drm/i915/tgl: Set subplatforms

There is no way to differentiate TGL-U from TGL-Y by the PCI ids as
some ids are available in both SKUs.
So here using the root device id in the PCI bus that iGPU is in
to differentiate between U and Y.

BSpec: 44455
Reviewed-by: Swathi Dhanavanthri <swathi.dhanavanthri@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200807192629.64134-1-jose.souza@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/i915/i915_drv.h

@@ -1497,6 +1497,12 @@ IS_SUBPLATFORM(const struct drm_i915_private *i915,
 #define IS_ICL_WITH_PORT_F(dev_priv) \
 	IS_SUBPLATFORM(dev_priv, INTEL_ICELAKE, INTEL_SUBPLATFORM_PORTF)
 
+#define IS_TGL_U(dev_priv) \
+	IS_SUBPLATFORM(dev_priv, INTEL_TIGERLAKE, INTEL_SUBPLATFORM_ULT)
+
+#define IS_TGL_Y(dev_priv) \
+	IS_SUBPLATFORM(dev_priv, INTEL_TIGERLAKE, INTEL_SUBPLATFORM_ULX)
+
 #define SKL_REVID_A0		0x0
 #define SKL_REVID_B0		0x1
 #define SKL_REVID_C0		0x2

drivers/gpu/drm/i915/i915_reg.h

@@ -12353,4 +12353,10 @@ enum skl_power_gate {
 #define   DSB_ENABLE			(1 << 31)
 #define   DSB_STATUS			(1 << 0)
 
+#define TGL_ROOT_DEVICE_ID		0x9A00
+#define TGL_ROOT_DEVICE_MASK		0xFF00
+#define TGL_ROOT_DEVICE_SKU_MASK	0xF
+#define TGL_ROOT_DEVICE_SKU_ULX		0x2
+#define TGL_ROOT_DEVICE_SKU_ULT		0x4
+
 #endif /* _I915_REG_H_ */

drivers/gpu/drm/i915/intel_device_info.c

@@ -346,6 +346,25 @@ void intel_device_info_subplatform_init(struct drm_i915_private *i915)
 		mask = BIT(INTEL_SUBPLATFORM_PORTF);
 	}
 
+	if (IS_TIGERLAKE(i915)) {
+		struct pci_dev *root, *pdev = i915->drm.pdev;
+
+		root = list_first_entry(&pdev->bus->devices, typeof(*root), bus_list);
+
+		drm_WARN_ON(&i915->drm, mask);
+		drm_WARN_ON(&i915->drm, (root->device & TGL_ROOT_DEVICE_MASK) !=
+			    TGL_ROOT_DEVICE_ID);
+
+		switch (root->device & TGL_ROOT_DEVICE_SKU_MASK) {
+		case TGL_ROOT_DEVICE_SKU_ULX:
+			mask = BIT(INTEL_SUBPLATFORM_ULX);
+			break;
+		case TGL_ROOT_DEVICE_SKU_ULT:
+			mask = BIT(INTEL_SUBPLATFORM_ULT);
+			break;
+		}
+	}
+
 	GEM_BUG_ON(mask & ~INTEL_SUBPLATFORM_BITS);
 
 	RUNTIME_INFO(i915)->platform_mask[pi] |= mask;