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.

src/drivers/bitbash/bitbash.c

@@ -37,7 +37,7 @@
  */
 void write_bit ( struct bit_basher *basher, unsigned int bit_id,
 		 unsigned long data ) {
-	basher->write ( basher, bit_id, ( data ? -1UL : 0 ) );
+	basher->op->write ( basher, bit_id, ( data ? -1UL : 0 ) );
 }
 
 /**
@@ -52,5 +52,5 @@ void write_bit ( struct bit_basher *basher, unsigned int bit_id,
  * it needs to apply.
  */
 int read_bit ( struct bit_basher *basher, unsigned int bit_id ) {
-	return ( basher->read ( basher, bit_id ) ? -1UL : 0 );
+	return ( basher->op->read ( basher, bit_id ) ? -1UL : 0 );
 }

src/drivers/bitbash/i2c_bit.c

@@ -314,8 +314,8 @@ static int i2c_bit_write ( struct i2c_interface *i2c,
 void init_i2c_bit_basher ( struct i2c_bit_basher *i2cbit ) {
 	struct bit_basher *basher = &i2cbit->basher;
 	
-	assert ( basher->read != NULL );
-	assert ( basher->write != NULL );
+	assert ( basher->op->read != NULL );
+	assert ( basher->op->write != NULL );
 	i2cbit->i2c.read = i2c_bit_read;
 	i2cbit->i2c.write = i2c_bit_write;
 	i2c_stop ( basher );

src/drivers/bitbash/spi_bit.c

@@ -19,11 +19,12 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
+#include <byteswap.h>
 #include <errno.h>
 #include <assert.h>
 #include <timer.h>
 #include <gpxe/bitbash.h>
-#include <gpxe/spi.h>
+#include <gpxe/spi_bit.h>
 
 /** @file
  *
@@ -32,65 +33,43 @@
  */
 
 /** Delay between SCLK changes and around SS changes */
-static void spi_delay ( void ) {
-	udelay ( SPI_UDELAY );
+static void spi_bit_delay ( void ) {
+	udelay ( SPI_BIT_UDELAY );
 }
 
+/** Chip select line will be asserted */
+#define SELECT_SLAVE 0
+
+/** Chip select line will be deasserted */
+#define DESELECT_SLAVE SPI_MODE_SSPOL
+
 /**
  * Select/deselect slave
  *
- * @v spi		SPI bit-bashing interface
+ * @v spibit		SPI bit-bashing interface
  * @v slave		Slave number
  * @v state		Slave select state
  *
- * @c state must be set to zero to select the specified slave, or to
- * @c SPI_MODE_SSPOL to deselect the slave.
+ * @c state must be @c SELECT_SLAVE or @c DESELECT_SLAVE.
  */
 static void spi_bit_set_slave_select ( struct spi_bit_basher *spibit,
 				       unsigned int slave,
 				       unsigned int state ) {
 	struct bit_basher *basher = &spibit->basher;
 
-	state ^= ( spibit->spi.mode & SPI_MODE_SSPOL );
+	state ^= ( spibit->bus.mode & SPI_MODE_SSPOL );
 	DBG ( "Setting slave %d select %s\n", slave,
 	      ( state ? "high" : "low" ) );
 
-	spi_delay();
+	spi_bit_delay();
 	write_bit ( basher, SPI_BIT_SS ( slave ), state );
-	spi_delay();
+	spi_bit_delay();
 }
 
