Improve support for the Intel 82371FB/SB/AB/EB/MB southbridge(s):

 - Implement ISA related support:
   - Initialize the RTC
   - Enable access to all BIOS regions (but _not_ write access to ROM)
   - Enable ISA (not EIO) support
   - Without the *_isa.c file, the Super I/O init is never performed
 - Improve IDE support:
   - Add config option to enable Ultra DMA/33 for each disk
   - Add config option to enable legacy IDE port access
 - Implement hard reset support
 - Implement USB controller support
 - Various code cleanups and improvements

The code partially supports southbridges other than the 82371EB (but
which are very similar), more complete support will follow.

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Stefan Reinauer <stepan@coresystems.de>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@2994 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
diff --git a/src/southbridge/intel/i82371eb/i82371eb_isa.c b/src/southbridge/intel/i82371eb/i82371eb_isa.c
new file mode 100644
index 0000000..12a26db
--- /dev/null
+++ b/src/southbridge/intel/i82371eb/i82371eb_isa.c
@@ -0,0 +1,72 @@
+/*
+ * This file is part of the LinuxBIOS project.
+ *
+ * Copyright (C) 2007 Uwe Hermann <uwe@hermann-uwe.de>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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 <console/console.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <pc80/isa-dma.h>
+#include <pc80/mc146818rtc.h>
+#include "i82371eb.h"
+
+static void isa_init(struct device *dev)
+{
+	u16 reg16;
+	u32 reg32;
+
+	/* Initialize the real time clock (RTC). */
+	rtc_init(0);
+
+	/* Enable access to all BIOS regions. */
+	reg16 = pci_read_config16(dev, XBCS);
+	reg16 |= LOWER_BIOS_ENABLE;
+	reg16 |= EXT_BIOS_ENABLE;
+	reg16 |= EXT_BIOS_ENABLE_1MB;
+	reg16 &= ~(WRITE_PROTECT_ENABLE);	/* Disable ROM write access. */
+	pci_write_config16(dev, XBCS, reg16);
+
+	/*
+	 * The PIIX4 can support the full ISA bus, or the Extended I/O (EIO)
+	 * bus, which is a subset of ISA. We select the full ISA bus here.
+	 */
+	reg32 = pci_read_config32(dev, GENCFG);
+	reg32 |= ISA;	/* Select ISA, not EIO. */
+	pci_write_config16(dev, GENCFG, reg32);
+
+	/* Initialize ISA DMA. */
+	isa_dma_init();
+}
+
+static const struct device_operations isa_ops = {
+	.read_resources		= pci_dev_read_resources,
+	.set_resources		= pci_dev_set_resources,
+	.enable_resources	= pci_dev_enable_resources,
+	.init			= isa_init,
+	.scan_bus		= scan_static_bus,	/* TODO: Needed? */
+	.enable			= 0,
+	.ops_pci		= 0, /* No subsystem IDs on 82371EB! */
+};
+
+static const struct pci_driver isa_driver __pci_driver = {
+	.ops	= &isa_ops,
+	.vendor	= PCI_VENDOR_ID_INTEL,
+	.device	= PCI_DEVICE_ID_INTEL_82371AB_ISA,
+};