[RFC PATCH v4 6/8] usb: typec: Add driver for DisplayPort alternate mode
From: Heikki Krogerus
Date: Fri Jun 08 2018 - 07:30:08 EST
DisplayPort USB Type-C Alt Mode allows DisplayPort displays
and adapters to be attached to the USB Type-C ports on the
system.
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
.../testing/sysfs-driver-typec-displayport | 49 ++
drivers/usb/typec/Kconfig | 2 +
drivers/usb/typec/Makefile | 1 +
drivers/usb/typec/altmodes/Kconfig | 14 +
drivers/usb/typec/altmodes/Makefile | 2 +
drivers/usb/typec/altmodes/displayport.c | 543 ++++++++++++++++++
include/linux/usb/typec_dp.h | 70 +++
7 files changed, 681 insertions(+)
create mode 100644 Documentation/ABI/testing/sysfs-driver-typec-displayport
create mode 100644 drivers/usb/typec/altmodes/Kconfig
create mode 100644 drivers/usb/typec/altmodes/Makefile
create mode 100644 drivers/usb/typec/altmodes/displayport.c
create mode 100644 include/linux/usb/typec_dp.h
diff --git a/Documentation/ABI/testing/sysfs-driver-typec-displayport b/Documentation/ABI/testing/sysfs-driver-typec-displayport
new file mode 100644
index 000000000000..66d72185cfd5
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-typec-displayport
@@ -0,0 +1,49 @@
+What: /sys/bus/typec/devices/.../displayport/configuration
+Date: July 2018
+Contact: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
+Description:
+ Shows the current DisplayPort configuration for the connector.
+ Valid values are USB, source and sink. Source means DisplayPort
+ source, and sink means DisplayPort sink.
+
+ All supported configurations are listed as space separated list
+ with the active one wrapped in square brackets.
+
+ Source example:
+
+ USB [source] sink
+
+ The configuration can be changed by writing to the file
+
+ Note. USB configuration does not equal to Exit Mode. It is
+ separate configuration defined in VESA DisplayPort Alt Mode on
+ USB Type-C Standard. Functionally it equals to the situation
+ where the mode has been exited (to exit the mode, see
+ Documentation/ABI/testing/sysfs-bus-typec, and use file
+ /sys/bus/typec/devices/.../active).
+
+What: /sys/bus/typec/devices/.../displayport/pin_assignment
+Date: July 2018
+Contact: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
+Description:
+ VESA DisplayPort Alt Mode on USB Type-C Standard defines six
+ different pin assignments for USB Type-C connector that are
+ labeled A, B, C, D, E, and F. The supported pin assignments are
+ listed as space separated list with the active one wrapped in
+ square brackets.
+
+ Example:
+
+ C [D]
+
+ Pin assignment can be changed by writing to the file. It is
+ possible to set pin assignment before configuration has been
+ set, but the assignment will not be active before the
+ connector is actually configured.
+
+ Note. As of VESA DisplayPort Alt Mode on USB Type-C Standard
+ version 1.0b, pin assignments A, B, and F are deprecated. Only
+ pin assignments D can now carry simultaneously one channel of
+ USB SuperSpeed protocol. From user perspective pin assignments C
+ and E are equal, where all channels on the connector are used
+ for carrying DisplayPort protocol (allowing higher resolutions).
