Merge tag 'drm-misc-intel-oob-hotplug-v1' of git://git.kernel.org/pub/scm/linux/kernel/git/hansg/linux into drm-misc-next

Topic branch for drm-misc / drm-intel for OOB hotplug support for Type-C connectors

Signed-off-by: Maxime Ripard <maxime@cerno.tech>

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# gpg: Signature made Fri 20 Aug 2021 07:29:15 PM CEST
# gpg:                using RSA key BAF03B5D2718411A5E9E177E92EC4779440327DC
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From: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/34f13e21-9b1a-5f54-7e03-9705a6b51428@redhat.com

3 files changed, 155 insertions, 13 deletions

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 2ba257b1ae20..e0a30e0ee86a 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -65,6 +65,14 @@
  * support can instead use e.g. drm_helper_hpd_irq_event().
  */
 
+/*
+ * Global connector list for drm_connector_find_by_fwnode().
+ * Note drm_connector_[un]register() first take connector->lock and then
+ * take the connector_list_lock.
+ */
+static DEFINE_MUTEX(connector_list_lock);
+static LIST_HEAD(connector_list);
+
 struct drm_conn_prop_enum_list {
 	int type;
 	const char *name;
@@ -267,6 +275,7 @@ int drm_connector_init(struct drm_device *dev,
 		goto out_put_type_id;
 	}
 
+	INIT_LIST_HEAD(&connector->global_connector_list_entry);
 	INIT_LIST_HEAD(&connector->probed_modes);
 	INIT_LIST_HEAD(&connector->modes);
 	mutex_init(&connector->mutex);
@@ -474,6 +483,8 @@ void drm_connector_cleanup(struct drm_connector *connector)
 	drm_mode_object_unregister(dev, &connector->base);
 	kfree(connector->name);
 	connector->name = NULL;
+	fwnode_handle_put(connector->fwnode);
+	connector->fwnode = NULL;
 	spin_lock_irq(&dev->mode_config.connector_list_lock);
 	list_del(&connector->head);
 	dev->mode_config.num_connector--;
@@ -532,6 +543,9 @@ int drm_connector_register(struct drm_connector *connector)
 	/* Let userspace know we have a new connector */
 	drm_sysfs_hotplug_event(connector->dev);
 
+	mutex_lock(&connector_list_lock);
+	list_add_tail(&connector->global_connector_list_entry, &connector_list);
+	mutex_unlock(&connector_list_lock);
 	goto unlock;
 
 err_debugfs:
@@ -560,6 +574,10 @@ void drm_connector_unregister(struct drm_connector *connector)
 		return;
 	}
 
+	mutex_lock(&connector_list_lock);
+	list_del_init(&connector->global_connector_list_entry);
+	mutex_unlock(&connector_list_lock);
+
 	if (connector->funcs->early_unregister)
 		connector->funcs->early_unregister(connector);
 
@@ -2543,6 +2561,67 @@ out:
 	return ret;
 }
 
+/**
+ * drm_connector_find_by_fwnode - Find a connector based on the associated fwnode
+ * @fwnode: fwnode for which to find the matching drm_connector
+ *
+ * This functions looks up a drm_connector based on its associated fwnode. When
+ * a connector is found a reference to the connector is returned. The caller must
+ * call drm_connector_put() to release this reference when it is done with the
+ * connector.
+ *
+ * Returns: A reference to the found connector or an ERR_PTR().
+ */
+struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode)
+{
+	struct drm_connector *connector, *found = ERR_PTR(-ENODEV);
+
+	if (!fwnode)
+		return ERR_PTR(-ENODEV);
+
+	mutex_lock(&connector_list_lock);
+
+	list_for_each_entry(connector, &connector_list, global_connector_list_entry) {
+		if (connector->fwnode == fwnode ||
+		    (connector->fwnode && connector->fwnode->secondary == fwnode)) {
+			drm_connector_get(connector);
+			found = connector;
+			break;
+		}
+	}
+
+	mutex_unlock(&connector_list_lock);
+
+	return found;
+}
+
+/**
+ * drm_connector_oob_hotplug_event - Report out-of-band hotplug event to connector
+ * @connector: connector to report the event on
+ *
+ * On some hardware a hotplug event notification may come from outside the display
+ * driver / device. An example of this is some USB Type-C setups where the hardware
+ * muxes the DisplayPort data and aux-lines but does not pass the altmode HPD
+ * status bit to the GPU's DP HPD pin.
+ *
+ * This function can be used to report these out-of-band events after obtaining
+ * a drm_connector reference through calling drm_connector_find_by_fwnode().
+ */
+void drm_connector_oob_hotplug_event(struct fwnode_handle *connector_fwnode)
+{
+	struct drm_connector *connector;
+
+	connector = drm_connector_find_by_fwnode(connector_fwnode);
+	if (IS_ERR(connector))
+		return;
+
+	if (connector->funcs->oob_hotplug_event)
+		connector->funcs->oob_hotplug_event(connector);
+
+	drm_connector_put(connector);
+}
+EXPORT_SYMBOL(drm_connector_oob_hotplug_event);
+
 
 /**
  * DOC: Tile group
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index edb772947cb4..63279e984342 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -58,6 +58,7 @@ struct drm_property;
 struct edid;
 struct kref;
 struct work_struct;
+struct fwnode_handle;
 
