Re: [PATCH v2 3/3] drm/i915: Add support for integrated privacy screens

Rajat Jain
2019-11-20T21:36:23Z

Hi Jani,

On Wed, Nov 20, 2019 at 7:11 AM Jani Nikula <jani.nikula@linux.intel.com> wrote:
>
> On Tue, 12 Nov 2019, Rajat Jain <rajatja@google.com> wrote:
> > On Mon, Nov 4, 2019 at 11:41 AM Rajat Jain <rajatja@google.com> wrote:
> >>
> >> Certain laptops now come with panels that have integrated privacy
> >> screens on them. This patch adds support for such panels by adding
> >> a privacy-screen property to the intel_connector for the panel, that
> >> the userspace can then use to control and check the status.
> >>
> >> Identifying the presence of privacy screen, and controlling it, is done
> >> via ACPI _DSM methods.
> >>
> >> Currently, this is done only for the Intel display ports. But in future,
> >> this can be done for any other ports if the hardware becomes available
> >> (e.g. external monitors supporting integrated privacy screens?).
> >>
> >> Signed-off-by: Rajat Jain <rajatja@google.com>
> >> Change-Id: Ic9ff07fc4a50797d2d0dfb919f11aa0821a4b548
> >
> >
> > Hi Folks,
> >
> > I posted a v2 taking care of the comments I received (also split it
> > into 3 patches now, and resused some ACPI code I found in i915
> > driver). . Wondering if any one got a chance to look at this?
>
> For future reference, please post the updated series standalone, *not*
> in reply to long, old threads. Besides myself, it'll also help our CI
> find your patches and crunch a bunch of tests on them.

Will do.

>
> Also, do you have an open userspace for this? See [1]. I think this
> looks like good stuff to me, but then I'm not responsible for any
> userspace component that would actually use this.

Not sure what you meant but the user for this on Chromebooks (what I
work on) would be the Chrome browser most likely.

