1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Intel ACPI functions 4 * 5 * _DSM related code stolen from nouveau_acpi.c. 6 */ 7 8 #include <linux/pci.h> 9 #include <linux/acpi.h> 10 11 #include "i915_drv.h" 12 #include "intel_acpi.h" 13 14 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */ 15 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */ 16 17 static const guid_t intel_dsm_guid = 18 GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f, 19 0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c); 20 21 static char *intel_dsm_port_name(u8 id) 22 { 23 switch (id) { 24 case 0: 25 return "Reserved"; 26 case 1: 27 return "Analog VGA"; 28 case 2: 29 return "LVDS"; 30 case 3: 31 return "Reserved"; 32 case 4: 33 return "HDMI/DVI_B"; 34 case 5: 35 return "HDMI/DVI_C"; 36 case 6: 37 return "HDMI/DVI_D"; 38 case 7: 39 return "DisplayPort_A"; 40 case 8: 41 return "DisplayPort_B"; 42 case 9: 43 return "DisplayPort_C"; 44 case 0xa: 45 return "DisplayPort_D"; 46 case 0xb: 47 case 0xc: 48 case 0xd: 49 return "Reserved"; 50 case 0xe: 51 return "WiDi"; 52 default: 53 return "bad type"; 54 } 55 } 56 57 static char *intel_dsm_mux_type(u8 type) 58 { 59 switch (type) { 60 case 0: 61 return "unknown"; 62 case 1: 63 return "No MUX, iGPU only"; 64 case 2: 65 return "No MUX, dGPU only"; 66 case 3: 67 return "MUXed between iGPU and dGPU"; 68 default: 69 return "bad type"; 70 } 71 } 72 73 static void intel_dsm_platform_mux_info(acpi_handle dhandle) 74 { 75 int i; 76 union acpi_object *pkg, *connector_count; 77 78 pkg = acpi_evaluate_dsm_typed(dhandle, &intel_dsm_guid, 79 INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO, 80 NULL, ACPI_TYPE_PACKAGE); 81 if (!pkg) { 82 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n"); 83 return; 84 } 85 86 connector_count = &pkg->package.elements[0]; 87 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n", 88 (unsigned long long)connector_count->integer.value); 89 for (i = 1; i < pkg->package.count; i++) { 90 union acpi_object *obj = &pkg->package.elements[i]; 91 union acpi_object *connector_id = &obj->package.elements[0]; 92 union acpi_object *info = &obj->package.elements[1]; 93 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n", 94 (unsigned long long)connector_id->integer.value); 95 DRM_DEBUG_DRIVER(" port id: %s\n", 96 intel_dsm_port_name(info->buffer.pointer[0])); 97 DRM_DEBUG_DRIVER(" display mux info: %s\n", 98 intel_dsm_mux_type(info->buffer.pointer[1])); 99 DRM_DEBUG_DRIVER(" aux/dc mux info: %s\n", 100 intel_dsm_mux_type(info->buffer.pointer[2])); 101 DRM_DEBUG_DRIVER(" hpd mux info: %s\n", 102 intel_dsm_mux_type(info->buffer.pointer[3])); 103 } 104 105 ACPI_FREE(pkg); 106 } 107 108 static acpi_handle intel_dsm_pci_probe(struct pci_dev *pdev) 109 { 110 acpi_handle dhandle; 111 112 dhandle = ACPI_HANDLE(&pdev->dev); 113 if (!dhandle) 114 return NULL; 115 116 if (!acpi_check_dsm(dhandle, &intel_dsm_guid, INTEL_DSM_REVISION_ID, 117 1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) { 118 DRM_DEBUG_KMS("no _DSM method for intel device\n"); 119 return NULL; 120 } 121 122 intel_dsm_platform_mux_info(dhandle); 123 124 return dhandle; 125 } 126 127 static bool intel_dsm_detect(void) 128 { 129 acpi_handle dhandle = NULL; 130 char acpi_method_name[255] = { 0 }; 131 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name}; 132 struct pci_dev *pdev = NULL; 133 int vga_count = 0; 134 135 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) { 136 vga_count++; 137 dhandle = intel_dsm_pci_probe(pdev) ?: dhandle; 138 } 139 140 if (vga_count == 2 && dhandle) { 141 acpi_get_name(dhandle, ACPI_FULL_PATHNAME, &buffer); 142 DRM_DEBUG_DRIVER("vga_switcheroo: detected DSM switching method %s handle\n", 143 acpi_method_name); 144 return true; 145 } 146 147 return false; 148 } 149 150 void intel_register_dsm_handler(void) 151 { 152 if (!intel_dsm_detect()) 153 return; 154 } 155 156 void intel_unregister_dsm_handler(void) 157 { 158 } 159