[PATCH resend 0/9] drm: Add privacy-screen class and connector properties

[PATCH resend 0/9] drm: Add privacy-screen class and connector properties

[Hans de Goede]

Hi All,

Here is the privacy-screen related code which I last posted in August
of last year. To the best of my knowledge there is consensus about /
everyone is in agreement with the new userspace API (2 connector properties)
this patch-set add (patch 1 of the series).

The blocker the last time was that there were no userspace users of
the new properties and as a rule we don't add new drm userspace API
without users.

There now is GNOME userspace code using the new properties:
https://hackmd.io/@3v1n0/rkyIy3BOw

The new API works as designed for this userspace user and the branches
mentioned at the above link add the following features to GNOME:

1. Showing an OSD notification when the privacy-screen is toggled on/off
   through hotkeys handled by the embedded-controller
2. Allowing control of the privacy-screen from the GNOME control-panel,
   including the on/off slider shown there updating to match the hw-setting
   when the setting is changed with the control-panel open.
3. Restoring the last user-setting at login

This series consists of a number of different parts:

1. A new version of Rajat's privacy-screen connector properties patch,
this adds new userspace API in the form of new properties

2. Since on most devices the privacy screen is actually controlled by
some vendor specific ACPI/WMI interface which has a driver under
drivers/platform/x86, we need some "glue" code to make this functionality
available to KMS drivers. Patches 2-4 add a new privacy-screen class for
this, which allows non KMS drivers (and possibly KMS drivers too) to
register a privacy-screen device and also adds an interface for KMS drivers
to get access to the privacy-screen associated with a specific connector.
This is modelled similar to how we deal with e.g. PWMs and GPIOs in the
kernel, including separate includes for consumers and providers(drivers).

3. Some drm_connector helper functions to keep the actual changes needed
for this in individual KMS drivers as small as possible (patch 5).

4. Make the thinkpad_acpi code register a privacy-screen device on
ThinkPads with a privacy-screen (patches 6-8)

5. Make the i915 driver export the privacy-screen functionality through
the connector properties on the eDP connector.

I believe that it would be best to merge the entire series, including
the thinkpad_acpi changes through drm-misc in one go. As the pdx86
subsys maintainer I hereby give my ack for merging the thinkpad_acpi
changes through drm-misc.

There is one small caveat with this series, which it is good to be
aware of. The i915 driver will now return -EPROBE_DEFER on Thinkpads
with an eprivacy screen, until the thinkpad_acpi driver is loaded.
This means that initrd generation tools will need to be updated to
include thinkpad_acpi when the i915 driver is added to the initrd.
Without this the loading of the i915 driver will be delayed to after
the switch to real rootfs.

Regards,

Hans


Hans de Goede (8):
  drm: Add privacy-screen class
  drm/privacy-screen: Add X86 specific arch init code
  drm/privacy-screen: Add notifier support
  drm/connector: Add a drm_connector privacy-screen helper functions
  platform/x86: thinkpad_acpi: Add hotkey_notify_extended_hotkey()
    helper
  platform/x86: thinkpad_acpi: Get privacy-screen / lcdshadow ACPI
    handles only once
  platform/x86: thinkpad_acpi: Register a privacy-screen device
  drm/i915: Add privacy-screen support

Rajat Jain (1):
  drm/connector: Add support for privacy-screen properties (v4)

 Documentation/gpu/drm-kms-helpers.rst        |  15 +
 Documentation/gpu/drm-kms.rst                |   2 +
 MAINTAINERS                                  |   8 +
 drivers/gpu/drm/Kconfig                      |   5 +
 drivers/gpu/drm/Makefile                     |   4 +
 drivers/gpu/drm/drm_atomic_uapi.c            |   4 +
 drivers/gpu/drm/drm_connector.c              | 214 ++++++++
 drivers/gpu/drm/drm_privacy_screen.c         | 493 +++++++++++++++++++
 drivers/gpu/drm/drm_privacy_screen_x86.c     |  82 +++
 drivers/gpu/drm/i915/display/intel_display.c |   5 +
 drivers/gpu/drm/i915/display/intel_dp.c      |  10 +
 drivers/gpu/drm/i915/i915_pci.c              |  12 +
 drivers/platform/x86/Kconfig                 |   1 +
 drivers/platform/x86/thinkpad_acpi.c         | 131 +++--
 include/drm/drm_connector.h                  |  56 +++
 include/drm/drm_privacy_screen_consumer.h    |  32 ++
 include/drm/drm_privacy_screen_driver.h      |  84 ++++
 include/drm/drm_privacy_screen_machine.h     |  46 ++
 18 files changed, 1162 insertions(+), 42 deletions(-)
 create mode 100644 drivers/gpu/drm/drm_privacy_screen.c
 create mode 100644 drivers/gpu/drm/drm_privacy_screen_x86.c
 create mode 100644 include/drm/drm_privacy_screen_consumer.h
 create mode 100644 include/drm/drm_privacy_screen_driver.h
 create mode 100644 include/drm/drm_privacy_screen_machine.h

-- 
2.31.1

[PATCH resend 1/9] drm/connector: Add support for privacy-screen properties (v4)

[Hans de Goede]

From: Rajat Jain <rajatja@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.

Changes in v3 (Hans de Goede)
- Some small tweaks to the kerneldoc describing the 2 properties

Changes in v4 (Hans de Goede)
- Change the "Enabled, locked" and "Disabled, locked" hw-state enum value
  names to "Enabled-locked" and "Disabled-locked". The xrandr command shows
  all possible enum values separated by commas in its output, so having a
  comma in an enum name is not a good idea.
- Do not add a privacy_screen_hw_state member to drm_connector_state
  since this property is immutable its value must be directly stored in the
  obj->properties->values array

Signed-off-by: Rajat Jain <rajatja@google.com>
Co-authored-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Pekka Paalanen <pekka.paalanen@collabora.com>
Reviewed-by: Mario Limonciello <Mario.limonciello@dell.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 Documentation/gpu/drm-kms.rst     |   2 +
 drivers/gpu/drm/drm_atomic_uapi.c |   4 ++
 drivers/gpu/drm/drm_connector.c   | 101 ++++++++++++++++++++++++++++++
 include/drm/drm_connector.h       |  44 +++++++++++++
 4 files changed, 151 insertions(+)

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 87e5023e3f55..36943f2b0c5d 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -475,6 +475,8 @@ 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 268bb69c2e2f..d5339b683156 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -796,6 +796,8 @@ 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);
@@ -873,6 +875,8 @@ 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 (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 7631f76e7f34..ca8a76decd4c 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -1244,6 +1244,46 @@ static const struct drm_prop_enum_list dp_colorspaces[] = {
  *	For DVI-I and TVout there is also a matching property "select subconnector"
  *	allowing to switch between signal types.
  *	DP subconnector corresponds to a downstream port.
+ *
+ * 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's actual state might change outside of
+ *	control of the DRM code. E.g. there might be a firmware handled hotkey
+ *	which toggles the actual state, or the actual 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. Any pending sw-state requests are thus discarded.
+ *
+ *	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. Caching 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)
@@ -2252,6 +2292,67 @@ 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 1922b278ffad..067bb5b112db 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -320,6 +320,30 @@ 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
@@ -781,6 +805,12 @@ 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;
+
 	/**
 	 * @hdr_output_metadata:
 	 * DRM blob property for HDR output metadata
@@ -1380,6 +1410,18 @@ 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)
@@ -1698,6 +1740,8 @@ 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
-- 
2.31.1

[PATCH resend 2/9] drm: Add privacy-screen class

[Hans de Goede]

On some new laptops the LCD panel has a builtin electronic privacy-screen.
We want to export this functionality as a property on the drm connector
object. But often this functionality is not exposed on the GPU but on some
other (ACPI) device.

This commit adds a privacy-screen class allowing the driver for these
other devices to register themselves as a privacy-screen provider; and
allowing the drm/kms code to get a privacy-screen provider associated
with a specific GPU/connector combo.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 Documentation/gpu/drm-kms-helpers.rst     |  15 +
 MAINTAINERS                               |   8 +
 drivers/gpu/drm/Kconfig                   |   5 +
 drivers/gpu/drm/Makefile                  |   1 +
 drivers/gpu/drm/drm_privacy_screen.c      | 426 ++++++++++++++++++++++
 include/drm/drm_privacy_screen_consumer.h |  27 ++
 include/drm/drm_privacy_screen_driver.h   |  80 ++++
 include/drm/drm_privacy_screen_machine.h  |  41 +++
 8 files changed, 603 insertions(+)
 create mode 100644 drivers/gpu/drm/drm_privacy_screen.c
 create mode 100644 include/drm/drm_privacy_screen_consumer.h
 create mode 100644 include/drm/drm_privacy_screen_driver.h
 create mode 100644 include/drm/drm_privacy_screen_machine.h

diff --git a/Documentation/gpu/drm-kms-helpers.rst b/Documentation/gpu/drm-kms-helpers.rst
index 389892f36185..5d8715d2f998 100644
--- a/Documentation/gpu/drm-kms-helpers.rst
+++ b/Documentation/gpu/drm-kms-helpers.rst
@@ -423,3 +423,18 @@ Legacy CRTC/Modeset Helper Functions Reference
 
