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;
65 struct mutex lock; /* device lock */
66 struct work_struct work;
67 struct typec_altmode *alt;
68 const struct typec_altmode *port;
69 struct fwnode_handle *connector_fwnode;
72 static int dp_altmode_notify(struct dp_altmode *dp)
78 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
79 conf = TYPEC_MODAL_STATE(state);
81 conf = TYPEC_STATE_USB;
84 return typec_altmode_notify(dp->alt, conf, &dp->data);
87 static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
93 conf = (dp->data.conf & DP_CONF_SIGNALLING_MASK) >> DP_CONF_SIGNALLING_SHIFT;
96 case DP_STATUS_CON_DISABLED:
98 case DP_STATUS_CON_DFP_D:
99 conf |= DP_CONF_UFP_U_AS_DFP_D;
100 pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
101 DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
103 case DP_STATUS_CON_UFP_D:
104 case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
105 conf |= DP_CONF_UFP_U_AS_UFP_D;
106 pin_assign = DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo) &
107 DP_CAP_PIN_ASSIGN_DFP_D(dp->port->vdo);
113 /* Determining the initial pin assignment. */
114 if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
115 /* Is USB together with DP preferred */
116 if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
117 pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
118 pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
119 else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
120 pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
121 /* Default to pin assign C if available */
122 if (pin_assign & BIT(DP_PIN_ASSIGN_C))
123 pin_assign = BIT(DP_PIN_ASSIGN_C);
129 conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
132 dp->data.conf = conf;
137 static int dp_altmode_status_update(struct dp_altmode *dp)
139 bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
140 bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
141 u8 con = DP_STATUS_CONNECTION(dp->data.status);
144 if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
146 dp->state = DP_STATE_CONFIGURE;
147 } else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
148 dp->state = DP_STATE_EXIT;
149 } else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
150 ret = dp_altmode_configure(dp, con);
152 dp->state = DP_STATE_CONFIGURE;
153 if (dp->hpd != hpd) {
155 dp->pending_hpd = true;
159 drm_connector_oob_hotplug_event(dp->connector_fwnode,
160 hpd ? connector_status_connected :
161 connector_status_disconnected);
163 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
169 static int dp_altmode_configured(struct dp_altmode *dp)
171 sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
172 sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
174 * If the DFP_D/UFP_D sends a change in HPD when first notifying the
175 * DisplayPort driver that it is connected, then we wait until
176 * configuration is complete to signal HPD.
178 if (dp->pending_hpd) {
179 drm_connector_oob_hotplug_event(dp->connector_fwnode,
180 connector_status_connected);
181 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
182 dp->pending_hpd = false;
185 return dp_altmode_notify(dp);
188 static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
190 int svdm_version = typec_altmode_get_svdm_version(dp->alt);
194 if (svdm_version < 0)
197 header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
198 ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
200 dev_err(&dp->alt->dev,
201 "unable to put to connector to safe mode\n");
205 ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
207 dp_altmode_notify(dp);
212 static void dp_altmode_work(struct work_struct *work)
214 struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
220 mutex_lock(&dp->lock);
224 ret = typec_altmode_enter(dp->alt, NULL);
225 if (ret && ret != -EBUSY)
226 dev_err(&dp->alt->dev, "failed to enter mode\n");
228 case DP_STATE_UPDATE:
229 svdm_version = typec_altmode_get_svdm_version(dp->alt);
230 if (svdm_version < 0)
232 header = DP_HEADER(dp, svdm_version, DP_CMD_STATUS_UPDATE);
234 ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
