LinuxLists.cc - [PATCH] drm: Add support for integrated privacy screens

2019-10-23 00:31:12

Subject: [PATCH] drm: Add support for integrated privacy screens

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 drm_connector for the panel, that
the userspace can then use to control and check the status. The idea
was discussed here:

https://lkml.org/lkml/2019/10/1/786

ACPI methods are used to identify, query and control privacy screen:

* Identifying an ACPI object corresponding to the panel: The patch
follows ACPI Spec 6.3 (available at
https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf).
Pages 1119 - 1123 describe what I believe, is a standard way of
identifying / addressing "display panels" in the ACPI tables, thus
allowing kernel to attach ACPI nodes to the panel. IMHO, this ability
to identify and attach ACPI nodes to drm connectors may be useful for
reasons other privacy-screens, in future.

* 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?).

Also, this code can be extended in future to support non-ACPI methods
(e.g. using a kernel GPIO driver to toggle a gpio that controls the
privacy-screen).

Signed-off-by: Rajat Jain <[email protected]>
---
drivers/gpu/drm/Makefile | 1 +
drivers/gpu/drm/drm_atomic_uapi.c | 5 +
drivers/gpu/drm/drm_connector.c | 38 +++++
drivers/gpu/drm/drm_privacy_screen.c | 176 ++++++++++++++++++++++++
drivers/gpu/drm/i915/display/intel_dp.c | 3 +
include/drm/drm_connector.h | 18 +++
include/drm/drm_mode_config.h | 7 +
include/drm/drm_privacy_screen.h | 33 +++++
8 files changed, 281 insertions(+)
create mode 100644 drivers/gpu/drm/drm_privacy_screen.c
create mode 100644 include/drm/drm_privacy_screen.h

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 82ff826b33cc..e1fc33d69bb7 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -19,6 +19,7 @@ drm-y := drm_auth.o drm_cache.o \
drm_syncobj.o drm_lease.o drm_writeback.o drm_client.o \
drm_client_modeset.o drm_atomic_uapi.o drm_hdcp.o

+drm-$(CONFIG_ACPI) += drm_privacy_screen.o
drm-$(CONFIG_DRM_LEGACY) += drm_legacy_misc.o drm_bufs.o drm_context.o drm_dma.o drm_scatter.o drm_lock.o
drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
drm-$(CONFIG_DRM_VM) += drm_vm.o
diff --git a/drivers/gpu/drm/drm_atomic_uapi.c b/drivers/gpu/drm/drm_atomic_uapi.c
index 7a26bfb5329c..44131165e4ea 100644
--- a/drivers/gpu/drm/drm_atomic_uapi.c
+++ b/drivers/gpu/drm/drm_atomic_uapi.c
@@ -30,6 +30,7 @@
#include <drm/drm_atomic.h>
#include <drm/drm_print.h>
#include <drm/drm_drv.h>
+#include <drm/drm_privacy_screen.h>
#include <drm/drm_writeback.h>
#include <drm/drm_vblank.h>

@@ -766,6 +767,8 @@ 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 == config->privacy_screen_property) {
+ drm_privacy_screen_set_val(connector, val);
} else if (connector->funcs->atomic_set_property) {
return connector->funcs->atomic_set_property(connector,
state, property, val);
@@ -842,6 +845,8 @@ 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 == config->privacy_screen_property) {
+ *val = drm_privacy_screen_get_val(connector);
} 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 4c766624b20d..a31e0382132b 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -821,6 +821,11 @@ static const struct drm_prop_enum_list drm_panel_orientation_enum_list[] = {
{ DRM_MODE_PANEL_ORIENTATION_RIGHT_UP, "Right Side Up" },
};

+static const struct drm_prop_enum_list drm_privacy_screen_enum_list[] = {
+ { DRM_PRIVACY_SCREEN_DISABLED, "Disabled" },
+ { DRM_PRIVACY_SCREEN_ENABLED, "Enabled" },
+};
+
static const struct drm_prop_enum_list drm_dvi_i_select_enum_list[] = {
{ DRM_MODE_SUBCONNECTOR_Automatic, "Automatic" }, /* DVI-I and TV-out */
{ DRM_MODE_SUBCONNECTOR_DVID, "DVI-D" }, /* DVI-I */
@@ -2253,6 +2258,39 @@ static void drm_tile_group_free(struct kref *kref)
kfree(tg);
}

