[U-Boot] [PATCH v2 1/3] mpc52xx: Add SPI driver.

Grzegorz Bernacki gjb at semihalf.com
Tue Jun 9 14:14:50 CEST 2009


Signed-off-by: Grzegorz Bernacki <gjb at semihalf.com>
---
v2:
 - use accessor macros

 drivers/spi/Makefile      |    1 +
 drivers/spi/mpc52xx_spi.c |  109 +++++++++++++++++++++++++++++++++++++++++++++
 include/mpc5xxx.h         |   18 +++++++
 3 files changed, 128 insertions(+), 0 deletions(-)
 create mode 100644 drivers/spi/mpc52xx_spi.c

diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 1350f3e..1272c17 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -28,6 +28,7 @@ LIB	:= $(obj)libspi.a
 COBJS-$(CONFIG_ATMEL_DATAFLASH_SPI) += atmel_dataflash_spi.o
 COBJS-$(CONFIG_ATMEL_SPI) += atmel_spi.o
 COBJS-$(CONFIG_BFIN_SPI) += bfin_spi.o
+COBJS-$(CONFIG_MPC52XX_SPI) += mpc52xx_spi.o
 COBJS-$(CONFIG_MPC8XXX_SPI) += mpc8xxx_spi.o
 COBJS-$(CONFIG_MXC_SPI) += mxc_spi.o
 COBJS-$(CONFIG_SOFT_SPI) += soft_spi.o
diff --git a/drivers/spi/mpc52xx_spi.c b/drivers/spi/mpc52xx_spi.c
new file mode 100644
index 0000000..a5483af
--- /dev/null
+++ b/drivers/spi/mpc52xx_spi.c
@@ -0,0 +1,109 @@
+/*
+ * (C) Copyright 2009
+ * Frank Bodammer <frank.bodammer at 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
+	 */
+	out8((u32)&spi->ddr, 0x0F);	/* set all SPI pins as output */
+	out8((u32)&spi->pdr, 0x00);	/* set SS low */
+	/* SPI is master, SS is general purpose output */
+	out8((u32)&spi->cr1, SPI_CR_MSTR | SPI_CR_SPE);
+	out8((u32)&spi->cr2, 0x00);	/* normal operation */
+	out8((u32)&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]);
+		out8((u32)&spi->dr, txp[i]);
+		while (!(in8((u32)&spi->sr) & SPI_SR_SPIF)) {
+			udelay(1000);
+			if (in8((u32)&spi->sr) & SPI_SR_WCOL) {
+				rxp[i] = in8((u32)&spi->dr);
+				puts("spi_xfer: write collision\n");
+				return -1;
+			}
+		}
+		rxp[i] = in8((u32)&spi->dr);
+		debug("spi_xfer: received %x\n", rxp[i]);
+	}
+	if (flags & SPI_XFER_END)
+		clrbits_8(&spi->pdr, SPI_PDR_SS);
+
+	return 0;
+}
diff --git a/include/mpc5xxx.h b/include/mpc5xxx.h
index 463d5ae..476d149 100644
--- a/include/mpc5xxx.h
+++ b/include/mpc5xxx.h
@@ -392,6 +392,24 @@
 #define I2C_IF		0x02
 #define I2C_RXAK	0x01
 
+/* SPI control register 1 bits */
+#define SPI_CR_LSBFE	0x01
+#define SPI_CR_SSOE	0x02
+#define SPI_CR_CPHA	0x04
+#define SPI_CR_CPOL	0x08
+#define SPI_CR_MSTR	0x10
+#define SPI_CR_SWOM	0x20
+#define SPI_CR_SPE	0x40
+#define SPI_CR_SPIE	0x80
+
+/* SPI status register bits */
+#define SPI_SR_MODF	0x10
+#define SPI_SR_WCOL	0x40
+#define SPI_SR_SPIF	0x80
+
+/* SPI port data register bits */
+#define SPI_PDR_SS	0x08
+
 /* Programmable Serial Controller (PSC) status register bits */
 #define PSC_SR_CDE		0x0080
 #define PSC_SR_RXRDY		0x0100
-- 
1.6.0.6



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