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)
89 u32 conf = DP_CONF_SIGNALING_DP; /* Only DP signaling supported */
93 case DP_STATUS_CON_DISABLED:
95 case DP_STATUS_CON_DFP_D:
96 conf |= DP_CONF_UFP_U_AS_DFP_D;
97 pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
98 DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
100 case DP_STATUS_CON_UFP_D:
101 case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
102 conf |= DP_CONF_UFP_U_AS_UFP_D;
103 pin_assign = DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo) &
104 DP_CAP_PIN_ASSIGN_DFP_D(dp->port->vdo);
110 /* Determining the initial pin assignment. */
111 if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
112 /* Is USB together with DP preferred */
113 if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
114 pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
115 pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
116 else if (pin_assign & DP_PIN_ASSIGN_DP_ONLY_MASK) {
117 pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
118 /* Default to pin assign C if available */
119 if (pin_assign & BIT(DP_PIN_ASSIGN_C))
120 pin_assign = BIT(DP_PIN_ASSIGN_C);
126 conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
129 dp->data.conf = conf;
134 static int dp_altmode_status_update(struct dp_altmode *dp)
136 bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
137 bool hpd = !!(dp->data.status & DP_STATUS_HPD_STATE);
138 u8 con = DP_STATUS_CONNECTION(dp->data.status);
141 if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
143 dp->state = DP_STATE_CONFIGURE;
144 } else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
145 dp->state = DP_STATE_EXIT;
146 } else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
147 ret = dp_altmode_configure(dp, con);
149 dp->state = DP_STATE_CONFIGURE;
150 if (dp->hpd != hpd) {
152 dp->pending_hpd = true;
156 if (dp->hpd != hpd) {
157 drm_connector_oob_hotplug_event(dp->connector_fwnode);
159 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
166 static int dp_altmode_configured(struct dp_altmode *dp)
168 sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
169 sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
171 * If the DFP_D/UFP_D sends a change in HPD when first notifying the
172 * DisplayPort driver that it is connected, then we wait until
173 * configuration is complete to signal HPD.
175 if (dp->pending_hpd) {
176 drm_connector_oob_hotplug_event(dp->connector_fwnode);
177 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
178 dp->pending_hpd = false;
181 return dp_altmode_notify(dp);
184 static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
186 int svdm_version = typec_altmode_get_svdm_version(dp->alt);
190 if (svdm_version < 0)
193 header = DP_HEADER(dp, svdm_version, DP_CMD_CONFIGURE);
194 ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE, &dp->data);
196 dev_err(&dp->alt->dev,
197 "unable to put to connector to safe mode\n");
201 ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
203 dp_altmode_notify(dp);
208 static void dp_altmode_work(struct work_struct *work)
210 struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
216 mutex_lock(&dp->lock);
220 ret = typec_altmode_enter(dp->alt, NULL);
221 if (ret && ret != -EBUSY)
222 dev_err(&dp->alt->dev, "failed to enter mode\n");
224 case DP_STATE_UPDATE:
225 svdm_version = typec_altmode_get_svdm_version(dp->alt);
226 if (svdm_version < 0)
228 header = DP_HEADER(dp, svdm_version, DP_CMD_STATUS_UPDATE);
230 ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
232 dev_err(&dp->alt->dev,
233 "unable to send Status Update command (%d)\n",
236 case DP_STATE_CONFIGURE:
237 ret = dp_altmode_configure_vdm(dp, dp->data.conf);
239 dev_err(&dp->alt->dev,
240 "unable to send Configure command (%d)\n", ret);