+/**
+ * drm_connector_init_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.
+ *
+ * Returns:
+ * Zero on success, negative errno on failure.
+ */
+int drm_connector_init_privacy_screen_property(struct drm_connector *connector)
+{
+ struct drm_device *dev = connector->dev;
+ struct drm_property *prop;
+
+ prop = dev->mode_config.privacy_screen_property;
+ if (!prop) {
+ prop = drm_property_create_enum(dev, DRM_MODE_PROP_ENUM,
+ "privacy-screen", drm_privacy_screen_enum_list,
+ ARRAY_SIZE(drm_privacy_screen_enum_list));
+ if (!prop)
+ return -ENOMEM;
+
+ dev->mode_config.privacy_screen_property = prop;
+ }
+
+ drm_object_attach_property(&connector->base, prop,
+ DRM_PRIVACY_SCREEN_DISABLED);
+ return 0;
+}
+EXPORT_SYMBOL(drm_connector_init_privacy_screen_property);
+
/**
* drm_mode_put_tile_group - drop a reference to a tile group.
* @dev: DRM device
diff --git a/drivers/gpu/drm/drm_privacy_screen.c b/drivers/gpu/drm/drm_privacy_screen.c
new file mode 100644
index 000000000000..1d68e8aa6c5f
--- /dev/null
+++ b/drivers/gpu/drm/drm_privacy_screen.c
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DRM privacy Screen code
+ *
+ * Copyright © 2019 Google Inc.
+ */
+
+#include <linux/acpi.h>
+#include <linux/pci.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+
+#define DRM_CONN_DSM_REVID 1
+
+#define DRM_CONN_DSM_FN_PRIVACY_GET_STATUS 1
+#define DRM_CONN_DSM_FN_PRIVACY_ENABLE 2
+#define DRM_CONN_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 or get privacy screen. Return
+ * value matters only for PRIVACY_GET_STATUS case. Returns 0 if disabled, 1 if
+ * enabled.
+ */
+static int acpi_privacy_screen_call_dsm(acpi_handle conn_handle, u64 func)
+{
+ union acpi_object *obj;
+ int ret = 0;
+
+ obj = acpi_evaluate_dsm(conn_handle, &drm_conn_dsm_guid,
+ DRM_CONN_DSM_REVID, func, NULL);
+ if (!obj) {
+ DRM_DEBUG_DRIVER("failed to evaluate _DSM for fn %llx\n", func);
+ /* Can't do much. For get_val, assume privacy_screen disabled */
+ goto done;
+ }
+
+ if (func == DRM_CONN_DSM_FN_PRIVACY_GET_STATUS &&
+ obj->type == ACPI_TYPE_INTEGER)
+ ret = !!obj->integer.value;
+done:
+ ACPI_FREE(obj);
+ return ret;
+}
+
+void drm_privacy_screen_set_val(struct drm_connector *connector,
+ enum drm_privacy_screen val)
+{
+ acpi_handle acpi_handle = connector->privacy_screen_handle;
+
+ if (!acpi_handle)
+ return;
+
+ if (val == DRM_PRIVACY_SCREEN_DISABLED)
+ acpi_privacy_screen_call_dsm(acpi_handle,
+ DRM_CONN_DSM_FN_PRIVACY_DISABLE);
+ else if (val == DRM_PRIVACY_SCREEN_ENABLED)
+ acpi_privacy_screen_call_dsm(acpi_handle,
+ DRM_CONN_DSM_FN_PRIVACY_ENABLE);
+}
+
+enum drm_privacy_screen drm_privacy_screen_get_val(struct drm_connector
+ *connector)
+{
+ acpi_handle acpi_handle = connector->privacy_screen_handle;
+
+ if (acpi_handle &&
+ acpi_privacy_screen_call_dsm(acpi_handle,
+ DRM_CONN_DSM_FN_PRIVACY_GET_STATUS))
+ return DRM_PRIVACY_SCREEN_ENABLED;
+
+ return DRM_PRIVACY_SCREEN_DISABLED;
+}
+
+/*
+ * See ACPI Spec v6.3, Table B-2, "Display Type" for details.
+ * In short, these macros define the base _ADR values for ACPI nodes
+ */
+#define ACPI_BASE_ADR_FOR_OTHERS (0ULL << 8)
+#define ACPI_BASE_ADR_FOR_VGA (1ULL << 8)
+#define ACPI_BASE_ADR_FOR_TV (2ULL << 8)
+#define ACPI_BASE_ADR_FOR_EXT_MON (3ULL << 8)
+#define ACPI_BASE_ADR_FOR_INTEGRATED (4ULL << 8)
+
+#define ACPI_DEVICE_ID_SCHEME (1ULL << 31)
