[RFC v2] drm/connector: Add support for privacy-screen properties (v2)
Hans de Goede
hdegoede at redhat.com
Mon May 11 17:47:24 UTC 2020
From: Rajat Jain <rajatja at google.com>
Add support for generic electronic privacy screen properties, that
can be added by systems that have an integrated EPS.
Changes in v2 (Hans de Goede)
- Create 2 properties, "privacy-screen sw-state" and
"privacy-screen hw-state", to deal with devices where the OS might be
locked out of making state changes
- Write kerneldoc explaining how the 2 properties work together, what
happens when changes to the state are made outside of the DRM code's
control, etc.
Signed-off-by: Rajat Jain <rajatja at google.com>
Co-authored-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Hans de Goede <hdegoede at redhat.com>
---
Documentation/gpu/drm-kms.rst | 2 +
drivers/gpu/drm/drm_atomic_uapi.c | 6 ++
drivers/gpu/drm/drm_connector.c | 100 ++++++++++++++++++++++++++++++
include/drm/drm_connector.h | 50 +++++++++++++++
4 files changed, 158 insertions(+)
diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 906771e03103..b72b1e0db343 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -445,6 +445,8 @@ Property Types and Blob Property Support
.. kernel-doc:: drivers/gpu/drm/drm_property.c
:export:
+.. _standard_connector_properties:
+
Standard Connector Properties
-----------------------------
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index a1e5e262bae2..e56a11208515 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -766,6 +766,8 @@ static int drm_atomic_connector_set_property(struct drm_connector *connector,
fence_ptr);
} else if (property == connector->max_bpc_property) {
state->max_requested_bpc = val;
+ } else if (property == connector->privacy_screen_sw_state_property) {
+ state->privacy_screen_sw_state = val;
} else if (connector->funcs->atomic_set_property) {
return connector->funcs->atomic_set_property(connector,
state, property, val);
@@ -842,6 +844,10 @@ drm_atomic_connector_get_property(struct drm_connector *connector,
*val = 0;
} else if (property == connector->max_bpc_property) {
*val = state->max_requested_bpc;
+ } else if (property == connector->privacy_screen_sw_state_property) {
+ *val = state->privacy_screen_sw_state;
+ } else if (property == connector->privacy_screen_hw_state_property) {
+ *val = state->privacy_screen_hw_state;
} else if (connector->funcs->atomic_get_property) {
return connector->funcs->atomic_get_property(connector,
state, property, val);
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 644f0ad10671..01360edc2376 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1186,6 +1186,45 @@ static const struct drm_prop_enum_list dp_colorspaces[] = {
* can also expose this property to external outputs, in which case they
* must support "None", which should be the default (since external screens
* have a built-in scaler).
+ *
+ * privacy-screen sw-state, privacy-screen hw-state:
+ * These 2 optional properties can be used to query the state of the
+ * electronic privacy screen that is available on some displays; and in
+ * some cases also control the state. If a driver implements these
+ * properties then both properties must be present.
+ *
+ * "privacy-screen hw-state" is read-only and reflects the actual state
+ * of the privacy-screen, possible values: "Enabled", "Disabled,
+ * "Enabled, locked", "Disabled, locked". The locked states indicate
+ * that the state cannot be changed through the DRM API. E.g. there
+ * might be devices where the firmware-setup options, or a hardware
+ * slider-switch, offer always on / off modes.
+ *
+ * "privacy-screen sw-state" can be set to change the privacy-screen state
+ * when not locked. In this case the driver must update the hw-state
+ * property to reflect the new state on completion of the commit of the
+ * sw-state property. Setting the sw-state property when the hw-state is
+ * locked must be interpreted by the driver as a request to change the
+ * state to the set state when the hw-state becomes unlocked. E.g. if
+ * "privacy-screen hw-state" is "Enabled, locked" and the sw-state
+ * gets set to "Disabled" followed by the user unlocking the state by
+ * changing the slider-switch position, then the driver must set the
+ * state to "Disabled" upon receiving the unlock event.
+ *
+ * In some cases the privacy-screen state might change outside of control
+ * of the DRM code. E.g. there might be a firmware handled hotkey which
+ * toggles the state, or the state might be changed through another
+ * userspace API such as writing /proc/acpi/ibm/lcdshadow. In this case
+ * the driver must update both the hw-state and the sw-state to reflect
+ * the new value, overwriting any pending state requests in the sw-state.
+ *
+ * Note that the ability for the state to change outside of control of
+ * the DRM master process means that userspace must not cache the value
+ * of the sw-state. Ccaching the sw-state value and including it in later
+ * atomic commits may lead to overriding a state change done through e.g.
+ * a firmware handled hotkey. Therefor userspace must not include the
+ * privacy-screen sw-state in an atomic commit unless it wants to change
+ * its value.
*/
int drm_connector_create_standard_properties(struct drm_device *dev)
@@ -2152,6 +2191,67 @@ int drm_connector_set_panel_orientation_with_quirk(
}
EXPORT_SYMBOL(drm_connector_set_panel_orientation_with_quirk);
+static const struct drm_prop_enum_list privacy_screen_enum[] = {
+ { PRIVACY_SCREEN_DISABLED, "Disabled" },
+ { PRIVACY_SCREEN_ENABLED, "Enabled" },
+ { PRIVACY_SCREEN_DISABLED_LOCKED, "Disabled, locked" },
+ { PRIVACY_SCREEN_ENABLED_LOCKED, "Enabled, locked" },
+};
+
+/**
+ * drm_connector_create_privacy_screen_properties -
+ * create the drm connecter's privacy-screen properties.