243 if (typec_altmode_exit(dp->alt))
244 dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
250 dp->state = DP_STATE_IDLE;
252 mutex_unlock(&dp->lock);
255 static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
257 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
260 mutex_lock(&dp->lock);
262 old_state = dp->state;
263 dp->data.status = vdo;
265 if (old_state != DP_STATE_IDLE)
266 dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
269 if (dp_altmode_status_update(dp))
270 dev_warn(&alt->dev, "%s: status update failed\n", __func__);
272 if (dp_altmode_notify(dp))
273 dev_err(&alt->dev, "%s: notification failed\n", __func__);
275 if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
276 schedule_work(&dp->work);
278 mutex_unlock(&dp->lock);
281 static int dp_altmode_vdm(struct typec_altmode *alt,
282 const u32 hdr, const u32 *vdo, int count)
284 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
285 int cmd_type = PD_VDO_CMDT(hdr);
286 int cmd = PD_VDO_CMD(hdr);
289 mutex_lock(&dp->lock);
291 if (dp->state != DP_STATE_IDLE) {
300 typec_altmode_update_active(alt, true);
301 dp->state = DP_STATE_UPDATE;
304 typec_altmode_update_active(alt, false);
308 drm_connector_oob_hotplug_event(dp->connector_fwnode);
310 sysfs_notify(&dp->alt->dev.kobj, "displayport", "hpd");
313 case DP_CMD_STATUS_UPDATE:
314 dp->data.status = *vdo;
315 ret = dp_altmode_status_update(dp);
317 case DP_CMD_CONFIGURE:
318 ret = dp_altmode_configured(dp);
326 case DP_CMD_CONFIGURE:
328 ret = dp_altmode_configured(dp);
338 if (dp->state != DP_STATE_IDLE)
339 schedule_work(&dp->work);
342 mutex_unlock(&dp->lock);
346 static int dp_altmode_activate(struct typec_altmode *alt, int activate)
348 return activate ? typec_altmode_enter(alt, NULL) :
349 typec_altmode_exit(alt);
352 static const struct typec_altmode_ops dp_altmode_ops = {
353 .attention = dp_altmode_attention,
354 .vdm = dp_altmode_vdm,
355 .activate = dp_altmode_activate,
358 static const char * const configurations[] = {
359 [DP_CONF_USB] = "USB",
360 [DP_CONF_DFP_D] = "source",
361 [DP_CONF_UFP_D] = "sink",
365 configuration_store(struct device *dev, struct device_attribute *attr,
366 const char *buf, size_t size)
368 struct dp_altmode *dp = dev_get_drvdata(dev);
374 con = sysfs_match_string(configurations, buf);
378 mutex_lock(&dp->lock);
380 if (dp->state != DP_STATE_IDLE) {
385 cap = DP_CAP_CAPABILITY(dp->alt->vdo);
387 if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
388 (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D))) {
393 conf = dp->data.conf & ~DP_CONF_DUAL_D;
396 if (dp->alt->active) {
397 ret = dp_altmode_configure_vdm(dp, conf);
402 dp->data.conf = conf;
405 mutex_unlock(&dp->lock);
407 return ret ? ret : size;
410 static ssize_t configuration_show(struct device *dev,
411 struct device_attribute *attr, char *buf)
413 struct dp_altmode *dp = dev_get_drvdata(dev);
419 mutex_lock(&dp->lock);
421 cap = DP_CAP_CAPABILITY(dp->alt->vdo);
422 cur = DP_CONF_CURRENTLY(dp->data.conf);
424 len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
426 for (i = 1; i < ARRAY_SIZE(configurations); i++) {
428 len += sprintf(buf + len, "[%s] ", configurations[i]);
429 else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
430 (i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
431 len += sprintf(buf + len, "%s ", configurations[i]);
434 mutex_unlock(&dp->lock);
439 static DEVICE_ATTR_RW(configuration);
441 static const char * const pin_assignments[] = {
442 [DP_PIN_ASSIGN_A] = "A",
443 [DP_PIN_ASSIGN_B] = "B",
444 [DP_PIN_ASSIGN_C] = "C",
445 [DP_PIN_ASSIGN_D] = "D",
446 [DP_PIN_ASSIGN_E] = "E",
447 [DP_PIN_ASSIGN_F] = "F",
451 * Helper function to extract a peripheral's currently supported
452 * Pin Assignments from its DisplayPort alternate mode state.