+#define ACPI_FIRMWARE_CAN_DETECT (1ULL << 16)
+
+/*
+ * Ref: ACPI Spec 6.3
+ * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
+ * Pages 1119 - 1123 describe, what I believe, a standard way of
+ * identifying / addressing "display panels" in the ACPI. Thus it provides
+ * a way for the ACPI to define devices for the display panels attached
+ * to the system. It thus provides a way for the BIOS to export any panel
+ * specific properties to the system via ACPI (like device trees).
+ *
+ * The following function looks up the ACPI node for a connector and links
+ * to it. Technically it is independent from the privacy_screen code, and
+ * ideally may be called for all connectors. It is generally a good idea to
+ * be able to attach an ACPI node to describe anything if needed. (This can
+ * help in future for other panel specific features maybe). However, it
+ * needs a "port index" which I believe is the index within a particular
+ * type of port (Ref to the pages of spec mentioned above). This port index
+ * unfortunately is not available in DRM code, so currently its call is
+ * originated from i915 driver.
+ */
+static int drm_connector_attach_acpi_node(struct drm_connector *connector,
+ u8 port_index)
+{
+ struct device *dev = &connector->dev->pdev->dev;
+ struct acpi_device *conn_dev;
+ u64 conn_addr;
+
+ /*
+ * Determine what _ADR to look for, depending on device type and
+ * port number. Potentially we only care about the
+ * eDP / integrated displays?
+ */
+ switch (connector->connector_type) {
+ case DRM_MODE_CONNECTOR_eDP:
+ conn_addr = ACPI_BASE_ADR_FOR_INTEGRATED + port_index;
+ break;
+ case DRM_MODE_CONNECTOR_VGA:
+ conn_addr = ACPI_BASE_ADR_FOR_VGA + port_index;
+ break;
+ case DRM_MODE_CONNECTOR_TV:
+ conn_addr = ACPI_BASE_ADR_FOR_TV + port_index;
+ break;
+ case DRM_MODE_CONNECTOR_DisplayPort:
+ conn_addr = ACPI_BASE_ADR_FOR_EXT_MON + port_index;
+ break;
+ default:
+ return -ENOTSUPP;
+ }
+
+ conn_addr |= ACPI_DEVICE_ID_SCHEME;
+ conn_addr |= ACPI_FIRMWARE_CAN_DETECT;
+
+ DRM_DEV_DEBUG(dev, "%s: Finding drm_connector ACPI node at _ADR=%llX\n",
+ __func__, conn_addr);
+
+ /* Look up the connector device, under the PCI device */
+ conn_dev = acpi_find_child_device(ACPI_COMPANION(dev),
+ conn_addr, false);
+ if (!conn_dev)
+ return -ENODEV;
+
+ connector->privacy_screen_handle = conn_dev->handle;
+ return 0;
+}
+
+bool drm_privacy_screen_present(struct drm_connector *connector, u8 port_index)
+{
+ acpi_handle handle;
+
+ if (drm_connector_attach_acpi_node(connector, port_index))
+ return false;
+
+ handle = connector->privacy_screen_handle;
+ if (!acpi_check_dsm(handle, &drm_conn_dsm_guid,
+ DRM_CONN_DSM_REVID,
+ 1 << DRM_CONN_DSM_FN_PRIVACY_GET_STATUS |
+ 1 << DRM_CONN_DSM_FN_PRIVACY_ENABLE |
+ 1 << DRM_CONN_DSM_FN_PRIVACY_DISABLE)) {
+ DRM_WARN("%s: Odd, connector ACPI node but no privacy scrn?\n",
+ connector->dev->dev);
+ return false;
+ }
+ DRM_DEV_INFO(connector->dev->dev, "supports privacy screen\n");
+ return true;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 57e9f0ba331b..3ff3962d27db 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -39,6 +39,7 @@
#include <drm/drm_dp_helper.h>
#include <drm/drm_edid.h>
#include <drm/drm_hdcp.h>
+#include <drm/drm_privacy_screen.h>
#include <drm/drm_probe_helper.h>
#include <drm/i915_drm.h>