 /**
- * Select slave
+ * Transfer bits over SPI bit-bashing bus
  *
- * @v spi		SPI interface
- * @v slave		Slave number
- */
-static void spi_bit_select_slave ( struct spi_interface *spi,
-				   unsigned int slave ) {
-	struct spi_bit_basher *spibit
-		= container_of ( spi, struct spi_bit_basher, spi );
-
-	spibit->slave = slave;
-	spi_bit_set_slave_select ( spibit, slave, 0 );
-}
-
-/**
- * Deselect slave
- *
- * @v spi		SPI interface
- */
-static void spi_bit_deselect_slave ( struct spi_interface *spi ) {
-	struct spi_bit_basher *spibit
-		= container_of ( spi, struct spi_bit_basher, spi );
-
-	spi_bit_set_slave_select ( spibit, spibit->slave, SPI_MODE_SSPOL );
-}
-
-/**
- * Transfer bits over SPI bit-bashing interface
- *
- * @v spi		SPI interface
+ * @v bus		SPI bus
  * @v data_out		TX data buffer (or NULL)
  * @v data_in		RX data buffer (or NULL)
  * @v len		Length of transfer (in @b bits)
@@ -101,19 +80,19 @@ static void spi_bit_deselect_slave ( struct spi_interface *spi ) {
  * NULL, then the data sent will be all zeroes.  If @c data_in is
  * NULL, then the incoming data will be discarded.
  */
-static void spi_bit_transfer ( struct spi_interface *spi, const void *data_out,
-			       void *data_in, unsigned int len ) {
-	struct spi_bit_basher *spibit
-		= container_of ( spi, struct spi_bit_basher, spi );
+static void spi_bit_transfer ( struct spi_bit_basher *spibit,
+			       const void *data_out, void *data_in,
+			       unsigned int len ) {
+	struct spi_bus *bus = &spibit->bus;
 	struct bit_basher *basher = &spibit->basher;
-	unsigned int sclk = ( ( spi->mode & SPI_MODE_CPOL ) ? 1 : 0 );
-	unsigned int cpha = ( ( spi->mode & SPI_MODE_CPHA ) ? 1 : 0 );
+	unsigned int sclk = ( ( bus->mode & SPI_MODE_CPOL ) ? 1 : 0 );
+	unsigned int cpha = ( ( bus->mode & SPI_MODE_CPHA ) ? 1 : 0 );
 	unsigned int offset;
 	unsigned int mask;
 	unsigned int bit;
 	int step;
 
-	DBG ( "Transferring %d bits in mode %x\n", len, spi->mode );
+	DBG ( "Transferring %d bits in mode %x\n", len, bus->mode );
 
 	for ( step = ( ( len * 2 ) - 1 ) ; step >= 0 ; step-- ) {
 		/* Calculate byte offset within data and bit mask */
@@ -145,21 +124,65 @@ static void spi_bit_transfer ( struct spi_interface *spi, const void *data_out,
 		}
 
 		/* Toggle clock line */
-		spi_delay();
+		spi_bit_delay();
 		sclk = ~sclk;
 		write_bit ( basher, SPI_BIT_SCLK, sclk );
 	}
 }
 
+/**
+ * Read/write data via SPI bit-bashing bus
+ *
+ * @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 words)
+ * @ret rc		Return status code
+ */
+static int spi_bit_rw ( struct spi_bus *bus, struct spi_device *device,
+			unsigned int command, int address,
+			const void *data_out, void *data_in,
+			unsigned int len ) {
+	struct spi_bit_basher *spibit
+		= container_of ( bus, struct spi_bit_basher, bus );
+	struct spi_device_type *devtype = device->type;
+	uint32_t tmp;
+
+	/* Assert chip select on specified slave */
+	spi_bit_set_slave_select ( spibit, device->slave, SELECT_SLAVE );
+
+	/* Transmit command */
+	assert ( devtype->command_len <= ( 8 * sizeof ( tmp ) ) );
+	tmp = cpu_to_le32 ( command );
+	spi_bit_transfer ( spibit, &tmp, NULL, devtype->command_len );
+
+	/* Transmit address, if present */
+	if ( address >= 0 ) {
+		assert ( devtype->address_len <= ( 8 * sizeof ( tmp ) ) );
+		tmp = cpu_to_le32 ( address );
+		spi_bit_transfer ( spibit, &tmp, NULL, devtype->address_len );
+	}
+
+	/* Transmit/receive data */
+	spi_bit_transfer ( spibit, data_out, data_in,
+			   ( len * devtype->word_len ) );
+
+	/* Deassert chip select on specified slave */
+	spi_bit_set_slave_select ( spibit, device->slave, DESELECT_SLAVE );
+
+	return 0;
+}
+
 /**
  * Initialise SPI bit-bashing interface
  *
  * @v spibit		SPI bit-bashing interface
  */
 void init_spi_bit_basher ( struct spi_bit_basher *spibit ) {
-	assert ( &spibit->basher.read != NULL );
-	assert ( &spibit->basher.write != NULL );
-	spibit->spi.select_slave = spi_bit_select_slave;
-	spibit->spi.deselect_slave = spi_bit_deselect_slave;
-	spibit->spi.transfer = spi_bit_transfer;
+	assert ( &spibit->basher.op->read != NULL );
+	assert ( &spibit->basher.op->write != NULL );
+	spibit->bus.rw = spi_bit_rw;
 }

src/drivers/net/etherfabric.c

@@ -1058,9 +1058,13 @@ static int ef1002_i2c_read_bit ( struct bit_basher *basher,
 	return ( EFAB_DWORD_FIELD ( reg, EF1_EEPROM ) & mask );
 }
 
