drivers/gpu/drm/i915/intel_acpi.c

   1 /*
   2  * Intel ACPI functions
   3  *
   4  * _DSM related code stolen from nouveau_acpi.c.
   5  */
   6 #include <linux/pci.h>
   7 #include <linux/acpi.h>
   8 #include <drm/drmP.h>
   9 #include "i915_drv.h"
  10
  11 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
  12 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
  13
  14 static struct intel_dsm_priv {
  15         acpi_handle dhandle;
  16 } intel_dsm_priv;
  17
  18 static const guid_t intel_dsm_guid =
  19         GUID_INIT(0x7ed873d3, 0xc2d0, 0x4e4f,
  20                   0xa8, 0x54, 0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c);
  21
  22 static char *intel_dsm_port_name(u8 id)
  23 {
  24         switch (id) {
  25         case 0:
  26                 return "Reserved";
  27         case 1:
  28                 return "Analog VGA";
  29         case 2:
  30                 return "LVDS";
  31         case 3:
  32                 return "Reserved";
  33         case 4:
  34                 return "HDMI/DVI_B";
  35         case 5:
  36                 return "HDMI/DVI_C";
  37         case 6:
  38                 return "HDMI/DVI_D";
  39         case 7:
  40                 return "DisplayPort_A";
  41         case 8:
  42                 return "DisplayPort_B";
  43         case 9:
  44                 return "DisplayPort_C";
  45         case 0xa:
  46                 return "DisplayPort_D";
  47         case 0xb:
  48         case 0xc:
  49         case 0xd:
  50                 return "Reserved";
  51         case 0xe:
  52                 return "WiDi";
  53         default:
  54                 return "bad type";
  55         }
  56 }
  57
  58 static char *intel_dsm_mux_type(u8 type)
  59 {
  60         switch (type) {
  61         case 0:
  62                 return "unknown";
  63         case 1:
  64                 return "No MUX, iGPU only";
  65         case 2:
  66                 return "No MUX, dGPU only";
  67         case 3:
  68                 return "MUXed between iGPU and dGPU";
  69         default:
  70                 return "bad type";
  71         }
  72 }
  73
  74 static void intel_dsm_platform_mux_info(void)
  75 {
  76         int i;
  77         union acpi_object *pkg, *connector_count;
  78
  79         pkg = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, &intel_dsm_guid,
  80                         INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
  81                         NULL, ACPI_TYPE_PACKAGE);
  82         if (!pkg) {
  83                 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
  84                 return;
  85         }
  86
  87         connector_count = &pkg->package.elements[0];
  88         DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
  89                   (unsigned long long)connector_count->integer.value);
  90         for (i = 1; i < pkg->package.count; i++) {
  91                 union acpi_object *obj = &pkg->package.elements[i];
  92                 union acpi_object *connector_id = &obj->package.elements[0];
  93                 union acpi_object *info = &obj->package.elements[1];
  94                 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
  95                           (unsigned long long)connector_id->integer.value);
  96                 DRM_DEBUG_DRIVER("  port id: %s\n",
  97                        intel_dsm_port_name(info->buffer.pointer[0]));
  98                 DRM_DEBUG_DRIVER("  display mux info: %s\n",
  99                        intel_dsm_mux_type(info->buffer.pointer[1]));
 100                 DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
 101                        intel_dsm_mux_type(info->buffer.pointer[2]));
 102                 DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
 103                        intel_dsm_mux_type(info->buffer.pointer[3]));
 104         }
 105
 106         ACPI_FREE(pkg);
 107 }
 108
 109 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
 110 {
 111         acpi_handle dhandle;
 112
 113         dhandle = ACPI_HANDLE(&pdev->dev);
 114         if (!dhandle)
 115                 return false;
 116
 117         if (!acpi_check_dsm(dhandle, &intel_dsm_guid, INTEL_DSM_REVISION_ID,
 118                             1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
 119                 DRM_DEBUG_KMS("no _DSM method for intel device\n");
 120                 return false;
 121         }
 122
 123         intel_dsm_priv.dhandle = dhandle;
 124         intel_dsm_platform_mux_info();
 125
 126         return true;
 127 }
 128
 129 static bool intel_dsm_detect(void)
 130 {
 131         char acpi_method_name[255] = { 0 };
 132         struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
 133         struct pci_dev *pdev = NULL;
 134         bool has_dsm = false;
 135         int vga_count = 0;
 136
 137         while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
 138                 vga_count++;
 139                 has_dsm |= intel_dsm_pci_probe(pdev);
 140         }
 141
 142         if (vga_count == 2 && has_dsm) {
 143                 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
 144                 DRM_DEBUG_DRIVER("vga_switcheroo: detected DSM switching method %s handle\n",
 145                                  acpi_method_name);
 146                 return true;
 147         }
 148
 149         return false;
 150 }
 151
 152 void intel_register_dsm_handler(void)
 153 {
 154         if (!intel_dsm_detect())
 155                 return;
 156 }
 157
 158 void intel_unregister_dsm_handler(void)
 159 {
 160 }