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>

3 files changed, 44 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index a9f8589490cf..d2daff1f8291 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1710,6 +1710,8 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
         /* Start out suspended */
         dev_priv->mm.suspended = 1;
 
+        intel_detect_pch(dev);
+
         if (drm_core_check_feature(dev, DRIVER_MODESET)) {
                 ret = i915_load_modeset_init(dev, prealloc_start,
                                              prealloc_size, agp_size);
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 0af3dcc85ce9..01e91ea5bdea 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -187,6 +187,35 @@ const static struct pci_device_id pciidlist[] = {
 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;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 94fc9b65f4d7..6ffabab3bb60 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -221,6 +221,11 @@ enum no_fbc_reason {
         FBC_NOT_TILED, /* buffer not tiled */
 };
 
+enum intel_pch {
+        PCH_IBX,        /* Ibexpeak PCH */
+        PCH_CPT,        /* Cougarpoint PCH */
+};
+
 typedef struct drm_i915_private {
         struct drm_device *dev;
 
@@ -331,6 +336,9 @@ typedef struct drm_i915_private {
         /* Display functions */
         struct drm_i915_display_funcs display;
 
+        /* PCH chipset type */
+        enum intel_pch pch_type;
+
         /* Register state */
         bool modeset_on_lid;
         u8 saveLBB;
@@ -992,6 +1000,8 @@ extern int intel_modeset_vga_set_state(struct drm_device *dev, bool state);
 extern void i8xx_disable_fbc(struct drm_device *dev);
 extern void g4x_disable_fbc(struct drm_device *dev);
 
+extern void intel_detect_pch (struct drm_device *dev);
+
 /**
  * Lock test for when it's just for synchronization of ring access.
  *
@@ -1137,6 +1147,9 @@ extern int i915_wait_ring(struct drm_device * dev, int n, const char *caller);
 #define HAS_PCH_SPLIT(dev) (IS_IRONLAKE(dev) || \
                             IS_GEN6(dev))
 
+#define INTEL_PCH_TYPE(dev) (((struct drm_i915_private *)(dev)->dev_private)->pch_type)
+#define HAS_PCH_CPT(dev) (INTEL_PCH_TYPE(dev) == PCH_CPT)
+
 #define PRIMARY_RINGBUFFER_SIZE         (128*1024)
 
 #endif