+static struct bit_basher_operations ef1002_basher_ops = {
+	.read = ef1002_i2c_read_bit,
+	.write = ef1002_i2c_write_bit,
+};
+
 static void ef1002_init_eeprom ( struct efab_nic *efab ) {
-	efab->ef1002_i2c.basher.write = ef1002_i2c_write_bit;
-	efab->ef1002_i2c.basher.read = ef1002_i2c_read_bit;
+	efab->ef1002_i2c.basher.op = &ef1002_basher_ops;
 	init_i2c_bit_basher ( &efab->ef1002_i2c );
 	efab->ef1002_eeprom.address = EF1_EEPROM_I2C_ID;
 }

src/drivers/net/rtl8139.c

@@ -77,7 +77,7 @@
 #include <gpxe/ethernet.h>
 #include <gpxe/pkbuff.h>
 #include <gpxe/netdevice.h>
-#include <gpxe/spi.h>
+#include <gpxe/spi_bit.h>
 #include <gpxe/threewire.h>
 
 #define TX_RING_SIZE 4
@@ -97,7 +97,7 @@ struct rtl8139_nic {
 	struct rtl8139_tx tx;
 	struct rtl8139_rx rx;
 	struct spi_bit_basher spibit;
-	struct threewire_device eeprom;
+	struct spi_device eeprom;
 };
 
 /* Tuning Parameters */
@@ -204,11 +204,6 @@ enum RxConfigBits {
 /* Offsets within EEPROM (these are word offsets) */
 #define EE_MAC 7
 
-static inline struct rtl8139_nic *
-basher_to_rtl ( struct bit_basher *basher ) {
-	return container_of ( basher, struct rtl8139_nic, spibit.basher );
-}
-
 static const uint8_t rtl_ee_bits[] = {
 	[SPI_BIT_SCLK]	= EE_SK,
 	[SPI_BIT_MOSI]	= EE_DI,
@@ -218,7 +213,8 @@ static const uint8_t rtl_ee_bits[] = {
 
 static int rtl_spi_read_bit ( struct bit_basher *basher,
 			      unsigned int bit_id ) {
-	struct rtl8139_nic *rtl = basher_to_rtl ( basher );
+	struct rtl8139_nic *rtl = container_of ( basher, struct rtl8139_nic,
+						 spibit.basher );
 	uint8_t mask = rtl_ee_bits[bit_id];
 	uint8_t eereg;
 
@@ -228,7 +224,8 @@ static int rtl_spi_read_bit ( struct bit_basher *basher,
 
 static void rtl_spi_write_bit ( struct bit_basher *basher,
 				unsigned int bit_id, unsigned long data ) {
-	struct rtl8139_nic *rtl = basher_to_rtl ( basher );
+	struct rtl8139_nic *rtl = container_of ( basher, struct rtl8139_nic,
+						 spibit.basher );
 	uint8_t mask = rtl_ee_bits[bit_id];
 	uint8_t eereg;
 
@@ -238,6 +235,14 @@ static void rtl_spi_write_bit ( struct bit_basher *basher,
 	outb ( eereg, rtl->ioaddr + Cfg9346 );
 }
 
+static struct bit_basher_operations rtl_basher_ops = {
+	.read = rtl_spi_read_bit,
+	.write = rtl_spi_write_bit,
+};
+
+static struct spi_device_type rtl_ee9346 = AT93C46 ( 16 );
+static struct spi_device_type rtl_ee9356 = AT93C56 ( 16 );
+
 /**
  * Set up for EEPROM access
  *
@@ -247,19 +252,15 @@ static void rtl_init_eeprom ( struct rtl8139_nic *rtl ) {
 	int ee9356;
 
