Generalised the SPI abstraction layer to also be able to handle interfaces

that don't provide the full flexibility of a bit-bashing interface.

Temporarily hacked rtl8139.c to use the new interface.

4 files changed, 275 insertions, 105 deletions

diff --git a/src/include/gpxe/bitbash.h b/src/include/gpxe/bitbash.h
index f479b5ad0..62bdce004 100644
--- a/src/include/gpxe/bitbash.h
+++ b/src/include/gpxe/bitbash.h
@@ -7,8 +7,10 @@
  *
  */
 
-/** A bit-bashing interface */
-struct bit_basher {
+struct bit_basher;
+
+/** Bit-bashing operations */
+struct bit_basher_operations {
 	/**
 	 * Set/clear output bit
 	 *
@@ -35,6 +37,12 @@ struct bit_basher {
 	int ( * read ) ( struct bit_basher *basher, unsigned int bit_id );
 };
 
+/** A bit-bashing interface */
+struct bit_basher {
+	/** Bit-bashing operations */
+	struct bit_basher_operations *op;
+};
+
 extern void write_bit ( struct bit_basher *basher, unsigned int bit_id,
 			unsigned long data );
 extern int read_bit ( struct bit_basher *basher, unsigned int bit_id );
diff --git a/src/include/gpxe/spi.h b/src/include/gpxe/spi.h
index 3ea858467..93214063c 100644
--- a/src/include/gpxe/spi.h
+++ b/src/include/gpxe/spi.h
@@ -9,8 +9,170 @@
 
 #include <gpxe/bitbash.h>
 
-/** An SPI interface */
-struct spi_interface {
+/**
+ * @defgroup spicmds SPI commands
+ * @{
+ */
+
+/** Write status register */
+#define SPI_WRSR 0x01
+
+/** Write data to memory array */
+#define SPI_WRITE 0x02
+
+/** Read data from memory array */
+#define SPI_READ 0x03
+
+/** Reset write enable latch */
+#define SPI_WRDI 0x04
+
+/** Read status register */
+#define SPI_RDSR 0x05
+
+/** Set write enable latch */
+#define SPI_WREN 0x06
+
+/**
+ * @defgroup atmelcmds Atmel-specific SPI commands
+ * @{
+ */
+
+/** Erase one sector in memory array (Not supported on all devices) */
+#define ATMEL_SECTOR_ERASE 0x52
+
+/** Erase all sections in memory array (Not supported on all devices) */
+#define ATMEL_CHIP_ERASE 0x62
+
+/** Read manufacturer and product ID (Not supported on all devices) */
+#define ATMEL_RDID 0x15
+
+/** @} */
+
+/** @} */
+
+/**
+ * @defgroup spistatus SPI status register bits (not present on all devices)
+ * @{
+ */
+
+/** Write-protect pin enabled */
+#define SPI_STATUS_WPEN 0x80
+
+/** Block protection bit 2 */
+#define SPI_STATUS_BP2 0x10
+
+/** Block protection bit 1 */
+#define SPI_STATUS_BP1 0x08
+
+/** Block protection bit 0 */
+#define SPI_STATUS_BP0 0x04
+
+/** State of the write enable latch */
+#define SPI_STATUS_WEN 0x02
+
+/** Device busy flag */
+#define SPI_STATUS_NRDY 0x01
+
+/** @} */
+
+struct spi_device;
+
+/**
+ * An SPI device type
+ *
+ * This data structure represents all the characteristics belonging to
+ * a particular type of SPI device, e.g. "an Atmel 251024 serial flash",
+ * or "a Microchip 25040 serial EEPROM".
+ */
+struct spi_device_type {
+	/** Word length, in bits */
+	unsigned int word_len;
+	/** Device size (in words) */
+	unsigned int size;
+	/** Data block size (in words)
+	 *
+	 * This is the block size used by the device.  It must be a
+	 * power of two.  Data reads and writes must not cross a block
+	 * boundary.
+	 *
+	 * Many devices allow reads to cross a block boundary, and
+	 * restrict only writes.  For the sake of simplicity, we
+	 * assume that the same restriction applies to both reads and
+	 * writes.
+	 */
+	unsigned int block_size;
