159 lines
3.8 KiB
C
159 lines
3.8 KiB
C
/*
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* (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
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* Stephan Linz <linz@li-pro.net>
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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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., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <linux/ctype.h>
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#if defined(CONFIG_NIOS_SPI)
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#include <nios-io.h>
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#include <spi.h>
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#if !defined(CFG_NIOS_SPIBASE)
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#error "*** CFG_NIOS_SPIBASE not defined ***"
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#endif
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#if !defined(CFG_NIOS_SPIBITS)
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#error "*** CFG_NIOS_SPIBITS not defined ***"
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#endif
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#if (CFG_NIOS_SPIBITS != 8) && (CFG_NIOS_SPIBITS != 16)
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#error "*** CFG_NIOS_SPIBITS should be either 8 or 16 ***"
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#endif
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static nios_spi_t *spi = (nios_spi_t *)CFG_NIOS_SPIBASE;
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/* Warning:
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* You cannot enable DEBUG for early system initalization, i. e. when
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* this driver is used to read environment parameters like "baudrate"
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* from EEPROM which are used to initialize the serial port which is
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* needed to print the debug messages...
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*/
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#undef DEBUG
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#ifdef DEBUG
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#define DPRINT(a) printf a;
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/* -----------------------------------------------
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* Helper functions to peek into tx and rx buffers
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* ----------------------------------------------- */
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static const char * const hex_digit = "0123456789ABCDEF";
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static char quickhex (int i)
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{
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return hex_digit[i];
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}
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static void memdump (void *pv, int num)
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{
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int i;
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unsigned char *pc = (unsigned char *) pv;
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for (i = 0; i < num; i++)
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printf ("%c%c ", quickhex (pc[i] >> 4), quickhex (pc[i] & 0x0f));
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printf ("\t");
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for (i = 0; i < num; i++)
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printf ("%c", isprint (pc[i]) ? pc[i] : '.');
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printf ("\n");
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}
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#else /* !DEBUG */
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#define DPRINT(a)
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#define memdump(p,n)
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#endif /* DEBUG */
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/*
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* SPI transfer:
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*
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* See include/spi.h and http://www.altera.com/literature/ds/ds_nios_spi.pdf
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* for more informations.
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*/
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int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din)
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{
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int j;
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DPRINT(("spi_xfer: chipsel %08X dout %08X din %08X bitlen %d\n",
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(int)chipsel, *(uint *)dout, *(uint *)din, bitlen));
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memdump((void*)dout, (bitlen + 7) / 8);
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if(chipsel != NULL) {
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chipsel(1); /* select the target chip */
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}
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if (bitlen > CFG_NIOS_SPIBITS) { /* leave chip select active */
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spi->control |= NIOS_SPI_SSO;
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}
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for ( j = 0; /* count each byte in */
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j < ((bitlen + 7) / 8); /* dout[] and din[] */
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#if (CFG_NIOS_SPIBITS == 8)
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j++) {
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while ((spi->status & NIOS_SPI_TRDY) == 0)
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;
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spi->txdata = (unsigned)(dout[j]);
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while ((spi->status & NIOS_SPI_RRDY) == 0)
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;
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din[j] = (unsigned char)(spi->rxdata & 0xff);
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#elif (CFG_NIOS_SPIBITS == 16)
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j++, j++) {
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while ((spi->status & NIOS_SPI_TRDY) == 0)
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;
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if ((j+1) < ((bitlen + 7) / 8))
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spi->txdata = (unsigned)((dout[j] << 8) | dout[j+1]);
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else
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spi->txdata = (unsigned)(dout[j] << 8);
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while ((spi->status & NIOS_SPI_RRDY) == 0)
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;
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din[j] = (unsigned char)((spi->rxdata >> 8) & 0xff);
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if ((j+1) < ((bitlen + 7) / 8))
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din[j+1] = (unsigned char)(spi->rxdata & 0xff);
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#else
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#error "*** unsupported value of CFG_NIOS_SPIBITS ***"
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#endif
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}
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if (bitlen > CFG_NIOS_SPIBITS) {
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spi->control &= ~NIOS_SPI_SSO;
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}
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if(chipsel != NULL) {
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chipsel(0); /* deselect the target chip */
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}
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memdump((void*)din, (bitlen + 7) / 8);
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return 0;
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}
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#endif /* CONFIG_NIOS_SPI */
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