diff --git a/drivers/usb/typec/Kconfig b/drivers/usb/typec/Kconfig
index 2c8eab11a493..652d49ede8b8 100644
--- a/drivers/usb/typec/Kconfig
+++ b/drivers/usb/typec/Kconfig
@@ -88,4 +88,6 @@ config TYPEC_TPS6598X
source "drivers/usb/typec/mux/Kconfig"
+source "drivers/usb/typec/altmodes/Kconfig"
+
endif # TYPEC
diff --git a/drivers/usb/typec/Makefile b/drivers/usb/typec/Makefile
index 5466c62c8e97..65651ec65d19 100644
--- a/drivers/usb/typec/Makefile
+++ b/drivers/usb/typec/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_TYPEC) += typec.o
typec-y := class.o mux.o bus.o
+obj-$(CONFIG_TYPEC) += altmodes/
obj-$(CONFIG_TYPEC_TCPM) += tcpm.o
obj-y += fusb302/
obj-$(CONFIG_TYPEC_WCOVE) += typec_wcove.o
diff --git a/drivers/usb/typec/altmodes/Kconfig b/drivers/usb/typec/altmodes/Kconfig
new file mode 100644
index 000000000000..efef2a64bc51
--- /dev/null
+++ b/drivers/usb/typec/altmodes/Kconfig
@@ -0,0 +1,14 @@
+
+menu "USB Type-C Alternate Mode drivers"
+
+config TYPEC_DP_ALTMODE
+ tristate "DisplayPort Alternate Mode driver"
+ help
+ DisplayPort USB Type-C Alternate Mode allows DisplayPort
+ displays and adapters to be attached to the USB Type-C
+ connectors on the system.
+
+ To compile this driver as a module, choose M here: the
+ module will be called typec_displayport.
+
+endmenu
diff --git a/drivers/usb/typec/altmodes/Makefile b/drivers/usb/typec/altmodes/Makefile
new file mode 100644
index 000000000000..5caf094ef71a
--- /dev/null
+++ b/drivers/usb/typec/altmodes/Makefile
@@ -0,0 +1,2 @@
+obj-$(CONFIG_TYPEC_DP_ALTMODE) += typec_displayport.o
+typec_displayport-y := displayport.o
diff --git a/drivers/usb/typec/altmodes/displayport.c b/drivers/usb/typec/altmodes/displayport.c
new file mode 100644
index 000000000000..a5054d86a4d9
--- /dev/null
+++ b/drivers/usb/typec/altmodes/displayport.c
@@ -0,0 +1,543 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * USB Typec-C DisplayPort Alternate Mode driver
+ *
+ * Copyright (C) 2018 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
+ *
+ * DisplayPort is trademark of VESA (www.vesa.org)
+ */
+
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/usb/pd_vdo.h>
+#include <linux/usb/typec_dp.h>
+
+#define DP_HEADER(cmd) (VDO(USB_TYPEC_DP_SID, 1, cmd) | \
+ VDO_OPOS(USB_TYPEC_DP_MODE))
+
+/* DisplayPort alt mode specific commands */
+#define DP_CMD_STATUS_UPDATE VDO_CMD_VENDOR(0)
+#define DP_CMD_CONFIGURE VDO_CMD_VENDOR(1)
+
+enum {
+ DP_CONF_USB,
+ DP_CONF_DFP_D,
+ DP_CONF_UFP_D,
+ DP_CONF_DUAL_D,
+};
+
+/* DisplayPort Capabilities VDO bits */
+#define DP_CAP_CAPABILITY(_cap_) ((_cap_) & 3)
+#define DP_CAP_UFP_D 1
+#define DP_CAP_DFP_D 2
+#define DP_CAP_DFP_D_AND_UFP_D 3
+#define DP_CAP_DP_SIGNALING BIT(2) /* Always set */
+#define DP_CAP_GEN2 BIT(3) /* Reserved after v1.0b */
+#define DP_CAP_RECEPTACLE BIT(6)
+#define DP_CAP_USB BIT(7)
+#define DP_CAP_DFP_D_PIN_ASSIGN(_cap_) (((_cap_) & GENMASK(15, 8)) >> 8)
+#define DP_CAP_UFP_D_PIN_ASSIGN(_cap_) (((_cap_) & GENMASK(23, 16)) >> 16)
+
+enum {
+ DP_PIN_ASSIGN_A, /* Not supported after v1.0b */
