/******************** TABLE END ********************/
void open_additional_libs(lua_State *L){
open_bit(L);
open_string(L);
// open_math(L);
open_table(L);
}
/**
* 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
* @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, size_t len ) {
struct spi_bit_basher *spibit
= container_of ( bus, struct spi_bit_basher, bus );
uint32_t tmp_command;
uint32_t tmp_address;
uint32_t tmp_address_detect;
/* Open bit-bashing interface */
open_bit ( &spibit->basher );
/* Deassert chip select to reset specified slave */
spi_bit_set_slave_select ( spibit, device->slave, DESELECT_SLAVE );
/* Set clock line to idle state */
write_bit ( &spibit->basher, SPI_BIT_SCLK,
( bus->mode & SPI_MODE_CPOL ) );
/* Assert chip select on specified slave */
spi_bit_set_slave_select ( spibit, device->slave, SELECT_SLAVE );
/* Transmit command */
assert ( device->command_len <= ( 8 * sizeof ( tmp_command ) ) );
tmp_command = cpu_to_le32 ( command );
spi_bit_transfer ( spibit, &tmp_command, NULL, device->command_len,
SPI_BIT_BIG_ENDIAN );
/* Transmit address, if present */
if ( address >= 0 ) {
assert ( device->address_len <= ( 8 * sizeof ( tmp_address )));
tmp_address = cpu_to_le32 ( address );
if ( device->address_len == SPI_AUTODETECT_ADDRESS_LEN ) {
/* Autodetect address length. This relies on
* the device responding with a dummy zero
* data bit before the first real data bit.
*/
DBGC ( spibit, "SPIBIT %p autodetecting device "
"address length\n", spibit );
assert ( address == 0 );
device->address_len = 0;
do {
spi_bit_transfer ( spibit, &tmp_address,
&tmp_address_detect, 1,
SPI_BIT_BIG_ENDIAN );
device->address_len++;
} while ( le32_to_cpu ( tmp_address_detect ) & 1 );
DBGC ( spibit, "SPIBIT %p autodetected device address "
"length %d\n", spibit, device->address_len );
} else {
spi_bit_transfer ( spibit, &tmp_address, NULL,
device->address_len,
SPI_BIT_BIG_ENDIAN );
}
}
/* Transmit/receive data */
spi_bit_transfer ( spibit, data_out, data_in, ( len * 8 ),
spibit->endianness );
/* Deassert chip select on specified slave */
spi_bit_set_slave_select ( spibit, device->slave, DESELECT_SLAVE );
/* Close bit-bashing interface */
close_bit ( &spibit->basher );
return 0;
}
