[PATCH v9 4/5] drm/i915: Add helper code for ACPI privacy screen
From: Rajat Jain
Date: Thu Mar 12 2020 - 14:56:50 EST
Add helper functions that can allow i915 to detect and control
an integrated privacy screen via ACPI methods. These shall be used
in the next patch.
Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx>
---
v9: same as v8
v8: Initial version. formed by refactoring the previous patch 4.
print the connector name in the debug messages.
drivers/gpu/drm/i915/Makefile | 3 +-
.../drm/i915/display/intel_privacy_screen.c | 184 ++++++++++++++++++
.../drm/i915/display/intel_privacy_screen.h | 27 +++
3 files changed, 213 insertions(+), 1 deletion(-)
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 9f887a86e555d..da42389107f9c 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -209,7 +209,8 @@ i915-y += \
display/intel_vga.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_privacy_screen.c b/drivers/gpu/drm/i915/display/intel_privacy_screen.c
new file mode 100644
index 0000000000000..66039103c821b
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_privacy_screen.c
@@ -0,0 +1,184 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Intel ACPI privacy screen code
+ *
+ * Copyright  2020 Google Inc.
+ *
+ * This code can help detect and control an integrated EPS (electronic
+ * privacy screen) via ACPI functions. It expects an ACPI node for the
+ * drm connector device with the following elements:
+ *
+ * UUID should be "c7033113-8720-4ceb-9090-9d52b3e52d73"
+ *
+ * _ADR = ACPI address per Spec (also see intel_acpi_device_id_update())
+ * https://uefi.org/sites/default/files/resources/ACPI_6_3_final_Jan30.pdf
+ * Pages 1119 - 1123.
+ *
+ * _DSM method that will perform the following functions according to
+ * Local1 argument passed to it:
+ * - Local1 = 0 (EPS capabilities): Report EPS presence and capabilities.
+ * - Local1 = 1 (EPS State) : _DSM returns 1 if EPS is enabled, 0 otherwise.
+ * - Local1 = 2 (EPS Enable) : _DSM enables EPS
+ * - Local1 = 3 (EPS Disable): _DSM disables EPS
+ *
+ * Here is a sample ACPI node:
+ *
+ * Scope (\_SB.PCI0.GFX0) // Intel graphics device (PCI device)
+ * {
+ * Method (_DOD, 0, NotSerialized) // _DOD: Display Output Devices
+ * {
+ * Return (Package (0x01)
+ * {
+ * 0x80010400
+ * })
+ * }
+ *
+ * Device (LCD)
+ * {
+ * Name (_ADR, 0x80010400) // _ADR: Address
+ * Name (_STA, 0x0F) // _STA: Status
+ *
+ * Method (EPSP, 0, NotSerialized) // EPS Present
+ * {
+ * Return (0x01)
+ * }
+ *
+ * Method (EPSS, 0, NotSerialized) // EPS State
+ * {
+ * Local0 = \_SB.PCI0.GRXS (0xCD)
+ * Return (Local0)
+ * }
+ *
+ * Method (EPSE, 0, NotSerialized) // EPS Enable
+ * {
+ * \_SB.PCI0.STXS (0xCD)
+ * }
+ *
+ * Method (EPSD, 0, NotSerialized) // EPS Disable
+ * {
+ * \_SB.PCI0.CTXS (0xCD)
+ * }
+ *
+ * Method (_DSM, 4, Serialized) // _DSM: Device-Specific Method
+ * {
+ * ToBuffer (Arg0, Local0)
+ * If ((Local0 == ToUUID ("c7033113-8720-4ceb-9090-9d52b3e52d73")))
+ * {
+ * ToInteger (Arg2, Local1)
+ * If ((Local1 == Zero))
+ * {
+ * Local2 = EPSP ()
+ * If ((Local2 == One))
+ * {
+ * Return (Buffer (One)
+ * {
+ * 0x0F
+ * })
+ * }
+ * }
+ *
+ * If ((Local1 == One))
+ * {
+ * Return (EPSS ())
+ * }
+ *
+ * If ((Local1 == 0x02))
+ * {
+ * EPSE ()
+ * }
+ *
+ * If ((Local1 == 0x03))
+ * {
+ * EPSD ()
+ * }
+ *
+ * Return (Buffer (One)
+ * {
+ * 0x00
+ * })
+ * }
+ *
+ * Return (Buffer (One)
+ * {
+ * 0x00
+ * })
+ * }
+ * }
+ * }
+ */
+
+#include <linux/acpi.h>
+
+#include "intel_privacy_screen.h"
+
+#define CONN_NAME(conn) \
+ (conn->base.kdev ? dev_name(conn->base.kdev) : "NONAME")
+
+#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(struct intel_connector *connector,
+ u64 func)
+{
+ union acpi_object *obj;
+ acpi_handle acpi_handle = connector->acpi_handle;
+ struct drm_device *drm = connector->base.dev;
+
+ if (!acpi_handle)
+ return;
+
+ obj = acpi_evaluate_dsm(acpi_handle, &drm_conn_dsm_guid,
+ CONNECTOR_DSM_REVID, func, NULL);
+ if (!obj) {
+ drm_err(drm, "%s: failed to evaluate _DSM for fn %llx\n",
+ CONN_NAME(connector), func);
+ return;
+ }
+
+ ACPI_FREE(obj);
+}
+
+void intel_privacy_screen_set_val(struct intel_connector *connector,
+ enum drm_privacy_screen_status val)
+{
+ struct drm_device *drm = connector->base.dev;
+
+ if (val == PRIVACY_SCREEN_DISABLED) {
+ drm_dbg_kms(drm, "%s: disabling privacy-screen\n",
+ CONN_NAME(connector));
+ acpi_privacy_screen_call_dsm(connector,
+ CONNECTOR_DSM_FN_PRIVACY_DISABLE);
+ } else {
+ drm_dbg_kms(drm, "%s: enabling privacy-screen\n",
+ CONN_NAME(connector));
+ acpi_privacy_screen_call_dsm(connector,
+ CONNECTOR_DSM_FN_PRIVACY_ENABLE);
+ }
+}
+
+bool intel_privacy_screen_present(struct intel_connector *connector)
+{
+ acpi_handle handle = connector->acpi_handle;
+ struct drm_device *drm = connector->base.dev;
+
+ if (handle &&
+ acpi_check_dsm(handle, &drm_conn_dsm_guid,
+ CONNECTOR_DSM_REVID,
+ 1 << CONNECTOR_DSM_FN_PRIVACY_ENABLE |
+ 1 << CONNECTOR_DSM_FN_PRIVACY_DISABLE)) {
+ drm_info(drm, "%s: supports ACPI privacy-screen\n",
+ CONN_NAME(connector));
+ return true;
+ }
+
+ drm_dbg_kms(drm, "%s: doesn't support ACPI privacy-screen\n",
+ CONN_NAME(connector));
+ return false;
+}
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 0000000000000..8655745ff9085
--- /dev/null
+++ b/drivers/gpu/drm/i915/display/intel_privacy_screen.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/*
+ * Copyright  2020 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 *connector);
+void intel_privacy_screen_set_val(struct intel_connector *connector,
+ enum drm_privacy_screen_status val);
+#else
+static bool intel_privacy_screen_present(struct intel_connector *connector)
+{
+ return false;
+}
+
+static void
+intel_privacy_screen_set_val(struct intel_connector *connector,
+ enum drm_privacy_screen_status val)
+{ }
+#endif /* CONFIG_ACPI */
+
+#endif /* __DRM_PRIVACY_SCREEN_H__ */
--
2.25.1.481.gfbce0eb801-goog