diff options
Diffstat (limited to 'drivers/spi/mpc52xx_spi.c')
-rw-r--r-- | drivers/spi/mpc52xx_spi.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/spi/mpc52xx_spi.c b/drivers/spi/mpc52xx_spi.c new file mode 100644 index 0000000..3e96b3f --- /dev/null +++ b/drivers/spi/mpc52xx_spi.c @@ -0,0 +1,109 @@ +/* + * (C) Copyright 2009 + * Frank Bodammer <frank.bodammer@gcd-solutions.de> + * (C) Copyright 2009 Semihalf, Grzegorz Bernacki + * + * 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 <asm/io.h> +#include <malloc.h> +#include <spi.h> +#include <mpc5xxx.h> + +void spi_init(void) +{ + struct mpc5xxx_spi *spi = (struct mpc5xxx_spi *)MPC5XXX_SPI; + /* + * Its important to use the correct order when initializing the + * registers + */ + out_8(&spi->ddr, 0x0F); /* set all SPI pins as output */ + out_8(&spi->pdr, 0x00); /* set SS low */ + /* SPI is master, SS is general purpose output */ + out_8(&spi->cr1, SPI_CR_MSTR | SPI_CR_SPE); + out_8(&spi->cr2, 0x00); /* normal operation */ + out_8(&spi->brr, 0x77); /* baud rate: IPB clock / 2048 */ +} + +struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, + unsigned int max_hz, unsigned int mode) +{ + struct spi_slave *slave; + + slave = malloc(sizeof(struct spi_slave)); + if (!slave) + return NULL; + + slave->bus = bus; + slave->cs = cs; + + 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) +{ + return; +} + +int spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout, + void *din, unsigned long flags) +{ + struct mpc5xxx_spi *spi = (struct mpc5xxx_spi *)MPC5XXX_SPI; + int i, iter = bitlen >> 3; + const uchar *txp = dout; + uchar *rxp = din; + + debug("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n", + slave->bus, slave->cs, *(uint *) dout, *(uint *) din, bitlen); + + if (flags & SPI_XFER_BEGIN) + setbits_8(&spi->pdr, SPI_PDR_SS); + + for (i = 0; i < iter; i++) { + udelay(1000); + debug("spi_xfer: sending %x\n", txp[i]); + out_8(&spi->dr, txp[i]); + while (!(in_8(&spi->sr) & SPI_SR_SPIF)) { + udelay(1000); + if (in_8(&spi->sr) & SPI_SR_WCOL) { + rxp[i] = in_8(&spi->dr); + puts("spi_xfer: write collision\n"); + return -1; + } + } + rxp[i] = in_8(&spi->dr); + debug("spi_xfer: received %x\n", rxp[i]); + } + if (flags & SPI_XFER_END) + clrbits_8(&spi->pdr, SPI_PDR_SS); + + return 0; +} |