> -----Original Message-----
> From: Hans de Goede <hdegoede@xxxxxxxxxx>
> Sent: Monday, May 11, 2020 12:47 PM
> To: Maarten Lankhorst; Maxime Ripard; Thomas Zimmermann; Daniel Vetter; David
> Airlie; Rajat Jain; Jani Nikula
> Cc: Hans de Goede; Pekka Paalanen; Limonciello, Mario; Quintanilla, Sonny;
> Jared Dominguez; Mark Pearson; dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Subject: [RFC v2] drm/connector: Add support for privacy-screen properties
> (v2)
>
>
> [EXTERNAL EMAIL]
>
> From: Rajat Jain <rajatja@xxxxxxxxxx>
>
> 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@xxxxxxxxxx>
> Co-authored-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> 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
Hans,
Thanks for putting together this set of modifications. I believe it does sufficiently
reflect the implementation of privacy screens present on Dell notebooks today containing
them: Latitude 7300 and Latitude 7400.
Those models only offer a HW controlled screen via a hotkey, but that hotkey control
can be removed permanently locking them in an enabled or disabled state.
I feel that your concept of HW state "Enabled, Locked" and "Disabled, Locked" sufficiently
reflects that.
Reviewed-by: Mario Limonciello <Mario.limonciello@xxxxxxxx>
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