 .. kernel-doc:: drivers/gpu/drm/drm_crtc_helper.c
    :export:
+
+Privacy-screen class
+====================
+
+.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
+   :doc: overview
+
+.. kernel-doc:: include/drm/drm_privacy_screen_driver.h
+   :internal:
+
+.. kernel-doc:: include/drm/drm_privacy_screen_machine.h
+   :internal:
+
+.. kernel-doc:: drivers/gpu/drm/drm_privacy_screen.c
+   :export:
diff --git a/MAINTAINERS b/MAINTAINERS
index 7c45120759e6..8220295b2670 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6129,6 +6129,14 @@ F:	drivers/gpu/drm/drm_panel.c
 F:	drivers/gpu/drm/panel/
 F:	include/drm/drm_panel.h
 
+DRM PRIVACY-SCREEN CLASS
+M:	Hans de Goede <hdegoede@redhat.com>
+L:	dri-devel@lists.freedesktop.org
+S:	Maintained
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+F:	drivers/gpu/drm/drm_privacy_screen*
+F:	include/drm/drm_privacy_screen*
+
 DRM TTM SUBSYSTEM
 M:	Christian Koenig <christian.koenig@amd.com>
 M:	Huang Rui <ray.huang@amd.com>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 3c16bd1afd87..da25ff3a0a34 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -474,3 +474,8 @@ config DRM_PANEL_ORIENTATION_QUIRKS
 config DRM_LIB_RANDOM
 	bool
 	default n
+
+# Separate option, used by drivers outside of drivers/gpu/drm
+config DRM_PRIVACY_SCREEN
+	tristate
+	default n
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 5279db4392df..9a802605249d 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_DRM)	+= drm.o
 obj-$(CONFIG_DRM_MIPI_DBI) += drm_mipi_dbi.o
 obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
 obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
+obj-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o
 obj-y			+= arm/
 obj-$(CONFIG_DRM_TTM)	+= ttm/
 obj-$(CONFIG_DRM_SCHED)	+= scheduler/
diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c
new file mode 100644
index 000000000000..6296fd46156c
--- /dev/null
+++ b/drivers/gpu/drm/drm_privacy_screen.c
@@ -0,0 +1,426 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <drm/drm_privacy_screen_machine.h>
+#include <drm/drm_privacy_screen_consumer.h>
+#include <drm/drm_privacy_screen_driver.h>
+
+/**
+ * DOC: overview
+ *
+ * This class allows non KMS drivers, from e.g. drivers/platform/x86 to
+ * register a privacy-screen device, which the KMS drivers can then use
+ * to implement the standard privacy-screen properties, see
+ * :ref:`Standard Connector Properties<standard_connector_properties>`.
+ *
+ * KMS drivers using a privacy-screen class device are advised to use the
+ * drm_connector_attach_privacy_screen_provider() and
+ * drm_connector_update_privacy_screen() helpers for dealing with this.
+ */
+
+#define to_drm_privacy_screen(dev) \
+	container_of(dev, struct drm_privacy_screen, dev)
+
+static DEFINE_MUTEX(drm_privacy_screen_lookup_lock);
+static LIST_HEAD(drm_privacy_screen_lookup_list);
+
+static DEFINE_MUTEX(drm_privacy_screen_devs_lock);
+static LIST_HEAD(drm_privacy_screen_devs);
+
+/*** drm_privacy_screen_machine.h functions ***/
+
+/**
+ * drm_privacy_screen_lookup_add - add an entry to the static privacy-screen
+ *    lookup list
+ * @lookup: lookup list entry to add
+ *
+ * Add an entry to the static privacy-screen lookup list. Note the
+ * &struct list_head which is part of the &struct drm_privacy_screen_lookup
+ * gets added to a list owned by the privacy-screen core. So the passed in
+ * &struct drm_privacy_screen_lookup must not be free-ed until it is removed
+ * from the lookup list by calling drm_privacy_screen_lookup_remove().
+ */
+void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup)
+{
+	mutex_lock(&drm_privacy_screen_lookup_lock);
+	list_add(&lookup->list, &drm_privacy_screen_lookup_list);
+	mutex_unlock(&drm_privacy_screen_lookup_lock);
+}
+EXPORT_SYMBOL(drm_privacy_screen_lookup_add);
+
+/**
+ * drm_privacy_screen_lookup_remove - remove an entry to the static
+ *    privacy-screen lookup list
+ * @lookup: lookup list entry to remove
+ *
+ * Remove an entry previously added with drm_privacy_screen_lookup_add()
+ * from the static privacy-screen lookup list.
+ */
+void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup *lookup)
+{
+	mutex_lock(&drm_privacy_screen_lookup_lock);
+	list_del(&lookup->list);
+	mutex_unlock(&drm_privacy_screen_lookup_lock);
+}
+EXPORT_SYMBOL(drm_privacy_screen_lookup_remove);
+
+/*** drm_privacy_screen_consumer.h functions ***/
+
+static struct drm_privacy_screen *drm_privacy_screen_get_by_name(
+	const char *name)
+{
+	struct drm_privacy_screen *priv;
+	struct device *dev = NULL;
+
+	mutex_lock(&drm_privacy_screen_devs_lock);
+
+	list_for_each_entry(priv, &drm_privacy_screen_devs, list) {
+		if (strcmp(dev_name(&priv->dev), name) == 0) {
+			dev = get_device(&priv->dev);
+			break;
+		}
+	}
+
+	mutex_unlock(&drm_privacy_screen_devs_lock);
+
+	return dev ? to_drm_privacy_screen(dev) : NULL;
+}
+
+/**
+ * drm_privacy_screen_get - get a privacy-screen provider
+ * @dev: consumer-device for which to get a privacy-screen provider
+ * @con_id: (video)connector name for which to get a privacy-screen provider
+ *
+ * Get a privacy-screen provider for a privacy-screen attached to the
+ * display described by the @dev and @con_id parameters.
+ *
+ * Return:
+ * * A pointer to a &struct drm_privacy_screen on success.
+ * * ERR_PTR(-ENODEV) if no matching privacy-screen is found
+ * * ERR_PTR(-EPROBE_DEFER) if there is a matching privacy-screen,
+ *                          but it has not been registered yet.
+ */
+struct drm_privacy_screen *drm_privacy_screen_get(struct device *dev,
+						  const char *con_id)
+{
+	const char *dev_id = dev ? dev_name(dev) : NULL;
+	struct drm_privacy_screen_lookup *l;
+	struct drm_privacy_screen *priv;
+	const char *provider = NULL;
+	int match, best = -1;
+
+	/*
+	 * For now we only support using a static lookup table, which is
+	 * populated by the drm_privacy_screen_arch_init() call. This should
+	 * be extended with device-tree / fw_node lookup when support is added
+	 * for device-tree using hardware with a privacy-screen.
+	 *
+	 * The lookup algorithm was shamelessly taken from the clock
+	 * framework:
+	 *
+	 * We do slightly fuzzy matching here:
+	 *  An entry with a NULL ID is assumed to be a wildcard.
+	 *  If an entry has a device ID, it must match
+	 *  If an entry has a connection ID, it must match
+	 * Then we take the most specific entry - with the following order
+	 * of precedence: dev+con > dev only > con only.
+	 */
+	mutex_lock(&drm_privacy_screen_lookup_lock);
+
+	list_for_each_entry(l, &drm_privacy_screen_lookup_list, list) {
+		match = 0;
+
+		if (l->dev_id) {
+			if (!dev_id || strcmp(l->dev_id, dev_id))
+				continue;
+
+			match += 2;
+		}
+
+		if (l->con_id) {
+			if (!con_id || strcmp(l->con_id, con_id))
+				continue;
+
+			match += 1;
+		}
+
+		if (match > best) {
+			provider = l->provider;
+			best = match;
+		}
+	}
+
+	mutex_unlock(&drm_privacy_screen_lookup_lock);
+
+	if (!provider)
+		return ERR_PTR(-ENODEV);
+
+	priv = drm_privacy_screen_get_by_name(provider);
+	if (!priv)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	return priv;
+}
+EXPORT_SYMBOL(drm_privacy_screen_get);
+
+/**
+ * drm_privacy_screen_put - release a privacy-screen reference
+ * @priv: privacy screen reference to release
+ *
+ * Release a privacy-screen provider reference gotten through
+ * drm_privacy_screen_get(). May be called with a NULL or ERR_PTR,
+ * in which case it is a no-op.
+ */
+void drm_privacy_screen_put(struct drm_privacy_screen *priv)
+{
+	if (IS_ERR_OR_NULL(priv))
+		return;
+
+	put_device(&priv->dev);
+}
+EXPORT_SYMBOL(drm_privacy_screen_put);
+
+/**
+ * drm_privacy_screen_set_sw_state - set a privacy-screen's sw-state
+ * @priv: privacy screen to set the sw-state for
+ * @sw_state: new sw-state value to set
+ *
+ * Set the sw-state of a privacy screen. If the privacy-screen is not
+ * in a locked hw-state, then the actual and hw-state of the privacy-screen
+ * will be immediately updated to the new value. If the privacy-screen is
+ * in a locked hw-state, then the new sw-state will be remembered as the
+ * requested state to put the privacy-screen in when it becomes unlocked.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int drm_privacy_screen_set_sw_state(struct drm_privacy_screen *priv,
+				    enum drm_privacy_screen_status sw_state)
+{
+	int ret = 0;
+
+	mutex_lock(&priv->lock);
+
+	if (!priv->ops) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	/*
+	 * As per the DRM connector properties documentation, setting the
+	 * sw_state while the hw_state is locked is allowed. In this case
+	 * it is a no-op other then storing the new sw_state so that it
+	 * can be honored when the state gets unlocked.
+	 */
+	if (priv->hw_state >= PRIVACY_SCREEN_DISABLED_LOCKED) {
+		priv->sw_state = sw_state;
+		goto out;
+	}
+
+	ret = priv->ops->set_sw_state(priv, sw_state);
+out:
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+EXPORT_SYMBOL(drm_privacy_screen_set_sw_state);
+
+/**
+ * drm_privacy_screen_get_state - get privacy-screen's current state
+ * @priv: privacy screen to get the state for
+ * @sw_state_ret: address where to store the privacy-screens current sw-state
+ * @hw_state_ret: address where to store the privacy-screens current hw-state
+ *
+ * Get the current state of a privacy-screen, both the sw-state and the
+ * hw-state.
+ */
+void drm_privacy_screen_get_state(struct drm_privacy_screen *priv,
+				  enum drm_privacy_screen_status *sw_state_ret,
+				  enum drm_privacy_screen_status *hw_state_ret)