Thanks & Best Regards,

Rajat

>
> BR,
> Jani.
>
>
> [1] https://www.kernel.org/doc/html/latest/gpu/drm-uapi.html#open-source-userspace-requirements
>
>
>
> >
> > Thanks,
> >
> > Rajat
> >
> >> ---
> >> v2: Formed by splitting the original patch into multiple patches.
> >> - All code has been moved into i915 now.
> >> - Privacy screen is a i915 property
> >> - Have a local state variable to store the prvacy screen. Don't read
> >> it from hardware.
> >>
> >> drivers/gpu/drm/i915/Makefile | 3 +-
> >> drivers/gpu/drm/i915/display/intel_atomic.c | 13 +++-
> >> .../gpu/drm/i915/display/intel_connector.c | 35 ++++++++++
> >> .../gpu/drm/i915/display/intel_connector.h | 1 +
> >> .../drm/i915/display/intel_display_types.h | 4 ++
> >> drivers/gpu/drm/i915/display/intel_dp.c | 5 ++
> >> .../drm/i915/display/intel_privacy_screen.c | 70 +++++++++++++++++++
> >> .../drm/i915/display/intel_privacy_screen.h | 25 +++++++
> >> include/uapi/drm/i915_drm.h | 14 ++++
> >> 9 files changed, 166 insertions(+), 4 deletions(-)
> >> create mode 100644 drivers/gpu/drm/i915/display/intel_privacy_screen.c
> >> create mode 100644 drivers/gpu/drm/i915/display/intel_privacy_screen.h
> >>
> >> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> >> index 2587ea834f06..3589ebcf27bc 100644
> >> --- a/drivers/gpu/drm/i915/Makefile
> >> +++ b/drivers/gpu/drm/i915/Makefile
> >> @@ -185,7 +185,8 @@ i915-y += \
> >> display/intel_tc.o
> >> i915-$(CONFIG_ACPI) += \
> >> display/intel_acpi.o \
> >> - display/intel_opregion.o
> >> + display/intel_opregion.o \
> >> + display/intel_privacy_screen.o
> >> i915-$(CONFIG_DRM_FBDEV_EMULATION) += \
> >> display/intel_fbdev.o
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
> >> index d3fb75bb9eb1..378772d3449c 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> >> @@ -37,6 +37,7 @@
> >> #include "intel_atomic.h"
> >> #include "intel_display_types.h"
> >> #include "intel_hdcp.h"
> >> +#include "intel_privacy_screen.h"
> >> #include "intel_sprite.h"
> >>
> >> /**
> >> @@ -57,11 +58,14 @@ int intel_digital_connector_atomic_get_property(struct drm_connector *connector,
> >> struct drm_i915_private *dev_priv = to_i915(dev);
> >> struct intel_digital_connector_state *intel_conn_state =
> >> to_intel_digital_connector_state(state);
> >> + struct intel_connector *intel_connector = to_intel_connector(connector);
> >>
> >> if (property == dev_priv->force_audio_property)
> >> *val = intel_conn_state->force_audio;
> >> else if (property == dev_priv->broadcast_rgb_property)
> >> *val = intel_conn_state->broadcast_rgb;
> >> + else if (property == intel_connector->privacy_screen_property)
> >> + *val = intel_conn_state->privacy_screen_status;
> >> else {
> >> DRM_DEBUG_ATOMIC("Unknown property [PROP:%d:%s]\n",
> >> property->base.id, property->name);
> >> @@ -89,15 +93,18 @@ int intel_digital_connector_atomic_set_property(struct drm_connector *connector,
> >> struct drm_i915_private *dev_priv = to_i915(dev);
> >> struct intel_digital_connector_state *intel_conn_state =
> >> to_intel_digital_connector_state(state);
> >> + struct intel_connector *intel_connector = to_intel_connector(connector);
> >>
> >> if (property == dev_priv->force_audio_property) {
> >> intel_conn_state->force_audio = val;
> >> return 0;
> >> - }
> >> -
> >> - if (property == dev_priv->broadcast_rgb_property) {
> >> + } else if (property == dev_priv->broadcast_rgb_property) {
> >> intel_conn_state->broadcast_rgb = val;
> >> return 0;
> >> + } else if (property == intel_connector->privacy_screen_property) {
> >> + intel_privacy_screen_set_val(intel_connector, val);
> >> + intel_conn_state->privacy_screen_status = val;
> >> + return 0;
> >> }
> >>
> >> DRM_DEBUG_ATOMIC("Unknown property [PROP:%d:%s]\n",
> >> diff --git a/drivers/gpu/drm/i915/display/intel_connector.c b/drivers/gpu/drm/i915/display/intel_connector.c
> >> index 308ec63207ee..3ccbf52aedf9 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_connector.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_connector.c
> >> @@ -281,3 +281,38 @@ intel_attach_colorspace_property(struct drm_connector *connector)