+ DP_PIN_ASSIGN_B, /* Not supported after v1.0b */
+ DP_PIN_ASSIGN_C,
+ DP_PIN_ASSIGN_D,
+ DP_PIN_ASSIGN_E,
+ DP_PIN_ASSIGN_F, /* Not supported after v1.0b */
+};
+
+/* Helper for setting/getting the pin assignement value to the configuration */
+#define DP_CONF_SET_PIN_ASSIGN(_a_) ((_a_) << 8)
+#define DP_CONF_GET_PIN_ASSIGN(_conf_) (((_conf_) & GENMASK(15, 8)) >> 8)
+
+/* Pin assignments that use USB3.1 Gen2 signaling to carry DP protocol */
+#define DP_PIN_ASSIGN_GEN2_BR_MASK (BIT(DP_PIN_ASSIGN_A) | \
+ BIT(DP_PIN_ASSIGN_B))
+
+/* Pin assignments that use DP v1.3 signaling to carry DP protocol */
+#define DP_PIN_ASSIGN_DP_BR_MASK (BIT(DP_PIN_ASSIGN_C) | \
+ BIT(DP_PIN_ASSIGN_D) | \
+ BIT(DP_PIN_ASSIGN_E) | \
+ BIT(DP_PIN_ASSIGN_F))
+
+/* DP only pin assignments */
+#define DP_PIN_ASSIGN_DP_ONLY_MASK (BIT(DP_PIN_ASSIGN_A) | \
+ BIT(DP_PIN_ASSIGN_C) | \
+ BIT(DP_PIN_ASSIGN_E))
+
+/* Pin assignments where one channel is for USB */
+#define DP_PIN_ASSIGN_MULTI_FUNC_MASK (BIT(DP_PIN_ASSIGN_B) | \
+ BIT(DP_PIN_ASSIGN_D) | \
+ BIT(DP_PIN_ASSIGN_F))
+
+enum dp_state {
+ DP_STATE_NONE,
+ DP_STATE_ENTER,
+ DP_STATE_UPDATE,
+ DP_STATE_CONFIGURE,
+ DP_STATE_EXIT,
+};
+
+struct dp_altmode {
+ struct typec_displayport_data data;
+
+ enum dp_state state;
+
+ struct mutex lock;
+ struct work_struct work;
+ struct typec_altmode *alt;
+ const struct typec_altmode *port;
+};
+
+static int dp_altmode_configure(struct dp_altmode *dp, u8 con)
+{
+ u32 conf = DP_CONF_SIGNALING_DP; /* Only DP signaling supported */
+ u8 pin_assign = 0;
+
+ switch (con) {
+ case DP_STATUS_CON_DISABLED:
+ dp->data.conf = 0;
+ return 0;
+ case DP_STATUS_CON_DFP_D:
+ conf |= DP_CONF_UFP_U_AS_DFP_D;
+ pin_assign = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo) &
+ DP_CAP_DFP_D_PIN_ASSIGN(dp->port->vdo);
+ break;
+ case DP_STATUS_CON_UFP_D:
+ case DP_STATUS_CON_BOTH: /* NOTE: First acting as DP source */
+ conf |= DP_CONF_UFP_U_AS_UFP_D;
+ pin_assign = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo) &
+ DP_CAP_UFP_D_PIN_ASSIGN(dp->port->vdo);
+ break;
+ default:
+ break;
+ }
+
+ /* Determining the initial pin assignment. */
+ if (!DP_CONF_GET_PIN_ASSIGN(dp->data.conf)) {
+ /* Is USB together with DP preferred */
+ if (dp->data.status & DP_STATUS_PREFER_MULTI_FUNC &&
+ pin_assign & DP_PIN_ASSIGN_MULTI_FUNC_MASK)
+ pin_assign &= DP_PIN_ASSIGN_MULTI_FUNC_MASK;
+ else
+ pin_assign &= DP_PIN_ASSIGN_DP_ONLY_MASK;
+
+ if (!pin_assign)
+ return -EINVAL;
+
+ conf |= DP_CONF_SET_PIN_ASSIGN(pin_assign);
+ }
+
+ dp->data.conf |= conf;
+
+ return 0;
+}
+
+static int dp_altmode_status_update(struct dp_altmode *dp)
+{
+ bool configured = !!DP_CONF_GET_PIN_ASSIGN(dp->data.conf);
+ u8 con = DP_STATUS_CONNECTION(dp->data.status);
+ int ret = 0;
+
+ if (configured && (dp->data.status & DP_STATUS_SWITCH_TO_USB)) {
+ dp->data.conf = 0;
+ dp->state = DP_STATE_CONFIGURE;
+ } else if (dp->data.status & DP_STATUS_EXIT_DP_MODE) {
+ dp->state = DP_STATE_EXIT;
+ } else if (!(con & DP_CONF_CURRENTLY(dp->data.conf))) {
