baytrail: initialize graphics before MRC

The graphics device needs to have its resource contraints
initialized before running the reference code. Right now just
use a 256MiB aperture, 32MiB of stolen memory data, and 2MiB
GTT memory.

BUG=chrome-os-partner:22869
BRANCH=None
TEST=Built and booted. Noted amount of stolen memory matches
     configuration as well as BAR size within the graphics
     device.

Change-Id: I328bf858f288363187cf705d6340947393b5ff10
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/170427
Reviewed-on: http://review.coreboot.org/4850
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

3 files changed, 52 insertions, 0 deletions

diff --git a/src/soc/intel/baytrail/romstage/Makefile.inc b/src/soc/intel/baytrail/romstage/Makefile.inc
index 188ce44ecd..118c3485cd 100644
--- a/src/soc/intel/baytrail/romstage/Makefile.inc
+++ b/src/soc/intel/baytrail/romstage/Makefile.inc
@@ -2,3 +2,4 @@ cpu_incs += $(src)/soc/intel/baytrail/romstage/cache_as_ram.inc
 romstage-y += romstage.c
 romstage-y += raminit.c
 romstage-$(CONFIG_ENABLE_BUILTIN_COM1) += uart.c
+romstage-y += gfx.c
diff --git a/src/soc/intel/baytrail/romstage/gfx.c b/src/soc/intel/baytrail/romstage/gfx.c
new file mode 100644
index 0000000000..3b47ccf954
--- /dev/null
+++ b/src/soc/intel/baytrail/romstage/gfx.c
@@ -0,0 +1,49 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <arch/io.h>
+#include <baytrail/gfx.h>
+#include <baytrail/pci_devs.h>
+#include <baytrail/romstage.h>
+
+void gfx_init(void)
+{
+	uint32_t ggc;
+	uint8_t msac;
+	const unsigned int gfx_dev = PCI_DEV(0, GFX_DEV, GFX_FUNC);
+
+	/* The GFX device needs to set the aperture, gtt stolen size, and
+	 * graphics stolen memory stolen size before running MRC. For now
+	 * just hard code the defaults. Options can be added to the device
+	 * tree if needed. */
+
+	ggc = pci_read_config32(gfx_dev, GGC);
+	msac = pci_read_config8(gfx_dev, MSAC);
+
+	ggc &= ~(GGC_GTT_SIZE_MASK | GGC_GSM_SIZE_MASK);
+	ggc |= GGC_GTT_SIZE_2MB | GGC_GSM_SIZE_32MB;
+	/* Enable VGA decoding as well. */
+	ggc &= ~(GGC_VGA_DISABLE);
+
+	msac &= ~(APERTURE_SIZE_MASK);
+	msac |= APERTURE_SIZE_256MB;
+
+	pci_write_config32(gfx_dev, GGC, ggc);
+	pci_write_config8(gfx_dev, MSAC, msac);
+}
diff --git a/src/soc/intel/baytrail/romstage/romstage.c b/src/soc/intel/baytrail/romstage/romstage.c
index d3538991bb..e4e6fdecee 100644
--- a/src/soc/intel/baytrail/romstage/romstage.c
+++ b/src/soc/intel/baytrail/romstage/romstage.c
@@ -89,6 +89,8 @@ void romstage_common(const struct romstage_params *params)
 
 	console_init();
 
+	gfx_init();
+
 	/* Initialize RAM */
 	raminit(params->mrc_params, 5);