2 * (C) Copyright 2004, Li-Pro.Net <www.li-pro.net>
3 * Stephan Linz <linz@li-pro.net>
5 * See file CREDITS for list of people who contributed to this
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 #include <linux/ctype.h>
27 #if defined(CONFIG_NIOS_SPI)
31 #if !defined(CFG_NIOS_SPIBASE)
32 #error "*** CFG_NIOS_SPIBASE not defined ***"
35 #if !defined(CFG_NIOS_SPIBITS)
36 #error "*** CFG_NIOS_SPIBITS not defined ***"
39 #if (CFG_NIOS_SPIBITS != 8) && (CFG_NIOS_SPIBITS != 16)
40 #error "*** CFG_NIOS_SPIBITS should be either 8 or 16 ***"
43 static nios_spi_t *spi = (nios_spi_t *)CFG_NIOS_SPIBASE;
46 * You cannot enable DEBUG for early system initalization, i. e. when
47 * this driver is used to read environment parameters like "baudrate"
48 * from EEPROM which are used to initialize the serial port which is
49 * needed to print the debug messages...
55 #define DPRINT(a) printf a;
56 /* -----------------------------------------------
57 * Helper functions to peek into tx and rx buffers
58 * ----------------------------------------------- */
59 static const char * const hex_digit = "0123456789ABCDEF";
61 static char quickhex (int i)
66 static void memdump (void *pv, int num)
69 unsigned char *pc = (unsigned char *) pv;
71 for (i = 0; i < num; i++)
72 printf ("%c%c ", quickhex (pc[i] >> 4), quickhex (pc[i] & 0x0f));
74 for (i = 0; i < num; i++)
75 printf ("%c", isprint (pc[i]) ? pc[i] : '.');
89 * See include/spi.h and http://www.altera.com/literature/ds/ds_nios_spi.pdf
90 * for more informations.
92 int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din)
96 DPRINT(("spi_xfer: chipsel %08X dout %08X din %08X bitlen %d\n",
97 (int)chipsel, *(uint *)dout, *(uint *)din, bitlen));
99 memdump((void*)dout, (bitlen + 7) / 8);
101 if(chipsel != NULL) {
102 chipsel(1); /* select the target chip */
105 if (bitlen > CFG_NIOS_SPIBITS) { /* leave chip select active */
106 spi->control |= NIOS_SPI_SSO;
109 for ( j = 0; /* count each byte in */
110 j < ((bitlen + 7) / 8); /* dout[] and din[] */
112 #if (CFG_NIOS_SPIBITS == 8)
115 while ((spi->status & NIOS_SPI_TRDY) == 0)
117 spi->txdata = (unsigned)(dout[j]);
119 while ((spi->status & NIOS_SPI_RRDY) == 0)
121 din[j] = (unsigned char)(spi->rxdata & 0xff);
123 #elif (CFG_NIOS_SPIBITS == 16)
126 while ((spi->status & NIOS_SPI_TRDY) == 0)
128 if ((j+1) < ((bitlen + 7) / 8))
129 spi->txdata = (unsigned)((dout[j] << 8) | dout[j+1]);
131 spi->txdata = (unsigned)(dout[j] << 8);
133 while ((spi->status & NIOS_SPI_RRDY) == 0)
135 din[j] = (unsigned char)((spi->rxdata >> 8) & 0xff);
136 if ((j+1) < ((bitlen + 7) / 8))
137 din[j+1] = (unsigned char)(spi->rxdata & 0xff);
140 #error "*** unsupported value of CFG_NIOS_SPIBITS ***"
145 if (bitlen > CFG_NIOS_SPIBITS) {
146 spi->control &= ~NIOS_SPI_SSO;
149 if(chipsel != NULL) {
150 chipsel(0); /* deselect the target chip */
153 memdump((void*)din, (bitlen + 7) / 8);
158 #endif /* CONFIG_NIOS_SPI */