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 struct intel_dsm_priv {
16 acpi_handle dhandle;
17 } intel_dsm_priv;
18
19 static const guid_t intel_dsm_guid =
20 GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f,
21 0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c);
22
intel_dsm_port_name(u8 id)23 static char *intel_dsm_port_name(u8 id)
24 {
25 switch (id) {
26 case 0:
27 return "Reserved";
28 case 1:
29 return "Analog VGA";
30 case 2:
31 return "LVDS";
32 case 3:
33 return "Reserved";
34 case 4:
35 return "HDMI/DVI_B";
36 case 5:
37 return "HDMI/DVI_C";
38 case 6:
39 return "HDMI/DVI_D";
40 case 7:
41 return "DisplayPort_A";
42 case 8:
43 return "DisplayPort_B";
44 case 9:
45 return "DisplayPort_C";
46 case 0xa:
47 return "DisplayPort_D";
48 case 0xb:
49 case 0xc:
50 case 0xd:
51 return "Reserved";
52 case 0xe:
53 return "WiDi";
54 default:
55 return "bad type";
56 }
57 }
58
intel_dsm_mux_type(u8 type)59 static char *intel_dsm_mux_type(u8 type)
60 {
61 switch (type) {
62 case 0:
63 return "unknown";
64 case 1:
65 return "No MUX, iGPU only";
66 case 2:
67 return "No MUX, dGPU only";
68 case 3:
69 return "MUXed between iGPU and dGPU";
70 default:
71 return "bad type";
72 }
73 }
74
intel_dsm_platform_mux_info(void)75 static void intel_dsm_platform_mux_info(void)
76 {
77 int i;
78 union acpi_object *pkg, *connector_count;
79
80 pkg = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, &intel_dsm_guid,
81 INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
82 NULL, ACPI_TYPE_PACKAGE);
83 if (!pkg) {
84 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
85 return;
86 }
87
88 connector_count = &pkg->package.elements[0];
89 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
90 (unsigned long long)connector_count->integer.value);
91 for (i = 1; i < pkg->package.count; i++) {
92 union acpi_object *obj = &pkg->package.elements[i];
93 union acpi_object *connector_id = &obj->package.elements[0];
94 union acpi_object *info = &obj->package.elements[1];
95 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
96 (unsigned long long)connector_id->integer.value);
97 DRM_DEBUG_DRIVER(" port id: %s\n",
98 intel_dsm_port_name(info->buffer.pointer[0]));
99 DRM_DEBUG_DRIVER(" display mux info: %s\n",
100 intel_dsm_mux_type(info->buffer.pointer[1]));
101 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n",
102 intel_dsm_mux_type(info->buffer.pointer[2]));
103 DRM_DEBUG_DRIVER(" hpd mux info: %s\n",
104 intel_dsm_mux_type(info->buffer.pointer[3]));
105 }
106
107 ACPI_FREE(pkg);
108 }
109
intel_dsm_pci_probe(struct pci_dev * pdev)110 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
111 {
112 acpi_handle dhandle;
113
114 dhandle = ACPI_HANDLE(&pdev->dev);
115 if (!dhandle)
116 return false;
117
118 if (!acpi_check_dsm(dhandle, &intel_dsm_guid, INTEL_DSM_REVISION_ID,
119 1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
120 DRM_DEBUG_KMS("no _DSM method for intel device\n");
121 return false;
122 }
123
124 intel_dsm_priv.dhandle = dhandle;
125 intel_dsm_platform_mux_info();
126
127 return true;
128 }
129
intel_dsm_detect(void)130 static bool intel_dsm_detect(void)
131 {
132 char acpi_method_name[255] = { 0 };
133 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
134 struct pci_dev *pdev = NULL;
135 bool has_dsm = false;
136 int vga_count = 0;
137
138 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
139 vga_count++;
140 has_dsm |= intel_dsm_pci_probe(pdev);
141 }
142
143 if (vga_count == 2 && has_dsm) {
144 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
145 DRM_DEBUG_DRIVER("vga_switcheroo: detected DSM switching method %s handle\n",
146 acpi_method_name);
147 return true;
148 }
149
150 return false;
151 }
152
intel_register_dsm_handler(void)153 void intel_register_dsm_handler(void)
154 {
155 if (!intel_dsm_detect())
156 return;
157 }
158
intel_unregister_dsm_handler(void)159 void intel_unregister_dsm_handler(void)
160 {
161 }
162