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 <acpi/acpi_drivers.h>
  10
  11 #include "drmP.h"
  12
  13 #define INTEL_DSM_REVISION_ID 1 /* For Calpella anyway... */
  14
  15 #define INTEL_DSM_FN_SUPPORTED_FUNCTIONS 0 /* No args */
  16 #define INTEL_DSM_FN_PLATFORM_MUX_INFO 1 /* No args */
  17
  18 static struct intel_dsm_priv {
  19         acpi_handle dhandle;
  20 } intel_dsm_priv;
  21
  22 static const u8 intel_dsm_guid[] = {
  23         0xd3, 0x73, 0xd8, 0x7e,
  24         0xd0, 0xc2,
  25         0x4f, 0x4e,
  26         0xa8, 0x54,
  27         0x0f, 0x13, 0x17, 0xb0, 0x1c, 0x2c
  28 };
  29
  30 static int intel_dsm(acpi_handle handle, int func, int arg)
  31 {
  32         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
  33         struct acpi_object_list input;
  34         union acpi_object params[4];
  35         union acpi_object *obj;
  36         u32 result;
  37         int ret = 0;
  38
  39         input.count = 4;
  40         input.pointer = params;
  41         params[0].type = ACPI_TYPE_BUFFER;
  42         params[0].buffer.length = sizeof(intel_dsm_guid);
  43         params[0].buffer.pointer = (char *)intel_dsm_guid;
  44         params[1].type = ACPI_TYPE_INTEGER;
  45         params[1].integer.value = INTEL_DSM_REVISION_ID;
  46         params[2].type = ACPI_TYPE_INTEGER;
  47         params[2].integer.value = func;
  48         params[3].type = ACPI_TYPE_INTEGER;
  49         params[3].integer.value = arg;
  50
  51         ret = acpi_evaluate_object(handle, "_DSM", &input, &output);
  52         if (ret) {
  53                 DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
  54                 return ret;
  55         }
  56
  57         obj = (union acpi_object *)output.pointer;
  58
  59         result = 0;
  60         switch (obj->type) {
  61         case ACPI_TYPE_INTEGER:
  62                 result = obj->integer.value;
  63                 break;
  64
  65         case ACPI_TYPE_BUFFER:
  66                 if (obj->buffer.length == 4) {
  67                         result = (obj->buffer.pointer[0] |
  68                                 (obj->buffer.pointer[1] <<  8) |
  69                                 (obj->buffer.pointer[2] << 16) |
  70                                 (obj->buffer.pointer[3] << 24));
  71                         break;
  72                 }
  73         default:
  74                 ret = -EINVAL;
  75                 break;
  76         }
  77         if (result == 0x80000002)
  78                 ret = -ENODEV;
  79
  80         kfree(output.pointer);
  81         return ret;
  82 }
  83
  84 static char *intel_dsm_port_name(u8 id)
  85 {
  86         switch (id) {
  87         case 0:
  88                 return "Reserved";
  89         case 1:
  90                 return "Analog VGA";
  91         case 2:
  92                 return "LVDS";
  93         case 3:
  94                 return "Reserved";
  95         case 4:
  96                 return "HDMI/DVI_B";
  97         case 5:
  98                 return "HDMI/DVI_C";
  99         case 6:
 100                 return "HDMI/DVI_D";
 101         case 7:
 102                 return "DisplayPort_A";
 103         case 8:
 104                 return "DisplayPort_B";
 105         case 9:
 106                 return "DisplayPort_C";
 107         case 0xa:
 108                 return "DisplayPort_D";
 109         case 0xb:
 110         case 0xc:
 111         case 0xd:
 112                 return "Reserved";
 113         case 0xe:
 114                 return "WiDi";
 115         default:
 116                 return "bad type";
 117         }
 118 }
 119
 120 static char *intel_dsm_mux_type(u8 type)
 121 {
 122         switch (type) {
 123         case 0:
 124                 return "unknown";
 125         case 1:
 126                 return "No MUX, iGPU only";
 127         case 2:
 128                 return "No MUX, dGPU only";
 129         case 3:
 130                 return "MUXed between iGPU and dGPU";
 131         default:
 132                 return "bad type";
 133         }
 134 }
 135
 136 static void intel_dsm_platform_mux_info(void)
 137 {
 138         struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
 139         struct acpi_object_list input;
 140         union acpi_object params[4];
 141         union acpi_object *pkg;
 142         int i, ret;
 143
 144         input.count = 4;