 /* drm_crtc.c */
 int drm_mode_crtc_set_obj_prop(struct drm_mode_object *obj,
@@ -186,6 +187,7 @@ int drm_connector_set_obj_prop(struct drm_mode_object *obj,
 int drm_connector_create_standard_properties(struct drm_device *dev);
 const char *drm_get_connector_force_name(enum drm_connector_force force);
 void drm_connector_free_work_fn(struct work_struct *work);
+struct drm_connector *drm_connector_find_by_fwnode(struct fwnode_handle *fwnode);
 
 /* IOCTL */
 int drm_connector_property_set_ioctl(struct drm_device *dev,
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index 968a9560b4aa..76ff6ec3421b 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -10,6 +10,7 @@
  * Copyright (c) 2003-2004 IBM Corp.
  */
 
+#include <linux/acpi.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/export.h>
@@ -50,8 +51,45 @@ static struct device_type drm_sysfs_device_minor = {
 	.name = "drm_minor"
 };
 
+static struct device_type drm_sysfs_device_connector = {
+	.name = "drm_connector",
+};
+
 struct class *drm_class;
 
+#ifdef CONFIG_ACPI
+static bool drm_connector_acpi_bus_match(struct device *dev)
+{
+	return dev->type == &drm_sysfs_device_connector;
+}
+
+static struct acpi_device *drm_connector_acpi_find_companion(struct device *dev)
+{
+	struct drm_connector *connector = to_drm_connector(dev);
+
+	return to_acpi_device_node(connector->fwnode);
+}
+
+static struct acpi_bus_type drm_connector_acpi_bus = {
+	.name = "drm_connector",
+	.match = drm_connector_acpi_bus_match,
+	.find_companion = drm_connector_acpi_find_companion,
+};
+
+static void drm_sysfs_acpi_register(void)
+{
+	register_acpi_bus_type(&drm_connector_acpi_bus);
+}
+
+static void drm_sysfs_acpi_unregister(void)
+{
+	unregister_acpi_bus_type(&drm_connector_acpi_bus);
+}
+#else
+static void drm_sysfs_acpi_register(void) { }
+static void drm_sysfs_acpi_unregister(void) { }
+#endif
+
 static char *drm_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "dri/%s", dev_name(dev));
@@ -85,6 +123,8 @@ int drm_sysfs_init(void)
 	}
 
 	drm_class->devnode = drm_devnode;
+
+	drm_sysfs_acpi_register();
 	return 0;
 }
 
@@ -97,11 +137,17 @@ void drm_sysfs_destroy(void)
 {
 	if (IS_ERR_OR_NULL(drm_class))
 		return;
+	drm_sysfs_acpi_unregister();
 	class_remove_file(drm_class, &class_attr_version.attr);
 	class_destroy(drm_class);
 	drm_class = NULL;
 }
 
+static void drm_sysfs_release(struct device *dev)
+{
+	kfree(dev);
+}
+
 /*
  * Connector properties
  */
@@ -273,27 +319,47 @@ static const struct attribute_group *connector_dev_groups[] = {
 int drm_sysfs_connector_add(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
+	struct device *kdev;
+	int r;
 
 	if (connector->kdev)
 		return 0;
 
-	connector->kdev =
-		device_create_with_groups(drm_class, dev->primary->kdev, 0,
-					  connector, connector_dev_groups,
-					  "card%d-%s", dev->primary->index,
-					  connector->name);
+	kdev = kzalloc(sizeof(*kdev), GFP_KERNEL);
+	if (!kdev)
+		return -ENOMEM;
+
+	device_initialize(kdev);
+	kdev->class = drm_class;
+	kdev->type = &drm_sysfs_device_connector;
+	kdev->parent = dev->primary->kdev;
+	kdev->groups = connector_dev_groups;
+	kdev->release = drm_sysfs_release;
+	dev_set_drvdata(kdev, connector);
+
+	r = dev_set_name(kdev, "card%d-%s", dev->primary->index, connector->name);
+	if (r)
+		goto err_free;
+
 	DRM_DEBUG("adding \"%s\" to sysfs\n",
 		  connector->name);
 
-	if (IS_ERR(connector->kdev)) {
-		DRM_ERROR("failed to register connector device: %ld\n", PTR_ERR(connector->kdev));
-		return PTR_ERR(connector->kdev);
+	r = device_add(kdev);
+	if (r) {
+		drm_err(dev, "failed to register connector device: %d\n", r);
+		goto err_free;
 	}
 
+	connector->kdev = kdev;
+
 	if (connector->ddc)
 		return sysfs_create_link(&connector->kdev->kobj,
 				 &connector->ddc->dev.kobj, "ddc");
 	return 0;
+
+err_free:
+	put_device(kdev);
+	return r;
 }
 
 void drm_sysfs_connector_remove(struct drm_connector *connector)
@@ -374,11 +440,6 @@ void drm_sysfs_connector_status_event(struct drm_connector *connector,
 }
 EXPORT_SYMBOL(drm_sysfs_connector_status_event);
 
-static void drm_sysfs_release(struct device *dev)
-{
-	kfree(dev);
-}
-
 struct device *drm_sysfs_minor_alloc(struct drm_minor *minor)
 {
 	const char *minor_str;