+ * @connector: connector for which to create the privacy-screen properties
+ *
+ * This function creates the "privacy-screen sw-state" and "privacy-screen
+ * hw-state" properties for the connector. They are not attached.
+ */
+void
+drm_connector_create_privacy_screen_properties(struct drm_connector *connector)
+{
+ if (connector->privacy_screen_sw_state_property)
+ return;
+
+ /* Note sw-state only supports the first 2 values of the enum */
+ connector->privacy_screen_sw_state_property =
+ drm_property_create_enum(connector->dev, DRM_MODE_PROP_ENUM,
+ "privacy-screen sw-state",
+ privacy_screen_enum, 2);
+
+ connector->privacy_screen_hw_state_property =
+ drm_property_create_enum(connector->dev,
+ DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_ENUM,
+ "privacy-screen hw-state",
+ privacy_screen_enum,
+ ARRAY_SIZE(privacy_screen_enum));
+}
+EXPORT_SYMBOL(drm_connector_create_privacy_screen_properties);
+
+/**
+ * drm_connector_attach_privacy_screen_properties -
+ * attach the drm connecter's privacy-screen properties.
+ * @connector: connector on which to attach the privacy-screen properties
+ *
+ * This function attaches the "privacy-screen sw-state" and "privacy-screen
+ * hw-state" properties to the connector. The initial state of both is set
+ * to "Disabled".
+ */
+void
+drm_connector_attach_privacy_screen_properties(struct drm_connector *connector)
+{
+ if (!connector->privacy_screen_sw_state_property)
+ return;
+
+ drm_object_attach_property(&connector->base,
+ connector->privacy_screen_sw_state_property,
+ PRIVACY_SCREEN_DISABLED);
+
+ drm_object_attach_property(&connector->base,
+ connector->privacy_screen_hw_state_property,
+ PRIVACY_SCREEN_DISABLED);
+}
+EXPORT_SYMBOL(drm_connector_attach_privacy_screen_properties);
+
int drm_connector_set_obj_prop(struct drm_mode_object *obj,
struct drm_property *property,
uint64_t value)
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 19ae6bb5c85b..a8844f4c6ae9 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -271,6 +271,30 @@ struct drm_monitor_range_info {
u8 max_vfreq;
};
+/**
+ * enum drm_privacy_screen_status - privacy screen status
+ *
+ * This enum is used to track and control the state of the integrated privacy
+ * screen present on some display panels, via the "privacy-screen sw-state"
+ * and "privacy-screen hw-state" properties. Note the _LOCKED enum values
+ * are only valid for the "privacy-screen hw-state" property.
+ *
+ * @PRIVACY_SCREEN_DISABLED:
+ * The privacy-screen on the panel is disabled
+ * @PRIVACY_SCREEN_ENABLED:
+ * The privacy-screen on the panel is enabled
+ * @PRIVACY_SCREEN_DISABLED_LOCKED:
+ * The privacy-screen on the panel is disabled and locked (cannot be changed)
+ * @PRIVACY_SCREEN_ENABLED_LOCKED:
+ * The privacy-screen on the panel is enabled and locked (cannot be changed)
+ */
+enum drm_privacy_screen_status {
+ PRIVACY_SCREEN_DISABLED = 0,
+ PRIVACY_SCREEN_ENABLED,
+ PRIVACY_SCREEN_DISABLED_LOCKED,
+ PRIVACY_SCREEN_ENABLED_LOCKED,
+};
+
/*
* This is a consolidated colorimetry list supported by HDMI and
* DP protocol standard. The respective connectors will register
@@ -686,6 +710,18 @@ struct drm_connector_state {
*/
u8 max_bpc;
+ /**
+ * @privacy_screen_sw_state: See :ref:`Standard Connector
+ * Properties<standard_connector_properties>`
+ */
+ enum drm_privacy_screen_status privacy_screen_sw_state;
+
+ /**
+ * @privacy_screen_hw_state: See :ref:`Standard Connector
+ * Properties<standard_connector_properties>`
+ */
+ enum drm_privacy_screen_status privacy_screen_hw_state;
+
/**
* @hdr_output_metadata:
* DRM blob property for HDR output metadata
@@ -1285,6 +1321,18 @@ struct drm_connector {
*/
struct drm_property *max_bpc_property;
+ /**
+ * @privacy_screen_sw_state_property: Optional atomic property for the
+ * connector to control the integrated privacy screen.
+ */
+ struct drm_property *privacy_screen_sw_state_property;
+
+ /**
+ * @privacy_screen_hw_state_property: Optional atomic property for the
+ * connector to report the actual integrated privacy screen state.
+ */
+ struct drm_property *privacy_screen_hw_state_property;
+
#define DRM_CONNECTOR_POLL_HPD (1 << 0)
#define DRM_CONNECTOR_POLL_CONNECT (1 << 1)
#define DRM_CONNECTOR_POLL_DISCONNECT (1 << 2)
@@ -1598,6 +1646,8 @@ int drm_connector_set_panel_orientation_with_quirk(
int width, int height);
int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
int min, int max);
+void drm_connector_create_privacy_screen_properties(struct drm_connector *conn);
+void drm_connector_attach_privacy_screen_properties(struct drm_connector *conn);
/**
* struct drm_tile_group - Tile group metadata
--
2.26.0
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