drm/i915: Probe for PCH chipset type
PCH is the new name for south bridge from Ironlake/Sandybridge,
which contains most of the display outputs except eDP. This one
adds a probe function to detect current PCH type, and method to
detect Cougarpoint PCH.
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0af3dcc..01e91ea 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -187,6 +187,35 @@
MODULE_DEVICE_TABLE(pci, pciidlist);
#endif
+#define INTEL_PCH_DEVICE_ID_MASK 0xff00
+#define INTEL_PCH_CPT_DEVICE_ID_TYPE 0x1c00
+
+void intel_detect_pch (struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct pci_dev *pch;
+
+ /*
+ * The reason to probe ISA bridge instead of Dev31:Fun0 is to
+ * make graphics device passthrough work easy for VMM, that only
+ * need to expose ISA bridge to let driver know the real hardware
+ * underneath. This is a requirement from virtualization team.
+ */
+ pch = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
+ if (pch) {
+ if (pch->vendor == PCI_VENDOR_ID_INTEL) {
+ int id;
+ id = pch->device & INTEL_PCH_DEVICE_ID_MASK;
+
+ if (id == INTEL_PCH_CPT_DEVICE_ID_TYPE) {
+ dev_priv->pch_type = PCH_CPT;
+ DRM_DEBUG_KMS("Found CougarPoint PCH\n");
+ }
+ }
+ pci_dev_put(pch);
+ }
+}
+
static int i915_drm_freeze(struct drm_device *dev)
{
struct drm_i915_private *dev_priv = dev->dev_private;
