1 files changed, 86 insertions, 0 deletions
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..a2cafb294ca6
--- /dev/null
+++ b/drivers/gpu/drm/drm_privacy_screen_x86.c
@@ -0,0 +1,86 @@
+// 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>
+
+#ifdef CONFIG_X86
+static struct drm_privacy_screen_lookup arch_lookup;
+
+struct arch_init_data {
+	struct drm_privacy_screen_lookup lookup;
+	bool (*detect)(void);
+};
+
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+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;
+}
+#endif
+
+static const struct arch_init_data arch_init_data[] __initconst = {
+#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
+	{
+		.lookup = {
+			.dev_id = NULL,
+			.con_id = NULL,
+			.provider = "privacy_screen-thinkpad_acpi",
+		},
+		.detect = detect_thinkpad_privacy_screen,
+	},
+#endif
+};
+
+void __init drm_privacy_screen_lookup_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 drm_privacy_screen_lookup_exit(void)
+{
+	if (arch_lookup.provider)
+		drm_privacy_screen_lookup_remove(&arch_lookup);
+}
+#endif /* ifdef CONFIG_X86 */