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usb: typec: Add driver for DisplayPort alternate mode
authorHeikki Krogerus <heikki.krogerus@linux.intel.com>
Wed, 27 Jun 2018 15:19:51 +0000 (18:19 +0300)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 2 Jul 2018 15:42:36 +0000 (17:42 +0200)
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@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/ABI/testing/sysfs-driver-typec-displayport [new file with mode: 0644]
drivers/usb/typec/Kconfig
drivers/usb/typec/Makefile
drivers/usb/typec/altmodes/Kconfig [new file with mode: 0644]
drivers/usb/typec/altmodes/Makefile [new file with mode: 0644]
drivers/usb/typec/altmodes/displayport.c [new file with mode: 0644]
include/linux/usb/typec_dp.h [new file with mode: 0644]

diff --git a/Documentation/ABI/testing/sysfs-driver-typec-displayport b/Documentation/ABI/testing/sysfs-driver-typec-displayport
new file mode 100644 (file)
index 0000000..231471a
--- /dev/null
@@ -0,0 +1,49 @@
+What:          /sys/bus/typec/devices/.../displayport/configuration
+Date:          July 2018
+Contact:       Heikki Krogerus <heikki.krogerus@linux.intel.com>
+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@linux.intel.com>
+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 assignment 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).
index ee80890..00878c3 100644 (file)
@@ -104,4 +104,6 @@ config TYPEC_TPS6598X
 
 source "drivers/usb/typec/mux/Kconfig"
 