@@ -6354,6 +6355,8 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect

connector->state->scaling_mode = DRM_MODE_SCALE_ASPECT;

+ if (drm_privacy_screen_present(connector, port - PORT_A))
+ drm_connector_init_privacy_screen_property(connector);
}
}

diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 681cb590f952..63b8318bd68c 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -225,6 +225,20 @@ enum drm_link_status {
DRM_LINK_STATUS_BAD = DRM_MODE_LINK_STATUS_BAD,
};

+/**
+ * enum drm_privacy_screen - privacy_screen status
+ *
+ * This enum is used to track and control the state of the privacy screen.
+ * There are no separate #defines for the uapi!
+ *
+ * @DRM_PRIVACY_SCREEN_DISABLED: The privacy-screen on the panel is disabled
+ * @DRM_PRIVACY_SCREEN_ENABLED: The privacy-screen on the panel is enabled
+ */
+enum drm_privacy_screen {
+ DRM_PRIVACY_SCREEN_DISABLED = 0,
+ DRM_PRIVACY_SCREEN_ENABLED = 1,
+};
+
/**
* enum drm_panel_orientation - panel_orientation info for &drm_display_info
*
@@ -1410,6 +1424,9 @@ struct drm_connector {

/** @hdr_sink_metadata: HDR Metadata Information read from sink */
struct hdr_sink_metadata hdr_sink_metadata;
+
+ /* Handle used by privacy screen code */
+ void *privacy_screen_handle;
};

#define obj_to_connector(x) container_of(x, struct drm_connector, base)
@@ -1543,6 +1560,7 @@ int drm_connector_init_panel_orientation_property(
struct drm_connector *connector, int width, int height);
int drm_connector_attach_max_bpc_property(struct drm_connector *connector,
int min, int max);
+int drm_connector_init_privacy_screen_property(struct drm_connector *connector);

/**
* struct drm_tile_group - Tile group metadata
diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h
index 3bcbe30339f0..6d5d23da90d4 100644
--- a/include/drm/drm_mode_config.h
+++ b/include/drm/drm_mode_config.h
@@ -813,6 +813,13 @@ struct drm_mode_config {
*/
struct drm_property *panel_orientation_property;

+ /**
+ * @privacy_screen_property: Optional connector property to indicate
+ * and control the state (enabled / disabled) of privacy-screen on the
+ * panel, if present.
+ */
+ struct drm_property *privacy_screen_property;
+
/**
* @writeback_fb_id_property: Property for writeback connectors, storing
* the ID of the output framebuffer.
diff --git a/include/drm/drm_privacy_screen.h b/include/drm/drm_privacy_screen.h
new file mode 100644
index 000000000000..c589bbc47656
--- /dev/null
+++ b/include/drm/drm_privacy_screen.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright © 2019 Google Inc.
+ */
+
+#ifndef __DRM_PRIVACY_SCREEN_H__
+#define __DRM_PRIVACY_SCREEN_H__
+
+#ifdef CONFIG_ACPI
+bool drm_privacy_screen_present(struct drm_connector *connector, u8 port);
+void drm_privacy_screen_set_val(struct drm_connector *connector,
+ enum drm_privacy_screen val);
+enum drm_privacy_screen drm_privacy_screen_get_val(struct drm_connector
+ *connector);
+#else
+static inline bool drm_privacy_screen_present(struct drm_connector *connector,
+ u8 port)
+{
+ return false;
+}
+
+void drm_privacy_screen_set_val(struct drm_connector *connector,
+ enum drm_privacy_screen val)
+{ }
+
+enum drm_privacy_screen drm_privacy_screen_get_val(
+ struct drm_connector *connector)
+{
+ return DRM_PRIVACY_SCREEN_DISABLED;
+}
+#endif /* CONFIG_ACPI */
+
+#endif /* __DRM_PRIVACY_SCREEN_H__ */
--
2.23.0.866.gb869b98d4c-goog