+{
+	mutex_lock(&priv->lock);
+	*sw_state_ret = priv->sw_state;
+	*hw_state_ret = priv->hw_state;
+	mutex_unlock(&priv->lock);
+}
+EXPORT_SYMBOL(drm_privacy_screen_get_state);
+
+/*** drm_privacy_screen_driver.h functions ***/
+
+static ssize_t sw_state_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct drm_privacy_screen *priv = to_drm_privacy_screen(dev);
+	const char * const sw_state_names[] = {
+		"Disabled",
+		"Enabled",
+	};
+	ssize_t ret;
+
+	mutex_lock(&priv->lock);
+
+	if (!priv->ops)
+		ret = -ENODEV;
+	else if (WARN_ON(priv->sw_state >= ARRAY_SIZE(sw_state_names)))
+		ret = -ENXIO;
+	else
+		ret = sprintf(buf, "%s\n", sw_state_names[priv->sw_state]);
+
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+/*
+ * RO: Do not allow setting the sw_state through sysfs, this MUST be done
+ * through the drm_properties on the drm_connector.
+ */
+static DEVICE_ATTR_RO(sw_state);
+
+static ssize_t hw_state_show(struct device *dev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct drm_privacy_screen *priv = to_drm_privacy_screen(dev);
+	const char * const hw_state_names[] = {
+		"Disabled",
+		"Enabled",
+		"Disabled, locked",
+		"Enabled, locked",
+	};
+	ssize_t ret;
+
+	mutex_lock(&priv->lock);
+
+	if (!priv->ops)
+		ret = -ENODEV;
+	else if (WARN_ON(priv->hw_state >= ARRAY_SIZE(hw_state_names)))
+		ret = -ENXIO;
+	else
+		ret = sprintf(buf, "%s\n", hw_state_names[priv->hw_state]);
+
+	mutex_unlock(&priv->lock);
+	return ret;
+}
+static DEVICE_ATTR_RO(hw_state);
+
+static struct attribute *drm_privacy_screen_attrs[] = {
+	&dev_attr_sw_state.attr,
+	&dev_attr_hw_state.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(drm_privacy_screen);
+
+static struct class drm_privacy_screen_class = {
+	.name = "privacy_screen",
+	.owner = THIS_MODULE,
+	.dev_groups = drm_privacy_screen_groups,
+};
+
+static void drm_privacy_screen_device_release(struct device *dev)
+{
+	struct drm_privacy_screen *priv = to_drm_privacy_screen(dev);
+
+	kfree(priv);
+}
+
+/**
+ * drm_privacy_screen_register - register a privacy-screen
+ * @parent: parent-device for the privacy-screen
+ * @ops: &struct drm_privacy_screen_ops pointer with ops for the privacy-screen
+ *
+ * Create and register a privacy-screen.
+ *
+ * Return:
+ * * A pointer to the created privacy-screen on success.
+ * * An ERR_PTR(errno) on failure.
+ */
+struct drm_privacy_screen *drm_privacy_screen_register(
+	struct device *parent, const struct drm_privacy_screen_ops *ops)
+{
+	struct drm_privacy_screen *priv;
+	int ret;
+
+	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return ERR_PTR(-ENOMEM);
+
+	mutex_init(&priv->lock);
+
+	priv->dev.class = &drm_privacy_screen_class;
+	priv->dev.parent = parent;
+	priv->dev.release = drm_privacy_screen_device_release;
+	dev_set_name(&priv->dev, "%s", dev_name(parent));
+	priv->ops = ops;
+
+	priv->ops->get_hw_state(priv);
+
+	ret = device_register(&priv->dev);
+	if (ret) {
+		put_device(&priv->dev);
+		return ERR_PTR(ret);
+	}
+
+	mutex_lock(&drm_privacy_screen_devs_lock);
+	list_add(&priv->list, &drm_privacy_screen_devs);
+	mutex_unlock(&drm_privacy_screen_devs_lock);
+
+	return priv;
+}
+EXPORT_SYMBOL(drm_privacy_screen_register);
+
+/**
+ * drm_privacy_screen_unregister - unregister privacy-screen
+ * @priv: privacy-screen to unregister
+ *
+ * Unregister a privacy-screen registered with drm_privacy_screen_register().
+ * May be called with a NULL or ERR_PTR, in which case it is a no-op.
+ */
+void drm_privacy_screen_unregister(struct drm_privacy_screen *priv)
+{
+	if (IS_ERR_OR_NULL(priv))
+		return;
+
+	mutex_lock(&drm_privacy_screen_devs_lock);
+	list_del(&priv->list);
+	mutex_unlock(&drm_privacy_screen_devs_lock);
+
+	mutex_lock(&priv->lock);
+	priv->ops = NULL;
+	mutex_unlock(&priv->lock);
+
+	device_unregister(&priv->dev);
+}
+EXPORT_SYMBOL(drm_privacy_screen_unregister);
+
+static int __init drm_privacy_screen_init(void)
+{
+	int ret;
+
+	ret = class_register(&drm_privacy_screen_class);
+	if (ret)
+		return ret;
+
+	drm_privacy_screen_arch_init();
+
+	return 0;
+}
+
+static void __exit drm_privacy_screen_exit(void)
+{
+	drm_privacy_screen_arch_exit();
+	class_unregister(&drm_privacy_screen_class);
+}
+
+subsys_initcall(drm_privacy_screen_init);
+module_exit(drm_privacy_screen_exit);
+
+MODULE_AUTHOR("Hans de Goede");
+MODULE_DESCRIPTION("DRM privacy-screen class");
+MODULE_LICENSE("GPL and additional rights");
diff --git a/include/drm/drm_privacy_screen_consumer.h b/include/drm/drm_privacy_screen_consumer.h
new file mode 100644
index 000000000000..169ba72bd60d
--- /dev/null
+++ b/include/drm/drm_privacy_screen_consumer.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede@redhat.com>
+ */
+
+#ifndef __DRM_PRIVACY_SCREEN_CONSUMER_H__
+#define __DRM_PRIVACY_SCREEN_CONSUMER_H__
+
+#include <linux/device.h>
+#include <drm/drm_connector.h>
+
+struct drm_privacy_screen;
+
+struct drm_privacy_screen *drm_privacy_screen_get(struct device *dev,
+						  const char *con_id);
+void drm_privacy_screen_put(struct drm_privacy_screen *priv);
+
+int drm_privacy_screen_set_sw_state(struct drm_privacy_screen *priv,
+				    enum drm_privacy_screen_status sw_state);
+void drm_privacy_screen_get_state(struct drm_privacy_screen *priv,
+				  enum drm_privacy_screen_status *sw_state_ret,
+				  enum drm_privacy_screen_status *hw_state_ret);
+
+#endif
diff --git a/include/drm/drm_privacy_screen_driver.h b/include/drm/drm_privacy_screen_driver.h
new file mode 100644
index 000000000000..5187ae52eb03
--- /dev/null
+++ b/include/drm/drm_privacy_screen_driver.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede@redhat.com>
+ */
+
+#ifndef __DRM_PRIVACY_SCREEN_DRIVER_H__
+#define __DRM_PRIVACY_SCREEN_DRIVER_H__
+
+#include <linux/device.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <drm/drm_connector.h>
+
+struct drm_privacy_screen;
+
+/**
+ * struct drm_privacy_screen_ops - drm_privacy_screen operations
+ *
+ * Defines the operations which the privacy-screen class code may call.
+ * These functions should be implemented by the privacy-screen driver.
+ */
+struct drm_privacy_screen_ops {
+	/**
+	 * @set_sw_state: Called to request a change of the privacy-screen
+	 * state. The privacy-screen class code contains a check to avoid this
+	 * getting called when the hw_state reports the state is locked.
+	 * It is the driver's responsibility to update sw_state and hw_state.
+	 * This is always called with the drm_privacy_screen's lock held.
+	 */
+	int (*set_sw_state)(struct drm_privacy_screen *priv,
+			    enum drm_privacy_screen_status sw_state);
+	/**
+	 * @get_hw_state: Called to request that the driver gets the current
+	 * privacy-screen state from the hardware and then updates sw_state and
+	 * hw_state accordingly. This will be called by the core just before
+	 * the privacy-screen is registered in sysfs.
+	 */
+	void (*get_hw_state)(struct drm_privacy_screen *priv);
+};
+
+/**
+ * struct drm_privacy_screen - central privacy-screen structure
+ *
+ * Central privacy-screen structure, this contains the struct device used
+ * to register the screen in sysfs, the screen's state, ops, etc.
+ */
+struct drm_privacy_screen {
+	/** @dev: device used to register the privacy-screen in sysfs. */
+	struct device dev;
+	/** @lock: mutex protection all fields in this struct. */
+	struct mutex lock;
+	/** @list: privacy-screen devices list list-entry. */
+	struct list_head list;
+	/**
+	 * @ops: &struct drm_privacy_screen_ops for this privacy-screen.
+	 * This is NULL if the driver has unregistered the privacy-screen.
+	 */
+	const struct drm_privacy_screen_ops *ops;
+	/**
+	 * @sw_state: The privacy-screen's software state, see
+	 * :ref:`Standard Connector Properties<standard_connector_properties>`
+	 * for more info.
+	 */
+	enum drm_privacy_screen_status sw_state;
+	/**
+	 * @hw_state: The privacy-screen's hardware state, see
+	 * :ref:`Standard Connector Properties<standard_connector_properties>`
+	 * for more info.
+	 */
+	enum drm_privacy_screen_status hw_state;
+};
+
+struct drm_privacy_screen *drm_privacy_screen_register(
+	struct device *parent, const struct drm_privacy_screen_ops *ops);
+void drm_privacy_screen_unregister(struct drm_privacy_screen *priv);
+
+#endif
diff --git a/include/drm/drm_privacy_screen_machine.h b/include/drm/drm_privacy_screen_machine.h
new file mode 100644
index 000000000000..55f4b4fd8e4e
--- /dev/null
+++ b/include/drm/drm_privacy_screen_machine.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede@redhat.com>
+ */
+
+#ifndef __DRM_PRIVACY_SCREEN_MACHINE_H__
+#define __DRM_PRIVACY_SCREEN_MACHINE_H__
+
+#include <linux/list.h>
+
+/**
+ * struct drm_privacy_screen_lookup -  static privacy-screen lookup list entry
+ *
+ * Used for the static lookup-list for mapping privacy-screen consumer
+ * dev-connector pairs to a privacy-screen provider.
+ */
+struct drm_privacy_screen_lookup {
+	/** @list: Lookup list list-entry. */
+	struct list_head list;
+	/** @dev_id: Consumer device name or NULL to match all devices. */
+	const char *dev_id;
+	/** @con_id: Consumer connector name or NULL to match all connectors. */
+	const char *con_id;
+	/** @provider: dev_name() of the privacy_screen provider. */
+	const char *provider;
+};
+
+void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup);
+void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup *lookup);
+
+static inline void drm_privacy_screen_arch_init(void)
+{
+}
+static inline void drm_privacy_screen_arch_exit(void)
+{
+}
+
+#endif
-- 
2.31.1