+source "drivers/usb/typec/altmodes/Kconfig"
+
 endif # TYPEC
index 335ee06..45b0aef 100644 (file)
@@ -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 (file)
index 0000000..efef2a6
--- /dev/null
@@ -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 (file)
index 0000000..5caf094
--- /dev/null
@@ -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 (file)
index 0000000..ef12b15
--- /dev/null
@@ -0,0 +1,578 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * USB Typec-C DisplayPort Alternate Mode driver
+ *
+ * Copyright (C) 2018 Intel Corporation
+ * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
+ *
+ * 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))
+
+enum {
+       DP_CONF_USB,
+       DP_CONF_DFP_D,
+       DP_CONF_UFP_D,
+       DP_CONF_DUAL_D,
+};
+
+/* 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_IDLE,
+       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; /* device lock */
+       struct work_struct work;
+       struct typec_altmode *alt;
+       const struct typec_altmode *port;
+};
+
+static int dp_altmode_notify(struct dp_altmode *dp)
+{
+       u8 state = get_count_order(DP_CONF_GET_PIN_ASSIGN(dp->data.conf));
+
+       return typec_altmode_notify(dp->alt, TYPEC_MODAL_STATE(state),
+                                  &dp->data);
+}
+
+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:
+               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)
+{
+       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);
+
+       ret = dp_altmode_notify(dp);
+       if (ret)
+               return ret;
+
+       sysfs_notify(&dp->alt->dev.kobj, "displayport", "pin_assignment");
+
+       return 0;
+}
+
+static int dp_altmode_configure_vdm(struct dp_altmode *dp, u32 conf)
+{
+       u32 header = DP_HEADER(DP_CMD_CONFIGURE);
+       int ret;
+
+       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");
+               return ret;
+       }
+
+       ret = typec_altmode_vdm(dp->alt, header, &conf, 2);
+       if (ret) {
+               if (DP_CONF_GET_PIN_ASSIGN(dp->data.conf))
+                       dp_altmode_notify(dp);
+               else
+                       typec_altmode_notify(dp->alt, TYPEC_STATE_USB,
+                                            &dp->data);
+       }
+
+       return ret;
+}
+
+static void dp_altmode_work(struct work_struct *work)
+{
+       struct dp_altmode *dp = container_of(work, struct dp_altmode, work);
+       u32 header;
+       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;
+               ret = typec_altmode_vdm(dp->alt, header, &vdo, 2);
+               if (ret)
+                       dev_err(&dp->alt->dev,
+                               "unable to send Status Update command (%d)\n",
+                               ret);
+               break;
+       case DP_STATE_CONFIGURE:
+               ret = dp_altmode_configure_vdm(dp, dp->data.conf);
+               if (ret)
+                       dev_err(&dp->alt->dev,
+                               "unable to send Configure command (%d)\n", ret);
+               break;
+       case DP_STATE_EXIT:
+               if (typec_altmode_exit(dp->alt))
+                       dev_err(&dp->alt->dev, "Exit Mode Failed!\n");
+               break;
+       default:
+               break;
+       }
+
+       dp->state = DP_STATE_IDLE;
+
+       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 old_state;
+
+       mutex_lock(&dp->lock);
+
+       old_state = dp->state;
+       dp->data.status = vdo;
+
+       if (old_state != DP_STATE_IDLE)
+               dev_warn(&alt->dev, "ATTENTION while processing state %d\n",
+                        old_state);
+
+       if (dp_altmode_status_update(dp))
+               dev_warn(&alt->dev, "%s: status update failed\n", __func__);
+
+       if (dp_altmode_notify(dp))
+               dev_err(&alt->dev, "%s: notification failed\n", __func__);
+
+       if (old_state == DP_STATE_IDLE && dp->state != DP_STATE_IDLE)
+               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);
+
+       if (dp->state != DP_STATE_IDLE) {
+               ret = -EBUSY;
+               goto err_unlock;
+       }
+
+       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_IDLE)
+               schedule_work(&dp->work);
+
+err_unlock:
+       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);
+       u32 conf;
+       u32 cap;
+       int con;
+       int ret;
+
+       con = sysfs_match_string(configurations, buf);
+       if (con < 0)
+               return con;
+
+       mutex_lock(&dp->lock);
+
+       if (dp->state != DP_STATE_IDLE) {
+               ret = -EBUSY;
+               goto err_unlock;
+       }
+
+       cap = DP_CAP_CAPABILITY(dp->alt->vdo);
+
+       if ((con == DP_CONF_DFP_D && !(cap & DP_CAP_DFP_D)) ||
+           (con == DP_CONF_UFP_D && !(cap & DP_CAP_UFP_D)))
+               return -EINVAL;
+
+       conf = dp->data.conf & ~DP_CONF_DUAL_D;
+       conf |= con;
+
+       if (dp->alt->active) {
+               ret = dp_altmode_configure_vdm(dp, conf);
+               if (ret)
+                       goto err_unlock;
+       }
+
+       dp->data.conf = conf;
+
+err_unlock:
+       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->state != DP_STATE_IDLE) {
+               ret = -EBUSY;
+               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;
+       }
+
+       conf |= dp->data.conf & ~DP_CONF_PIN_ASSIGNEMENT_MASK;
+
+       /* Only send Configure command if a configuration has been set */
+       if (dp->alt->active && DP_CONF_CURRENTLY(dp->data.conf)) {
+               ret = dp_altmode_configure_vdm(dp, conf);
+               if (ret)
+                       goto out_unlock;
+       }
+
+       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)
+{
+       struct dp_altmode *dp = typec_altmode_get_drvdata(alt);
+
+       sysfs_remove_group(&alt->dev.kobj, &dp_altmode_group);
+       cancel_work_sync(&dp->work);
+}
+
+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@linux.intel.com>");
+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 (file)
index 0000000..55ae781
--- /dev/null
@@ -0,0 +1,95 @@
+/* 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;
+};
+
+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 */
+};
+
+/* DisplayPort alt mode specific commands */
+#define DP_CMD_STATUS_UPDATE           VDO_CMD_VENDOR(0)
+#define DP_CMD_CONFIGURE               VDO_CMD_VENDOR(1)
+
+/* DisplayPort Capabilities VDO bits (returned with Discover Modes) */
+#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)
+
+/* 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 */