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)
acpi_set_handle(acpi_handle handle,u32 level,void * context,void ** return_value)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
detect_thinkpad_privacy_screen(void)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("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)
detect_chromeos_privacy_screen(void)54 static bool __init detect_chromeos_privacy_screen(void)
55 {
56 return acpi_dev_present("GOOG0010", NULL, -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
drm_privacy_screen_lookup_init(void)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(&arch_lookup);
97 break;
98 }
99 }
100
drm_privacy_screen_lookup_exit(void)101 void 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