x86: broadwell: Add a northbridge driver

Add a driver for the broadwell northbridge. This sets up the location of
several blocks of registers.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/cpu/broadwell/Makefile

@@ -6,6 +6,7 @@
 
 obj-y += cpu.o
 obj-y += iobp.o
+obj-y += northbridge.o
 obj-y += pch.o
 obj-y += pinctrl_broadwell.o
 obj-y += sata.o

arch/x86/cpu/broadwell/northbridge.c

+/*
+ * Copyright (C) 2011 The Chromium Authors
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <asm/io.h>
+#include <asm/arch/iomap.h>
+#include <asm/arch/pch.h>
+
+static int broadwell_northbridge_early_init(struct udevice *dev)
+{
+	/* Move earlier? */
+	dm_pci_write_config32(dev, PCIEXBAR + 4, 0);
+	/* 64MiB - 0-63 buses */
+	dm_pci_write_config32(dev, PCIEXBAR, MCFG_BASE_ADDRESS | 4 | 1);
+
+	dm_pci_write_config32(dev, MCHBAR, MCH_BASE_ADDRESS | 1);
+	dm_pci_write_config32(dev, DMIBAR, DMI_BASE_ADDRESS | 1);
+	dm_pci_write_config32(dev, EPBAR, EP_BASE_ADDRESS | 1);
+	writel(EDRAM_BASE_ADDRESS | 1, MCH_BASE_ADDRESS + EDRAMBAR);
+	writel(GDXC_BASE_ADDRESS | 1, MCH_BASE_ADDRESS + GDXCBAR);
+
+	/* Set C0000-FFFFF to access RAM on both reads and writes */
+	dm_pci_write_config8(dev, PAM0, 0x30);
+	dm_pci_write_config8(dev, PAM1, 0x33);
+	dm_pci_write_config8(dev, PAM2, 0x33);
+	dm_pci_write_config8(dev, PAM3, 0x33);
+	dm_pci_write_config8(dev, PAM4, 0x33);
+	dm_pci_write_config8(dev, PAM5, 0x33);
+	dm_pci_write_config8(dev, PAM6, 0x33);
+
+	/* Device enable: IGD and Mini-HD */
+	dm_pci_write_config32(dev, DEVEN, DEVEN_D0EN | DEVEN_D2EN | DEVEN_D3EN);
+
+	return 0;
+}
+
+static int broadwell_northbridge_probe(struct udevice *dev)
+{
+	if (!(gd->flags & GD_FLG_RELOC))
+		return broadwell_northbridge_early_init(dev);
+
+	return 0;
+}
+
+static const struct udevice_id broadwell_northbridge_ids[] = {
+	{ .compatible = "intel,broadwell-northbridge" },
+	{ }
+};
+
+U_BOOT_DRIVER(broadwell_northbridge_drv) = {
+	.name		= "broadwell_northbridge",
+	.id		= UCLASS_NORTHBRIDGE,
+	.of_match	= broadwell_northbridge_ids,
+	.probe		= broadwell_northbridge_probe,
+};