gm45: Ensure that brightness register in gma contains sane value.

Change-Id: Ia66c71c3adf2ae0d413750b5e59e3eaba3888a0b
Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com>
Reviewed-on: http://review.coreboot.org/6587
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

src/northbridge/intel/gm45/Makefile.inc

@@ -35,5 +35,6 @@ ramstage-$(CONFIG_GENERATE_ACPI_TABLES) += acpi.c
 
 ramstage-y += ram_calc.c
 ramstage-y += northbridge.c
+ramstage-y += gma.c
 
 smm-$(CONFIG_HAVE_SMI_HANDLER) += delay.c

src/northbridge/intel/gm45/gma.c

@@ -0,0 +1,99 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 Chromium OS Authors
+ * Copyright (C) 2013 Vladimir Serbinenko
+ *
+ * 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 <console/console.h>
+#include <delay.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <string.h>
+#include <device/pci_ops.h>
+#include <cpu/x86/msr.h>
+#include <cpu/x86/mtrr.h>
+
+#include "drivers/intel/gma/i915_reg.h"
+#include "chip.h"
+#include "gm45.h"
+
+static struct resource *gtt_res = NULL;
+
+static inline void gtt_write(u32 reg, u32 data)
+{
+	write32(gtt_res->base + reg, data);
+}
+
+static void gma_func0_init(struct device *dev)
+{
+	u32 reg32;
+
+	/* IGD needs to be Bus Master */
+	reg32 = pci_read_config32(dev, PCI_COMMAND);
+	reg32 |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY | PCI_COMMAND_IO;
+	pci_write_config32(dev, PCI_COMMAND, reg32);
+
+	/* Init graphics power management */
+	gtt_res = find_resource(dev, PCI_BASE_ADDRESS_0);
+
+	/* PCI Init, will run VBIOS */
+	pci_dev_init(dev);
+
+	/* Post VBIOS init */
+	/* Enable Backlight  */
+	gtt_write(BLC_PWM_CTL2, (1 << 31));
+	gtt_write(BLC_PWM_CTL, 0x06100610);
+}
+
+static void gma_set_subsystem(device_t dev, unsigned vendor, unsigned device)
+{
+	if (!vendor || !device) {
+		pci_write_config32(dev, PCI_SUBSYSTEM_VENDOR_ID,
+				   pci_read_config32(dev, PCI_VENDOR_ID));
+	} else {
+		pci_write_config32(dev, PCI_SUBSYSTEM_VENDOR_ID,
+				   ((device & 0xffff) << 16) | (vendor &
+								0xffff));
+	}
+}
+
+static struct pci_operations gma_pci_ops = {
+	.set_subsystem = gma_set_subsystem,
+};
+
+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,
+	.init = gma_func0_init,
+	.scan_bus = 0,
+	.enable = 0,
+	.ops_pci = &gma_pci_ops,
+};
+
+static const unsigned short pci_device_ids[] =
+{
+	0x2a42, 0
+};
+
+static const struct pci_driver gma __pci_driver = {
+	.ops = &gma_func0_ops,
+	.vendor = PCI_VENDOR_ID_INTEL,
+	.devices = pci_device_ids,
+};