> >> drm_object_attach_property(&connector->base,
> >> connector->colorspace_property, 0);
> >> }
> >> +
> >> +static const struct drm_prop_enum_list privacy_screen_enum[] = {
> >> + { PRIVACY_SCREEN_DISABLED, "Disabled" },
> >> + { PRIVACY_SCREEN_ENABLED, "Enabled" },
> >> +};
> >> +
> >> +/**
> >> + * intel_attach_privacy_screen_property -
> >> + * create and attach the connecter's privacy-screen property. *
> >> + * @connector: connector for which to init the privacy-screen property
> >> + *
> >> + * This function creates and attaches the "privacy-screen" property to the
> >> + * connector. Initial state of privacy-screen is set to disabled.
> >> + */
> >> +void
> >> +intel_attach_privacy_screen_property(struct drm_connector *connector)
> >> +{
> >> + struct intel_connector *intel_connector = to_intel_connector(connector);
> >> + struct drm_property *prop;
> >> +
> >> + if (!intel_connector->privacy_screen_property) {
> >> + prop = drm_property_create_enum(connector->dev,
> >> + DRM_MODE_PROP_ENUM,
> >> + "privacy-screen",
> >> + privacy_screen_enum,
> >> + ARRAY_SIZE(privacy_screen_enum));
> >> + if (!prop)
> >> + return;
> >> +
> >> + intel_connector->privacy_screen_property = prop;
> >> + }
> >> +
> >> + drm_object_attach_property(&connector->base, prop,
> >> + PRIVACY_SCREEN_DISABLED);
> >> +}
> >> diff --git a/drivers/gpu/drm/i915/display/intel_connector.h b/drivers/gpu/drm/i915/display/intel_connector.h
> >> index 93a7375c8196..61005f37a338 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_connector.h
> >> +++ b/drivers/gpu/drm/i915/display/intel_connector.h
> >> @@ -31,5 +31,6 @@ void intel_attach_force_audio_property(struct drm_connector *connector);
> >> void intel_attach_broadcast_rgb_property(struct drm_connector *connector);
> >> void intel_attach_aspect_ratio_property(struct drm_connector *connector);
> >> void intel_attach_colorspace_property(struct drm_connector *connector);
> >> +void intel_attach_privacy_screen_property(struct drm_connector *connector);
> >>
> >> #endif /* __INTEL_CONNECTOR_H__ */
> >> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> >> index c2706afc069b..83b8c98049a7 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> >> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> >> @@ -426,6 +426,9 @@ struct intel_connector {
> >> struct work_struct modeset_retry_work;
> >>
> >> struct intel_hdcp hdcp;
> >> +
> >> + /* Optional "privacy-screen" property for the connector panel */
> >> + struct drm_property *privacy_screen_property;
> >> };
> >>
> >> struct intel_digital_connector_state {
> >> @@ -433,6 +436,7 @@ struct intel_digital_connector_state {
> >>
> >> enum hdmi_force_audio force_audio;
> >> int broadcast_rgb;
> >> + enum intel_privacy_screen_status privacy_screen_status;
> >> };
> >>
> >> #define to_intel_digital_connector_state(x) container_of(x, struct intel_digital_connector_state, base)
> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> >> index 4fac408a4299..1963e92404ba 100644
> >> --- a/drivers/gpu/drm/i915/display/intel_dp.c
> >> +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> >> @@ -62,6 +62,7 @@
> >> #include "intel_lspcon.h"
> >> #include "intel_lvds.h"
> >> #include "intel_panel.h"
> >> +#include "intel_privacy_screen.h"
> >> #include "intel_psr.h"
> >> #include "intel_sideband.h"
> >> #include "intel_tc.h"
> >> @@ -6358,6 +6359,10 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
> >>
> >> /* Lookup the ACPI node corresponding to the connector */
> >> intel_connector_lookup_acpi_node(intel_connector);
> >> +
> >> + /* Check for integrated Privacy screen support */
> >> + if (intel_privacy_screen_present(intel_connector))
> >> + intel_attach_privacy_screen_property(connector);
> >> }
> >> }
> >>
> >> diff --git a/drivers/gpu/drm/i915/display/intel_privacy_screen.c b/drivers/gpu/drm/i915/display/intel_privacy_screen.c
> >> new file mode 100644
> >> index 000000000000..4c422e38c51a
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/i915/display/intel_privacy_screen.c
> >> @@ -0,0 +1,70 @@
> >> +// SPDX-License-Identifier: GPL-2.0-or-later
> >> +/*
