intel/gm45: new northbridge

The code supports DDR3 boards only. RAM init for DDR2 is sufficiently
different that it requires separate code, and we have no boards to
test that.

Change-Id: I9076546faf8a2033c89eb95f5eec524439ab9fe1
Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com>
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1689
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/northbridge/intel/gm45/igd.c b/src/northbridge/intel/gm45/igd.c
new file mode 100644
index 0000000..c07fdfc2
--- /dev/null
+++ b/src/northbridge/intel/gm45/igd.c
@@ -0,0 +1,154 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012 secunet Security Networks AG
+ *
+ * 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 <stdint.h>
+#include <stddef.h>
+#include <arch/io.h>
+#include <arch/romcc_io.h>
+#include <device/pci_def.h>
+#include <console/console.h>
+
+#include "gm45.h"
+
+/* TODO: Chipset supports Protected Audio Video Path (PAVP) */
+
+/* TODO: We could pass DVMT structure in GetBIOSData() SCI interface */
+
+/* The PEG settings have to be set before ASPM is setup on DMI. */
+static void enable_igd(const sysinfo_t *const sysinfo, const int no_peg)
+{
+	const device_t mch_dev	= PCI_DEV(0, 0, 0);
+	const device_t peg_dev	= PCI_DEV(0, 1, 0);
+	const device_t igd_dev	= PCI_DEV(0, 2, 0);
+
+	u16 reg16;
+	u32 reg32;
+
+	printk(BIOS_DEBUG, "Enabling IGD.\n");
+
+	/* HSync/VSync */
+	MCHBAR8(0xbd0 + 3) = 0x5a;
+	MCHBAR8(0xbd0 + 4) = 0x5a;
+
+	static const u16 display_clock_from_f0_and_vco[][4] = {
+		  /* VCO 2666    VCO 3200    VCO 4000    VCO 5333 */
+		{         222,        228,        222,        222,  },
+		{         333,        320,        333,        333,  },
+	};
+	const int f0_12 = (pci_read_config16(igd_dev, 0xf0) >> 12) & 1;
+	const int vco = raminit_read_vco_index();
+	reg16 = pci_read_config16(igd_dev, 0xcc);
+	reg16 &= 0xfc00;
+	reg16 |= display_clock_from_f0_and_vco[f0_12][vco];
+	pci_write_config16(igd_dev, 0xcc, reg16);
+
+	/* Graphics Stolen Memory: 2MB GTT (0x0300) when VT-d disabled,
+	                           2MB GTT + 2MB shadow GTT (0x0b00) else. */
+	/* Graphics Mode Select: 32MB framebuffer (0x0050) */
+	/* TODO: We could switch to 64MB (0x0070), config flag? */
+	const u32 capid = pci_read_config32(mch_dev, D0F0_CAPID0 + 4);
+	reg16 = pci_read_config16(mch_dev, D0F0_GGC);
+	reg16 &= 0xf00f;
+	reg16 |= 0x0350;
+	if (capid & (1 << (48 - 32)))
+		reg16 |= 0x0800;
+	pci_write_config16(mch_dev, D0F0_GGC, reg16);
+
+	if ((sysinfo->gfx_type != GMCH_GL40) &&
+			(sysinfo->gfx_type != GMCH_GS40) &&
+			(sysinfo->gfx_type != GMCH_GL43)) {
+		const u32 deven = pci_read_config32(mch_dev, D0F0_DEVEN);
+		if (!(deven & 2))
+			/* Enable PEG temporarily to access D1:F0. */
+			pci_write_config32(mch_dev, D0F0_DEVEN, deven | 2);
+
+		/* Some IGD related settings on D1:F0. */
+		reg16 = pci_read_config16(peg_dev, 0xa08);
+		reg16 &= ~(1 << 15);
+		pci_write_config16(peg_dev, 0xa08, reg16);
+
+		reg16 = pci_read_config16(peg_dev, 0xa84);
+		reg16 |= (1 << 8);
+		pci_write_config16(peg_dev, 0xa84, reg16);
+
+		reg16 = pci_read_config16(peg_dev, 0xb00);
+		reg16 |= (3 << 8) | (7 << 3);
+		pci_write_config16(peg_dev, 0xb00, reg16);
+
+		reg32 = pci_read_config32(peg_dev, 0xb14);
+		reg32 &= ~(1 << 17);
+		pci_write_config32(peg_dev, 0xb14, reg32);
+
+		if (!(deven & 2) || no_peg) {
+			/* Disable PEG finally. */
+			printk(BIOS_DEBUG, "Finally disabling "
+					   "PEG in favor of IGD.\n");
+			MCHBAR8(0xc14) |= (1 << 5) | (1 << 0);
+
+			reg32 = pci_read_config32(peg_dev, 0x200);
+			reg32 |= (1 << 18);
+			pci_write_config32(peg_dev, 0x200, reg32);
+			reg16 = pci_read_config16(peg_dev, 0x224);
+			reg16 |= (1 << 8);
+			pci_write_config16(peg_dev, 0x224, reg16);
+			reg32 = pci_read_config32(peg_dev, 0x200);
+			reg32 &= ~(1 << 18);
+			pci_write_config32(peg_dev, 0x200, reg32);
+			while (pci_read_config32(peg_dev, 0x214) & 0x000f0000);
+
+			pci_write_config32(mch_dev, D0F0_DEVEN, deven & ~2);
+			MCHBAR8(0xc14) &= ~((1 << 5) | (1 << 0));
+		}
+	}
+}
+
+static void disable_igd(const sysinfo_t *const sysinfo)
+{
+	const device_t mch_dev	= PCI_DEV(0, 0, 0);
+
+	printk(BIOS_DEBUG, "Disabling IGD.\n");
+
+	u16 reg16;
+
+	reg16 = pci_read_config16(mch_dev, D0F0_GGC);
+	reg16 &= 0xff0f; /* Disable Graphics Stolen Memory. */
+	reg16 |= 0x0002; /* Disable IGD. */
+	pci_write_config16(mch_dev, D0F0_GGC, reg16);
+	MCHBAR8(0xf10) |= (1 << 0);
+
+	if (!(pci_read_config8(mch_dev, D0F0_CAPID0 + 4) & (1 << (33 - 32)))) {
+		MCHBAR16(0x1190) |= (1 << 14);
+		MCHBAR16(0x119e) = (MCHBAR16(0x119e) & ~(7 << 13)) | (4 << 13);
+		MCHBAR16(0x119e) |= (1 << 12);
+	}
+}
+
+void init_igd(const sysinfo_t *const sysinfo,
+	      const int no_igd, const int no_peg)
+{
+	const device_t mch_dev	= PCI_DEV(0, 0, 0);
+
+	const u8 capid = pci_read_config8(mch_dev, D0F0_CAPID0 + 4);
+	if (no_igd || (capid & (1 << (33 - 32))))
+		disable_igd(sysinfo);
+	else
+		enable_igd(sysinfo, no_peg);
+}