2019-10-23 12:38:13

by Daniel Vetter

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2019-10-25 18:59:50

HI Jani,

On Thu, Dec 5, 2019 at 1:34 AM Rajat Jain <[email protected]> wrote:
>
> On Wed, Nov 20, 2019 at 7:04 AM Jani Nikula <[email protected]> wrote:
> >
> > On Mon, 04 Nov 2019, Rajat Jain <[email protected]> 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 <[email protected]>
> > > Change-Id: Ic9ff07fc4a50797d2d0dfb919f11aa0821a4b548
> > > ---
> > > 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-$(CONFIG_ACPI) += \
> > > display/intel_acpi.o \
> > > - display/intel_opregion.o
> > > + display/intel_opregion.o \
> > > + display/intel_privacy_screen.o
> >
> > Mmmh, wonder if there'll be non-ACPI based privacy screens. I guess we
> > can sort this out then. *shrug*
> >
> > > i915-$(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);
> > > +}
> >
> > I think this should be a drm core level property in drm_connector.[ch]
> > so that *all* drivers would use the same thing for privacy screens. Not
> > i915 specific.
> >
> > I think this is the biggest issue in the patch series.
>
> I actually would be happy to make it a drm_connector property, like I
> had in my original patch series. I changed it to i915 specific because
> it seemed to me based on the comments that the general sentiment is
> that anything to do with acpi should be in i915.
>
> Note that the privacy screen property essentially needs an ACPI handle
> to work on, so if I were to move the property into drm_connector, I'd
> likely rename the intel_privacy_screen* code to drm_privacy_screen*
> code, and it'll still operate on an ACPI handle (stored in
> drm_connector structure). The i915's job will then be to lookup that
> ACPI handle (because lookup requires display index) and populate it in
> drm_connector. Does this sound OK?

Wondering if you ever got my email. I found out this week that I
needed to be a member of intel-gfx mailing list otherwise my patches
won't show up on patchwork.freedesktop.org. I'm now a member, and I
have posted my latest patchset at:

https://patchwork.freedesktop.org/patch/346275/

I'd appreciate if you could please review and comment and provide your
valuable suggestions.

Thanks & Best Regards,

Rajat

>
> >
> > > 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
> >
> > Please read http://mid.mail-archive.com/CAKMK7uH-8+tbKsAoiChsxELEc_77RVVxP2wapHWhqB+0Viifog@mail.gmail.com
>
> OK, I changed it to SPDX-License-Identifier: GPL-2.0 OR MIT
>
>
> >
> > > +/*
> > > + * 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)
> >
> > Just name the parameter connector, not intel_connector. This throughout.
>
> Done.
>
> >
> > > +{
> > > + 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);
> >
> > else complain?
> >
>
> Done.
>
> > > +}
> > > +
> > > +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,
> > > +};
> > > +
> >
> > The drm_property interface UAPI is based on the strings, *not* on the
> > values. Please move the enum out of uapi into the drm code.
>
> Oh, so we don't have to expose this to userspace? Understand, so I
> moved it to intel_display_types.h
>
> Thanks,
>
> Rajat.
>
>
> >
> > BR,
> > jani.
> >
> > > #if defined(__cplusplus)
> > > }
> > > #endif
> >
> > --
> > Jani Nikula, Intel Open Source Graphics Center