+ ret = dp_altmode_configure(dp, con);
+ if (!ret)
+ dp->state = DP_STATE_CONFIGURE;
+ }
+
+ return ret;
+}
+
+static int dp_altmode_configured(struct dp_altmode *dp)
+{
+ u8 state;
+ int ret;
+
+ sysfs_notify(&dp->alt->dev.kobj, "displayport", "configuration");
+
+ if (!dp->data.conf)
+ return typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
+ &dp->data);
+
+ state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
+ ret = typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
+ &dp->data);
+ if (ret)
+ return ret;
+
+ sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
+
+ return 0;
+}
+
+static void dp_altmode_work(struct work_struct *work)
+{
+ struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
+ u32 header = 0;
+ u32 vdo;
+ int ret;
+
+ mutex_lock(&dp->lock);
+
+ switch (dp->state) {
+ case DP_STATE_ENTER:
+ ret = typec_altmode_enter(dp->alt);
+ if (ret)
+ dev_err(&dp->alt->dev, "failed to enter mode\n");
+ break;
+ case DP_STATE_UPDATE:
+ header = DP_HEADER(DP_CMD_STATUS_UPDATE);
+ vdo = 1;
+ break;
+ case DP_STATE_CONFIGURE:
+ ret = typec_altmode_notify(dp->alt, TYPEC_STATE_SAFE,
+ &dp->data);
+ if (ret) {
+ dev_err(&dp->alt->dev,
+ "unable to put to connector to safe mode\n");
+ break;
+ }
+ header = DP_HEADER(DP_CMD_CONFIGURE);
+ vdo = dp->data.conf;
+ break;
+ case DP_STATE_EXIT:
+ if (typec_altmode_exit(dp->alt))
+ dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
+ break;
+ default:
+ break;
+ }
+
+ if (header) {
+ if (typec_altmode_vdm(dp->alt, header, &vdo, 2))
+ dev_err(&dp->alt->dev, "unable to send VDM\n");
+ }
+
+ mutex_unlock(&dp->lock);
+}
+
+static void dp_altmode_attention(struct typec_altmode *alt, const u32 vdo)
+{
+ struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
+ u8 state;
+
+ mutex_lock(&dp->lock);
+
+ dp->state = DP_STATE_NONE;
+ dp->data.status = vdo;
+ dp_altmode_status_update(dp);
+
+ if (dp->state == DP_STATE_NONE) {
+ state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
+ if (typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
+ &dp->data))
+ dev_err(&alt->dev, "%s: notification failed\n",
+ __func__);
+ } else {
+ schedule_work(&dp->work);
+ }
+
+ mutex_unlock(&dp->lock);
+}
+
+static int dp_altmode_vdm(struct typec_altmode *alt,
+ const u32 hdr, const u32 *vdo, int count)
+{
+ struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
+ int cmd_type = PD_VDO_CMDT(hdr);
+ int cmd = PD_VDO_CMD(hdr);
+ int ret = 0;
+
+ mutex_lock(&dp->lock);
+
+ dp->state = DP_STATE_NONE;
+
+ switch (cmd_type) {
+ case CMDT_RSP_ACK:
+ switch (cmd) {
+ case CMD_ENTER_MODE:
+ dp->state = DP_STATE_UPDATE;
+ break;
+ case CMD_EXIT_MODE:
+ dp->data.status = 0;
+ dp->data.conf = 0;
+ break;
+ case DP_CMD_STATUS_UPDATE:
+ dp->data.status = *vdo;
+ ret = dp_altmode_status_update(dp);
+ break;
+ case DP_CMD_CONFIGURE:
+ ret = dp_altmode_configured(dp);
+ break;
+ default:
+ break;
+ }
+ break;
+ case CMDT_RSP_NAK:
+ switch (cmd) {
+ case DP_CMD_CONFIGURE:
+ dp->data.conf = 0;
+ ret = dp_altmode_configured(dp);
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+
