diff options
Diffstat (limited to 'src/drivers/bitbash/spi_bit.c')
| -rw-r--r-- | src/drivers/bitbash/spi_bit.c | 51 |
1 files changed, 39 insertions, 12 deletions
diff --git a/src/drivers/bitbash/spi_bit.c b/src/drivers/bitbash/spi_bit.c index 8b5060c1..8e703936 100644 --- a/src/drivers/bitbash/spi_bit.c +++ b/src/drivers/bitbash/spi_bit.c @@ -60,8 +60,8 @@ static void spi_bit_set_slave_select ( struct spi_bit_basher *spibit, struct bit_basher *basher = &spibit->basher; state ^= ( spibit->bus.mode & SPI_MODE_SSPOL ); - DBG ( "Setting slave %d select %s\n", slave, - ( state ? "high" : "low" ) ); + DBGC2 ( spibit, "SPIBIT %p setting slave %d select %s\n", + spibit, slave, ( state ? "high" : "low" ) ); spi_bit_delay(); write_bit ( basher, SPI_BIT_SS ( slave ), state ); @@ -96,7 +96,8 @@ static void spi_bit_transfer ( struct spi_bit_basher *spibit, unsigned int bit; unsigned int step; - DBG ( "Transferring %d bits in mode %x\n", len, bus->mode ); + DBGC2 ( spibit, "SPIBIT %p transferring %d bits in mode %#x\n", + spibit, len, bus->mode ); for ( step = 0 ; step < ( len * 2 ) ; step++ ) { /* Calculate byte offset and byte mask */ @@ -113,6 +114,8 @@ static void spi_bit_transfer ( struct spi_bit_basher *spibit, if ( data_out ) { byte = ( data_out + byte_offset ); bit = ( *byte & byte_mask ); + DBGCP ( spibit, "SPIBIT %p wrote bit %d\n", + spibit, ( bit ? 1 : 0 ) ); } else { bit = 0; } @@ -123,6 +126,8 @@ static void spi_bit_transfer ( struct spi_bit_basher *spibit, /* Shift data in */ bit = read_bit ( basher, SPI_BIT_MISO ); if ( data_in ) { + DBGCP ( spibit, "SPIBIT %p read bit %d\n", + spibit, ( bit ? 1 : 0 ) ); byte = ( data_in + byte_offset ); *byte &= ~byte_mask; *byte |= ( bit & byte_mask ); @@ -131,7 +136,7 @@ static void spi_bit_transfer ( struct spi_bit_basher *spibit, /* Toggle clock line */ spi_bit_delay(); - sclk = ~sclk; + sclk ^= 1; write_bit ( basher, SPI_BIT_SCLK, sclk ); } } @@ -153,7 +158,9 @@ static int spi_bit_rw ( struct spi_bus *bus, struct spi_device *device, 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; + uint32_t tmp_command; + uint32_t tmp_address; + uint32_t tmp_address_detect; /* Set clock line to idle state */ write_bit ( &spibit->basher, SPI_BIT_SCLK, @@ -163,17 +170,37 @@ static int spi_bit_rw ( struct spi_bus *bus, struct spi_device *device, spi_bit_set_slave_select ( spibit, device->slave, SELECT_SLAVE ); /* Transmit command */ - assert ( device->command_len <= ( 8 * sizeof ( tmp ) ) ); - tmp = cpu_to_le32 ( command ); - spi_bit_transfer ( spibit, &tmp, NULL, device->command_len, + 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 ) ) ); - tmp = cpu_to_le32 ( address ); - spi_bit_transfer ( spibit, &tmp, NULL, device->address_len, - SPI_BIT_BIG_ENDIAN ); + 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 */ |