Make ASUS P3B-F RAM init actually work by enabling SPD access.

On this board all reads from SPD return 0xff by default, there's a custom
GPIO fiddling needed to enable access to the SPD SMBus offsets at
0x50-0x53. While coreboot actually sort of booted sometimes before r5193,
that was just sheer luck as the RAM init was hardcoded in certain ways.
Since the proper, more heavily SPD-based RAM init the brokenness of the
ASUS P3B-F RAM init was becoming visible.

This patch uses GPIOs to enable access to the SPD SMBus offsets,
and resets the GPIOs again after RAM init (this is needed to allow for
lm-sensors to work, for example).

Tested successfully on hardware.

Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de>
Acked-by: Idwer Vollering <vidwer@gmail.com>



git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5819 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1

3 files changed, 56 insertions, 4 deletions

diff --git a/src/southbridge/intel/i82371eb/i82371eb.h b/src/southbridge/intel/i82371eb/i82371eb.h
index cb4356ef8a..1093766dbe 100644
--- a/src/southbridge/intel/i82371eb/i82371eb.h
+++ b/src/southbridge/intel/i82371eb/i82371eb.h
@@ -72,5 +72,6 @@ void i82371eb_hard_reset(void);
 #define SSDE1			(1 << 3)  /* Secondary Drive 1 UDMA/33 */
 #define ISA			(1 << 0)  /* Select ISA */
 #define EIO			(0 << 0)  /* Select EIO */
+#define PMIOSE			(1 << 0)  /* PM I/O Space Enable */
 
 #endif /* SOUTHBRIDGE_INTEL_I82371EB_I82371EB_H */
diff --git a/src/southbridge/intel/i82371eb/i82371eb_early_pm.c b/src/southbridge/intel/i82371eb/i82371eb_early_pm.c
new file mode 100644
index 0000000000..e6dd68eb7a
--- /dev/null
+++ b/src/southbridge/intel/i82371eb/i82371eb_early_pm.c
@@ -0,0 +1,53 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2010 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 <device/pci_ids.h>
+#include "i82371eb.h"
+
+#define PM_IO_BASE 0xe400
+
+static void enable_pm(void)
+{
+	device_t dev;
+	u8 reg8;
+	u16 reg16;
+
+	/* Check for SMBus/PM device PCI ID on the 82371AB/EB/MB. */
+	dev = pci_locate_device(PCI_ID(PCI_VENDOR_ID_INTEL,
+				PCI_DEVICE_ID_INTEL_82371AB_SMB_ACPI), 0);
+
+	if (dev == PCI_DEV_INVALID)
+		die("SMBus/PM controller not found\n");
+
+	/* Set the PM I/O base. */
+	pci_write_config32(dev, PMBA, PM_IO_BASE | 1);
+
+	/* Enable access to the PM I/O space. */
+	reg16 = pci_read_config16(dev, PCI_COMMAND);
+	reg16 |= PCI_COMMAND_IO;
+	pci_write_config16(dev, PCI_COMMAND, reg16);
+
+	/* PM I/O Space Enable (PMIOSE). */
+	reg8 = pci_read_config8(dev, PMREGMISC);
+	reg8 |= PMIOSE;
+	pci_write_config8(dev, PMREGMISC, reg8);
+}
+
diff --git a/src/southbridge/intel/i82371eb/i82371eb_early_smbus.c b/src/southbridge/intel/i82371eb/i82371eb_early_smbus.c
index ada781ec26..76ae9f50b2 100644
--- a/src/southbridge/intel/i82371eb/i82371eb_early_smbus.c
+++ b/src/southbridge/intel/i82371eb/i82371eb_early_smbus.c
@@ -33,14 +33,12 @@ static void enable_smbus(void)
 	u8 reg8;
 	u16 reg16;
 
-	/* Check for SMBus device PCI ID on the 82371AB/EB/MB. */
+	/* Check for SMBus/PM device PCI ID on the 82371AB/EB/MB. */
 	dev = pci_locate_device(PCI_ID(PCI_VENDOR_ID_INTEL,
 				PCI_DEVICE_ID_INTEL_82371AB_SMB_ACPI), 0);
 
 	if (dev == PCI_DEV_INVALID)
-		die("SMBus controller not found\n");
-
-	print_spew("SMBus controller enabled\n");
+		die("SMBus/PM controller not found\n");
 
 	/* Set the SMBus I/O base. */
 	pci_write_config32(dev, SMBBA, SMBUS_IO_BASE | 1);