[PATCH resend 3/9] drm/privacy-screen: Add X86 specific arch init code

[Hans de Goede]

Add X86 specific arch init code, which fills the privacy-screen lookup
table by checking for various vendor specific ACPI interfaces for
controlling the privacy-screen.

This initial version only checks for the Lenovo Thinkpad specific ACPI
methods for privacy-screen control.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/Makefile                 |  5 +-
 drivers/gpu/drm/drm_privacy_screen_x86.c | 82 ++++++++++++++++++++++++
 include/drm/drm_privacy_screen_machine.h |  5 ++
 3 files changed, 91 insertions(+), 1 deletion(-)
 create mode 100644 drivers/gpu/drm/drm_privacy_screen_x86.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 9a802605249d..75166bd53e00 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -58,11 +58,14 @@ drm_kms_helper-$(CONFIG_DRM_DP_CEC) += drm_dp_cec.o
 obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
 obj-$(CONFIG_DRM_DEBUG_SELFTEST) += selftests/
 
+drm_privacy_screen_helper-y := drm_privacy_screen.o
+drm_privacy_screen_helper-$(CONFIG_X86) += drm_privacy_screen_x86.o
+obj-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen_helper.o
+
 obj-$(CONFIG_DRM)	+= drm.o
 obj-$(CONFIG_DRM_MIPI_DBI) += drm_mipi_dbi.o
 obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o
 obj-$(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS) += drm_panel_orientation_quirks.o
-obj-$(CONFIG_DRM_PRIVACY_SCREEN) += drm_privacy_screen.o
 obj-y			+= arm/
 obj-$(CONFIG_DRM_TTM)	+= ttm/
 obj-$(CONFIG_DRM_SCHED)	+= scheduler/
diff --git a/drivers/gpu/drm/drm_privacy_screen_x86.c b/drivers/gpu/drm/drm_privacy_screen_x86.c
new file mode 100644
index 000000000000..f486d9087819
--- /dev/null
+++ b/drivers/gpu/drm/drm_privacy_screen_x86.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2020 Red Hat, Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede@redhat.com>
+ */
+
+#include <linux/acpi.h>
+#include <drm/drm_privacy_screen_machine.h>
+
+static struct drm_privacy_screen_lookup arch_lookup;
+
+struct arch_init_data {
+	struct drm_privacy_screen_lookup lookup;
+	bool (*detect)(void);
+};
+
+static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
+					  void *context, void **return_value)
+{
+	*(acpi_handle *)return_value = handle;
+	return AE_CTRL_TERMINATE;
+}
+
+static bool __init detect_thinkpad_privacy_screen(void)
+{
+	union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
+	struct acpi_object_list args = { .count = 1, .pointer = &obj, };
+	acpi_handle ec_handle = NULL;
+	unsigned long long output;
+	acpi_status status;
+
+	/* Get embedded-controller handle */
+	status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
+	if (ACPI_FAILURE(status) || !ec_handle)
+		return false;
+
+	/* And call the privacy-screen get-status method */
+	status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
+	if (ACPI_FAILURE(status))
+		return false;
+
+	return (output & 0x10000) ? true : false;
+}
+
+static const struct arch_init_data arch_init_data[] __initconst = {
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+	{
+		.lookup = {
+			.dev_id = NULL,
+			.con_id = NULL,
+			.provider = "thinkpad_acpi",
+		},
+		.detect = detect_thinkpad_privacy_screen,
+	},
+#endif
+};
+
+void __init drm_privacy_screen_arch_init(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
+		if (!arch_init_data[i].detect())
+			continue;
+
+		pr_info("Found '%s' privacy-screen provider\n",
+			arch_init_data[i].lookup.provider);
+
+		/* Make a copy because arch_init_data is __initconst */
+		arch_lookup = arch_init_data[i].lookup;
+		drm_privacy_screen_lookup_add(&arch_lookup);
+		break;
+	}
+}
+
+void __exit drm_privacy_screen_arch_exit(void)
+{
+	if (arch_lookup.provider)
+		drm_privacy_screen_lookup_remove(&arch_lookup);
+}
diff --git a/include/drm/drm_privacy_screen_machine.h b/include/drm/drm_privacy_screen_machine.h
index 55f4b4fd8e4e..0d2f2a443e8c 100644
--- a/include/drm/drm_privacy_screen_machine.h
+++ b/include/drm/drm_privacy_screen_machine.h
@@ -31,11 +31,16 @@ struct drm_privacy_screen_lookup {
 void drm_privacy_screen_lookup_add(struct drm_privacy_screen_lookup *lookup);
 void drm_privacy_screen_lookup_remove(struct drm_privacy_screen_lookup *lookup);
 
+#ifdef CONFIG_X86
+void drm_privacy_screen_arch_init(void);
+void drm_privacy_screen_arch_exit(void);
+#else
 static inline void drm_privacy_screen_arch_init(void)
 {
 }
 static inline void drm_privacy_screen_arch_exit(void)
 {
 }
+#endif
 
 #endif
-- 
2.31.1

[PATCH resend 4/9] drm/privacy-screen: Add notifier support

[Hans de Goede]

Add support for privacy-screen consumers to register a notifier to
be notified of external (e.g. done by the hw itself on a hotkey press)
state changes.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/drm_privacy_screen.c      | 67 +++++++++++++++++++++++
 include/drm/drm_privacy_screen_consumer.h |  5 ++
 include/drm/drm_privacy_screen_driver.h   |  4 ++
 3 files changed, 76 insertions(+)

diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c
index 6296fd46156c..7e78b4068e8f 100644
--- a/drivers/gpu/drm/drm_privacy_screen.c
+++ b/drivers/gpu/drm/drm_privacy_screen.c
@@ -254,6 +254,49 @@ void drm_privacy_screen_get_state(struct drm_privacy_screen *priv,
 }
 EXPORT_SYMBOL(drm_privacy_screen_get_state);
 
