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/*
* This file is part of the flashrom project.
*
* 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; 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
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include "flash.h"
#include "chipdrivers.h"
#include "programmer.h"
#include "spi.h"
/* Length of half a clock period in usecs. */
static int bitbang_spi_half_period;
static const struct bitbang_spi_master *bitbang_spi_master = NULL;
/* Note that CS# is active low, so val=0 means the chip is active. */
static void bitbang_spi_set_cs(int val)
{
bitbang_spi_master->set_cs(val);
}
static void bitbang_spi_set_sck(int val)
{
bitbang_spi_master->set_sck(val);
}
static void bitbang_spi_set_mosi(int val)
{
bitbang_spi_master->set_mosi(val);
}
static int bitbang_spi_get_miso(void)
{
return bitbang_spi_master->get_miso();
}
static void bitbang_spi_request_bus(void)
{
if (bitbang_spi_master->request_bus)
bitbang_spi_master->request_bus();
}
static void bitbang_spi_release_bus(void)
{
if (bitbang_spi_master->release_bus)
bitbang_spi_master->release_bus();
}
static int bitbang_spi_send_command(unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr);
static const struct spi_programmer spi_programmer_bitbang = {
.type = SPI_CONTROLLER_BITBANG,
.max_data_read = MAX_DATA_READ_UNLIMITED,
.max_data_write = MAX_DATA_WRITE_UNLIMITED,
.command = bitbang_spi_send_command,
.multicommand = default_spi_send_multicommand,
.read = default_spi_read,
.write_256 = default_spi_write_256,
};
int bitbang_spi_init(const struct bitbang_spi_master *master, int halfperiod)
{
/* BITBANG_SPI_INVALID is 0, so if someone forgot to initialize ->type,
* we catch it here. Same goes for missing initialization of bitbanging
* functions.
*/
if (!master || master->type == BITBANG_SPI_INVALID || !master->set_cs ||
!master->set_sck || !master->set_mosi || !master->get_miso) {
msg_perr("Incomplete SPI bitbang master setting!\n"
"Please report a bug at flashrom@flashrom.org\n");
return 1;
}
if (bitbang_spi_master) {
msg_perr("SPI bitbang master already initialized!\n"
"Please report a bug at flashrom@flashrom.org\n");
return 1;
}
bitbang_spi_master = master;
bitbang_spi_half_period = halfperiod;
register_spi_programmer(&spi_programmer_bitbang);
/* FIXME: Run bitbang_spi_request_bus here or in programmer init? */
bitbang_spi_set_cs(1);
bitbang_spi_set_sck(0);
bitbang_spi_set_mosi(0);
return 0;
}
int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
{
if (!bitbang_spi_master) {
msg_perr("Shutting down an uninitialized SPI bitbang master!\n"
"Please report a bug at flashrom@flashrom.org\n");
return 1;
}
if (master != bitbang_spi_master) {
msg_perr("Shutting down a mismatched SPI bitbang master!\n"
"Please report a bug at flashrom@flashrom.org\n");
return 1;
}
/* FIXME: Run bitbang_spi_release_bus here or per command? */
bitbang_spi_master = NULL;
return 0;
}
static uint8_t bitbang_spi_readwrite_byte(uint8_t val)
{
uint8_t ret = 0;
int i;
for (i = 7; i >= 0; i--) {
bitbang_spi_set_mosi((val >> i) & 1);
programmer_delay(bitbang_spi_half_period);
bitbang_spi_set_sck(1);
ret <<= 1;
ret |= bitbang_spi_get_miso();
programmer_delay(bitbang_spi_half_period);
bitbang_spi_set_sck(0);
}
return ret;
}
static int bitbang_spi_send_command(unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr, unsigned char *readarr)
{
int i;
/* FIXME: Run bitbang_spi_request_bus here or in programmer init?
* Requesting and releasing the SPI bus is handled in here to allow the
* programmer to use its own SPI engine for native accesses.
*/
bitbang_spi_request_bus();
bitbang_spi_set_cs(0);
for (i = 0; i < writecnt; i++)
bitbang_spi_readwrite_byte(writearr[i]);
for (i = 0; i < readcnt; i++)
readarr[i] = bitbang_spi_readwrite_byte(0);
programmer_delay(bitbang_spi_half_period);
bitbang_spi_set_cs(1);
programmer_delay(bitbang_spi_half_period);
/* FIXME: Run bitbang_spi_release_bus here or in programmer init? */
bitbang_spi_release_bus();
return 0;
}
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