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