+/**
+ * drm_privacy_screen_register_notifier - register a notifier
+ * @priv: Privacy screen to register the notifier with
+ * @nb: Notifier-block for the notifier to register
+ *
+ * Register a notifier with the privacy-screen to be notified of changes made
+ * to the privacy-screen state from outside of the privacy-screen class.
+ * E.g. the state may be changed by the hardware itself in response to a
+ * hotkey press.
+ *
+ * The notifier is called with no locks held. The new hw_state and sw_state
+ * can be retrieved using the drm_privacy_screen_get_state() function.
+ * A pointer to the drm_privacy_screen's struct is passed as the void *data
+ * argument of the notifier_block's notifier_call.
+ *
+ * The notifier will NOT be called when changes are made through
+ * drm_privacy_screen_set_sw_state(). It is only called for external changes.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int drm_privacy_screen_register_notifier(struct drm_privacy_screen *priv,
+					 struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&priv->notifier_head, nb);
+}
+EXPORT_SYMBOL(drm_privacy_screen_register_notifier);
+
+/**
+ * drm_privacy_screen_unregister_notifier - unregister a notifier
+ * @priv: Privacy screen to register the notifier with
+ * @nb: Notifier-block for the notifier to register
+ *
+ * Unregister a notifier registered with drm_privacy_screen_register_notifier().
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int drm_privacy_screen_unregister_notifier(struct drm_privacy_screen *priv,
+					   struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&priv->notifier_head, nb);
+}
+EXPORT_SYMBOL(drm_privacy_screen_unregister_notifier);
+
 /*** drm_privacy_screen_driver.h functions ***/
 
 static ssize_t sw_state_show(struct device *dev,
@@ -352,6 +395,7 @@ struct drm_privacy_screen *drm_privacy_screen_register(
 		return ERR_PTR(-ENOMEM);
 
 	mutex_init(&priv->lock);
+	BLOCKING_INIT_NOTIFIER_HEAD(&priv->notifier_head);
 
 	priv->dev.class = &drm_privacy_screen_class;
 	priv->dev.parent = parent;
@@ -399,6 +443,29 @@ void drm_privacy_screen_unregister(struct drm_privacy_screen *priv)
 }
 EXPORT_SYMBOL(drm_privacy_screen_unregister);
 
+/**
+ * drm_privacy_screen_call_notifier_chain - notify consumers of state change
+ * @priv: Privacy screen to register the notifier with
+ *
+ * A privacy-screen provider driver can call this functions upon external
+ * changes to the privacy-screen state. E.g. the state may be changed by the
+ * hardware itself in response to a hotkey press.
+ * This function must be called without holding the privacy-screen lock.
+ * the driver must update sw_state and hw_state to reflect the new state before
+ * calling this function.
+ * The expected behavior from the driver upon receiving an external state
+ * change event is: 1. Take the lock; 2. Update sw_state and hw_state;
+ * 3. Release the lock. 4. Call drm_privacy_screen_call_notifier_chain().
+ */
+void drm_privacy_screen_call_notifier_chain(struct drm_privacy_screen *priv)
+{
+	if (WARN_ON(mutex_is_locked(&priv->lock)))
+		return;
+
+	blocking_notifier_call_chain(&priv->notifier_head, 0, priv);
+}
+EXPORT_SYMBOL(drm_privacy_screen_call_notifier_chain);
+
 static int __init drm_privacy_screen_init(void)
 {
 	int ret;
diff --git a/include/drm/drm_privacy_screen_consumer.h b/include/drm/drm_privacy_screen_consumer.h
index 169ba72bd60d..1f33dc1457ff 100644
--- a/include/drm/drm_privacy_screen_consumer.h
+++ b/include/drm/drm_privacy_screen_consumer.h
@@ -24,4 +24,9 @@ void drm_privacy_screen_get_state(struct drm_privacy_screen *priv,
 				  enum drm_privacy_screen_status *sw_state_ret,
 				  enum drm_privacy_screen_status *hw_state_ret);
 
+int drm_privacy_screen_register_notifier(struct drm_privacy_screen *priv,
+					 struct notifier_block *nb);
+int drm_privacy_screen_unregister_notifier(struct drm_privacy_screen *priv,
+					   struct notifier_block *nb);
+
 #endif
diff --git a/include/drm/drm_privacy_screen_driver.h b/include/drm/drm_privacy_screen_driver.h
index 5187ae52eb03..24591b607675 100644
--- a/include/drm/drm_privacy_screen_driver.h
+++ b/include/drm/drm_privacy_screen_driver.h
@@ -54,6 +54,8 @@ struct drm_privacy_screen {
 	struct mutex lock;
 	/** @list: privacy-screen devices list list-entry. */
 	struct list_head list;
+	/** @notifier_head: privacy-screen notifier head. */
+	struct blocking_notifier_head notifier_head;
 	/**
 	 * @ops: &struct drm_privacy_screen_ops for this privacy-screen.
 	 * This is NULL if the driver has unregistered the privacy-screen.
@@ -77,4 +79,6 @@ struct drm_privacy_screen *drm_privacy_screen_register(
 	struct device *parent, const struct drm_privacy_screen_ops *ops);
 void drm_privacy_screen_unregister(struct drm_privacy_screen *priv);
 
+void drm_privacy_screen_call_notifier_chain(struct drm_privacy_screen *priv);
+
 #endif
-- 
2.31.1

[PATCH resend 5/9] drm/connector: Add a drm_connector privacy-screen helper functions

[Hans de Goede]

Add 2 drm_connector privacy-screen helper functions:

1. drm_connector_attach_privacy_screen_provider(), this function creates
and attaches the standard privacy-screen properties and registers a
generic notifier for generating sysfs-connector-status-events on external
changes to the privacy-screen status.

2. drm_connector_update_privacy_screen(), Check if the passed in atomic
state contains a privacy-screen sw_state change for the connector and if
it does, call drm_privacy_screen_set_sw_state() with the new sw_state.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/drm_connector.c | 113 ++++++++++++++++++++++++++++++++
 include/drm/drm_connector.h     |  12 ++++
 2 files changed, 125 insertions(+)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index ca8a76decd4c..958a332374af 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -20,6 +20,7 @@
  * OF THIS SOFTWARE.
  */
 
+#include <drm/drm_atomic.h>
 #include <drm/drm_connector.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_encoder.h>
@@ -27,6 +28,7 @@
 #include <drm/drm_print.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
+#include <drm/drm_privacy_screen_consumer.h>
 #include <drm/drm_sysfs.h>
 
 #include <linux/uaccess.h>
@@ -451,6 +453,11 @@ void drm_connector_cleanup(struct drm_connector *connector)
 		    DRM_CONNECTOR_REGISTERED))
 		drm_connector_unregister(connector);
 
+	if (connector->privacy_screen) {
+		drm_privacy_screen_put(connector->privacy_screen);
+		connector->privacy_screen = NULL;
+	}
+
 	if (connector->tile_group) {
 		drm_mode_put_tile_group(dev, connector->tile_group);
 		connector->tile_group = NULL;
@@ -530,6 +537,10 @@ int drm_connector_register(struct drm_connector *connector)
 	/* Let userspace know we have a new connector */
 	drm_sysfs_hotplug_event(connector->dev);
 
+	if (connector->privacy_screen)
+		drm_privacy_screen_register_notifier(connector->privacy_screen,
+					   &connector->privacy_screen_notifier);
+
 	goto unlock;
 
 err_debugfs:
@@ -558,6 +569,11 @@ void drm_connector_unregister(struct drm_connector *connector)
 		return;
 	}
 
+	if (connector->privacy_screen)
+		drm_privacy_screen_unregister_notifier(
+					connector->privacy_screen,
+					&connector->privacy_screen_notifier);
+
 	if (connector->funcs->early_unregister)
 		connector->funcs->early_unregister(connector);
 
@@ -2353,6 +2369,103 @@ drm_connector_attach_privacy_screen_properties(struct drm_connector *connector)
 }
 EXPORT_SYMBOL(drm_connector_attach_privacy_screen_properties);
 
