soft_spi: move to drivers/spi

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

1 files changed, 193 insertions, 0 deletions

diff --git a/drivers/spi/soft_spi.c b/drivers/spi/soft_spi.c
new file mode 100644
index 0000000..25b589a
--- /dev/null
+++ b/drivers/spi/soft_spi.c
@@ -0,0 +1,193 @@
+/*
+ * (C) Copyright 2002
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
+ *
+ * Influenced by code from:
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * 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 <spi.h>
+
+#include <malloc.h>
+
+/*-----------------------------------------------------------------------
+ * Definitions
+ */
+
+#ifdef DEBUG_SPI
+#define PRINTD(fmt,args...)	printf (fmt ,##args)
+#else
+#define PRINTD(fmt,args...)
+#endif
+
+struct soft_spi_slave {
+	struct spi_slave slave;
+	unsigned int mode;
+};
+
+static inline struct soft_spi_slave *to_soft_spi(struct spi_slave *slave)
+{
+	return container_of(slave, struct soft_spi_slave, slave);
+}
+
+/*=====================================================================*/
+/*                         Public Functions                            */
+/*=====================================================================*/
+
+/*-----------------------------------------------------------------------
+ * Initialization
+ */
+void spi_init (void)
+{
+#ifdef	SPI_INIT
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+
+	SPI_INIT;
+#endif
+}
+
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+		unsigned int max_hz, unsigned int mode)
+{
+	struct soft_spi_slave *ss;
+
+	if (!spi_cs_is_valid(bus, cs))
+		return NULL;
+
+	ss = malloc(sizeof(struct soft_spi_slave));
+	if (!ss)
+		return NULL;
+
+	ss->slave.bus = bus;
+	ss->slave.cs = cs;
+	ss->mode = mode;
+
+	/* TODO: Use max_hz to limit the SCK rate */
+
+	return &ss->slave;
+}
+
+void spi_free_slave(struct spi_slave *slave)
+{
+	struct soft_spi_slave *ss = to_soft_spi(slave);
+
+	free(ss);
+}
+
+int spi_claim_bus(struct spi_slave *slave)
+{
+#ifdef CFG_IMMR
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+#endif
+	struct soft_spi_slave *ss = to_soft_spi(slave);
+
+	/*
+	 * Make sure the SPI clock is in idle state as defined for
+	 * this slave.
+	 */
+	if (ss->mode & SPI_CPOL)
+		SPI_SCL(1);
+	else
+		SPI_SCL(0);
+
+	return 0;
+}
+
+void spi_release_bus(struct spi_slave *slave)
+{
+	/* Nothing to do */
+}
+
+/*-----------------------------------------------------------------------
+ * SPI transfer
+ *
+ * This writes "bitlen" bits out the SPI MOSI port and simultaneously clocks
+ * "bitlen" bits in the SPI MISO port.  That's just the way SPI works.
+ *
+ * The source of the outgoing bits is the "dout" parameter and the
+ * destination of the input bits is the "din" parameter.  Note that "dout"
+ * and "din" can point to the same memory location, in which case the
+ * input data overwrites the output data (since both are buffered by
+ * temporary variables, this is OK).
+ */
+int  spi_xfer(struct spi_slave *slave, unsigned int bitlen,
+		const void *dout, void *din, unsigned long flags)
+{
+#ifdef CFG_IMMR
+	volatile immap_t *immr = (immap_t *)CFG_IMMR;
+#endif
+	struct soft_spi_slave *ss = to_soft_spi(slave);
+	uchar		tmpdin  = 0;
+	uchar		tmpdout = 0;
+	const u8	*txd = dout;
+	u8		*rxd = din;
+	int		cpol = ss->mode & SPI_CPOL;
+	int		cpha = ss->mode & SPI_CPHA;
+	unsigned int	j;
+
+	PRINTD("spi_xfer: slave %u:%u dout %08X din %08X bitlen %u\n",
+		slave->bus, slave->cs, *(uint *)txd, *(uint *)rxd, bitlen);
+
+	if (flags & SPI_XFER_BEGIN)
+		spi_cs_activate(slave);
+
+	for(j = 0; j < bitlen; j++) {
+		/*
+		 * Check if it is time to work on a new byte.
+		 */
+		if((j % 8) == 0) {
+			tmpdout = *txd++;
+			if(j != 0) {
+				*rxd++ = tmpdin;
+			}
+			tmpdin  = 0;
+		}
+
+		if (!cpha)
+			SPI_SCL(!cpol);
+		SPI_SDA(tmpdout & 0x80);
+		SPI_DELAY;
+		if (cpha)
+			SPI_SCL(!cpol);
+		else
+			SPI_SCL(cpol);
+		tmpdin	<<= 1;
+		tmpdin	|= SPI_READ;
+		tmpdout	<<= 1;
+		SPI_DELAY;
+		if (cpha)
+			SPI_SCL(cpol);
+	}
+	/*
+	 * If the number of bits isn't a multiple of 8, shift the last
+	 * bits over to left-justify them.  Then store the last byte
+	 * read in.
+	 */
+	if((bitlen % 8) != 0)
+		tmpdin <<= 8 - (bitlen % 8);
+	*rxd++ = tmpdin;
+
+	if (flags & SPI_XFER_END)
+		spi_cs_deactivate(slave);
+
+	return(0);
+}