diff options
Diffstat (limited to 'src/southbridge/intel/i3100/smbus.h')
-rw-r--r-- | src/southbridge/intel/i3100/smbus.h | 112 |
1 files changed, 112 insertions, 0 deletions
diff --git a/src/southbridge/intel/i3100/smbus.h b/src/southbridge/intel/i3100/smbus.h new file mode 100644 index 0000000000..7023a5b751 --- /dev/null +++ b/src/southbridge/intel/i3100/smbus.h @@ -0,0 +1,112 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2008 Arastra, Inc. + * + * 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 + */ + +/* This code is based on src/southbridge/intel/esb6300/esb6300_smbus.h */ + +#include <device/smbus_def.h> + +#define SMBHSTSTAT 0x0 +#define SMBHSTCTL 0x2 +#define SMBHSTCMD 0x3 +#define SMBXMITADD 0x4 +#define SMBHSTDAT0 0x5 +#define SMBHSTDAT1 0x6 +#define SMBBLKDAT 0x7 +#define SMBTRNSADD 0x9 +#define SMBSLVDATA 0xa +#define SMLINK_PIN_CTL 0xe +#define SMBUS_PIN_CTL 0xf +#define SMBSLVCMD 0x11 + +#define SMBUS_TIMEOUT (100*1000*10) + +static void smbus_delay(void) +{ + outb(0x80, 0x80); +} + +static int smbus_wait_until_ready(u32 smbus_io_base) +{ + u32 loops = SMBUS_TIMEOUT; + u8 byte; + do { + smbus_delay(); + if (--loops == 0) + break; + byte = inb(smbus_io_base + SMBHSTSTAT); + } while (byte & 1); + return loops ? 0 : -1; +} + +static int smbus_wait_until_done(u32 smbus_io_base) +{ + u32 loops = SMBUS_TIMEOUT; + u8 byte; + do { + smbus_delay(); + if (--loops == 0) + break; + byte = inb(smbus_io_base + SMBHSTSTAT); + } while ((byte & 1) || (byte & ~((1 << 6)|(1 << 0))) == 0); + return loops ? 0 : -1; +} + +static int do_smbus_read_byte(u32 smbus_io_base, u16 device, u8 address) +{ + u8 global_status_register; + u8 byte; + + if (smbus_wait_until_ready(smbus_io_base) < 0) { + return SMBUS_WAIT_UNTIL_READY_TIMEOUT; + } + /* 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 + SMBXMITADD); + /* 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 */ + if (smbus_wait_until_done(smbus_io_base) < 0) { + return SMBUS_WAIT_UNTIL_DONE_TIMEOUT; + } + + global_status_register = inb(smbus_io_base + SMBHSTSTAT); + + /* Ignore the In Use Status... */ + global_status_register &= ~(3 << 5); + + /* read results of transaction */ + byte = inb(smbus_io_base + SMBHSTDAT0); + if (global_status_register != (1 << 1)) { + return SMBUS_ERROR; + } + return byte; +} |