[PATCH 2/2] drm: Add Content Protection Desired property to drm

Sean Paul seanpaul at chromium.org
Wed Dec 3 11:57:41 PST 2014


Add a new standard connector property to track whether content protection
(ex: hdcp) is desired by userspace. While there are 3 possible states for the
property, userspace should only change the value to desired or undesired.
Upon setting the value to desired, the driver is responsible for protecting
the link and setting the value to enabled. Disabling protection should happen
immediately.

Cc: Rob Clark <robdclark at gmail.com>
Signed-off-by: Sean Paul <seanpaul at chromium.org>
---
 Documentation/DocBook/drm.tmpl | 19 +++++++++++++++++--
 drivers/gpu/drm/drm_crtc.c     | 14 ++++++++++++++
 drivers/gpu/drm/drm_sysfs.c    | 22 ++++++++++++++++++++++
 include/drm/drm_crtc.h         |  2 ++
 include/uapi/drm/drm_mode.h    |  5 +++++
 5 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index 85287cb..86633f2 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -2546,8 +2546,8 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >Description/Restrictions</td>
 	</tr>
 	<tr>
-	<td rowspan="24" valign="top" >DRM</td>
-	<td rowspan="3" valign="top" >Generic</td>
+	<td rowspan="25" valign="top" >DRM</td>
+	<td rowspan="4" valign="top" >Generic</td>
 	<td valign="top" >“EDID”</td>
 	<td valign="top" >BLOB | IMMUTABLE</td>
 	<td valign="top" >0</td>
@@ -2562,6 +2562,21 @@ void intel_crt_init(struct drm_device *dev)
 	<td valign="top" >Contains DPMS operation mode value.</td>
 	</tr>
 	<tr>
+	<td valign="top" >“Content Protection”</td>
+	<td valign="top" >ENUM</td>
+	<td valign="top" >{ “Undesired”, “Desired”, “Enabled” }</td>
+	<td valign="top" >Connector</td>
+	<td valign="top" >Contains the current state of content protection on
+		the link. User space should set this property to "Desired" to
+		enable protection. Once the driver has authenticated the
+		connection, it shall set the value to "Enabled". To disable
+		protection, user space shall set the value to "Undesired", which
+		will tear down the encryption. If at any point the link becomes
+		unprotected, the driver shall transition from "Enabled" down to
+		"Desired" and may retry if appropriate.
+	</td>
+	</tr>
+	<tr>
 	<td valign="top" >“PATH”</td>
 	<td valign="top" >BLOB | IMMUTABLE</td>
 	<td valign="top" >0</td>
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index de79283..5df5b7b 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -77,6 +77,14 @@ static const struct drm_prop_enum_list drm_plane_type_enum_list[] =
 	{ DRM_PLANE_TYPE_CURSOR, "Cursor" },
 };
 
+static struct drm_prop_enum_list drm_cp_enum_list[] = {
+	{ DRM_MODE_CONTENT_PROTECTION_UNDESIRED, "Undesired" },
+	{ DRM_MODE_CONTENT_PROTECTION_DESIRED, "Desired" },
+	{ DRM_MODE_CONTENT_PROTECTION_ENABLED, "Enabled" },
+};
+
+DRM_ENUM_NAME_FN(drm_get_content_protection_name, drm_cp_enum_list)
+
 /*
  * Optional properties
  */
@@ -1319,6 +1327,7 @@ static int drm_mode_create_standard_connector_properties(struct drm_device *dev)
 	struct drm_property *edid;
 	struct drm_property *dpms;
 	struct drm_property *dev_path;
+	struct drm_property *content_protection;
 
 	/*
 	 * Standard properties (apply to all connectors)
@@ -1339,6 +1348,11 @@ static int drm_mode_create_standard_connector_properties(struct drm_device *dev)
 				       "PATH", 0);
 	dev->mode_config.path_property = dev_path;
 
+	content_protection = drm_property_create_enum(dev, 0,
+			"Content Protection", drm_cp_enum_list,
+			ARRAY_SIZE(drm_cp_enum_list));
+	dev->mode_config.content_protection_property = content_protection;
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/drm_sysfs.c b/drivers/gpu/drm/drm_sysfs.c
index cc3d6d6..b4019b5 100644
--- a/drivers/gpu/drm/drm_sysfs.c
+++ b/drivers/gpu/drm/drm_sysfs.c
@@ -214,6 +214,27 @@ static ssize_t enabled_show(struct device *device,
 			"disabled");
 }
 
+static ssize_t content_protection_show(struct device *device,
+				struct device_attribute *attr, char *buf)
+{
+	struct drm_connector *connector = to_drm_connector(device);
+	struct drm_device *dev = connector->dev;
+	struct drm_property *prop;
+	uint64_t cp;
+	int ret;
+
+	prop = dev->mode_config.content_protection_property;
+	if (!prop)
+		return 0;
+
+	ret = drm_object_property_get_value(&connector->base, prop, &cp);
+	if (ret)
+		return 0;
+
+	return snprintf(buf, PAGE_SIZE, "%s\n",
+			drm_get_content_protection_name((int)cp));
+}
+
 static ssize_t edid_show(struct file *filp, struct kobject *kobj,
 			 struct bin_attribute *attr, char *buf, loff_t off,
 			 size_t count)
@@ -344,6 +365,7 @@ static struct device_attribute connector_attrs[] = {
 	__ATTR_RO(enabled),
 	__ATTR_RO(dpms),
 	__ATTR_RO(modes),
+	__ATTR_RO(content_protection),
 };
 
 /* These attributes are for both DVI-I connectors and all types of tv-out. */
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index dd2c16e..b185f13 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1023,6 +1023,7 @@ struct drm_mode_config {
 	struct drm_property *path_property;
 	struct drm_property *plane_type_property;
 	struct drm_property *rotation_property;
+	struct drm_property *content_protection_property;
 
 	/* DVI-I properties */
 	struct drm_property *dvi_i_subconnector_property;
@@ -1171,6 +1172,7 @@ extern void drm_encoder_cleanup(struct drm_encoder *encoder);
 extern const char *drm_get_connector_status_name(enum drm_connector_status status);
 extern const char *drm_get_subpixel_order_name(enum subpixel_order order);
 extern const char *drm_get_dpms_name(int val);
+extern const char *drm_get_content_protection_name(int val);
 extern const char *drm_get_dvi_i_subconnector_name(int val);
 extern const char *drm_get_dvi_i_select_name(int val);
 extern const char *drm_get_tv_subconnector_name(int val);
diff --git a/include/uapi/drm/drm_mode.h b/include/uapi/drm/drm_mode.h
index 86574b0..e1f0e41 100644
--- a/include/uapi/drm/drm_mode.h
+++ b/include/uapi/drm/drm_mode.h
@@ -81,6 +81,11 @@
 #define DRM_MODE_DPMS_SUSPEND	2
 #define DRM_MODE_DPMS_OFF	3
 
+/* Content Protection Flags */
+#define DRM_MODE_CONTENT_PROTECTION_UNDESIRED   0
+#define DRM_MODE_CONTENT_PROTECTION_DESIRED     1
+#define DRM_MODE_CONTENT_PROTECTION_ENABLED     2
+
 /* Scaling mode options */
 #define DRM_MODE_SCALE_NONE		0 /* Unmodified timing (display or
 					     software can still scale) */
-- 
2.2.0.rc0.207.ga3a616c



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