> >> + * Intel ACPI privacy screen code
> >> + *
> >> + * Copyright © 2019 Google Inc.
> >> + */
> >> +
> >> +#include <linux/acpi.h>
> >> +
> >> +#include "intel_privacy_screen.h"
> >> +
> >> +#define CONNECTOR_DSM_REVID 1
> >> +
> >> +#define CONNECTOR_DSM_FN_PRIVACY_ENABLE 2
> >> +#define CONNECTOR_DSM_FN_PRIVACY_DISABLE 3
> >> +
> >> +static const guid_t drm_conn_dsm_guid =
> >> + GUID_INIT(0xC7033113, 0x8720, 0x4CEB,
> >> + 0x90, 0x90, 0x9D, 0x52, 0xB3, 0xE5, 0x2D, 0x73);
> >> +
> >> +/* Makes _DSM call to set privacy screen status */
> >> +static void acpi_privacy_screen_call_dsm(acpi_handle conn_handle, u64 func)
> >> +{
> >> + union acpi_object *obj;
> >> +
> >> + obj = acpi_evaluate_dsm(conn_handle, &drm_conn_dsm_guid,
> >> + CONNECTOR_DSM_REVID, func, NULL);
> >> + if (!obj) {
> >> + DRM_DEBUG_DRIVER("failed to evaluate _DSM for fn %llx\n", func);
> >> + return;
> >> + }
> >> +
> >> + ACPI_FREE(obj);
> >> +}
> >> +
> >> +void intel_privacy_screen_set_val(struct intel_connector *intel_connector,
> >> + enum intel_privacy_screen_status val)
> >> +{
> >> + acpi_handle acpi_handle = intel_connector->acpi_handle;
> >> +
> >> + if (!acpi_handle)
> >> + return;
> >> +
> >> + if (val == PRIVACY_SCREEN_DISABLED)
> >> + acpi_privacy_screen_call_dsm(acpi_handle,
> >> + CONNECTOR_DSM_FN_PRIVACY_DISABLE);
> >> + else if (val == PRIVACY_SCREEN_ENABLED)
> >> + acpi_privacy_screen_call_dsm(acpi_handle,
> >> + CONNECTOR_DSM_FN_PRIVACY_ENABLE);
> >> +}
> >> +
> >> +bool intel_privacy_screen_present(struct intel_connector *intel_connector)
> >> +{
> >> + acpi_handle handle = intel_connector->acpi_handle;
> >> +
> >> + if (!handle)
> >> + return false;
> >> +
> >> + if (!acpi_check_dsm(handle, &drm_conn_dsm_guid,
> >> + CONNECTOR_DSM_REVID,
> >> + 1 << CONNECTOR_DSM_FN_PRIVACY_ENABLE |
> >> + 1 << CONNECTOR_DSM_FN_PRIVACY_DISABLE)) {
> >> + DRM_WARN("%s: Odd, connector ACPI node but no privacy scrn?\n",
> >> + dev_name(intel_connector->base.dev->dev));
> >> + return false;
> >> + }
> >> + DRM_DEV_INFO(intel_connector->base.dev->dev,
> >> + "supports privacy screen\n");
> >> + return true;
> >> +}
> >> diff --git a/drivers/gpu/drm/i915/display/intel_privacy_screen.h b/drivers/gpu/drm/i915/display/intel_privacy_screen.h
> >> new file mode 100644
> >> index 000000000000..212f73349a00
> >> --- /dev/null
> >> +++ b/drivers/gpu/drm/i915/display/intel_privacy_screen.h
> >> @@ -0,0 +1,25 @@
> >> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> >> +/*
> >> + * Copyright © 2019 Google Inc.
> >> + */
> >> +
> >> +#ifndef __DRM_PRIVACY_SCREEN_H__
> >> +#define __DRM_PRIVACY_SCREEN_H__
> >> +
> >> +#include "intel_display_types.h"
> >> +
> >> +#ifdef CONFIG_ACPI
> >> +bool intel_privacy_screen_present(struct intel_connector *intel_connector);
> >> +void intel_privacy_screen_set_val(struct intel_connector *intel_connector,
> >> + enum intel_privacy_screen_status val);
> >> +#else
> >> +bool intel_privacy_screen_present(struct intel_connector *intel_connector);
> >> +{
> >> + return false;
> >> +}
> >> +void intel_privacy_screen_set_val(struct intel_connector *intel_connector,
> >> + enum intel_privacy_screen_status val)
> >> +{ }
> >> +#endif /* CONFIG_ACPI */
> >> +
> >> +#endif /* __DRM_PRIVACY_SCREEN_H__ */
> >> diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> >> index 469dc512cca3..cf08d5636363 100644
> >> --- a/include/uapi/drm/i915_drm.h
> >> +++ b/include/uapi/drm/i915_drm.h
> >> @@ -2123,6 +2123,20 @@ struct drm_i915_query_engine_info {
> >> struct drm_i915_engine_info engines[];
> >> };
> >>
> >> +/**
> >> + * enum intel_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" property.
> >> + *
> >> + * @PRIVACY_SCREEN_DISABLED: The privacy-screen on the panel is disabled
> >> + * @PRIVACY_SCREEN_ENABLED: The privacy-screen on the panel is enabled
> >> + **/
> >> +enum intel_privacy_screen_status {
> >> + PRIVACY_SCREEN_DISABLED = 0,
> >> + PRIVACY_SCREEN_ENABLED = 1,
> >> +};
> >> +
> >> #if defined(__cplusplus)
> >> }
> >> #endif
> >> --
> >> 2.24.0.rc1.363.gb1bccd3e3d-goog
> >>
>
> --
> Jani Nikula, Intel Open Source Graphics Center