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/*
* (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
* Stephan Linz <linz@li-pro.net>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <linux/ctype.h>
#if defined(CONFIG_NIOS_SPI)
#include <nios-io.h>
#include <spi.h>
#if !defined(CFG_NIOS_SPIBASE)
#error "*** CFG_NIOS_SPIBASE not defined ***"
#endif
#if !defined(CFG_NIOS_SPIBITS)
#error "*** CFG_NIOS_SPIBITS not defined ***"
#endif
#if (CFG_NIOS_SPIBITS != 8) && (CFG_NIOS_SPIBITS != 16)
#error "*** CFG_NIOS_SPIBITS should be either 8 or 16 ***"
#endif
static nios_spi_t *spi = (nios_spi_t *)CFG_NIOS_SPIBASE;
/* Warning:
* You cannot enable DEBUG for early system initalization, i. e. when
* this driver is used to read environment parameters like "baudrate"
* from EEPROM which are used to initialize the serial port which is
* needed to print the debug messages...
*/
#undef DEBUG
#ifdef DEBUG
#define DPRINT(a) printf a;
/* -----------------------------------------------
* Helper functions to peek into tx and rx buffers
* ----------------------------------------------- */
static const char * const hex_digit = "0123456789ABCDEF";
static char quickhex (int i)
{
return hex_digit[i];
}
static void memdump (const void *pv, int num)
{
int i;
const unsigned char *pc = (const unsigned char *) pv;
for (i = 0; i < num; i++)
printf ("%c%c ", quickhex (pc[i] >> 4), quickhex (pc[i] & 0x0f));
printf ("\t");
for (i = 0; i < num; i++)
printf ("%c", isprint (pc[i]) ? pc[i] : '.');
printf ("\n");
}
#else /* !DEBUG */
#define DPRINT(a)
#define memdump(p,n)
#endif /* DEBUG */
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
struct spi_slave *slave;
if (!spi_cs_is_valid(bus, cs))
return NULL;
slave = malloc(sizeof(struct spi_slave));
if (!slave)
return NULL;
slave->bus = bus;
slave->cs = cs;
/* TODO: Add support for different modes and speeds */
return slave;
}
void spi_free_slave(struct spi_slave *slave)
{
free(slave);
}
int spi_claim_bus(struct spi_slave *slave)
{
return 0;
}
void spi_release_bus(struct spi_slave *slave)
{
}
/*
* SPI transfer:
*
* See include/spi.h and http://www.altera.com/literature/ds/ds_nios_spi.pdf
* for more informations.
*/
int spi_xfer(struct spi_slave *slave, int bitlen, const void *dout,
void *din, unsigned long flags)
{
const u8 *txd = dout;
u8 *rxd = din;
int j;
DPRINT(("spi_xfer: slave %u:%u dout %08X din %08X bitlen %d\n",
slave->bus, slave->cs, *(uint *)dout, *(uint *)din, bitlen));
memdump(dout, (bitlen + 7) / 8);
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(slave);
if (!(flags & SPI_XFER_END) || bitlen > CFG_NIOS_SPIBITS) {
/* leave chip select active */
spi->control |= NIOS_SPI_SSO;
}
for ( j = 0; /* count each byte in */
j < ((bitlen + 7) / 8); /* dout[] and din[] */
#if (CFG_NIOS_SPIBITS == 8)
j++) {
while ((spi->status & NIOS_SPI_TRDY) == 0)
;
spi->txdata = (unsigned)(txd[j]);
while ((spi->status & NIOS_SPI_RRDY) == 0)
;
rxd[j] = (unsigned char)(spi->rxdata & 0xff);
#elif (CFG_NIOS_SPIBITS == 16)
j++, j++) {
while ((spi->status & NIOS_SPI_TRDY) == 0)
;
if ((j+1) < ((bitlen + 7) / 8))
spi->txdata = (unsigned)((txd[j] << 8) | txd[j+1]);
else
spi->txdata = (unsigned)(txd[j] << 8);
while ((spi->status & NIOS_SPI_RRDY) == 0)
;
rxd[j] = (unsigned char)((spi->rxdata >> 8) & 0xff);
if ((j+1) < ((bitlen + 7) / 8))
rxd[j+1] = (unsigned char)(spi->rxdata & 0xff);
#else
#error "*** unsupported value of CFG_NIOS_SPIBITS ***"
#endif
}
if (bitlen > CFG_NIOS_SPIBITS && (flags & SPI_XFER_END)) {
spi->control &= ~NIOS_SPI_SSO;
}
if (flags & SPI_XFER_END)
spi_cs_deactivate(slave);
memdump(din, (bitlen + 7) / 8);
return 0;
}
#endif /* CONFIG_NIOS_SPI */
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