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authorstepan <stepan@coresystems.de>2010-12-08 05:42:47 +0000
committerStefan Reinauer <stepan@openbios.org>2010-12-08 05:42:47 +0000
commit836ae29ee325b1e3d28ff59468cc50913b1e24ce (patch)
treee2691a1e1ee1d795ffe7a99fb93778a9910044c2 /src/southbridge/intel/i82801dx/smbus.c
parent1bc5ccac51d94cfb4f9666ecf2cac619d8dc80a6 (diff)
downloadcoreboot-836ae29ee325b1e3d28ff59468cc50913b1e24ce.tar.xz
first round name simplification. drop the <component>_ prefix.
the prefix was introduced in the early v2 tree many years ago because our old build system "newconfig" could not handle two files with the same name in different paths like /path/to/usb.c and /another/path/to/usb.c correctly. Only one of the files would end up being compiled into the final image. Since Kconfig (actually since shortly before we switched to Kconfig) we don't suffer from that problem anymore. So we could drop the sb700_ prefix from all those filenames (or, the <componentname>_ prefix in general) - makes it easier to fork off a new chipset - makes it easier to diff against other chipsets - storing redundant information in filenames seems wrong Signed-off-by: <stepan@coresystems.de> Acked-by: Patrick Georgi <patrick@georgi-clan.de> Acked-by: Peter Stuge <peter@stuge.se> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@6149 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
Diffstat (limited to 'src/southbridge/intel/i82801dx/smbus.c')
-rw-r--r--src/southbridge/intel/i82801dx/smbus.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/src/southbridge/intel/i82801dx/smbus.c b/src/southbridge/intel/i82801dx/smbus.c
new file mode 100644
index 0000000000..1f7e47be95
--- /dev/null
+++ b/src/southbridge/intel/i82801dx/smbus.c
@@ -0,0 +1,105 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2004 Ronald G. Minnich
+ *
+ * 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 "i82801dx.h"
+#include <smbus.h>
+#include <pci.h>
+#include <arch/io.h>
+
+#define PM_BUS 0
+#define PM_DEVFN PCI_DEVFN(0x1f,3)
+
+void smbus_enable(void)
+{
+ unsigned char byte;
+ /* iobase addr */
+ pcibios_write_config_dword(PM_BUS, PM_DEVFN, 0x20, SMBUS_IO_BASE | 1);
+ /* smbus enable */
+ pcibios_write_config_byte(PM_BUS, PM_DEVFN, 0x40, 1);
+ /* iospace enable */
+ pcibios_write_config_word(PM_BUS, PM_DEVFN, 0x4, 1);
+
+ /* Disable interrupt generation */
+ outb(0, SMBUS_IO_BASE + SMBHSTCTL);
+
+}
+
+void smbus_setup(void)
+{
+ outb(0, SMBUS_IO_BASE + SMBHSTSTAT);
+}
+
+static void smbus_wait_until_ready(void)
+{
+ while ((inb(SMBUS_IO_BASE + SMBHSTSTAT) & 1) == 1) {
+ /* nop */
+ }
+}
+
+static void smbus_wait_until_done(void)
+{
+ unsigned char byte;
+ do {
+ byte = inb(SMBUS_IO_BASE + SMBHSTSTAT);
+ }
+ while ((byte & 1) == 1);
+ while ((byte & ~1) == 0) {
+ byte = inb(SMBUS_IO_BASE + SMBHSTSTAT);
+ }
+}
+
+int smbus_read_byte(unsigned device, unsigned address, unsigned char *result)
+{
+ unsigned char host_status_register;
+ unsigned char byte;
+
+ smbus_wait_until_ready();
+
+ /* setup transaction */
+ /* disable interrupts */
+ outb(inb(SMBUS_IO_BASE + SMBHSTCTL) & (~1), SMBUS_IO_BASE + SMBHSTCTL);
+ /* set the device I'm talking too */
+ outb(((device & 0x7f) << 1) | 1, SMBUS_IO_BASE + SMBHSTADD);
+ /* set the command/address... */
+ outb(address & 0xFF, SMBUS_IO_BASE + SMBHSTCMD);
+ /* set up for a byte data read */
+ outb((inb(SMBUS_IO_BASE + SMBHSTCTL) & 0xE3) | (0x2 << 2),
+ SMBUS_IO_BASE + SMBHSTCTL);
+
+ /* clear any lingering errors, so the transaction will run */
+ outb(inb(SMBUS_IO_BASE + SMBHSTSTAT), SMBUS_IO_BASE + SMBHSTSTAT);
+
+ /* clear the data byte... */
+ outb(0, SMBUS_IO_BASE + SMBHSTDAT0);
+
+ /* start the command */
+ outb((inb(SMBUS_IO_BASE + SMBHSTCTL) | 0x40),
+ SMBUS_IO_BASE + SMBHSTCTL);
+
+ /* poll for transaction completion */
+ smbus_wait_until_done();
+
+ host_status_register = inb(SMBUS_IO_BASE + SMBHSTSTAT);
+
+ /* read results of transaction */
+ byte = inb(SMBUS_IO_BASE + SMBHSTDAT0);
+
+ *result = byte;
+ return host_status_register != 0x02;
+}