/* * (C) Copyright 2004, Li-Pro.Net * Stephan Linz * * 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 #include #if defined(CONFIG_NIOS_SPI) #include #include #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 */