260 schedule_work(&dp->work);
262 mutex_unlock(&dp->lock);
265 static int dp_altmode_vdm(struct typec_altmode *alt,
266 const u32 hdr, const u32 *vdo, int count)
268 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
269 int cmd_type = PD_VDO_CMDT(hdr);
270 int cmd = PD_VDO_CMD(hdr);
273 mutex_lock(&dp->lock);
275 if (dp->state != DP_STATE_IDLE) {
284 typec_altmode_update_active(alt, true);
285 dp->state = DP_STATE_UPDATE;
288 typec_altmode_update_active(alt, false);
292 case DP_CMD_STATUS_UPDATE:
293 dp->data.status = *vdo;
294 ret = dp_altmode_status_update(dp);
296 case DP_CMD_CONFIGURE:
297 ret = dp_altmode_configured(dp);
305 case DP_CMD_CONFIGURE:
307 ret = dp_altmode_configured(dp);
317 if (dp->state != DP_STATE_IDLE)
318 schedule_work(&dp->work);
321 mutex_unlock(&dp->lock);
325 static int dp_altmode_activate(struct typec_altmode *alt, int activate)
327 return activate ? typec_altmode_enter(alt, NULL) :
328 typec_altmode_exit(alt);
331 static const struct typec_altmode_ops dp_altmode_ops = {
332 .attention = dp_altmode_attention,
333 .vdm = dp_altmode_vdm,
334 .activate = dp_altmode_activate,
337 static const char * const configurations[] = {
338 [DP_CONF_USB] = "USB",
339 [DP_CONF_DFP_D] = "source",
340 [DP_CONF_UFP_D] = "sink",
344 configuration_store(struct device *dev, struct device_attribute *attr,
345 const char *buf, size_t size)
347 struct dp_altmode *dp = dev_get_drvdata(dev);
353 con = sysfs_match_string(configurations, buf);
357 mutex_lock(&dp->lock);
359 if (dp->state != DP_STATE_IDLE) {
364 cap = DP_CAP_CAPABILITY(dp->alt->vdo);
366 if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
367 (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
372 conf = dp->data.conf & ~DP_CONF_DUAL_D;
375 if (dp->alt->active) {
376 ret = dp_altmode_configure_vdm(dp, conf);
381 dp->data.conf = conf;
384 mutex_unlock(&dp->lock);
386 return ret ? ret : size;
389 static ssize_t configuration_show(struct device *dev,
390 struct device_attribute *attr, char *buf)
392 struct dp_altmode *dp = dev_get_drvdata(dev);
398 mutex_lock(&dp->lock);
400 cap = DP_CAP_CAPABILITY(dp->alt->vdo);
401 cur = DP_CONF_CURRENTLY(dp->data.conf);
403 len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
405 for (i = 1; i < ARRAY_SIZE(configurations); i++) {
407 len += sprintf(buf + len, "[%s] ", configurations[i]);
408 else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
409 (i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
410 len += sprintf(buf + len, "%s ", configurations[i]);
413 mutex_unlock(&dp->lock);
418 static DEVICE_ATTR_RW(configuration);
420 static const char * const pin_assignments[] = {
421 [DP_PIN_ASSIGN_A] = "A",
422 [DP_PIN_ASSIGN_B] = "B",
423 [DP_PIN_ASSIGN_C] = "C",
424 [DP_PIN_ASSIGN_D] = "D",
425 [DP_PIN_ASSIGN_E] = "E",
426 [DP_PIN_ASSIGN_F] = "F",
430 * Helper function to extract a peripheral's currently supported
431 * Pin Assignments from its DisplayPort alternate mode state.
433 static u8 get_current_pin_assignments(struct dp_altmode *dp)
435 if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_UFP_U_AS_DFP_D)
436 return DP_CAP_PIN_ASSIGN_DFP_D(dp->alt->vdo);
438 return DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo);
442 pin_assignment_store(struct device *dev, struct device_attribute *attr,
443 const char *buf, size_t size)
445 struct dp_altmode *dp = dev_get_drvdata(dev);
450 ret = sysfs_match_string(pin_assignments, buf);
454 conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
457 mutex_lock(&dp->lock);
459 if (conf & dp->data.conf)
462 if (dp->state != DP_STATE_IDLE) {
467 assignments = get_current_pin_assignments(dp);
469 if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
474 conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
476 /* Only send Configure command if a configuration has been set */
477 if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
478 ret = dp_altmode_configure_vdm(dp, conf);
483 dp->data.conf = conf;
486 mutex_unlock(&dp->lock);
488 return ret ? ret : size;
491 static ssize_t pin_assignment_show(struct device *dev,
492 struct device_attribute *attr, char *buf)
494 struct dp_altmode *dp = dev_get_drvdata(dev);
500 mutex_lock(&dp->lock);
502 cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
504 assignments = get_current_pin_assignments(dp);
506 for (i = 0; assignments; assignments >>= 1, i++) {
507 if (assignments & 1) {
509 len += sprintf(buf + len, "[%s] ",
512 len += sprintf(buf + len, "%s ",
517 mutex_unlock(&dp->lock);
519 /* get_current_pin_assignments can return 0 when no matching pin assignments are found */
526 static DEVICE_ATTR_RW(pin_assignment);
528 static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
530 struct dp_altmode *dp = dev_get_drvdata(dev);
532 return sysfs_emit(buf, "%d\n", dp->hpd);
534 static DEVICE_ATTR_RO(hpd);
536 static struct attribute *dp_altmode_attrs[] = {
537 &dev_attr_configuration.attr,
538 &dev_attr_pin_assignment.attr,
543 static const struct attribute_group dp_altmode_group = {
544 .name = "displayport",
545 .attrs = dp_altmode_attrs,
548 int dp_altmode_probe(struct typec_altmode *alt)
550 const struct typec_altmode *port = typec_altmode_get_partner(alt);
551 struct fwnode_handle *fwnode;
552 struct dp_altmode *dp;
555 /* FIXME: Port can only be DFP_U. */
557 /* Make sure we have compatiple pin configurations */
558 if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
559 DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
560 !(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
561 DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
564 ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
568 dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
572 INIT_WORK(&dp->work, dp_altmode_work);
573 mutex_init(&dp->lock);
577 alt->desc = "DisplayPort";
578 alt->ops = &dp_altmode_ops;
580 fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
581 dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
582 if (IS_ERR(dp->connector_fwnode))
583 dp->connector_fwnode = NULL;
585 typec_altmode_set_drvdata(alt, dp);
587 dp->state = DP_STATE_ENTER;
588 schedule_work(&dp->work);
592 EXPORT_SYMBOL_GPL(dp_altmode_probe);
594 void dp_altmode_remove(struct typec_altmode *alt)
596 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
598 sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
599 cancel_work_sync(&dp->work);
601 if (dp->connector_fwnode) {
603 drm_connector_oob_hotplug_event(dp->connector_fwnode);
605 fwnode_handle_put(dp->connector_fwnode);
608 EXPORT_SYMBOL_GPL(dp_altmode_remove);
610 static const struct typec_device_id dp_typec_id[] = {
611 { USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
614 MODULE_DEVICE_TABLE(typec, dp_typec_id);
616 static struct typec_altmode_driver dp_altmode_driver = {
617 .id_table = dp_typec_id,
618 .probe = dp_altmode_probe,
619 .remove = dp_altmode_remove,
621 .name = "typec_displayport",
622 .owner = THIS_MODULE,
625 module_typec_altmode_driver(dp_altmode_driver);
627 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
628 MODULE_LICENSE("GPL v2");
629 MODULE_DESCRIPTION("DisplayPort Alternate Mode");