+static void drm_connector_update_privacy_screen_properties(
+	struct drm_connector *connector)
+{
+	enum drm_privacy_screen_status sw_state, hw_state;
+
+	drm_privacy_screen_get_state(connector->privacy_screen,
+				     &sw_state, &hw_state);
+
+	connector->state->privacy_screen_sw_state = sw_state;
+	drm_object_property_set_value(&connector->base,
+			connector->privacy_screen_hw_state_property, hw_state);
+}
+
+static int drm_connector_privacy_screen_notifier(
+	struct notifier_block *nb, unsigned long action, void *data)
+{
+	struct drm_connector *connector =
+		container_of(nb, struct drm_connector, privacy_screen_notifier);
+	struct drm_device *dev = connector->dev;
+
+	drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
+	drm_connector_update_privacy_screen_properties(connector);
+	drm_modeset_unlock(&dev->mode_config.connection_mutex);
+
+	drm_sysfs_connector_status_event(connector,
+				connector->privacy_screen_sw_state_property);
+	drm_sysfs_connector_status_event(connector,
+				connector->privacy_screen_hw_state_property);
+
+	return NOTIFY_DONE;
+}
+
+/**
+ * drm_connector_attach_privacy_screen_provider - attach a privacy-screen to
+ *    the connector
+ * @connector: connector to attach the privacy-screen to
+ * @priv: drm_privacy_screen to attach
+ *
+ * Create and attach the standard privacy-screen properties and register
+ * a generic notifier for generating sysfs-connector-status-events
+ * on external changes to the privacy-screen status.
+ * This function takes ownership of the passed in drm_privacy_screen and will
+ * call drm_privacy_screen_put() on it when the connector is destroyed.
+ */
+void drm_connector_attach_privacy_screen_provider(
+	struct drm_connector *connector, struct drm_privacy_screen *priv)
+{
+	connector->privacy_screen = priv;
+	connector->privacy_screen_notifier.notifier_call =
+		drm_connector_privacy_screen_notifier;
+
+	drm_connector_create_privacy_screen_properties(connector);
+	drm_connector_update_privacy_screen_properties(connector);
+	drm_connector_attach_privacy_screen_properties(connector);
+}
+EXPORT_SYMBOL(drm_connector_attach_privacy_screen_provider);
+
+/**
+ * drm_connector_update_privacy_screen - update connector's privacy-screen
+ *    state (if changed)
+ * @connector: connector to update the privacy-screen for
+ * @state: drm_atomic state describing the state change
+ *
+ * This function checks if the passed in connector has a privacy-screen
+ * attached and if it does, it checks if the
+ * drm_connector_state.privacy_screen_sw_state setting has changed.
+ * If both conditions are true it calls drm_privacy_screen_set_sw_state() on
+ * the connector's privacy-screen to update the privacy-screen's state.
+ */
+void drm_connector_update_privacy_screen(struct drm_connector *connector,
+					 struct drm_atomic_state *state)
+{
+	struct drm_connector_state *new_connector_state, *old_connector_state;
+	int ret;
+
+	if (!connector->privacy_screen)
+		return;
+
+	new_connector_state = drm_atomic_get_new_connector_state(state, connector);
+	old_connector_state = drm_atomic_get_old_connector_state(state, connector);
+
+	if (new_connector_state->privacy_screen_sw_state ==
+	    old_connector_state->privacy_screen_sw_state)
+		return;
+
+	ret = drm_privacy_screen_set_sw_state(connector->privacy_screen,
+				new_connector_state->privacy_screen_sw_state);
+	if (ret) {
+		drm_err(connector->dev, "Error updating privacy-screen sw_state\n");
+		return;
+	}
+
+	/* The hw_state property value may have changed, update the props. */
+	drm_connector_update_privacy_screen_properties(connector);
+}
+EXPORT_SYMBOL(drm_connector_update_privacy_screen);
+
 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 067bb5b112db..4aece468a2db 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -27,6 +27,7 @@
 #include <linux/llist.h>
 #include <linux/ctype.h>
 #include <linux/hdmi.h>
+#include <linux/notifier.h>
 #include <drm/drm_mode_object.h>
 #include <drm/drm_util.h>
 
@@ -40,6 +41,7 @@ struct drm_encoder;
 struct drm_property;
 struct drm_property_blob;
 struct drm_printer;
+struct drm_privacy_screen;
 struct edid;
 struct i2c_adapter;
 
@@ -1410,6 +1412,12 @@ struct drm_connector {
 	 */
 	struct drm_property *max_bpc_property;
 
+	/** @privacy_screen: drm_privacy_screen for this connector, or NULL. */
+	struct drm_privacy_screen *privacy_screen;
+
+	/** @privacy_screen_notifier: privacy-screen notifier_block */
+	struct notifier_block privacy_screen_notifier;
+
 	/**
 	 * @privacy_screen_sw_state_property: Optional atomic property for the
 	 * connector to control the integrated privacy screen.
@@ -1742,6 +1750,10 @@ 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);
+void drm_connector_attach_privacy_screen_provider(
+	struct drm_connector *connector, struct drm_privacy_screen *priv);
+void drm_connector_update_privacy_screen(struct drm_connector *connector,
+					 struct drm_atomic_state *state);
 
 /**
  * struct drm_tile_group - Tile group metadata
-- 
2.31.1

[PATCH resend 6/9] platform/x86: thinkpad_acpi: Add hotkey_notify_extended_hotkey() helper

[Hans de Goede]

Factor the extended hotkey handling out of hotkey_notify_hotkey() and
into a new hotkey_notify_extended_hotkey() helper.

This is a preparation patch for adding support the privacy-screen hotkey
toggle (which needs some special handling, it should NOT send an evdev
key-event to userspace...).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/thinkpad_acpi.c | 30 ++++++++++++++++++----------
 1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 0d9e2ddbf904..683c175cc28a 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -3878,6 +3878,24 @@ static bool adaptive_keyboard_hotkey_notify_hotkey(unsigned int scancode)
 	}
 }
 
+static bool hotkey_notify_extended_hotkey(const u32 hkey)
+{
+	unsigned int scancode;
+
+	/* Extended keycodes start at 0x300 and our offset into the map
+	 * TP_ACPI_HOTKEYSCAN_EXTENDED_START. The calculated scancode
+	 * will be positive, but might not be in the correct range.
+	 */
+	scancode = (hkey & 0xfff) - (0x300 - TP_ACPI_HOTKEYSCAN_EXTENDED_START);
+	if (scancode >= TP_ACPI_HOTKEYSCAN_EXTENDED_START &&
+	    scancode < TPACPI_HOTKEY_MAP_LEN) {
+		tpacpi_input_send_key(scancode);
+		return true;
+	}
+
+	return false;
+}
+
 static bool hotkey_notify_hotkey(const u32 hkey,
 				 bool *send_acpi_ev,
 				 bool *ignore_acpi_ev)
@@ -3912,17 +3930,7 @@ static bool hotkey_notify_hotkey(const u32 hkey,
 		return adaptive_keyboard_hotkey_notify_hotkey(scancode);
 
 	case 3:
-		/* Extended keycodes start at 0x300 and our offset into the map
-		 * TP_ACPI_HOTKEYSCAN_EXTENDED_START. The calculated scancode
-		 * will be positive, but might not be in the correct range.
-		 */
-		scancode -= (0x300 - TP_ACPI_HOTKEYSCAN_EXTENDED_START);
-		if (scancode >= TP_ACPI_HOTKEYSCAN_EXTENDED_START &&
-		    scancode < TPACPI_HOTKEY_MAP_LEN) {
-			tpacpi_input_send_key(scancode);
-			return true;
-		}
-		break;
+		return hotkey_notify_extended_hotkey(hkey);
 	}
 
 	return false;
-- 
2.31.1

[PATCH resend 7/9] platform/x86: thinkpad_acpi: Get privacy-screen / lcdshadow ACPI handles only once

[Hans de Goede]

Get the privacy-screen / lcdshadow ACPI handles once and cache them,
instead of retrieving them every time we need them.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/platform/x86/thinkpad_acpi.c | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index 683c175cc28a..fe919700b8ae 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -9759,19 +9759,15 @@ static struct ibm_struct battery_driver_data = {
  * LCD Shadow subdriver, for the Lenovo PrivacyGuard feature
  */
 
+static acpi_handle lcdshadow_get_handle;
+static acpi_handle lcdshadow_set_handle;
 static int lcdshadow_state;
 
 static int lcdshadow_on_off(bool state)
 {
-	acpi_handle set_shadow_handle;
 	int output;
 
-	if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "SSSS", &set_shadow_handle))) {
-		pr_warn("Thinkpad ACPI has no %s interface.\n", "SSSS");
-		return -EIO;
-	}
-
-	if (!acpi_evalf(set_shadow_handle, &output, NULL, "dd", (int)state))
+	if (!acpi_evalf(lcdshadow_set_handle, &output, NULL, "dd", (int)state))
 		return -EIO;
 
 	lcdshadow_state = state;
@@ -9789,15 +9785,17 @@ static int lcdshadow_set(bool on)
 
 static int tpacpi_lcdshadow_init(struct ibm_init_struct *iibm)
 {
-	acpi_handle get_shadow_handle;
+	acpi_status status1, status2;
 	int output;
 
-	if (ACPI_FAILURE(acpi_get_handle(hkey_handle, "GSSS", &get_shadow_handle))) {
+	status1 = acpi_get_handle(hkey_handle, "GSSS", &lcdshadow_get_handle);
+	status2 = acpi_get_handle(hkey_handle, "SSSS", &lcdshadow_set_handle);
+	if (ACPI_FAILURE(status1) || ACPI_FAILURE(status2)) {
 		lcdshadow_state = -ENODEV;
 		return 0;
 	}
 
-	if (!acpi_evalf(get_shadow_handle, &output, NULL, "dd", 0)) {
+	if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0)) {
 		lcdshadow_state = -EIO;
 		return -EIO;
 	}
-- 
2.31.1

[PATCH resend 8/9] platform/x86: thinkpad_acpi: Register a privacy-screen device

[Hans de Goede]

Register a privacy-screen device on laptops with a privacy-screen,
this exports the PrivacyGuard features to user-space using a
standardized vendor-agnostic sysfs interface. Note the sysfs interface
is read-only.

