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5
6#include <linux/pci.h>
7#include <linux/acpi.h>
8#include <linux/vga_switcheroo.h>
9#include <drm/drmP.h>
10#include "i915_drv.h"
11
12#define INTEL_DSM_REVISION_ID 1
13#define INTEL_DSM_FN_PLATFORM_MUX_INFO 1
14
15static struct intel_dsm_priv {
16 acpi_handle dhandle;
17} intel_dsm_priv;
18
19static const u8 intel_dsm_guid[] = {
20 0xd3, 0x73, 0xd8, 0x7e,
21 0xd0, 0xc2,
22 0x4f, 0x4e,
23 0xa8, 0x54,
24 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
25};
26
27static char *intel_dsm_port_name(u8 id)
28{
29 switch (id) {
30 case 0:
31 return "Reserved";
32 case 1:
33 return "Analog VGA";
34 case 2:
35 return "LVDS";
36 case 3:
37 return "Reserved";
38 case 4:
39 return "HDMI/DVI_B";
40 case 5:
41 return "HDMI/DVI_C";
42 case 6:
43 return "HDMI/DVI_D";
44 case 7:
45 return "DisplayPort_A";
46 case 8:
47 return "DisplayPort_B";
48 case 9:
49 return "DisplayPort_C";
50 case 0xa:
51 return "DisplayPort_D";
52 case 0xb:
53 case 0xc:
54 case 0xd:
55 return "Reserved";
56 case 0xe:
57 return "WiDi";
58 default:
59 return "bad type";
60 }
61}
62
63static char *intel_dsm_mux_type(u8 type)
64{
65 switch (type) {
66 case 0:
67 return "unknown";
68 case 1:
69 return "No MUX, iGPU only";
70 case 2:
71 return "No MUX, dGPU only";
72 case 3:
73 return "MUXed between iGPU and dGPU";
74 default:
75 return "bad type";
76 }
77}
78
79static void intel_dsm_platform_mux_info(void)
80{
81 int i;
82 union acpi_object *pkg, *connector_count;
83
84 pkg = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, intel_dsm_guid,
85 INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
86 NULL, ACPI_TYPE_PACKAGE);
87 if (!pkg) {
88 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
89 return;
90 }
91
92 connector_count = &pkg->package.elements[0];
93 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
94 (unsigned long long)connector_count->integer.value);
95 for (i = 1; i < pkg->package.count; i++) {
96 union acpi_object *obj = &pkg->package.elements[i];
97 union acpi_object *connector_id = &obj->package.elements[0];
98 union acpi_object *info = &obj->package.elements[1];
99 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
100 (unsigned long long)connector_id->integer.value);
101 DRM_DEBUG_DRIVER(" port id: %s\n",
102 intel_dsm_port_name(info->buffer.pointer[0]));
103 DRM_DEBUG_DRIVER(" display mux info: %s\n",
104 intel_dsm_mux_type(info->buffer.pointer[1]));
105 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n",
106 intel_dsm_mux_type(info->buffer.pointer[2]));
107 DRM_DEBUG_DRIVER(" hpd mux info: %s\n",
108 intel_dsm_mux_type(info->buffer.pointer[3]));
109 }
110
111 ACPI_FREE(pkg);
112}
113
114static bool intel_dsm_pci_probe(struct pci_dev *pdev)
115{
116 acpi_handle dhandle;
117
118 dhandle = ACPI_HANDLE(&pdev->dev);
119 if (!dhandle)
120 return false;
121
122 if (!acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
123 1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
124 DRM_DEBUG_KMS("no _DSM method for intel device\n");
125 return false;
126 }
127
128 intel_dsm_priv.dhandle = dhandle;
129 intel_dsm_platform_mux_info();
130
131 return true;
132}
133
134static bool intel_dsm_detect(void)
135{
136 char acpi_method_name[255] = { 0 };
137 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
138 struct pci_dev *pdev = NULL;
139 bool has_dsm = false;
140 int vga_count = 0;
141
142 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
143 vga_count++;
144 has_dsm |= intel_dsm_pci_probe(pdev);
145 }
146
147 if (vga_count == 2 && has_dsm) {
148 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
149 DRM_DEBUG_DRIVER("VGA switcheroo: detected DSM switching method %s handle\n",
150 acpi_method_name);
151 return true;
152 }
153
154 return false;
155}
156
157void intel_register_dsm_handler(void)
158{
159 if (!intel_dsm_detect())
160 return;
161}
162
163void intel_unregister_dsm_handler(void)
164{
165}
166
