diff options
Diffstat (limited to 'src/southbridge/nvidia/mcp55/smbus.h')
| -rw-r--r-- | src/southbridge/nvidia/mcp55/smbus.h | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/southbridge/nvidia/mcp55/smbus.h b/src/southbridge/nvidia/mcp55/smbus.h new file mode 100644 index 0000000000..d1dade9c45 --- /dev/null +++ b/src/southbridge/nvidia/mcp55/smbus.h @@ -0,0 +1,177 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2004 Tyan Computer + * Written by Yinghai Lu <yhlu@tyan.com> for Tyan Computer. + * Copyright (C) 2006,2007 AMD + * Written by Yinghai Lu <yinghai.lu@amd.com> for AMD. + * + * 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 <device/smbus_def.h> + +#define SMBHSTSTAT 0x1 +#define SMBHSTPRTCL 0x0 +#define SMBHSTCMD 0x3 +#define SMBXMITADD 0x2 +#define SMBHSTDAT0 0x4 +#define SMBHSTDAT1 0x5 + +/* Between 1-10 seconds, We should never timeout normally + * Longer than this is just painful when a timeout condition occurs. + */ +#define SMBUS_TIMEOUT (100*1000*10) + +static inline void smbus_delay(void) +{ + outb(0x80, 0x80); +} + +static int smbus_wait_until_done(unsigned smbus_io_base) +{ + unsigned long loops; + loops = SMBUS_TIMEOUT; + do { + unsigned char val; + smbus_delay(); + + val = inb(smbus_io_base + SMBHSTSTAT); + if ( (val & 0xff) != 0) { + return 0; + } + } while(--loops); + return -3; +} +static int do_smbus_recv_byte(unsigned smbus_io_base, unsigned device) +{ + unsigned char global_status_register; + unsigned char byte; + + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBXMITADD); + smbus_delay(); + + /* byte data recv */ + outb(0x05, smbus_io_base + SMBHSTPRTCL); + smbus_delay(); + + /* poll for transaction completion */ + if (smbus_wait_until_done(smbus_io_base) < 0) { + return -3; + } + + global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */ + + /* read results of transaction */ + byte = inb(smbus_io_base + SMBHSTCMD); + + if (global_status_register != 0x80) { // lose check, otherwise it should be 0 + return -1; + } + return byte; +} +static int do_smbus_send_byte(unsigned smbus_io_base, unsigned device, unsigned char val) +{ + unsigned global_status_register; + + outb(val, smbus_io_base + SMBHSTDAT0); + smbus_delay(); + + /* set the command... */ + outb(val, smbus_io_base + SMBHSTCMD); + smbus_delay(); + + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1) | 0, smbus_io_base + SMBXMITADD); + smbus_delay(); + + /* set up for a byte data write */ + outb(0x04, smbus_io_base + SMBHSTPRTCL); + smbus_delay(); + + /* poll for transaction completion */ + if (smbus_wait_until_done(smbus_io_base) < 0) { + return -3; + } + global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */; + + if (global_status_register != 0x80) { + return -1; + } + return 0; +} +static int do_smbus_read_byte(unsigned smbus_io_base, unsigned device, unsigned address) +{ + unsigned char global_status_register; + unsigned char byte; + + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1)|1 , smbus_io_base + SMBXMITADD); + smbus_delay(); + /* set the command/address... */ + outb(address & 0xff, smbus_io_base + SMBHSTCMD); + smbus_delay(); + /* byte data read */ + outb(0x07, smbus_io_base + SMBHSTPRTCL); + smbus_delay(); + + /* poll for transaction completion */ + if (smbus_wait_until_done(smbus_io_base) < 0) { + return -3; + } + + global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */ + + /* read results of transaction */ + byte = inb(smbus_io_base + SMBHSTDAT0); + + if (global_status_register != 0x80) { // lose check, otherwise it should be 0 + return -1; + } + return byte; +} + + +static int do_smbus_write_byte(unsigned smbus_io_base, unsigned device, unsigned address, unsigned char val) +{ + unsigned global_status_register; + + outb(val, smbus_io_base + SMBHSTDAT0); + smbus_delay(); + + /* set the device I'm talking too */ + outb(((device & 0x7f) << 1) | 0, smbus_io_base + SMBXMITADD); + smbus_delay(); + + outb(address & 0xff, smbus_io_base + SMBHSTCMD); + smbus_delay(); + + /* set up for a byte data write */ + outb(0x06, smbus_io_base + SMBHSTPRTCL); + smbus_delay(); + + /* poll for transaction completion */ + if (smbus_wait_until_done(smbus_io_base) < 0) { + return -3; + } + global_status_register = inb(smbus_io_base + SMBHSTSTAT) & 0x80; /* lose check */; + + if (global_status_register != 0x80) { + return -1; + } + return 0; +} + |