236 dev_err(&dp->alt->dev,
237 "unable to send Status Update command (%d)\n",
240 case DP_STATE_CONFIGURE:
241 ret = dp_altmode_configure_vdm(dp, dp->data.conf);
243 dev_err(&dp->alt->dev,
244 "unable to send Configure command (%d)\n", ret);
247 if (typec_altmode_exit(dp->alt))
248 dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
254 dp->state = DP_STATE_IDLE;
256 mutex_unlock(&dp->lock);
259 static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
261 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
264 mutex_lock(&dp->lock);
266 old_state = dp->state;
267 dp->data.status = vdo;
269 if (old_state != DP_STATE_IDLE)
270 dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
273 if (dp_altmode_status_update(dp))
274 dev_warn(&alt->dev, "%s: status update failed\n", __func__);
276 if (dp_altmode_notify(dp))
277 dev_err(&alt->dev, "%s: notification failed\n", __func__);
279 if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
280 schedule_work(&dp->work);
282 mutex_unlock(&dp->lock);
285 static int dp_altmode_vdm(struct typec_altmode *alt,
286 const u32 hdr, const u32 *vdo, int count)
288 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
289 int cmd_type = PD_VDO_CMDT(hdr);
290 int cmd = PD_VDO_CMD(hdr);
293 mutex_lock(&dp->lock);
295 if (dp->state != DP_STATE_IDLE) {
304 typec_altmode_update_active(alt, true);
305 dp->state = DP_STATE_UPDATE;
308 typec_altmode_update_active(alt, false);
312 drm_connector_oob_hotplug_event(dp->connector_fwnode,
313 connector_status_disconnected);
315 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
318 case DP_CMD_STATUS_UPDATE:
319 dp->data.status = *vdo;
320 ret = dp_altmode_status_update(dp);
322 case DP_CMD_CONFIGURE:
323 ret = dp_altmode_configured(dp);
331 case DP_CMD_CONFIGURE:
333 ret = dp_altmode_configured(dp);
343 if (dp->state != DP_STATE_IDLE)
344 schedule_work(&dp->work);
347 mutex_unlock(&dp->lock);
351 static int dp_altmode_activate(struct typec_altmode *alt, int activate)
353 return activate ? typec_altmode_enter(alt, NULL) :
354 typec_altmode_exit(alt);
357 static const struct typec_altmode_ops dp_altmode_ops = {
358 .attention = dp_altmode_attention,
359 .vdm = dp_altmode_vdm,
360 .activate = dp_altmode_activate,
363 static const char * const configurations[] = {
364 [DP_CONF_USB] = "USB",
365 [DP_CONF_DFP_D] = "source",
366 [DP_CONF_UFP_D] = "sink",
370 configuration_store(struct device *dev, struct device_attribute *attr,
371 const char *buf, size_t size)
373 struct dp_altmode *dp = dev_get_drvdata(dev);
379 con = sysfs_match_string(configurations, buf);
383 mutex_lock(&dp->lock);
385 if (dp->state != DP_STATE_IDLE) {
390 cap = DP_CAP_CAPABILITY(dp->alt->vdo);
392 if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
393 (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
398 conf = dp->data.conf & ~DP_CONF_DUAL_D;
401 if (dp->alt->active) {
402 ret = dp_altmode_configure_vdm(dp, conf);
407 dp->data.conf = conf;
410 mutex_unlock(&dp->lock);
412 return ret ? ret : size;
415 static ssize_t configuration_show(struct device *dev,
416 struct device_attribute *attr, char *buf)
418 struct dp_altmode *dp = dev_get_drvdata(dev);
424 mutex_lock(&dp->lock);
426 cap = DP_CAP_CAPABILITY(dp->alt->vdo);
427 cur = DP_CONF_CURRENTLY(dp->data.conf);
429 len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
431 for (i = 1; i < ARRAY_SIZE(configurations); i++) {
433 len += sprintf(buf + len, "[%s] ", configurations[i]);
434 else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
435 (i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
436 len += sprintf(buf + len, "%s ", configurations[i]);
439 mutex_unlock(&dp->lock);
444 static DEVICE_ATTR_RW(configuration);
446 static const char * const pin_assignments[] = {
447 [DP_PIN_ASSIGN_A] = "A",
448 [DP_PIN_ASSIGN_B] = "B",
449 [DP_PIN_ASSIGN_C] = "C",
450 [DP_PIN_ASSIGN_D] = "D",
451 [DP_PIN_ASSIGN_E] = "E",
452 [DP_PIN_ASSIGN_F] = "F",
456 * Helper function to extract a peripheral's currently supported
457 * Pin Assignments from its DisplayPort alternate mode state.