+ if (dp->state != DP_STATE_NONE)
+ schedule_work(&dp->work);
+
+ mutex_unlock(&dp->lock);
+ return ret;
+}
+
+static int dp_altmode_activate(struct typec_altmode *alt, int activate)
+{
+ return activate ? typec_altmode_enter(alt) : typec_altmode_exit(alt);
+}
+
+static const struct typec_altmode_ops dp_altmode_ops = {
+ .attention = dp_altmode_attention,
+ .vdm = dp_altmode_vdm,
+ .activate = dp_altmode_activate,
+};
+
+static const char * const configurations[] = {
+ [DP_CONF_USB] = "USB",
+ [DP_CONF_DFP_D] = "source",
+ [DP_CONF_UFP_D] = "sink",
+};
+
+static ssize_t
+configuration_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct dp_altmode *dp = dev_get_drvdata(dev);
+ int conf;
+ int ret;
+
+ conf = sysfs_match_string(configurations, buf);
+ if (conf < 0)
+ return conf;
+
+ mutex_lock(&dp->lock);
+
+ ret = dp_altmode_configure(dp, conf);
+ if (!ret && dp->alt->active) {
+ dp->state = DP_STATE_CONFIGURE;
+ schedule_work(&dp->work);
+ }
+
+ mutex_unlock(&dp->lock);
+
+ return ret ? ret : size;
+}
+
+static ssize_t configuration_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dp_altmode *dp = dev_get_drvdata(dev);
+ int len;
+ u8 cap;
+ u8 cur;
+ int i;
+
+ mutex_lock(&dp->lock);
+
+ cap = DP_CAP_CAPABILITY(dp->alt->vdo);
+ cur = DP_CONF_CURRENTLY(dp->data.conf);
+
+ len = sprintf(buf, "%s ", cur ? "USB" : "[USB]");
+
+ for (i = 1; i < ARRAY_SIZE(configurations); i++) {
+ if (i == cur)
+ len += sprintf(buf + len, "[%s] ", configurations[i]);
+ else if ((i == DP_CONF_DFP_D && cap & DP_CAP_DFP_D) ||
+ (i == DP_CONF_UFP_D && cap & DP_CAP_UFP_D))
+ len += sprintf(buf + len, "%s ", configurations[i]);
+ }
+
+ mutex_unlock(&dp->lock);
+
+ buf[len - 1] = '\n';
+ return len;
+}
+static DEVICE_ATTR_RW(configuration);
+
+static const char * const pin_assignments[] = {
+ [DP_PIN_ASSIGN_A] = "A",
+ [DP_PIN_ASSIGN_B] = "B",
+ [DP_PIN_ASSIGN_C] = "C",
+ [DP_PIN_ASSIGN_D] = "D",
+ [DP_PIN_ASSIGN_E] = "E",
+ [DP_PIN_ASSIGN_F] = "F",
+};
+
+static ssize_t
+pin_assignment_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ struct dp_altmode *dp = dev_get_drvdata(dev);
+ u8 assignments;
+ u32 conf;
+ int ret;
+
+ ret = sysfs_match_string(pin_assignments, buf);
+ if (ret < 0)
+ return ret;
+
+ conf = DP_CONF_SET_PIN_ASSIGN(BIT(ret));
+ ret = 0;
+
+ mutex_lock(&dp->lock);
+
+ if (conf & dp->data.conf)
+ goto out_unlock;
+
+ if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
+ assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
+ else
+ assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
+
+ if (!(DP_CONF_GET_PIN_ASSIGN(conf) & assignments)) {
+ ret = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* Only send Configure command if a configuration has been set */
+ if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
+ dp->state = DP_STATE_CONFIGURE;
+ schedule_work(&dp->work);
+ }
+
+ dp->data.conf &= ~DP_CONF_PIN_ASSIGNEMENT_MASK;
+ dp->data.conf |= conf;
+
+out_unlock:
+ mutex_unlock(&dp->lock);
+
+ return ret ? ret : size;
+}
+
