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 <linux/vga_switcheroo.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 u8 intel_dsm_guid[] = {
  20         0xd3, 0x73, 0xd8, 0x7e,
  21         0xd0, 0xc2,
  22         0x4f, 0x4e,
  23         0xa8, 0x54,
  24         0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
  25 };
  26
  27 static char *intel_dsm_port_name(u8 id)
  28 {
  29         switch (id) {
  30         case 0:
  31                 return "Reserved";
  32         case 1:
  33                 return "Analog VGA";
  34         case 2:
  35                 return "LVDS";
  36         case 3:
  37                 return "Reserved";
  38         case 4:
  39                 return "HDMI/DVI_B";
  40         case 5:
  41                 return "HDMI/DVI_C";
  42         case 6:
  43                 return "HDMI/DVI_D";
  44         case 7:
  45                 return "DisplayPort_A";
  46         case 8:
  47                 return "DisplayPort_B";
  48         case 9:
  49                 return "DisplayPort_C";
  50         case 0xa:
  51                 return "DisplayPort_D";
  52         case 0xb:
  53         case 0xc:
  54         case 0xd:
  55                 return "Reserved";
  56         case 0xe:
  57                 return "WiDi";
  58         default:
  59                 return "bad type";
  60         }
  61 }
  62
  63 static char *intel_dsm_mux_type(u8 type)
  64 {
  65         switch (type) {
  66         case 0:
  67                 return "unknown";
  68         case 1:
  69                 return "No MUX, iGPU only";
  70         case 2:
  71                 return "No MUX, dGPU only";
  72         case 3:
  73                 return "MUXed between iGPU and dGPU";
  74         default:
  75                 return "bad type";
  76         }
  77 }
  78
  79 static void intel_dsm_platform_mux_info(void)
  80 {
  81         int i;
  82         union acpi_object *pkg, *connector_count;
  83
  84         pkg = acpi_evaluate_dsm_typed(intel_dsm_priv.dhandle, intel_dsm_guid,
  85                         INTEL_DSM_REVISION_ID, INTEL_DSM_FN_PLATFORM_MUX_INFO,
  86                         NULL, ACPI_TYPE_PACKAGE);
  87         if (!pkg) {
  88                 DRM_DEBUG_DRIVER("failed to evaluate _DSM\n");
  89                 return;
  90         }
  91
  92         connector_count = &pkg->package.elements[0];
  93         DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
  94                   (unsigned long long)connector_count->integer.value);
  95         for (i = 1; i < pkg->package.count; i++) {
  96                 union acpi_object *obj = &pkg->package.elements[i];
  97                 union acpi_object *connector_id = &obj->package.elements[0];
  98                 union acpi_object *info = &obj->package.elements[1];
  99                 DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
 100                           (unsigned long long)connector_id->integer.value);
 101                 DRM_DEBUG_DRIVER("  port id: %s\n",
 102                        intel_dsm_port_name(info->buffer.pointer[0]));
 103                 DRM_DEBUG_DRIVER("  display mux info: %s\n",
 104                        intel_dsm_mux_type(info->buffer.pointer[1]));
 105                 DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
 106                        intel_dsm_mux_type(info->buffer.pointer[2]));
 107                 DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
 108                        intel_dsm_mux_type(info->buffer.pointer[3]));
 109         }
 110
 111         ACPI_FREE(pkg);
 112 }
 113
 114 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
 115 {
 116         acpi_handle dhandle;
 117
 118         dhandle = ACPI_HANDLE(&pdev->dev);
 119         if (!dhandle)
 120                 return false;
 121
 122         if (!acpi_check_dsm(dhandle, intel_dsm_guid, INTEL_DSM_REVISION_ID,
 123                             1 << INTEL_DSM_FN_PLATFORM_MUX_INFO)) {
 124                 DRM_DEBUG_KMS("no _DSM method for intel device\n");
 125                 return false;
 126         }
 127
 128         intel_dsm_priv.dhandle = dhandle;
 129         intel_dsm_platform_mux_info();
 130
 131         return true;
 132 }
 133
 134 static bool intel_dsm_detect(void)
 135 {
 136         char acpi_method_name[255] = { 0 };
 137         struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
 138         struct pci_dev *pdev = NULL;
 139         bool has_dsm = false;
 140         int vga_count = 0;
 141
 142         while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
 143                 vga_count++;
 144                 has_dsm |= intel_dsm_pci_probe(pdev);
 145         }
 146
 147         if (vga_count == 2 && has_dsm) {
 148                 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
 149                 DRM_DEBUG_DRIVER("VGA switcheroo: detected DSM switching method %s handle\n",
 150                                  acpi_method_name);
 151                 return true;
 152         }
 153
 154         return false;
 155 }
 156
 157 void intel_register_dsm_handler(void)
 158 {
 159         if (!intel_dsm_detect())
 160                 return;
 161 }
 162
 163 void intel_unregister_dsm_handler(void)
 164 {
 165 }