454 static u8 get_current_pin_assignments(struct dp_altmode *dp)
456 if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_UFP_U_AS_DFP_D)
457 return DP_CAP_PIN_ASSIGN_DFP_D(dp->alt->vdo);
459 return DP_CAP_PIN_ASSIGN_UFP_D(dp->alt->vdo);
463 pin_assignment_store(struct device *dev, struct device_attribute *attr,
464 const char *buf, size_t size)
466 struct dp_altmode *dp = dev_get_drvdata(dev);
471 ret = sysfs_match_string(pin_assignments, buf);
475 conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
478 mutex_lock(&dp->lock);
480 if (conf & dp->data.conf)
483 if (dp->state != DP_STATE_IDLE) {
488 assignments = get_current_pin_assignments(dp);
490 if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
495 conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
497 /* Only send Configure command if a configuration has been set */
498 if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
499 ret = dp_altmode_configure_vdm(dp, conf);
504 dp->data.conf = conf;
507 mutex_unlock(&dp->lock);
509 return ret ? ret : size;
512 static ssize_t pin_assignment_show(struct device *dev,
513 struct device_attribute *attr, char *buf)
515 struct dp_altmode *dp = dev_get_drvdata(dev);
521 mutex_lock(&dp->lock);
523 cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
525 assignments = get_current_pin_assignments(dp);
527 for (i = 0; assignments; assignments >>= 1, i++) {
528 if (assignments & 1) {
530 len += sprintf(buf + len, "[%s] ",
533 len += sprintf(buf + len, "%s ",
538 mutex_unlock(&dp->lock);
540 /* get_current_pin_assignments can return 0 when no matching pin assignments are found */
547 static DEVICE_ATTR_RW(pin_assignment);
549 static ssize_t hpd_show(struct device *dev, struct device_attribute *attr, char *buf)
551 struct dp_altmode *dp = dev_get_drvdata(dev);
553 return sysfs_emit(buf, "%d\n", dp->hpd);
555 static DEVICE_ATTR_RO(hpd);
557 static struct attribute *dp_altmode_attrs[] = {
558 &dev_attr_configuration.attr,
559 &dev_attr_pin_assignment.attr,
564 static const struct attribute_group dp_altmode_group = {
565 .name = "displayport",
566 .attrs = dp_altmode_attrs,
569 int dp_altmode_probe(struct typec_altmode *alt)
571 const struct typec_altmode *port = typec_altmode_get_partner(alt);
572 struct fwnode_handle *fwnode;
573 struct dp_altmode *dp;
576 /* FIXME: Port can only be DFP_U. */
578 /* Make sure we have compatiple pin configurations */
579 if (!(DP_CAP_PIN_ASSIGN_DFP_D(port->vdo) &
580 DP_CAP_PIN_ASSIGN_UFP_D(alt->vdo)) &&
581 !(DP_CAP_PIN_ASSIGN_UFP_D(port->vdo) &
582 DP_CAP_PIN_ASSIGN_DFP_D(alt->vdo)))
585 ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
589 dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
593 INIT_WORK(&dp->work, dp_altmode_work);
594 mutex_init(&dp->lock);
598 alt->desc = "DisplayPort";
599 alt->ops = &dp_altmode_ops;
601 fwnode = dev_fwnode(alt->dev.parent->parent); /* typec_port fwnode */
602 if (fwnode_property_present(fwnode, "displayport"))
603 dp->connector_fwnode = fwnode_find_reference(fwnode, "displayport", 0);
605 dp->connector_fwnode = fwnode_handle_get(fwnode); /* embedded DP */
606 if (IS_ERR(dp->connector_fwnode))
607 dp->connector_fwnode = NULL;
609 typec_altmode_set_drvdata(alt, dp);
611 dp->state = DP_STATE_ENTER;
612 schedule_work(&dp->work);
616 EXPORT_SYMBOL_GPL(dp_altmode_probe);
618 void dp_altmode_remove(struct typec_altmode *alt)
620 struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
622 sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
623 cancel_work_sync(&dp->work);
625 if (dp->connector_fwnode) {
627 drm_connector_oob_hotplug_event(dp->connector_fwnode);
629 fwnode_handle_put(dp->connector_fwnode);
632 EXPORT_SYMBOL_GPL(dp_altmode_remove);
634 static const struct typec_device_id dp_typec_id[] = {
635 { USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
638 MODULE_DEVICE_TABLE(typec, dp_typec_id);
640 static struct typec_altmode_driver dp_altmode_driver = {
641 .id_table = dp_typec_id,
642 .probe = dp_altmode_probe,
643 .remove = dp_altmode_remove,
645 .name = "typec_displayport",
646 .owner = THIS_MODULE,
649 module_typec_altmode_driver(dp_altmode_driver);
651 MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>");
652 MODULE_LICENSE("GPL v2");
653 MODULE_DESCRIPTION("DisplayPort Alternate Mode");