blob: caf1a99316e2296932153eec4c69647ba6ae7375 [file] [log] [blame]
/*
* This file is part of the flashrom project.
*
* Copyright (C) 2008 Wang Qingpei <Qingpei.Wang@amd.com>
* Copyright (C) 2008 Joe Bao <Zheng.Bao@amd.com>
* Copyright (C) 2008 Advanced Micro Devices, Inc.
* Copyright (C) 2009, 2010 Carl-Daniel Hailfinger
*
* 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
*/
#if defined(__i386__) || defined(__x86_64__)
#include "flash.h"
#include "chipdrivers.h"
#include "spi.h"
/* This struct is unused, but helps visualize the SB600 SPI BAR layout.
*struct sb600_spi_controller {
* unsigned int spi_cntrl0; / * 00h * /
* unsigned int restrictedcmd1; / * 04h * /
* unsigned int restrictedcmd2; / * 08h * /
* unsigned int spi_cntrl1; / * 0ch * /
* unsigned int spi_cmdvalue0; / * 10h * /
* unsigned int spi_cmdvalue1; / * 14h * /
* unsigned int spi_cmdvalue2; / * 18h * /
* unsigned int spi_fakeid; / * 1Ch * /
*};
*/
uint8_t *sb600_spibar = NULL;
int sb600_spi_read(struct flashchip *flash, uint8_t *buf, int start, int len)
{
/* Maximum read length is 8 bytes. */
return spi_read_chunked(flash, buf, start, len, 8);
}
int sb600_spi_write_256(struct flashchip *flash, uint8_t *buf, int start, int len)
{
return spi_write_chunked(flash, buf, start, len, 5);
}
static void reset_internal_fifo_pointer(void)
{
mmio_writeb(mmio_readb(sb600_spibar + 2) | 0x10, sb600_spibar + 2);
while (mmio_readb(sb600_spibar + 0xD) & 0x7)
msg_pspew("reset\n");
}
static void execute_command(void)
{
mmio_writeb(mmio_readb(sb600_spibar + 2) | 1, sb600_spibar + 2);
while (mmio_readb(sb600_spibar + 2) & 1)
;
}
int sb600_spi_send_command(unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr)
{
int count;
/* First byte is cmd which can not being sent through FIFO. */
unsigned char cmd = *writearr++;
unsigned int readoffby1;
writecnt--;
msg_pspew("%s, cmd=%x, writecnt=%x, readcnt=%x\n",
__func__, cmd, writecnt, readcnt);
if (readcnt > 8) {
msg_pinfo("%s, SB600 SPI controller can not receive %d bytes, "
"it is limited to 8 bytes\n", __func__, readcnt);
return SPI_INVALID_LENGTH;
}
if (writecnt > 8) {
msg_pinfo("%s, SB600 SPI controller can not send %d bytes, "
"it is limited to 8 bytes\n", __func__, writecnt);
return SPI_INVALID_LENGTH;
}
/* This is a workaround for a bug in SB600 and SB700. If we only send
* an opcode and no additional data/address, the SPI controller will
* read one byte too few from the chip. Basically, the last byte of
* the chip response is discarded and will not end up in the FIFO.
* It is unclear if the CS# line is set high too early as well.
*/
readoffby1 = (writecnt) ? 0 : 1;
mmio_writeb((readcnt + readoffby1) << 4 | (writecnt), sb600_spibar + 1);
mmio_writeb(cmd, sb600_spibar + 0);
/* Before we use the FIFO, reset it first. */
reset_internal_fifo_pointer();
/* Send the write byte to FIFO. */
for (count = 0; count < writecnt; count++, writearr++) {
msg_pspew(" [%x]", *writearr);
mmio_writeb(*writearr, sb600_spibar + 0xC);
}
msg_pspew("\n");
/*
* We should send the data by sequence, which means we need to reset
* the FIFO pointer to the first byte we want to send.
*/
reset_internal_fifo_pointer();
execute_command();
/*
* After the command executed, we should find out the index of the
* received byte. Here we just reset the FIFO pointer and skip the
* writecnt.
* It would be possible to increase the FIFO pointer by one instead
* of reading and discarding one byte from the FIFO.
* The FIFO is implemented on top of an 8 byte ring buffer and the
* buffer is never cleared. For every byte that is shifted out after
* the opcode, the FIFO already stores the response from the chip.
* Usually, the chip will respond with 0x00 or 0xff.
*/
reset_internal_fifo_pointer();
/* Skip the bytes we sent. */
for (count = 0; count < writecnt; count++) {
cmd = mmio_readb(sb600_spibar + 0xC);
msg_pspew("[ %2x]", cmd);
}
msg_pspew("The FIFO pointer after skipping is %d.\n",
mmio_readb(sb600_spibar + 0xd) & 0x07);
for (count = 0; count < readcnt; count++, readarr++) {
*readarr = mmio_readb(sb600_spibar + 0xC);
msg_pspew("[%02x]", *readarr);
}
msg_pspew("\n");
return 0;
}
#endif