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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.
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include "flash.h"
#include "programmer.h"
#include "spi.h"
/* Note that CS# is active low, so val=0 means the chip is active. */
static void bitbang_spi_set_cs(const struct bitbang_spi_master * const master, int val)
{
master->set_cs(val);
}
static void bitbang_spi_set_sck(const struct bitbang_spi_master * const master, int val)
{
master->set_sck(val);
}
static void bitbang_spi_request_bus(const struct bitbang_spi_master * const master)
{
if (master->request_bus)
master->request_bus();
}
static void bitbang_spi_release_bus(const struct bitbang_spi_master * const master)
{
if (master->release_bus)
master->release_bus();
}
static void bitbang_spi_set_sck_set_mosi(const struct bitbang_spi_master * const master, int sck, int mosi)
{
if (master->set_sck_set_mosi) {
master->set_sck_set_mosi(sck, mosi);
return;
}
master->set_sck(sck);
master->set_mosi(mosi);
}
static int bitbang_spi_set_sck_get_miso(const struct bitbang_spi_master * const master, int sck)
{
if (master->set_sck_get_miso)
return master->set_sck_get_miso(sck);
master->set_sck(sck);
return master->get_miso();
}
static int bitbang_spi_send_command(struct flashctx *flash,
unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr,
unsigned char *readarr);
static const struct spi_master spi_master_bitbang = {
.features = SPI_MASTER_4BA,
.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,
.write_aai = default_spi_write_aai,
};
#if 0 // until it is needed
static int bitbang_spi_shutdown(const struct bitbang_spi_master *master)
{
/* FIXME: Run bitbang_spi_release_bus here or per command? */
return 0;
}
#endif
int register_spi_bitbang_master(const struct bitbang_spi_master *master)
{
struct spi_master mst = spi_master_bitbang;
/* If someone forgot to initialize a bitbang function, we catch it here. */
if (!master || !master->set_cs ||
!master->set_sck || !master->set_mosi || !master->get_miso ||
(master->request_bus && !master->release_bus) ||
(!master->request_bus && master->release_bus)) {
msg_perr("Incomplete SPI bitbang master setting!\n"
"Please report a bug at flashrom@flashrom.org\n");
return ERROR_FLASHROM_BUG;
}
mst.data = master;
register_spi_master(&mst);
/* Only mess with the bus if we're sure nobody else uses it. */
bitbang_spi_request_bus(master);
bitbang_spi_set_cs(master, 1);
bitbang_spi_set_sck_set_mosi(master, 0, 0);
/* FIXME: Release SPI bus here and request it again for each command or
* don't release it now and only release it on programmer shutdown?
*/
bitbang_spi_release_bus(master);
return 0;
}
static uint8_t bitbang_spi_read_byte(const struct bitbang_spi_master *master)
{
uint8_t ret = 0;
int i;
for (i = 7; i >= 0; i--) {
if (i == 0)
bitbang_spi_set_sck_set_mosi(master, 0, 0);
else
bitbang_spi_set_sck(master, 0);
programmer_delay(master->half_period);
ret <<= 1;
ret |= bitbang_spi_set_sck_get_miso(master, 1);
programmer_delay(master->half_period);
}
return ret;
}
static void bitbang_spi_write_byte(const struct bitbang_spi_master *master, uint8_t val)
{
int i;
for (i = 7; i >= 0; i--) {
bitbang_spi_set_sck_set_mosi(master, 0, (val >> i) & 1);
programmer_delay(master->half_period);
bitbang_spi_set_sck(master, 1);
programmer_delay(master->half_period);
}
}
static int bitbang_spi_send_command(struct flashctx *flash,
unsigned int writecnt, unsigned int readcnt,
const unsigned char *writearr,
unsigned char *readarr)
{
unsigned int i;
const struct bitbang_spi_master *master = flash->mst->spi.data;
/* 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(master);
bitbang_spi_set_cs(master, 0);
for (i = 0; i < writecnt; i++)
bitbang_spi_write_byte(master, writearr[i]);
for (i = 0; i < readcnt; i++)
readarr[i] = bitbang_spi_read_byte(master);
bitbang_spi_set_sck(master, 0);
programmer_delay(master->half_period);
bitbang_spi_set_cs(master, 1);
programmer_delay(master->half_period);
/* FIXME: Run bitbang_spi_release_bus here or in programmer init? */
bitbang_spi_release_bus(master);
return 0;
}
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