 	/* Initialise three-wire bus */
-	rtl->spibit.basher.read = rtl_spi_read_bit;
-	rtl->spibit.basher.write = rtl_spi_write_bit;
-	rtl->spibit.spi.mode = SPI_MODE_THREEWIRE;
+	rtl->spibit.basher.op = &rtl_basher_ops;
+	rtl->spibit.bus.mode = SPI_MODE_THREEWIRE;
 	init_spi_bit_basher ( &rtl->spibit );
 
 	/* Detect EEPROM type and initialise three-wire device */
 	ee9356 = ( inw ( rtl->ioaddr + RxConfig ) & Eeprom9356 );
-	DBG ( "EEPROM is an %s\n", ee9356 ? "AT93C56" : "AT93C46" );
-	rtl->eeprom.adrsize =
-		( ee9356 ? AT93C56_ORG16_ADRSIZE : AT93C46_ORG16_ADRSIZE );
-	rtl->eeprom.datasize =
-		( ee9356 ? AT93C56_ORG16_DATASIZE : AT93C46_ORG16_DATASIZE );
-	rtl->eeprom.spi = &rtl->spibit.spi;
+	DBG ( "EEPROM is an %s\n", ( ee9356 ? "AT93C56" : "AT93C46" ) );
+	rtl->eeprom.type = ( ee9356 ? &rtl_ee9356 : &rtl_ee9346 );
+	rtl->eeprom.bus = &rtl->spibit.bus;
 }
 
 /**
@@ -269,18 +270,15 @@ static void rtl_init_eeprom ( struct rtl8139_nic *rtl ) {
  * @v mac_addr		Buffer to contain MAC address (ETH_ALEN bytes)
  */
 static void rtl_read_mac ( struct rtl8139_nic *rtl, uint8_t *mac_addr ) {
-	union {
-		uint16_t word;
-		uint8_t bytes[2];
-	} u;
+
+	struct spi_device *device = &rtl->eeprom;
 	int i;
 	
 	DBG ( "MAC address is " );
 	for ( i = EE_MAC ; i < ( EE_MAC + ( ETH_ALEN / 2 ) ) ; i++ ) {
-		u.word = cpu_to_le16 ( threewire_read ( &rtl->eeprom, i ) );
-		*mac_addr++ = u.bytes[0];
-		*mac_addr++ = u.bytes[1];
-		DBG ( "%02x%02x", u.bytes[0], u.bytes[1] );
+		device->type->read ( device, i, mac_addr, 1 );
+		DBG ( "%02x%02x", mac_addr[0], mac_addr[1] );
+		mac_addr += 2;
 	}
 	DBG ( "\n" );
 }

src/drivers/nvs/threewire.c

@@ -17,8 +17,7 @@
  */
 
 #include <stddef.h>
-#include <byteswap.h>
-#include <gpxe/spi.h>
+#include <assert.h>
 #include <gpxe/threewire.h>
 
 /** @file
@@ -27,31 +26,23 @@
  *
  */
 
-/**
- * Read from a three-wire device
+/** Read data from three-wire device
  *
- * @v three	Three-wire device
- * @v address	Address
- * @ret data	Data
+ * @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
  */
-unsigned long threewire_read ( struct threewire_device *three,
-			       unsigned long address ) {
-	struct spi_interface *spi = three->spi;
-	uint32_t data;
+int threewire_read ( struct spi_device *device, unsigned int address,
+		     void *data, unsigned int len ) {
+	struct spi_bus *bus = device->bus;
 
-	/* Activate chip select line */
-	spi->select_slave ( spi, three->slave );
+	assert ( bus->mode == SPI_MODE_THREEWIRE );
 
-	/* Send command and address */
-	data = cpu_to_le32 ( threewire_cmd_read ( three, address ) );
-	spi->transfer ( spi, &data, NULL, threewire_cmd_len ( three ) );
-	
-	/* Read back data */
-	data = 0;
-	spi->transfer ( spi, NULL, &data, three->datasize );
+	DBG ( "3wire %p reading words [%04x,%04x)\n", device,
+	      address, ( address + len ) );
 
-	/* Deactivate chip select line */
-	spi->deselect_slave ( spi );
-
-	return le32_to_cpu ( data );;
+	return bus->rw ( bus, device, THREEWIRE_READ, address,
+			 NULL, data, len );
 }