+	/** Command length, in bits */
+	unsigned int command_len;
+	/** Address length, in bits */
+	unsigned int address_len;
+	/** Address is munged
+	 *
+	 * Some devices with 9-bit addresses (e.g. AT25040A EEPROM)
+	 * use bit 3 of the command byte as address bit A8, rather
+	 * than having a two-byte address.  If this flag is set, then
+	 * commands should be munged in this way.
+	 */
+	unsigned int munge_address : 1;
+	/** Read data from device
+	 *
+	 * @v device		SPI device
+	 * @v address		Address from which to read
+	 * @v data		Data buffer
+	 * @v len		Length of data to read, in @b words
+	 * @ret rc		Return status code
+	 */
+	int ( * read ) ( struct spi_device *device, unsigned int address,
+			 void *data, unsigned int len );
+	/** Write data to device
+	 *
+	 * @v device		SPI device
+	 * @v address		Address to which to write
+	 * @v data		Data buffer
+	 * @v len		Length of data to write, in @b words
+	 * @ret rc		Return status code
+	 */
+	int ( * write ) ( struct spi_device *device, unsigned int address,
+			  const void *data, unsigned int len );
+};
+
+/**
+ * @defgroup spidevs SPI device types
+ * @{
+ */
+
+/** Atmel AT25010 serial EEPROM */
+#define AT25010 {		\
+	.word_len = 8,		\
+	.size = 128,		\
+	.block_size = 8,	\
+	.command_len = 8,	\
+	.address_len = 8,	\
+	}
+
+/** @} */
+
+/**
+ * An SPI device
+ *
+ * This data structure represents a real, physical SPI device attached
+ * to an SPI controller.  It comprises the device type plus
+ * instantiation-specific information such as the slave number.
+ */
+struct spi_device {
+	/** SPI device type */
+	struct spi_device_type *type;
+	/** SPI bus to which device is attached */
+	struct spi_bus *bus;
+	/** Slave number */
+	unsigned int slave;
+};
+
+/**
+ * An SPI bus
+ *
+ * 
+ */
+struct spi_bus {
 	/** SPI interface mode
 	 *
 	 * This is the bitwise OR of zero or more of @c SPI_MODE_CPHA
@@ -22,29 +184,26 @@ struct spi_interface {
 	 */
 	unsigned int mode;
 	/**
-	 * Select slave
-	 *
-	 * @v spi		SPI interface
-	 * @v slave		Slave number
-	 */
-	void ( * select_slave ) ( struct spi_interface *spi,
-				  unsigned int slave );
-	/**
-	 * Deselect slave
-	 *
-	 * @v spi		SPI interface
-	 */
-	void ( * deselect_slave ) ( struct spi_interface *spi );
-	/**
-	 * Transfer bits over SPI bit-bashing interface
+	 * Read/write data via SPI bus
 	 *
-	 * @v spi		SPI interface
+	 * @v bus		SPI bus
+	 * @v device		SPI device
+	 * @v command		Command
+	 * @v address		Address to read/write (<0 for no address)
 	 * @v data_out		TX data buffer (or NULL)
 	 * @v data_in		RX data buffer (or NULL)
-	 * @v len		Length of transfer (in @b bits)
+	 * @v len		Length of transfer (in @b words)
+	 *
+	 * This issues the specified command and optional address to
+	 * the SPI device, then reads and/or writes data to/from the
+	 * data buffers.  Note that the transfer length is measured in
+	 * words, not in bytes.  Some SPI devices have 16-bit word
+	 * lengths; take care with these devices not to accidentally
+	 * read or write twice as much data as intended.
 	 */
-	void ( * transfer ) ( struct spi_interface *spi, const void *data_out,
-			      void *data_in, unsigned int len );
+	int ( * rw ) ( struct spi_bus *bus, struct spi_device *device,
+		       unsigned int command, int address,
+		       const void *data_out, void *data_in, unsigned int len );
 };
 
