nb/intel/gm45: Simplify GMA SSDT generator

Simplify generation of GMA SSDT, using updated naming convention.
If acpi_fill_ssdt is being invoked, then we know the IGD device is
present and enabled, so we can skip those checks. And the SSDT
generator now checks that the gfx struct is populated, so we can
skip that too.

Change-Id: Ideddfc3d327c4421faffb6583e347cd2b094e155
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39959
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
diff --git a/src/northbridge/intel/gm45/gma.c b/src/northbridge/intel/gm45/gma.c
index 821487a..0bbd3d5 100644
--- a/src/northbridge/intel/gm45/gma.c
+++ b/src/northbridge/intel/gm45/gma.c
@@ -219,25 +219,11 @@
 	intel_gma_restore_opregion();
 }
 
-const struct i915_gpu_controller_info *
-intel_gma_get_controller_info(void)
+static void gma_generate_ssdt(struct device *device)
 {
-	struct device *dev = pcidev_on_root(0x2, 0);
-	if (!dev) {
-		return NULL;
-	}
-	struct northbridge_intel_gm45_config *chip = dev->chip_info;
-	return &chip->gfx;
-}
+	const struct northbridge_intel_gm45_config *chip = device->chip_info;
 
-static void gma_ssdt(struct device *device)
-{
-	const struct i915_gpu_controller_info *gfx = intel_gma_get_controller_info();
-	if (!gfx) {
-		return;
-	}
-
-	drivers_intel_gma_displays_ssdt_generate(gfx);
+	drivers_intel_gma_displays_ssdt_generate(&chip->gfx);
 }
 
 static unsigned long
@@ -276,16 +262,16 @@
 };
 
 static struct device_operations gma_func0_ops = {
-	.read_resources = pci_dev_read_resources,
-	.set_resources = pci_dev_set_resources,
-	.enable_resources = pci_dev_enable_resources,
-	.acpi_fill_ssdt = gma_ssdt,
-	.init = gma_func0_init,
-	.scan_bus = 0,
-	.enable = 0,
-	.ops_pci = &gma_pci_ops,
-	.acpi_name = gma_acpi_name,
-	.write_acpi_tables = gma_write_acpi_tables,
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.acpi_fill_ssdt		= gma_generate_ssdt,
+	.init			= gma_func0_init,
+	.scan_bus		= 0,
+	.enable			= 0,
+	.ops_pci		= &gma_pci_ops,
+	.acpi_name		= gma_acpi_name,
+	.write_acpi_tables	= gma_write_acpi_tables,
 };
 
 static const unsigned short pci_device_ids[] =