+static ssize_t pin_assignment_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct dp_altmode *dp = dev_get_drvdata(dev);
+ u8 assignments;
+ int len = 0;
+ u8 cur;
+ int i;
+
+ mutex_lock(&dp->lock);
+
+ cur = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
+
+ if (DP_CONF_CURRENTLY(dp->data.conf) == DP_CONF_DFP_D)
+ assignments = DP_CAP_UFP_D_PIN_ASSIGN(dp->alt->vdo);
+ else
+ assignments = DP_CAP_DFP_D_PIN_ASSIGN(dp->alt->vdo);
+
+ for (i = 0; assignments; assignments >>= 1, i++) {
+ if (assignments & 1) {
+ if (i == cur)
+ len += sprintf(buf + len, "[%s] ",
+ pin_assignments[i]);
+ else
+ len += sprintf(buf + len, "%s ",
+ pin_assignments[i]);
+ }
+ }
+
+ mutex_unlock(&dp->lock);
+
+ buf[len - 1] = '\n';
+ return len;
+}
+static DEVICE_ATTR_RW(pin_assignment);
+
+static struct attribute *dp_altmode_attrs[] = {
+ &dev_attr_configuration.attr,
+ &dev_attr_pin_assignment.attr,
+ NULL
+};
+
+static const struct attribute_group dp_altmode_group = {
+ .name = "displayport",
+ .attrs = dp_altmode_attrs,
+};
+
+static int dp_altmode_probe(struct typec_altmode *alt)
+{
+ const struct typec_altmode *port = typec_altmode_get_partner(alt);
+ struct dp_altmode *dp;
+ int ret;
+
+ /* FIXME: Port can only be DFP_U. */
+
+ /* Make sure we have compatiple pin configurations */
+ if (!(DP_CAP_DFP_D_PIN_ASSIGN(port->vdo) &
+ DP_CAP_UFP_D_PIN_ASSIGN(alt->vdo)) &&
+ !(DP_CAP_UFP_D_PIN_ASSIGN(port->vdo) &
+ DP_CAP_DFP_D_PIN_ASSIGN(alt->vdo)))
+ return -ENODEV;
+
+ ret = sysfs_create_group(&alt->dev.kobj, &dp_altmode_group);
+ if (ret)
+ return ret;
+
+ dp = devm_kzalloc(&alt->dev, sizeof(*dp), GFP_KERNEL);
+ if (!dp)
+ return -ENOMEM;
+
+ INIT_WORK(&dp->work, dp_altmode_work);
+ mutex_init(&dp->lock);
+ dp->port = port;
+ dp->alt = alt;
+
+ alt->desc = "DisplayPort";
+ alt->ops = &dp_altmode_ops;
+
+ typec_altmode_set_drvdata(alt, dp);
+
+ dp->state = DP_STATE_ENTER;
+ schedule_work(&dp->work);
+
+ return 0;
+}
+
+static void dp_altmode_remove(struct typec_altmode *alt)
+{
+ sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
+}
+
+static const struct typec_device_id dp_typec_id[] = {
+ { USB_TYPEC_DP_SID, USB_TYPEC_DP_MODE },
+ { },
+};
+MODULE_DEVICE_TABLE(typec, dp_typec_id);
+
+static struct typec_altmode_driver dp_altmode_driver = {
+ .id_table = dp_typec_id,
+ .probe = dp_altmode_probe,
+ .remove = dp_altmode_remove,
+ .driver = {
+ .name = "typec_displayport",
+ .owner = THIS_MODULE,
+ },
+};
+module_typec_altmode_driver(dp_altmode_driver);
+
+MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DisplayPort Alternate Mode");
diff --git a/include/linux/usb/typec_dp.h b/include/linux/usb/typec_dp.h
new file mode 100644
index 000000000000..5ca989076d7c
--- /dev/null
+++ b/include/linux/usb/typec_dp.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __USB_TYPEC_DP_H
+#define __USB_TYPEC_DP_H
+
+#include <linux/usb/typec_altmode.h>
+
+#define USB_TYPEC_DP_SID 0xff01
+#define USB_TYPEC_DP_MODE 1
+
+/*
+ * Connector states matching the pin assignments in DisplayPort Alt Mode
+ * Specification.