 /** Clock phase (CPHA) mode bit
@@ -91,42 +250,4 @@ struct spi_interface {
  */
 #define SPI_MODE_THREEWIRE ( SPI_MODE_MICROWIRE_PLUS | SPI_MODE_SSPOL )
 
-/** A bit-bashing SPI interface */
-struct spi_bit_basher {
-	/** SPI interface */
-	struct spi_interface spi;
-	/** Bit-bashing interface */
-	struct bit_basher basher;
-	/** Currently selected slave
-	 *
-	 * Valid only when a slave is actually selected.
-	 */
-	unsigned int slave;
-};
-
-/** Bit indices used for SPI bit-bashing interface */
-enum {
-	/** Serial clock */
-	SPI_BIT_SCLK = 0,
-	/** Master Out Slave In */
-	SPI_BIT_MOSI,
-	/** Master In Slave Out */
-	SPI_BIT_MISO,
-	/** Slave 0 select */
-	SPI_BIT_SS0,
-};
-
-/**
- * Determine bit index for a particular slave
- *
- * @v slave		Slave number
- * @ret index		Bit index (i.e. SPI_BIT_SSN, where N=slave) 
- */
-#define SPI_BIT_SS( slave ) ( SPI_BIT_SS0 + (slave) )
-
-/** Delay between SCLK transitions */
-#define SPI_UDELAY 1
-
-extern void init_spi_bit_basher ( struct spi_bit_basher *spibit );
-
 #endif /* _GPXE_SPI_H */
diff --git a/src/include/gpxe/spi_bit.h b/src/include/gpxe/spi_bit.h
new file mode 100644
index 000000000..46f6af761
--- /dev/null
+++ b/src/include/gpxe/spi_bit.h
@@ -0,0 +1,45 @@
+#ifndef _GPXE_SPI_BIT_H
+#define _GPXE_SPI_BIT_H
+
+/** @file
+ *
+ * SPI bit-bashing interface
+ *
+ */
+
+#include <gpxe/spi.h>
+
+/** A bit-bashing SPI bus */
+struct spi_bit_basher {
+	/** SPI bus */
+	struct spi_bus bus;
+	/** Bit-bashing interface */
+	struct bit_basher basher;
+};
+
+/** Bit indices used for SPI bit-bashing interface */
+enum {
+	/** Serial clock */
+	SPI_BIT_SCLK = 0,
+	/** Master Out Slave In */
+	SPI_BIT_MOSI,
+	/** Master In Slave Out */
+	SPI_BIT_MISO,
+	/** Slave 0 select */
+	SPI_BIT_SS0,
+};
+
+/**
+ * Determine bit index for a particular slave
+ *
+ * @v slave		Slave number
+ * @ret index		Bit index (i.e. SPI_BIT_SSN, where N=slave) 
+ */
+#define SPI_BIT_SS( slave ) ( SPI_BIT_SS0 + (slave) )
+
+/** Delay between SCLK transitions */
+#define SPI_BIT_UDELAY 1
+
+extern void init_spi_bit_basher ( struct spi_bit_basher *spibit );
+
+#endif /* _GPXE_SPI_BIT_H */
diff --git a/src/include/gpxe/threewire.h b/src/include/gpxe/threewire.h
index d9d885671..28cfea103 100644
--- a/src/include/gpxe/threewire.h
+++ b/src/include/gpxe/threewire.h
@@ -10,56 +10,52 @@
  * support.
  */
 
-struct spi_interface;
-
-/** A three-wire device */
-struct threewire_device {
-	/** SPI interface to which device is attached */
-	struct spi_interface *spi;
-	/** SPI slave number */
-	unsigned int slave;
-	/** Address size (in bits) */
-	unsigned int adrsize;
-	/** Data size (in bits) */
-	unsigned int datasize;
-};
+#include <gpxe/spi.h>
 
 /**
- * Calculate read command for a specified address
- *
- * @v three	Three-wire interface
- * @v address	Address
- * @ret cmd	Command
+ * @defgroup tcmds Three-wire commands
+ * @{
  */
-static inline __attribute__ (( always_inline )) unsigned long
-threewire_cmd_read ( struct threewire_device *three, unsigned long address ) {
-	return ( ( 0x6 << three->adrsize ) | address );
-}
+
+/** Read data from memory array */
+#define THREEWIRE_READ 0x6
+
+/** @} */
 
 /**
- * Calculate command length
- *
- * @v three	Three-wire interface
- * @ret len	Command length, in bits
+ * @defgroup spidevs SPI device types
+ * @{
  */
-static inline __attribute__ (( always_inline )) unsigned int
-threewire_cmd_len ( struct threewire_device *three ) {
-	return ( three->adrsize + 3 );
-}
 
-/* Constants for some standard parts */
-#define AT93C46_ORG8_ADRSIZE	7
-#define AT93C46_ORG8_DATASIZE	8
-#define AT93C46_ORG16_ADRSIZE	6
-#define AT93C46_ORG16_DATASIZE	16
-#define AT93C46_UDELAY		1
-#define AT93C56_ORG8_ADRSIZE	9
-#define AT93C56_ORG8_DATASIZE	8
-#define AT93C56_ORG16_ADRSIZE	8
-#define AT93C56_ORG16_DATASIZE	16
-#define AT93C56_UDELAY		1
-
-extern unsigned long threewire_read ( struct threewire_device *three,
-				      unsigned long address );
+/** Atmel AT93C46 serial EEPROM
+ *
+ * @v org	Word size (8 or 16)
+ */
+#define AT93C46( org ) {				\
+	.word_len = (org),				\
+	.size = ( 1024 / (org) ),			\
+	.block_size = 1,				\
+	.command_len = 3,				\
+	.address_len = ( ( (org) == 8 ) ? 7 : 6 ),	\
+	.read = threewire_read,				\
+	}
+
+/** Atmel AT93C56 serial EEPROM
+ *
+ * @v org	Word size (8 or 16)
+ */
+#define AT93C56( org ) {				\
+	.word_len = (org),				\
+	.size = ( 2048 / (org) ),			\
+	.block_size = 1,				\
+	.command_len = 3,				\
+	.address_len = ( ( (org) == 8 ) ? 9 : 8 ),	\
+	.read = threewire_read,				\
+	}
+
+/** @} */
+
+extern int threewire_read ( struct spi_device *device, unsigned int address,
+			    void *data, unsigned int len );
 
 #endif /* _GPXE_THREEWIRE_H */