459 static u8 get_current_pin_assignments(struct dp_altmode *dp)
461 if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_UFP_U_AS_DFP_D)
462 return DP_CAP_PIN_ASSIGN_DFP_D(dp->alt->vdo);
464 return DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo);
468 pin_assignment_store(struct device *dev, struct device_attribute *attr,
469 const char *buf, size_t size)
471 struct dp_altmode *dp = dev_get_drvdata(dev);
476 ret = sysfs_match_string(pin_assignments, buf);
480 conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
483 mutex_lock(&dp->lock);
485 if (conf & dp->data.conf)
488 if (dp->state != DP_STATE_IDLE) {
493 assignments = get_current_pin_assignments(dp);
495 if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
500 conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
502 /* Only send Configure command if a configuration has been set */
503 if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
504 ret = dp_altmode_configure_vdm(dp, conf);
509 dp->data.conf = conf;
512 mutex_unlock(&dp->lock);
514 return ret ? ret : size;
517 static ssize_t pin_assignment_show(struct device *dev,
518 struct device_attribute *attr, char *buf)
520 struct dp_altmode *dp = dev_get_drvdata(dev);
526 mutex_lock(&dp->lock);
528 cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
530 assignments = get_current_pin_assignments(dp);
532 for (i = 0; assignments; assignments >>= 1, i++) {
533 if (assignments & 1) {
535 len += sprintf(buf + len, "[%s] ",
538 len += sprintf(buf + len, "%s ",
543 mutex_unlock(&dp->lock);
545 /* get_current_pin_assignments can return 0 when no matching pin assignments are found */
552 static DEVICE_ATTR_RW(pin_assignment);
554 static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
556 struct dp_altmode *dp = dev_get_drvdata(dev);
558 return sysfs_emit(buf, "%d\n", dp->hpd);
560 static DEVICE_ATTR_RO(hpd);
562 static struct attribute *displayport_attrs[] = {
563 &dev_attr_configuration.attr,
564 &dev_attr_pin_assignment.attr,
569 static const struct attribute_group displayport_group = {
570 .name = "displayport",
571 .attrs = displayport_attrs,
574 static const struct attribute_group *displayport_groups[] = {
579 int dp_altmode_probe(struct typec_altmode *alt)
581 const struct typec_altmode *port = typec_altmode_get_partner(alt);
582 struct fwnode_handle *fwnode;
583 struct dp_altmode *dp;
585 /* FIXME: Port can only be DFP_U. */
587 /* Make sure we have compatiple pin configurations */
588 if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
589 DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
590 !(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
591 DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
594 dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
598 INIT_WORK(&dp->work, dp_altmode_work);
599 mutex_init(&dp->lock);
603 alt->desc = "DisplayPort";
604 alt->ops = &dp_altmode_ops;
606 fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
607 if (fwnode_property_present(fwnode, "displayport"))
608 dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
610 dp->connector_fwnode = fwnode_handle_get(fwnode); /* embedded DP */
611 if (IS_ERR(dp->connector_fwnode))
612 dp->connector_fwnode = NULL;
614 typec_altmode_set_drvdata(alt, dp);
616 dp->state = DP_STATE_ENTER;
617 schedule_work(&dp->work);
621 EXPORT_SYMBOL_GPL(dp_altmode_probe);
623 void dp_altmode_remove(struct typec_altmode *alt)
625 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
627 cancel_work_sync(&dp->work);
629 if (dp->connector_fwnode) {
630 drm_connector_oob_hotplug_event(dp->connector_fwnode,
631 connector_status_disconnected);
633 fwnode_handle_put(dp->connector_fwnode);
636 EXPORT_SYMBOL_GPL(dp_altmode_remove);
638 static const struct typec_device_id dp_typec_id[] = {
639 { USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
642 MODULE_DEVICE_TABLE(typec, dp_typec_id);
644 static struct typec_altmode_driver dp_altmode_driver = {
645 .id_table = dp_typec_id,
646 .probe = dp_altmode_probe,
647 .remove = dp_altmode_remove,
649 .name = "typec_displayport",
650 .owner = THIS_MODULE,
651 .dev_groups = displayport_groups,
654 module_typec_altmode_driver(dp_altmode_driver);
656 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
657 MODULE_LICENSE("GPL v2");
658 MODULE_DESCRIPTION("DisplayPort Alternate Mode");