Merge branch 'master' of git://git.denx.de/u-boot

1 files changed, 127 insertions, 23 deletions

diff --git a/include/spi.h b/include/spi.h
index 3a55a68..7744c2e 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -31,22 +31,87 @@
 #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			/* chipselect active high? */
+#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 */
 
-/*
- * The function call pointer type used to drive the chip select.
- */
-typedef void (*spi_chipsel_type)(int cs);
+/* 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
@@ -60,28 +125,67 @@ void spi_init(void);
  * input data overwrites the output data (since both are buffered by
  * temporary variables, this is OK).
  *
- * If the chipsel() function is not NULL, it is called with a parameter
- * of '1' (chip select active) at the start of the transfer and again with
- * a parameter of '0' at the end of the transfer.
- *
- * If the chipsel() function _is_ NULL, it the responsibility of the
- * caller to make the appropriate chip select active before calling
- * spi_xfer() and making it inactive after spi_xfer() returns.
- *
  * spi_xfer() interface:
- *   chipsel: Routine to call to set/clear the chip select:
- *              if chipsel is NULL, it is not used.
- *              if(cs),  make the chip select active (typically '0').
- *              if(!cs), make the chip select inactive (typically '1').
- *   dout:    Pointer to a string of bits to send out.  The bits are
- *              held in a byte array and are sent MSB first.
- *   din:     Pointer to a string of bits that will be filled in.
- *   bitlen:  How many bits to write and read.
+ *   slave:	The SPI slave which will be sending/receiving the data.
+ *   bitlen:	How many bits to write and read.
+ *   dout:	Pointer to a string of bits to send out.  The bits are
+ *		held in a byte array and are sent MSB first.
+ *   din:	Pointer to a string of bits that will be filled in.
+ *   flags:	A bitwise combination of SPI_XFER_* flags.
  *
  *   Returns: 0 on success, not 0 on failure
  */
-int spi_xfer(spi_chipsel_type chipsel, int bitlen, uchar *dout, uchar *din);
+int  spi_xfer(struct spi_slave *slave, unsigned int bitlen, const void *dout,
+		void *din, unsigned long flags);
+
+/*-----------------------------------------------------------------------
+ * 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);
+
+/*-----------------------------------------------------------------------
+ * 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;
 
-int spi_select(unsigned int bus, unsigned int dev, unsigned long mode);
+	ret = spi_xfer(slave, 16, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
+	return ret < 0 ? ret : din[1];
+}
 
 #endif	/* _SPI_H_ */