diff options
Diffstat (limited to 'qemu/roms/ipxe/src/drivers/bitbash/spi_bit.c')
-rw-r--r-- | qemu/roms/ipxe/src/drivers/bitbash/spi_bit.c | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/qemu/roms/ipxe/src/drivers/bitbash/spi_bit.c b/qemu/roms/ipxe/src/drivers/bitbash/spi_bit.c deleted file mode 100644 index 04fddc20b..000000000 --- a/qemu/roms/ipxe/src/drivers/bitbash/spi_bit.c +++ /dev/null @@ -1,239 +0,0 @@ -/* - * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License as - * published by the Free Software Foundation; either version 2 of the - * License, or any later version. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA - * 02110-1301, USA. - * - * You can also choose to distribute this program under the terms of - * the Unmodified Binary Distribution Licence (as given in the file - * COPYING.UBDL), provided that you have satisfied its requirements. - */ - -FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL ); - -#include <stddef.h> -#include <stdint.h> -#include <string.h> -#include <byteswap.h> -#include <errno.h> -#include <assert.h> -#include <unistd.h> -#include <ipxe/bitbash.h> -#include <ipxe/spi_bit.h> - -/** @file - * - * SPI bit-bashing interface - * - */ - -/** Delay between SCLK changes and around SS changes */ -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 spibit SPI bit-bashing interface - * @v slave Slave number - * @v state Slave select state - * - * @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->bus.mode & SPI_MODE_SSPOL ); - 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 ); - spi_bit_delay(); -} - -/** - * Transfer bits over SPI bit-bashing bus - * - * @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) - * @v endianness Endianness of this data transfer - * - * This issues @c len clock cycles on the SPI bus, shifting out data - * from the @c data_out buffer to the MOSI line and shifting in data - * from the MISO line to the @c data_in buffer. If @c data_out is - * 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_bit_basher *spibit, - const void *data_out, void *data_in, - unsigned int len, int endianness ) { - struct spi_bus *bus = &spibit->bus; - struct bit_basher *basher = &spibit->basher; - unsigned int sclk = ( ( bus->mode & SPI_MODE_CPOL ) ? 1 : 0 ); - unsigned int cpha = ( ( bus->mode & SPI_MODE_CPHA ) ? 1 : 0 ); - unsigned int bit_offset; - unsigned int byte_offset; - unsigned int byte_mask; - unsigned int bit; - unsigned int step; - - 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 */ - bit_offset = ( ( endianness == SPI_BIT_BIG_ENDIAN ) ? - ( len - ( step / 2 ) - 1 ) : ( step / 2 ) ); - byte_offset = ( bit_offset / 8 ); - byte_mask = ( 1 << ( bit_offset % 8 ) ); - - /* Shift data in or out */ - if ( sclk == cpha ) { - const uint8_t *byte; - - /* Shift data out */ - 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; - } - write_bit ( basher, SPI_BIT_MOSI, bit ); - } else { - uint8_t *byte; - - /* 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 ); - } - } - - /* Toggle clock line */ - spi_bit_delay(); - sclk ^= 1; - 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 - * @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; -} - -/** - * Initialise SPI bit-bashing interface - * - * @v spibit SPI bit-bashing interface - */ -void init_spi_bit_basher ( struct spi_bit_basher *spibit ) { - assert ( &spibit->basher.op->read != NULL ); - assert ( &spibit->basher.op->write != NULL ); - spibit->bus.rw = spi_bit_rw; -} |