c70e9fc233
- Consistently use the same wording and formatting for all license headers. - Remove useless whitespace, add missing whitespace, fix indentation. - Add missing "This file is part of the coreboot project." where needed. - Change "(C) Copyright John Doe" to "Copyright (C) John Doe" for consistency. - Add some missing "(C)" strings and copyright years where needed. - Move random comments and file descriptions out of the license header. - Drop incorrect file descriptions completely (e.g. lpc47m10x/Makefile.inc). There should be no changes in _content_ of the license headers, if you spot such changes that's a bug, please report! Signed-off-by: Uwe Hermann <uwe@hermann-uwe.de> Acked-by: Uwe Hermann <uwe@hermann-uwe.de> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5127 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
99 lines
2.7 KiB
C
99 lines
2.7 KiB
C
/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2005 Yinghai Lu <yinghailu@gmail.com>
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* Copyright (C) 2009 coresystems GmbH
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <device/smbus_def.h>
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static void smbus_delay(void)
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{
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inb(0x80);
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}
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static int smbus_wait_until_ready(u16 smbus_base)
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{
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unsigned loops = SMBUS_TIMEOUT;
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unsigned char byte;
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do {
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smbus_delay();
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if (--loops == 0)
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break;
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byte = inb(smbus_base + SMBHSTSTAT);
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} while (byte & 1);
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return loops ? 0 : -1;
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}
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static int smbus_wait_until_done(u16 smbus_base)
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{
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unsigned loops = SMBUS_TIMEOUT;
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unsigned char byte;
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do {
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smbus_delay();
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if (--loops == 0)
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break;
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byte = inb(smbus_base + SMBHSTSTAT);
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} while ((byte & 1) || (byte & ~((1 << 6) | (1 << 0))) == 0);
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return loops ? 0 : -1;
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}
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static int do_smbus_read_byte(unsigned smbus_base, unsigned device, unsigned address)
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{
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unsigned char global_status_register;
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unsigned char byte;
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if (smbus_wait_until_ready(smbus_base) < 0) {
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return SMBUS_WAIT_UNTIL_READY_TIMEOUT;
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}
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/* Setup transaction */
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/* Disable interrupts */
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outb(inb(smbus_base + SMBHSTCTL) & (~1), smbus_base + SMBHSTCTL);
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/* Set the device I'm talking too */
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outb(((device & 0x7f) << 1) | 1, smbus_base + SMBXMITADD);
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/* Set the command/address... */
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outb(address & 0xff, smbus_base + SMBHSTCMD);
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/* Set up for a byte data read */
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outb((inb(smbus_base + SMBHSTCTL) & 0xe3) | (0x2 << 2),
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(smbus_base + SMBHSTCTL));
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/* Clear any lingering errors, so the transaction will run */
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outb(inb(smbus_base + SMBHSTSTAT), smbus_base + SMBHSTSTAT);
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/* Clear the data byte... */
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outb(0, smbus_base + SMBHSTDAT0);
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/* Start the command */
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outb((inb(smbus_base + SMBHSTCTL) | 0x40),
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smbus_base + SMBHSTCTL);
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/* Poll for transaction completion */
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if (smbus_wait_until_done(smbus_base) < 0) {
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return SMBUS_WAIT_UNTIL_DONE_TIMEOUT;
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}
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global_status_register = inb(smbus_base + SMBHSTSTAT);
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/* Ignore the "In Use" status... */
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global_status_register &= ~(3 << 5);
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/* Read results of transaction */
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byte = inb(smbus_base + SMBHSTDAT0);
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if (global_status_register != (1 << 1)) {
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return SMBUS_ERROR;
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}
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return byte;
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}
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