LXR uboot/drivers/spi/mpc52xx

   1/*
   2 * (C) Copyright 2009
   3 * Frank Bodammer <frank.bodammer@gcd-solutions.de>
   4 * (C) Copyright 2009 Semihalf, Grzegorz Bernacki
   5 *
   6 * See file CREDITS for list of people who contributed to this
   7 * project.
   8 *
   9 * This program is free software; you can redistribute it and/or
  10 * modify it under the terms of the GNU General Public License as
  11 * published by the Free Software Foundation; either version 2 of
  12 * the License, or (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 *
  19 * You should have received a copy of the GNU General Public License
  20 * along with this program; if not, write to the Free Software
  21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22 * MA 02111-1307 USA
  23 */
  24
  25#include <common.h>
  26#include <asm/io.h>
  27#include <malloc.h>
  28#include <spi.h>
  29#include <mpc5xxx.h>
  30
  31void spi_init(void)
  32{
  33        struct mpc5xxx_spi *spi = (struct mpc5xxx_spi *)MPC5XXX_SPI;
  34        /*
  35         * Its important to use the correct order when initializing the
  36         * registers
  37         */
  38        out_8(&spi->ddr, 0x0F); /* set all SPI pins as output */
  39        out_8(&spi->pdr, 0x00); /* set SS low */
  40        /* SPI is master, SS is general purpose output */
  41        out_8(&spi->cr1, SPI_CR_MSTR | SPI_CR_SPE);
  42        out_8(&spi->cr2, 0x00); /* normal operation */
  43        out_8(&spi->brr, 0x77); /* baud rate: IPB clock / 2048 */
  44}
  45
  46struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
  47                                  unsigned int max_hz, unsigned int mode)
  48{
  49        struct spi_slave *slave;
  50
  51        slave = malloc(sizeof(struct spi_slave));
  52        if (!slave)
  53                return NULL;
  54
  55        slave->bus = bus;
  56        slave->cs = cs;
  57
  58        return slave;
  59}
  60
  61void spi_free_slave(struct spi_slave *slave)
  62{
  63        free(slave);
  64}
  65
  66int spi_claim_bus(struct spi_slave *slave)
  67{
  68        return 0;
  69}
  70
  71void spi_release_bus(struct spi_slave *slave)
  72{
  73        return;
  74}
  75
  76int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
  77             void *din, unsigned long flags)
  78{
  79        struct mpc5xxx_spi *spi = (struct mpc5xxx_spi *)MPC5XXX_SPI;
  80        int i, iter = bitlen >> 3;
  81        const uchar *txp = dout;
  82        uchar *rxp = din;
  83
  84        debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
  85              slave->bus, slave->cs, *(uint *) dout, *(uint *) din, bitlen);
  86
  87        if (flags & SPI_XFER_BEGIN)
  88                setbits_8(&spi->pdr, SPI_PDR_SS);
  89
  90        for (i = 0; i < iter; i++) {
  91                udelay(1000);
  92                debug("spi_xfer: sending %x\n", txp[i]);
  93                out_8(&spi->dr, txp[i]);
  94                while (!(in_8(&spi->sr) & SPI_SR_SPIF)) {
  95                        udelay(1000);
  96                        if (in_8(&spi->sr) & SPI_SR_WCOL) {
  97                                rxp[i] = in_8(&spi->dr);
  98                                puts("spi_xfer: write collision\n");
  99                                return -1;
 100                        }
 101                }
 102                rxp[i] = in_8(&spi->dr);
 103                debug("spi_xfer: received %x\n", rxp[i]);
 104        }
 105        if (flags & SPI_XFER_END)
 106                clrbits_8(&spi->pdr, SPI_PDR_SS);
 107
 108        return 0;
 109}
 110