 145         input.pointer = params;
 146         params[0].type = ACPI_TYPE_BUFFER;
 147         params[0].buffer.length = sizeof(intel_dsm_guid);
 148         params[0].buffer.pointer = (char *)intel_dsm_guid;
 149         params[1].type = ACPI_TYPE_INTEGER;
 150         params[1].integer.value = INTEL_DSM_REVISION_ID;
 151         params[2].type = ACPI_TYPE_INTEGER;
 152         params[2].integer.value = INTEL_DSM_FN_PLATFORM_MUX_INFO;
 153         params[3].type = ACPI_TYPE_INTEGER;
 154         params[3].integer.value = 0;
 155
 156         ret = acpi_evaluate_object(intel_dsm_priv.dhandle, "_DSM", &input,
 157                                    &output);
 158         if (ret) {
 159                 DRM_DEBUG_DRIVER("failed to evaluate _DSM: %d\n", ret);
 160                 goto out;
 161         }
 162
 163         pkg = (union acpi_object *)output.pointer;
 164
 165         if (pkg->type == ACPI_TYPE_PACKAGE) {
 166                 union acpi_object *connector_count = &pkg->package.elements[0];
 167                 DRM_DEBUG_DRIVER("MUX info connectors: %lld\n",
 168                           (unsigned long long)connector_count->integer.value);
 169                 for (i = 1; i < pkg->package.count; i++) {
 170                         union acpi_object *obj = &pkg->package.elements[i];
 171                         union acpi_object *connector_id =
 172                                 &obj->package.elements[0];
 173                         union acpi_object *info = &obj->package.elements[1];
 174                         DRM_DEBUG_DRIVER("Connector id: 0x%016llx\n",
 175                                   (unsigned long long)connector_id->integer.value);
 176                         DRM_DEBUG_DRIVER("  port id: %s\n",
 177                                intel_dsm_port_name(info->buffer.pointer[0]));
 178                         DRM_DEBUG_DRIVER("  display mux info: %s\n",
 179                                intel_dsm_mux_type(info->buffer.pointer[1]));
 180                         DRM_DEBUG_DRIVER("  aux/dc mux info: %s\n",
 181                                intel_dsm_mux_type(info->buffer.pointer[2]));
 182                         DRM_DEBUG_DRIVER("  hpd mux info: %s\n",
 183                                intel_dsm_mux_type(info->buffer.pointer[3]));
 184                 }
 185         } else {
 186                 DRM_ERROR("MUX INFO call failed\n");
 187         }
 188
 189 out:
 190         kfree(output.pointer);
 191 }
 192
 193 static bool intel_dsm_pci_probe(struct pci_dev *pdev)
 194 {
 195         acpi_handle dhandle, intel_handle;
 196         acpi_status status;
 197         int ret;
 198
 199         dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
 200         if (!dhandle)
 201                 return false;
 202
 203         status = acpi_get_handle(dhandle, "_DSM", &intel_handle);
 204         if (ACPI_FAILURE(status)) {
 205                 DRM_DEBUG_KMS("no _DSM method for intel device\n");
 206                 return false;
 207         }
 208
 209         ret = intel_dsm(dhandle, INTEL_DSM_FN_SUPPORTED_FUNCTIONS, 0);
 210         if (ret < 0) {
 211                 DRM_ERROR("failed to get supported _DSM functions\n");
 212                 return false;
 213         }
 214
 215         intel_dsm_priv.dhandle = dhandle;
 216
 217         intel_dsm_platform_mux_info();
 218         return true;
 219 }
 220
 221 static bool intel_dsm_detect(void)
 222 {
 223         char acpi_method_name[255] = { 0 };
 224         struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
 225         struct pci_dev *pdev = NULL;
 226         bool has_dsm = false;
 227         int vga_count = 0;
 228
 229         while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
 230                 vga_count++;
 231                 has_dsm |= intel_dsm_pci_probe(pdev);
 232         }
 233
 234         if (vga_count == 2 && has_dsm) {
 235                 acpi_get_name(intel_dsm_priv.dhandle, ACPI_FULL_PATHNAME, &buffer);
 236                 DRM_DEBUG_DRIVER("VGA switcheroo: detected DSM switching method %s handle\n",
 237                                  acpi_method_name);
 238                 return true;
 239         }
 240
 241         return false;
 242 }
 243
 244 void intel_register_dsm_handler(void)
 245 {
 246         if (!intel_dsm_detect())
 247                 return;
 248 }
 249
 250 void intel_unregister_dsm_handler(void)
 251 {
 252 }