Alexandru Gagniuc (mr.nuke.me@gmail.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/143
-gerrit
commit 9d152c129b6f9fdd084185ed67cc1fc31529ad74 Author: Alexandru Gagniuc mr.nuke.me@gmail.com Date: Tue Aug 9 01:26:52 2011 -0500
coreboot: Add generic SMBUS implementation
Early SMBUS code with similar functionality is duplicated for all southbridges. Add a generic SMBUS implementation, with functions declared weak, so that they can be overridden by the southbridge code if necessary.
Change-Id: I0861b7a3f098115182ae6de9f016dd671c500bad Signed-off-by: Alexandru Gagniuc mr.nuke.me@gmail.com --- src/devices/smbus/early_smbus.c | 141 +++++++++++++++++++++++++++++++++++++++ src/devices/smbus/smbus.h | 100 +++++++++++++++++++++++++++ 2 files changed, 241 insertions(+), 0 deletions(-)
diff --git a/src/devices/smbus/early_smbus.c b/src/devices/smbus/early_smbus.c new file mode 100644 index 0000000..4583aca --- /dev/null +++ b/src/devices/smbus/early_smbus.c @@ -0,0 +1,141 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2011 Alexandru Gagniuc mr.nuke.me@gmail.com + * + * 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, see http://www.gnu.org/licenses/. + */ +/** + * @file post_codes.h + * + * This file defines the implementations for the functions defined in smbus.h + * These are a generic SMBUS implementation, which should work with a majority + * of chipsets. + * They are marked weak so that they can be overridden by the chipset code if + * necessary. + */ + +#include "smbus.h" + +/** + * \brief Brief delay for SMBUS transactions + */ +__attribute__((weak)) +void __smbus_delay(void) +{ + inb(0x80); +} + +/** + * \brief Clear the SMBUS host status register + */ +__attribute__((weak)) +void __smbus_reset(u16 __smbus_io_base) +{ + outb(0xdf, SMBHSTSTAT); +} + +/** + * \brief Print an error, should it occur. If no error, just exit. + * + * @param host_status The data returned on the host status register after + * a transaction is processed. + * @param loops The number of times a transaction was attempted. + * @return 0 if no error occurred + * 1 if an error was detected + */ +__attribute__((weak)) +int __smbus_print_error(u8 host_status, int loops, u16 __smbus_io_base) +{ + /* Check if there actually was an error. */ + if ((host_status == 0x00 || host_status == 0x40 || + host_status == 0x42) && (loops < SMBUS_TIMEOUT)) + return 0; + + if (loops >= SMBUS_TIMEOUT) + printsmbus("SMBus timeout\n"); + if (host_status & (1 << 4)) + printsmbus("Interrupt/SMI# was Failed Bus Transaction\n"); + if (host_status & (1 << 3)) + printsmbus("Bus error\n"); + if (host_status & (1 << 2)) + printsmbus("Device error\n"); + if (host_status & (1 << 1)) + printsmbus("Interrupt/SMI# completed successfully\n"); + if (host_status & (1 << 0)) + printsmbus("Host busy\n"); + return 1; +} + +/** + * \brief Checks if the SMBUS is currently busy with a transaction + */ +__attribute__((weak)) +int __smbus_is_busy(u16 __smbus_io_base) +{ + /* Check if bit 0 of the status register is 1 (busy) or 0 (ready) */ + return ( (inb(SMBHSTSTAT) & (1 << 0)) == 1); +} + +/** + * \brief Wait for the SMBUS to become ready to process a new transaction. + */ +__attribute__((weak)) +int __smbus_wait_until_ready(u16 __smbus_io_base) +{ + int loops; + + printsmbus("Waiting until SMBus ready\n"); + + /* Loop up to SMBUS_TIMEOUT times, waiting for bit 0 of the + * SMBus Host Status register to go to 0, indicating the operation + * was completed successfully. I don't remember why I did it this way, + * but I think it was because ROMCC was running low on registers */ + loops = 0; + while (__smbus_is_busy(__smbus_io_base) && loops < SMBUS_TIMEOUT) + ++loops; + + return __smbus_print_error(inb(SMBHSTSTAT), loops, __smbus_io_base); +} + +/** + * \brief Read a byte from the SMBUS. + * + * @param dimm The address location of the DIMM on the SMBus. + * @param offset The offset the data is located at. + */ +__attribute__((weak)) +u8 __smbus_read_byte(u8 dimm, u8 offset, u16 __smbus_io_base) +{ + u8 val; + + /* Initialize SMBUS sequence */ + __smbus_reset(__smbus_io_base); + /* Clear host data port. */ + outb(0x00, SMBHSTDAT0); + + __smbus_wait_until_ready(__smbus_io_base); + + /* Actual addr to reg format. */ + dimm = (dimm << 1); + dimm |= 1; /* read command */ + outb(dimm, SMBXMITADD); + outb(offset, SMBHSTCMD); + /* Start transaction, byte data read. */ + outb(0x48, SMBHSTCTL); + __smbus_wait_until_ready(__smbus_io_base); + + val = inb(SMBHSTDAT0); + return val; +} \ No newline at end of file diff --git a/src/devices/smbus/smbus.h b/src/devices/smbus/smbus.h new file mode 100644 index 0000000..c730669 --- /dev/null +++ b/src/devices/smbus/smbus.h @@ -0,0 +1,100 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2011 Alexandru Gagniuc mr.nuke.me@gmail.com + * + * 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, see http://www.gnu.org/licenses/. + */ + +/** + * @file post_codes.h + * + * This file defines the prototypes for several common SMBUS functions + * These functions are prefixed with __smbus_ so that they do not conflict with + * the dozens of similar (duplicated) implementations in many southbridges. + * + * As a last parameter, the SMBUS functions take a u16 value __smbus_io_base, + * which represents the base IO port for smbus transactions + */ + +#include <arch/io.h> + +/** + * \brief SMBUS IO ports in relation to the base IO port + */ +#define SMBHSTSTAT __smbus_io_base + 0x0 +#define SMBSLVSTAT __smbus_io_base + 0x1 +#define SMBHSTCTL __smbus_io_base + 0x2 +#define SMBHSTCMD __smbus_io_base + 0x3 +#define SMBXMITADD __smbus_io_base + 0x4 +#define SMBHSTDAT0 __smbus_io_base + 0x5 +#define SMBHSTDAT1 __smbus_io_base + 0x6 +#define SMBBLKDAT __smbus_io_base + 0x7 +#define SMBSLVCTL __smbus_io_base + 0x8 +#define SMBTRNSADD __smbus_io_base + 0x9 +#define SMBSLVDATA __smbus_io_base + 0xa + +#define SMBUS_TIMEOUT (100*1000*10) + +/** + * \brief printk macro for SMBUS debugging + */ +#if defined(CONFIG_DEBUG_SMBUS_SETUP) && (CONFIG_DEBUG_SMBUS_SETUP) +#define printsmbus(x, ...) printk(BIOS_DEBUG, x, ##__VA_ARGS__) +#else +#define printsmbus(x, ...) +#endif + + +void __smbus_reset(u16 __smbus_io_base); +int __smbus_print_error(u8 host_status, int loops, u16 __smbus_io_base); +int __smbus_is_busy(u16 __smbus_io_base); +int __smbus_wait_until_ready(u16 __smbus_io_base); +u8 __smbus_read_byte(u8 dimm, u8 offset, u16 __smbus_io_base); + +void __smbus_delay(void); + +#if defined(SMBUS_IO_BASE) && (SMBUS_IO_BASE != 0) + +__attribute__((always_inline, unused)) +static void smbus_reset(void) +{ + __smbus_reset(SMBUS_IO_BASE); +} + +__attribute__((always_inline, unused)) +static int smbus_is_busy(void) +{ + return __smbus_is_busy(SMBUS_IO_BASE); +} + +__attribute__((always_inline, unused)) +static int smbus_wait_until_ready(void) +{ + return __smbus_wait_until_ready(SMBUS_IO_BASE); +} + +__attribute__((always_inline, unused)) +static int smbus_print_error(u8 host_status, int loops) +{ + return __smbus_print_error(host_status, loops, SMBUS_IO_BASE); +} + +__attribute__((always_inline, unused)) +static u8 smbus_read_byte(u8 dimm, u8 offset) +{ + return __smbus_read_byte(dimm, offset, SMBUS_IO_BASE); +} + +#endif \ No newline at end of file