mpc52xx: Add SPI driver.

Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>

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;
+}