Registering a privacy-screen device with the new privacy-screen class
code will also allow the GPU driver to get a handle to it and export
the privacy-screen setting as a property on the DRM connector object
for the LCD panel. This DRM connector property is news standardized
interface which all user-space code should use to query and control
the privacy-screen.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v2:
- Make the new lcdshadow_set_sw_state, lcdshadow_get_hw_state and
  lcdshadow_ops symbols static
- Update state and call drm_privacy_screen_call_notifier_chain()
  when the state is changed by pressing the Fn + D hotkey combo
---
 drivers/platform/x86/Kconfig         |  1 +
 drivers/platform/x86/thinkpad_acpi.c | 91 ++++++++++++++++++++--------
 2 files changed, 67 insertions(+), 25 deletions(-)

diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
index 461ec61530eb..404d80f99a03 100644
--- a/drivers/platform/x86/Kconfig
+++ b/drivers/platform/x86/Kconfig
@@ -485,6 +485,7 @@ config THINKPAD_ACPI
 	depends on ACPI_VIDEO || ACPI_VIDEO = n
 	depends on BACKLIGHT_CLASS_DEVICE
 	select ACPI_PLATFORM_PROFILE
+	select DRM_PRIVACY_SCREEN
 	select HWMON
 	select NVRAM
 	select NEW_LEDS
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index fe919700b8ae..766c6d64b0fb 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -73,6 +73,7 @@
 #include <linux/uaccess.h>
 #include <acpi/battery.h>
 #include <acpi/video.h>
+#include <drm/drm_privacy_screen_driver.h>
 
 /* ThinkPad CMOS commands */
 #define TP_CMOS_VOLUME_DOWN	0
@@ -156,6 +157,7 @@ enum tpacpi_hkey_event_t {
 	TP_HKEY_EV_VOL_UP		= 0x1015, /* Volume up or unmute */
 	TP_HKEY_EV_VOL_DOWN		= 0x1016, /* Volume down or unmute */
 	TP_HKEY_EV_VOL_MUTE		= 0x1017, /* Mixer output mute */
+	TP_HKEY_EV_PRIVACYGUARD_TOGGLE	= 0x130f, /* Toggle priv.guard on/off */
 
 	/* Reasons for waking up from S3/S4 */
 	TP_HKEY_EV_WKUP_S3_UNDOCK	= 0x2304, /* undock requested, S3 */
@@ -3882,6 +3884,12 @@ static bool hotkey_notify_extended_hotkey(const u32 hkey)
 {
 	unsigned int scancode;
 
+	switch (hkey) {
+	case TP_HKEY_EV_PRIVACYGUARD_TOGGLE:
+		tpacpi_driver_event(hkey);
+		return true;
+	}
+
 	/* Extended keycodes start at 0x300 and our offset into the map
 	 * TP_ACPI_HOTKEYSCAN_EXTENDED_START. The calculated scancode
 	 * will be positive, but might not be in the correct range.
@@ -9759,30 +9767,40 @@ static struct ibm_struct battery_driver_data = {
  * LCD Shadow subdriver, for the Lenovo PrivacyGuard feature
  */
 
+static struct drm_privacy_screen *lcdshadow_dev;
 static acpi_handle lcdshadow_get_handle;
 static acpi_handle lcdshadow_set_handle;
-static int lcdshadow_state;
 
-static int lcdshadow_on_off(bool state)
+static int lcdshadow_set_sw_state(struct drm_privacy_screen *priv,
+				  enum drm_privacy_screen_status state)
 {
 	int output;
 
+	if (WARN_ON(!mutex_is_locked(&priv->lock)))
+		return -EIO;
+
 	if (!acpi_evalf(lcdshadow_set_handle, &output, NULL, "dd", (int)state))
 		return -EIO;
 
-	lcdshadow_state = state;
+	priv->hw_state = priv->sw_state = state;
 	return 0;
 }
 
-static int lcdshadow_set(bool on)
+static void lcdshadow_get_hw_state(struct drm_privacy_screen *priv)
 {
-	if (lcdshadow_state < 0)
-		return lcdshadow_state;
-	if (lcdshadow_state == on)
-		return 0;
-	return lcdshadow_on_off(on);
+	int output;
+
+	if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0))
+		return;
+
+	priv->hw_state = priv->sw_state = output & 0x1;
 }
 
+static const struct drm_privacy_screen_ops lcdshadow_ops = {
+	.set_sw_state = lcdshadow_set_sw_state,
+	.get_hw_state = lcdshadow_get_hw_state,
+};
+
 static int tpacpi_lcdshadow_init(struct ibm_init_struct *iibm)
 {
 	acpi_status status1, status2;
@@ -9790,36 +9808,44 @@ static int tpacpi_lcdshadow_init(struct ibm_init_struct *iibm)
 
 	status1 = acpi_get_handle(hkey_handle, "GSSS", &lcdshadow_get_handle);
 	status2 = acpi_get_handle(hkey_handle, "SSSS", &lcdshadow_set_handle);
-	if (ACPI_FAILURE(status1) || ACPI_FAILURE(status2)) {
-		lcdshadow_state = -ENODEV;
+	if (ACPI_FAILURE(status1) || ACPI_FAILURE(status2))
 		return 0;
-	}
 
-	if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0)) {
-		lcdshadow_state = -EIO;
+	if (!acpi_evalf(lcdshadow_get_handle, &output, NULL, "dd", 0))
 		return -EIO;
-	}
-	if (!(output & 0x10000)) {
-		lcdshadow_state = -ENODEV;
+
+	if (!(output & 0x10000))
 		return 0;
-	}
-	lcdshadow_state = output & 0x1;
+
+	lcdshadow_dev = drm_privacy_screen_register(&tpacpi_pdev->dev,
+						    &lcdshadow_ops);
+	if (IS_ERR(lcdshadow_dev))
+		return PTR_ERR(lcdshadow_dev);
 
 	return 0;
 }
 
+static void lcdshadow_exit(void)
+{
+	drm_privacy_screen_unregister(lcdshadow_dev);
+}
+
 static void lcdshadow_resume(void)
 {
-	if (lcdshadow_state >= 0)
-		lcdshadow_on_off(lcdshadow_state);
+	if (!lcdshadow_dev)
+		return;
+
+	mutex_lock(&lcdshadow_dev->lock);
+	lcdshadow_set_sw_state(lcdshadow_dev, lcdshadow_dev->sw_state);
+	mutex_unlock(&lcdshadow_dev->lock);
 }
 
 static int lcdshadow_read(struct seq_file *m)
 {
-	if (lcdshadow_state < 0) {
+	if (!lcdshadow_dev) {
 		seq_puts(m, "status:\t\tnot supported\n");
 	} else {
-		seq_printf(m, "status:\t\t%d\n", lcdshadow_state);
+		seq_printf(m, "status:\t\t%d\n", lcdshadow_dev->hw_state);
 		seq_puts(m, "commands:\t0, 1\n");
 	}
 
@@ -9831,7 +9857,7 @@ static int lcdshadow_write(char *buf)
 	char *cmd;
 	int res, state = -EINVAL;
 
-	if (lcdshadow_state < 0)
+	if (!lcdshadow_dev)
 		return -ENODEV;
 
 	while ((cmd = strsep(&buf, ","))) {
@@ -9843,11 +9869,18 @@ static int lcdshadow_write(char *buf)
 	if (state >= 2 || state < 0)
 		return -EINVAL;
 
-	return lcdshadow_set(state);
+	mutex_lock(&lcdshadow_dev->lock);
+	res = lcdshadow_set_sw_state(lcdshadow_dev, state);
+	mutex_unlock(&lcdshadow_dev->lock);
+
+	drm_privacy_screen_call_notifier_chain(lcdshadow_dev);
+
+	return res;
 }
 
 static struct ibm_struct lcdshadow_driver_data = {
 	.name = "lcdshadow",
+	.exit = lcdshadow_exit,
 	.resume = lcdshadow_resume,
 	.read = lcdshadow_read,
 	.write = lcdshadow_write,
@@ -10533,6 +10566,14 @@ static void tpacpi_driver_event(const unsigned int hkey_event)
 		if (!atomic_add_unless(&dytc_ignore_event, -1, 0))
 			dytc_profile_refresh();
 	}
+
+	if (lcdshadow_dev && hkey_event == TP_HKEY_EV_PRIVACYGUARD_TOGGLE) {
+		mutex_lock(&lcdshadow_dev->lock);
+		lcdshadow_get_hw_state(lcdshadow_dev);
+		mutex_unlock(&lcdshadow_dev->lock);
+
+		drm_privacy_screen_call_notifier_chain(lcdshadow_dev);
+	}
 }
 
 static void hotkey_driver_event(const unsigned int scancode)
-- 
2.31.1

[PATCH resend 9/9] drm/i915: Add privacy-screen support

[Hans de Goede]

Add support for eDP panels with a built-in privacy screen using the
new drm_privacy_screen class.

One thing which stands out here is the addition of these 2 lines to
intel_atomic_commit_tail:

	for_each_new_connector_in_state(&state->base, connector, ...
		drm_connector_update_privacy_screen(connector, state);

It may seem more logical to instead take care of updating the
privacy-screen state by marking the crtc as needing a modeset and then
do this in both the encoder update_pipe (for fast-sets) and enable
(for full modesets) callbacks. But ATM these callbacks only get passed
the new connector_state and these callbacks are all called after
drm_atomic_helper_swap_state() at which point there is no way to get
the old state from the new state.

Without access to the old state, we do not know if the sw_state of
the privacy-screen has changes so we would need to call
drm_privacy_screen_set_sw_state() unconditionally. This is undesirable
since all current known privacy-screen providers use ACPI calls which
are somewhat expensive to make.

