1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Intel ACPI functions
4 *
5 * _DSM related code stolen from nouveau_acpi.c.
6 */
7 #include <linux/pci.h>
8 #include <linux/acpi.h>
9 #include <drm/drmP.h>
10 #include "i915_drv.h"
11
12 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
13 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
14
15 static const guid_t intel_dsm_guid =
16 GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f,
17 0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c);
18
intel_dsm_port_name(u8 id)19 static char *intel_dsm_port_name(u8 id)
20 {
21 switch (id) {
22 case 0:
23 return "Reserved";
24 case 1:
25 return "Analog VGA";
26 case 2:
27 return "LVDS";
28 case 3:
29 return "Reserved";
30 case 4:
31 return "HDMI/DVI_B";
32 case 5:
33 return "HDMI/DVI_C";
34 case 6:
35 return "HDMI/DVI_D";
36 case 7:
37 return "DisplayPort_A";
38 case 8:
39 return "DisplayPort_B";
40 case 9:
41 return "DisplayPort_C";
42 case 0xa:
43 return "DisplayPort_D";
44 case 0xb:
45 case 0xc:
46 case 0xd:
47 return "Reserved";
48 case 0xe:
49 return "WiDi";
50 default:
51 return "bad type";
52 }
53 }
54
intel_dsm_mux_type(u8 type)55 static char *intel_dsm_mux_type(u8 type)
56 {
57 switch (type) {
58 case 0:
59 return "unknown";
60 case 1:
61 return "No MUX, iGPU only";
62 case 2:
63 return "No MUX, dGPU only";
64 case 3:
65 return "MUXed between iGPU and dGPU";
66 default:
67 return "bad type";
68 }
69 }
70
intel_dsm_platform_mux_info(acpi_handle dhandle)71 static void intel_dsm_platform_mux_info(acpi_handle dhandle)
72 {
73 int i;
74 union acpi_object *pkg, *connector_count;
75
76 pkg = acpi_evaluate_dsm_typed(dhandle, &intel_dsm_guid,
77 INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
78 NULL, ACPI_TYPE_PACKAGE);
79 if (!pkg) {
80 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
81 return;
82 }
83
84 connector_count = &pkg->package.elements[0];
85 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
86 (unsigned long long)connector_count->integer.value);
87 for (i = 1; i < pkg->package.count; i++) {
88 union acpi_object *obj = &pkg->package.elements[i];
89 union acpi_object *connector_id = &obj->package.elements[0];
90 union acpi_object *info = &obj->package.elements[1];
91 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
92 (unsigned long long)connector_id->integer.value);
93 DRM_DEBUG_DRIVER(" port id: %s\n",
94 intel_dsm_port_name(info->buffer.pointer[0]));
95 DRM_DEBUG_DRIVER(" display mux info: %s\n",
96 intel_dsm_mux_type(info->buffer.pointer[1]));
97 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n",
98 intel_dsm_mux_type(info->buffer.pointer[2]));
99 DRM_DEBUG_DRIVER(" hpd mux info: %s\n",
100 intel_dsm_mux_type(info->buffer.pointer[3]));
101 }
102
103 ACPI_FREE(pkg);
104 }
105
intel_dsm_pci_probe(struct pci_dev * pdev)106 static acpi_handle intel_dsm_pci_probe(struct pci_dev *pdev)
107 {
108 acpi_handle dhandle;
109
110 dhandle = ACPI_HANDLE(&pdev->dev);
111 if (!dhandle)
112 return NULL;
113
114 if (!acpi_check_dsm(dhandle, &intel_dsm_guid, INTEL_DSM_REVISION_ID,
115 1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
116 DRM_DEBUG_KMS("no _DSM method for intel device\n");
117 return NULL;
118 }
119
120 intel_dsm_platform_mux_info(dhandle);
121
122 return dhandle;
123 }
124
intel_dsm_detect(void)125 static bool intel_dsm_detect(void)
126 {
127 acpi_handle dhandle = NULL;
128 char acpi_method_name[255] = { 0 };
129 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
130 struct pci_dev *pdev = NULL;
131 int vga_count = 0;
132
133 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
134 vga_count++;
135 dhandle = intel_dsm_pci_probe(pdev) ?: dhandle;
136 }
137
138 if (vga_count == 2 && dhandle) {
139 acpi_get_name(dhandle, ACPI_FULL_PATHNAME, &buffer);
140 DRM_DEBUG_DRIVER("vga_switcheroo: detected DSM switching method %s handle\n",
141 acpi_method_name);
142 return true;
143 }
144
145 return false;
146 }
147
intel_register_dsm_handler(void)148 void intel_register_dsm_handler(void)
149 {
150 if (!intel_dsm_detect())
151 return;
152 }
153
intel_unregister_dsm_handler(void)154 void intel_unregister_dsm_handler(void)
155 {
156 }
157
