1// SPDX-License-Identifier: MIT
2/*
3 * Copyright (C) 2020 Red Hat, Inc.
4 *
5 * Authors:
6 * Hans de Goede <hdegoede@redhat.com>
7 */
8
9#include <linux/acpi.h>
10#include <drm/drm_privacy_screen_machine.h>
11
12#ifdef CONFIG_X86
13static struct drm_privacy_screen_lookup arch_lookup;
14
15struct arch_init_data {
16	struct drm_privacy_screen_lookup lookup;
17	bool (*detect)(void);
18};
19
20#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
21static acpi_status __init acpi_set_handle(acpi_handle handle, u32 level,
22					  void *context, void **return_value)
23{
24	*(acpi_handle *)return_value = handle;
25	return AE_CTRL_TERMINATE;
26}
27
28static bool __init detect_thinkpad_privacy_screen(void)
29{
30	union acpi_object obj = { .type = ACPI_TYPE_INTEGER };
31	struct acpi_object_list args = { .count = 1, .pointer = &obj, };
32	acpi_handle ec_handle = NULL;
33	unsigned long long output;
34	acpi_status status;
35
36	if (acpi_disabled)
37		return false;
38
39	/* Get embedded-controller handle */
40	status = acpi_get_devices("PNP0C09", acpi_set_handle, NULL, &ec_handle);
41	if (ACPI_FAILURE(status) || !ec_handle)
42		return false;
43
44	/* And call the privacy-screen get-status method */
45	status = acpi_evaluate_integer(ec_handle, "HKEY.GSSS", &args, &output);
46	if (ACPI_FAILURE(status))
47		return false;
48
49	return (output & 0x10000) ? true : false;
50}
51#endif
52
53#if IS_ENABLED(CONFIG_CHROMEOS_PRIVACY_SCREEN)
54static bool __init detect_chromeos_privacy_screen(void)
55{
56	return acpi_dev_present("GOOG0010", NULL, -1);
57}
58#endif
59
60static const struct arch_init_data arch_init_data[] __initconst = {
61#if IS_ENABLED(CONFIG_THINKPAD_ACPI)
62	{
63		.lookup = {
64			.dev_id = NULL,
65			.con_id = NULL,
66			.provider = "privacy_screen-thinkpad_acpi",
67		},
68		.detect = detect_thinkpad_privacy_screen,
69	},
70#endif
71#if IS_ENABLED(CONFIG_CHROMEOS_PRIVACY_SCREEN)
72	{
73		.lookup = {
74			.dev_id = NULL,
75			.con_id = NULL,
76			.provider = "privacy_screen-GOOG0010:00",
77		},
78		.detect = detect_chromeos_privacy_screen,
79	},
80#endif
81};
82
83void __init drm_privacy_screen_lookup_init(void)
84{
85	int i;
86
87	for (i = 0; i < ARRAY_SIZE(arch_init_data); i++) {
88		if (!arch_init_data[i].detect())
89			continue;
90
91		pr_info("Found '%s' privacy-screen provider\n",
92			arch_init_data[i].lookup.provider);
93
94		/* Make a copy because arch_init_data is __initconst */
95		arch_lookup = arch_init_data[i].lookup;
96		drm_privacy_screen_lookup_add(&arch_lookup);
97		break;
98	}
99}
100
101void drm_privacy_screen_lookup_exit(void)
102{
103	if (arch_lookup.provider)
104		drm_privacy_screen_lookup_remove(&arch_lookup);
105}
106#endif /* ifdef CONFIG_X86 */
107