Also, as all providers use ACPI calls, rather then poking GPU registers,
there is no need to order this together with other encoder operations.
Since no GPU poking is involved having this as a separate step of the
commit process actually is the logical thing to do.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/i915/display/intel_display.c |  5 +++++
 drivers/gpu/drm/i915/display/intel_dp.c      | 10 ++++++++++
 drivers/gpu/drm/i915/i915_pci.c              | 12 ++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 411b46c012f8..620d11d6bb31 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -10169,6 +10169,8 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	struct drm_device *dev = state->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct intel_crtc_state *new_crtc_state, *old_crtc_state;
+	struct drm_connector_state *new_connector_state;
+	struct drm_connector *connector;
 	struct intel_crtc *crtc;
 	u64 put_domains[I915_MAX_PIPES] = {};
 	intel_wakeref_t wakeref = 0;
@@ -10266,6 +10268,9 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 			intel_color_load_luts(new_crtc_state);
 	}
 
+	for_each_new_connector_in_state(&state->base, connector, new_connector_state, i)
+		drm_connector_update_privacy_screen(connector, &state->base);
+
 	/*
 	 * Now that the vblank has passed, we can go ahead and program the
 	 * optimal watermarks on platforms that need two-step watermark
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 6750949aa261..8ca3909e2ec9 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -37,6 +37,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_dp_helper.h>
 #include <drm/drm_edid.h>
+#include <drm/drm_privacy_screen_consumer.h>
 #include <drm/drm_probe_helper.h>
 
 #include "g4x_dp.h"
@@ -5178,6 +5179,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 	struct drm_connector *connector = &intel_connector->base;
 	struct drm_display_mode *fixed_mode = NULL;
 	struct drm_display_mode *downclock_mode = NULL;
+	struct drm_privacy_screen *privacy_screen;
 	bool has_dpcd;
 	enum pipe pipe = INVALID_PIPE;
 	struct edid *edid;
@@ -5268,6 +5270,14 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
 				fixed_mode->hdisplay, fixed_mode->vdisplay);
 	}
 
+	privacy_screen = drm_privacy_screen_get(&dev->pdev->dev, NULL);
+	if (!IS_ERR(privacy_screen)) {
+		drm_connector_attach_privacy_screen_provider(connector,
+							     privacy_screen);
+	} else if (PTR_ERR(privacy_screen) != -ENODEV) {
+		drm_warn(&dev_priv->drm, "Error getting privacy-screen\n");
+	}
+
 	return true;
 
 out_vdd_off:
diff --git a/drivers/gpu/drm/i915/i915_pci.c b/drivers/gpu/drm/i915/i915_pci.c
index 480553746794..95426e365400 100644
--- a/drivers/gpu/drm/i915/i915_pci.c
+++ b/drivers/gpu/drm/i915/i915_pci.c
@@ -26,6 +26,7 @@
 #include <linux/vga_switcheroo.h>
 
 #include <drm/drm_drv.h>
+#include <drm/drm_privacy_screen_consumer.h>
 #include <drm/i915_pciids.h>
 
 #include "display/intel_fbdev.h"
@@ -1064,6 +1065,7 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
 	struct intel_device_info *intel_info =
 		(struct intel_device_info *) ent->driver_data;
+	struct drm_privacy_screen *privacy_screen;
 	int err;
 
 	if (intel_info->require_force_probe &&
@@ -1092,7 +1094,17 @@ static int i915_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (vga_switcheroo_client_probe_defer(pdev))
 		return -EPROBE_DEFER;
 
+	/*
+	 * We do not handle -EPROBE_DEFER further into the probe process, so
+	 * check if we have a laptop-panel privacy-screen for which the driver
+	 * has not loaded yet here.
+	 */
+	privacy_screen = drm_privacy_screen_get(&pdev->dev, NULL);
+	if (IS_ERR(privacy_screen) && PTR_ERR(privacy_screen) == -EPROBE_DEFER)
+		return -EPROBE_DEFER;
+
 	err = i915_driver_probe(pdev, ent);
+	drm_privacy_screen_put(privacy_screen);
 	if (err)
 		return err;
 
-- 
2.31.1

Re: [PATCH resend 0/9] drm: Add privacy-screen class and connector properties

[Rajat Jain]

+Jesse Barnes

Hello,

On Wed, Apr 14, 2021 at 8:11 AM Hans de Goede <hdegoede@redhat.com> wrote:
>
> Hi All,
>
> Here is the privacy-screen related code which I last posted in August
> of last year. To the best of my knowledge there is consensus about /
> everyone is in agreement with the new userspace API (2 connector properties)
> this patch-set add (patch 1 of the series).
>
> The blocker the last time was that there were no userspace users of
> the new properties and as a rule we don't add new drm userspace API
> without users.
>
> There now is GNOME userspace code using the new properties:
> https://hackmd.io/@3v1n0/rkyIy3BOw
>
> The new API works as designed for this userspace user and the branches
> mentioned at the above link add the following features to GNOME:
>
> 1. Showing an OSD notification when the privacy-screen is toggled on/off
>    through hotkeys handled by the embedded-controller
> 2. Allowing control of the privacy-screen from the GNOME control-panel,
>    including the on/off slider shown there updating to match the hw-setting
>    when the setting is changed with the control-panel open.
> 3. Restoring the last user-setting at login
>
> This series consists of a number of different parts:
>
> 1. A new version of Rajat's privacy-screen connector properties patch,
> this adds new userspace API in the form of new properties

Thanks a lot Hans!

>
> 2. Since on most devices the privacy screen is actually controlled by
> some vendor specific ACPI/WMI interface which has a driver under
> drivers/platform/x86, we need some "glue" code to make this functionality
> available to KMS drivers. Patches 2-4 add a new privacy-screen class for
> this, which allows non KMS drivers (and possibly KMS drivers too) to
> register a privacy-screen device and also adds an interface for KMS drivers
> to get access to the privacy-screen associated with a specific connector.
> This is modelled similar to how we deal with e.g. PWMs and GPIOs in the
> kernel, including separate includes for consumers and providers(drivers).
>
> 3. Some drm_connector helper functions to keep the actual changes needed
> for this in individual KMS drivers as small as possible (patch 5).
>
> 4. Make the thinkpad_acpi code register a privacy-screen device on
> ThinkPads with a privacy-screen (patches 6-8)
>
> 5. Make the i915 driver export the privacy-screen functionality through
> the connector properties on the eDP connector.
>
> I believe that it would be best to merge the entire series, including
> the thinkpad_acpi changes through drm-misc in one go. As the pdx86
> subsys maintainer I hereby give my ack for merging the thinkpad_acpi
> changes through drm-misc.

Huge +1 to this. This feature has been waiting for acceptance for
almost 1.5 years now, and we (Chromeos) have been carrying it out of
the tree since then. We have real products today that use this
feature. If a version of it can please be accepted and applied, we
look forward to cherry-pick / backport it to our kernels (and adapt chrome
code to the new API).

Thanks,
Rajat



>
> There is one small caveat with this series, which it is good to be
> aware of. The i915 driver will now return -EPROBE_DEFER on Thinkpads
> with an eprivacy screen, until the thinkpad_acpi driver is loaded.
> This means that initrd generation tools will need to be updated to
> include thinkpad_acpi when the i915 driver is added to the initrd.
> Without this the loading of the i915 driver will be delayed to after
> the switch to real rootfs.
>
> Regards,
>
> Hans
>
>
> Hans de Goede (8):
>   drm: Add privacy-screen class
>   drm/privacy-screen: Add X86 specific arch init code
>   drm/privacy-screen: Add notifier support
>   drm/connector: Add a drm_connector privacy-screen helper functions
>   platform/x86: thinkpad_acpi: Add hotkey_notify_extended_hotkey()
>     helper
>   platform/x86: thinkpad_acpi: Get privacy-screen / lcdshadow ACPI
>     handles only once
>   platform/x86: thinkpad_acpi: Register a privacy-screen device
>   drm/i915: Add privacy-screen support
>
> Rajat Jain (1):
>   drm/connector: Add support for privacy-screen properties (v4)
>
>  Documentation/gpu/drm-kms-helpers.rst        |  15 +
>  Documentation/gpu/drm-kms.rst                |   2 +
>  MAINTAINERS                                  |   8 +
>  drivers/gpu/drm/Kconfig                      |   5 +
>  drivers/gpu/drm/Makefile                     |   4 +
>  drivers/gpu/drm/drm_atomic_uapi.c            |   4 +
>  drivers/gpu/drm/drm_connector.c              | 214 ++++++++
>  drivers/gpu/drm/drm_privacy_screen.c         | 493 +++++++++++++++++++
>  drivers/gpu/drm/drm_privacy_screen_x86.c     |  82 +++
>  drivers/gpu/drm/i915/display/intel_display.c |   5 +
>  drivers/gpu/drm/i915/display/intel_dp.c      |  10 +
>  drivers/gpu/drm/i915/i915_pci.c              |  12 +
>  drivers/platform/x86/Kconfig                 |   1 +
>  drivers/platform/x86/thinkpad_acpi.c         | 131 +++--
>  include/drm/drm_connector.h                  |  56 +++
>  include/drm/drm_privacy_screen_consumer.h    |  32 ++
>  include/drm/drm_privacy_screen_driver.h      |  84 ++++
>  include/drm/drm_privacy_screen_machine.h     |  46 ++
>  18 files changed, 1162 insertions(+), 42 deletions(-)
>  create mode 100644 drivers/gpu/drm/drm_privacy_screen.c
>  create mode 100644 drivers/gpu/drm/drm_privacy_screen_x86.c
>  create mode 100644 include/drm/drm_privacy_screen_consumer.h
>  create mode 100644 include/drm/drm_privacy_screen_driver.h
>  create mode 100644 include/drm/drm_privacy_screen_machine.h
>
> --
> 2.31.1
>