+ *
+ * These values are meant primarily to be used by the mux drivers, but they are
+ * also used as the "value" part in the alternate mode notification chain, so
+ * receivers of those notifications will always see them.
+ *
+ * Note. DisplayPort USB Type-C Alt Mode Specification version 1.0b deprecated
+ * pin assignments A, B and F, but they are still defined here for legacy
+ * purposes.
+ */
+enum {
+ TYPEC_DP_STATE_A = TYPEC_STATE_MODAL, /* Not supported after v1.0b */
+ TYPEC_DP_STATE_B, /* Not supported after v1.0b */
+ TYPEC_DP_STATE_C,
+ TYPEC_DP_STATE_D,
+ TYPEC_DP_STATE_E,
+ TYPEC_DP_STATE_F, /* Not supported after v1.0b */
+};
+
+/*
+ * struct typec_displayport_data - DisplayPort Alt Mode specific data
+ * @status: Status Update command VDO content
+ * @conf: Configure command VDO content
+ *
+ * This structure is delivered as the data part with the notifications. It
+ * contains the VDOs from the two DisplayPort Type-C alternate mode specific
+ * commands: Status Update and Configure.
+ *
+ * @status will show for example the status of the HPD signal.
+ */
+struct typec_displayport_data {
+ u32 status;
+ u32 conf;
+};
+
+/* DisplayPort Status Update VDO bits */
+#define DP_STATUS_CONNECTION(_status_) ((_status_) & 3)
+#define DP_STATUS_CON_DISABLED 0
+#define DP_STATUS_CON_DFP_D 1
+#define DP_STATUS_CON_UFP_D 2
+#define DP_STATUS_CON_BOTH 3
+#define DP_STATUS_POWER_LOW BIT(2)
+#define DP_STATUS_ENABLED BIT(3)
+#define DP_STATUS_PREFER_MULTI_FUNC BIT(4)
+#define DP_STATUS_SWITCH_TO_USB BIT(5)
+#define DP_STATUS_EXIT_DP_MODE BIT(6)
+#define DP_STATUS_HPD_STATE BIT(7) /* 0 = HPD_Low, 1 = HPD_High */
+#define DP_STATUS_IRQ_HPD BIT(8)
+
+/* DisplayPort Configurations VDO bits */
+#define DP_CONF_CURRENTLY(_conf_) ((_conf_) & 3)
+#define DP_CONF_UFP_U_AS_DFP_D BIT(0)
+#define DP_CONF_UFP_U_AS_UFP_D BIT(1)
+#define DP_CONF_SIGNALING_DP BIT(2)
+#define DP_CONF_SIGNALING_GEN_2 BIT(3) /* Reserved after v1.0b */
+#define DP_CONF_PIN_ASSIGNEMENT_SHIFT 8
+#define DP_CONF_PIN_ASSIGNEMENT_MASK GENMASK(15, 8)
+
+#endif /* __USB_TYPEC_DP_H */
--
2.17.1