1 // SPDX-License-Identifier: GPL-2.0
5 * _DSM related code stolen from nouveau_acpi.c.
8 #include <linux/acpi.h>
11 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
12 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
14 static const guid_t intel_dsm_guid =
15 GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f,
16 0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c);
18 static char *intel_dsm_port_name(u8 id)
36 return "DisplayPort_A";
38 return "DisplayPort_B";
40 return "DisplayPort_C";
42 return "DisplayPort_D";
54 static char *intel_dsm_mux_type(u8 type)
60 return "No MUX, iGPU only";
62 return "No MUX, dGPU only";
64 return "MUXed between iGPU and dGPU";
70 static void intel_dsm_platform_mux_info(acpi_handle dhandle)
73 union acpi_object *pkg, *connector_count;
75 pkg = acpi_evaluate_dsm_typed(dhandle, &intel_dsm_guid,
76 INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
77 NULL, ACPI_TYPE_PACKAGE);
79 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
83 connector_count = &pkg->package.elements[0];
84 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
85 (unsigned long long)connector_count->integer.value);
86 for (i = 1; i < pkg->package.count; i++) {
87 union acpi_object *obj = &pkg->package.elements[i];
88 union acpi_object *connector_id = &obj->package.elements[0];
89 union acpi_object *info = &obj->package.elements[1];
90 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
91 (unsigned long long)connector_id->integer.value);
92 DRM_DEBUG_DRIVER(" port id: %s\n",
93 intel_dsm_port_name(info->buffer.pointer[0]));
94 DRM_DEBUG_DRIVER(" display mux info: %s\n",
95 intel_dsm_mux_type(info->buffer.pointer[1]));
96 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n",
97 intel_dsm_mux_type(info->buffer.pointer[2]));
98 DRM_DEBUG_DRIVER(" hpd mux info: %s\n",
99 intel_dsm_mux_type(info->buffer.pointer[3]));
105 static acpi_handle intel_dsm_pci_probe(struct pci_dev *pdev)
109 dhandle = ACPI_HANDLE(&pdev->dev);
113 if (!acpi_check_dsm(dhandle, &intel_dsm_guid, INTEL_DSM_REVISION_ID,
114 1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
115 DRM_DEBUG_KMS("no _DSM method for intel device\n");
119 intel_dsm_platform_mux_info(dhandle);
124 static bool intel_dsm_detect(void)
126 acpi_handle dhandle = NULL;
127 char acpi_method_name[255] = { 0 };
128 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
129 struct pci_dev *pdev = NULL;
132 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
134 dhandle = intel_dsm_pci_probe(pdev) ?: dhandle;
137 if (vga_count == 2 && dhandle) {
138 acpi_get_name(dhandle, ACPI_FULL_PATHNAME, &buffer);
139 DRM_DEBUG_DRIVER("vga_switcheroo: detected DSM switching method %s handle\n",
147 void intel_register_dsm_handler(void)
149 if (!intel_dsm_detect())
153 void intel_unregister_dsm_handler(void)