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 |
13 | static struct drm_privacy_screen_lookup arch_lookup; |
14 | |
15 | struct arch_init_data { |
16 | struct drm_privacy_screen_lookup lookup; |
17 | bool (*detect)(void); |
18 | }; |
19 | |
20 | #if IS_ENABLED(CONFIG_THINKPAD_ACPI) |
21 | static 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 | |
28 | static 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(HID: "PNP0C09" , user_function: acpi_set_handle, NULL, return_value: &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(handle: ec_handle, pathname: "HKEY.GSSS" , arguments: &args, data: &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) |
54 | static bool __init detect_chromeos_privacy_screen(void) |
55 | { |
56 | return acpi_dev_present(hid: "GOOG0010" , NULL, hrv: -1); |
57 | } |
58 | #endif |
59 | |
60 | static 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 | |
83 | void __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(lookup: &arch_lookup); |
97 | break; |
98 | } |
99 | } |
100 | |
101 | void drm_privacy_screen_lookup_exit(void) |
102 | { |
103 | if (arch_lookup.provider) |
104 | drm_privacy_screen_lookup_remove(lookup: &arch_lookup); |
105 | } |
106 | #endif /* ifdef CONFIG_X86 */ |
107 | |