Add SPI flash driver

This driver is taken from u-boot and adapted to match
coreboot. It still contains some hacks and is ICH specific
at places.

Change-Id: I97dd8096f7db3b62f8f4f4e4d08bdee10d88f689
Signed-off-by: Patrick Georgi <patrick@georgi-clan.de>
Reviewed-on: http://review.coreboot.org/997
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 203 insertions, 0 deletions

diff --git a/src/include/spi.h b/src/include/spi.h
new file mode 100644
index 0000000000..bb84258137
--- /dev/null
+++ b/src/include/spi.h
@@ -0,0 +1,203 @@
+/*
+ * (C) Copyright 2001
+ * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
+ *
+ * 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
+ */
+
+#ifndef _SPI_H_
+#define _SPI_H_
+
+#include <stdint.h>
+
+/* Controller-specific definitions: */
+
+/* SPI mode flags */
+#define	SPI_CPHA	0x01			/* clock phase */
+#define	SPI_CPOL	0x02			/* clock polarity */
+#define	SPI_MODE_0	(0|0)			/* (original MicroWire) */
+#define	SPI_MODE_1	(0|SPI_CPHA)
+#define	SPI_MODE_2	(SPI_CPOL|0)
+#define	SPI_MODE_3	(SPI_CPOL|SPI_CPHA)
+#define	SPI_CS_HIGH	0x04			/* CS active high */
+#define	SPI_LSB_FIRST	0x08			/* per-word bits-on-wire */
+#define	SPI_3WIRE	0x10			/* SI/SO signals shared */
+#define	SPI_LOOP	0x20			/* loopback mode */
+
+/* SPI transfer flags */
+#define SPI_XFER_BEGIN	0x01			/* Assert CS before transfer */
+#define SPI_XFER_END	0x02			/* Deassert CS after transfer */
+
+/*-----------------------------------------------------------------------
+ * Representation of a SPI slave, i.e. what we're communicating with.
+ *
+ * Drivers are expected to extend this with controller-specific data.
+ *
+ *   bus:	ID of the bus that the slave is attached to.
+ *   cs:	ID of the chip select connected to the slave.
+ */
+struct spi_slave {
+	unsigned int	bus;
+	unsigned int	cs;
+};
+
+/*-----------------------------------------------------------------------
+ * Initialization, must be called once on start up.
+ *
+ * TODO: I don't think we really need this.
+ */
+void spi_init(void);
+
+/*-----------------------------------------------------------------------
+ * Set up communications parameters for a SPI slave.
+ *
+ * This must be called once for each slave. Note that this function
+ * usually doesn't touch any actual hardware, it only initializes the
+ * contents of spi_slave so that the hardware can be easily
+ * initialized later.
+ *
+ *   bus:     Bus ID of the slave chip.
+ *   cs:      Chip select ID of the slave chip on the specified bus.
+ *   max_hz:  Maximum SCK rate in Hz.
+ *   mode:    Clock polarity, clock phase and other parameters.
+ *
+ * Returns: A spi_slave reference that can be used in subsequent SPI
+ * calls, or NULL if one or more of the parameters are not supported.
+ */
+struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
+		unsigned int max_hz, unsigned int mode);
+
+/*-----------------------------------------------------------------------
+ * Free any memory associated with a SPI slave.
+ *
+ *   slave:	The SPI slave
+ */
+void spi_free_slave(struct spi_slave *slave);
+
+/*-----------------------------------------------------------------------
+ * Claim the bus and prepare it for communication with a given slave.
+ *
+ * This must be called before doing any transfers with a SPI slave. It
+ * will enable and initialize any SPI hardware as necessary, and make
+ * sure that the SCK line is in the correct idle state. It is not
+ * allowed to claim the same bus for several slaves without releasing
+ * the bus in between.
+ *
+ *   slave:	The SPI slave
+ *
+ * Returns: 0 if the bus was claimed successfully, or a negative value
+ * if it wasn't.
+ */
+int spi_claim_bus(struct spi_slave *slave);
+
+/*-----------------------------------------------------------------------
+ * Release the SPI bus
+ *
+ * This must be called once for every call to spi_claim_bus() after
+ * all transfers have finished. It may disable any SPI hardware as
+ * appropriate.
+ *
+ *   slave:	The SPI slave
+ */
+void spi_release_bus(struct spi_slave *slave);
+
+/*-----------------------------------------------------------------------
+ * 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).
+ *
+ * spi_xfer() interface:
+ *   slave:	The SPI slave which will be sending/receiving the data.
+ *   dout:	Pointer to a string of bits to send out.  The bits are
+ *		held in a byte array and are sent MSB first.
+ *   bitsout:	How many bits to write.
+ *   din:	Pointer to a string of bits that will be filled in.
+ *   bitsin:	How many bits to read.
+ *
+ *   Returns: 0 on success, not 0 on failure
+ */
+int  spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bitsout,
+		void *din, unsigned int bitsin);
+
+/*-----------------------------------------------------------------------
+ * Determine if a SPI chipselect is valid.
+ * This function is provided by the board if the low-level SPI driver
+ * needs it to determine if a given chipselect is actually valid.
+ *
+ * Returns: 1 if bus:cs identifies a valid chip on this board, 0
+ * otherwise.
+ */
+int  spi_cs_is_valid(unsigned int bus, unsigned int cs);
+
+/*-----------------------------------------------------------------------
+ * Activate a SPI chipselect.
+ * This function is provided by the board code when using a driver
+ * that can't control its chipselects automatically (e.g.
+ * common/soft_spi.c). When called, it should activate the chip select
+ * to the device identified by "slave".
+ */
+void spi_cs_activate(struct spi_slave *slave);
+
+/*-----------------------------------------------------------------------
+ * Deactivate a SPI chipselect.
+ * This function is provided by the board code when using a driver
+ * that can't control its chipselects automatically (e.g.
+ * common/soft_spi.c). When called, it should deactivate the chip
+ * select to the device identified by "slave".
+ */
+void spi_cs_deactivate(struct spi_slave *slave);
+
+/*-----------------------------------------------------------------------
+ * Set transfer speed.
+ * This sets a new speed to be applied for next spi_xfer().
+ *   slave:	The SPI slave
+ *   hz:	The transfer speed
+ */
+void spi_set_speed(struct spi_slave *slave, uint32_t hz);
+
+/*-----------------------------------------------------------------------
+ * Write 8 bits, then read 8 bits.
+ *   slave:	The SPI slave we're communicating with
+ *   byte:	Byte to be written
+ *
+ * Returns: The value that was read, or a negative value on error.
+ *
+ * TODO: This function probably shouldn't be inlined.
+ */
+static inline int spi_w8r8(struct spi_slave *slave, unsigned char byte)
+{
+	unsigned char dout[2];
+	unsigned char din[2];
+	int ret;
+
+	dout[0] = byte;
+	dout[1] = 0;
+
+	ret = spi_xfer(slave, dout, 16, din, 16);
+	return ret < 0 ? ret : din[1];
+}
+
+#endif	/* _SPI_H_ */