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|
/* -*- c++ -*- */
/*
* Copyright 2004,2006 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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 3, or (at your option)
* any later version.
*
* GNU Radio 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 GNU Radio; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "spi.h"
#include "usrp_rev2_regs.h"
static void
setup_enables (unsigned char enables)
{
// Software eanbles are active high.
// Hardware enables are active low.
// Uhh, the CODECs are active low, but the FPGA is active high...
enables ^= SPI_ENABLE_FPGA;
// KLUDGE: This code is fragile, but reasonably fast...
// low three bits of enables go into port A
USRP_PA = USRP_PA | (0x7 << 3); // disable FPGA, CODEC_A, CODEC_B
USRP_PA ^= (enables & 0x7) << 3; // enable specified devs
// high four bits of enables go into port E
USRP_PE = USRP_PE | (0xf << 4); // disable TX_A, RX_A, TX_B, RX_B
USRP_PE ^= (enables & 0xf0); // enable specified devs
}
#define disable_all() setup_enables (0)
void
init_spi (void)
{
disable_all (); /* disable all devs */
bitS_OUT = 0; /* idle state has CLK = 0 */
}
#if 0
static unsigned char
count_bits8 (unsigned char v)
{
static unsigned char count4[16] = {
0, // 0
1, // 1
1, // 2
2, // 3
1, // 4
2, // 5
2, // 6
3, // 7
1, // 8
2, // 9
2, // a
3, // b
2, // c
3, // d
3, // e
4 // f
};
return count4[v & 0xf] + count4[(v >> 4) & 0xf];
}
#else
static unsigned char
count_bits8 (unsigned char v)
{
unsigned char count = 0;
if (v & (1 << 0)) count++;
if (v & (1 << 1)) count++;
if (v & (1 << 2)) count++;
if (v & (1 << 3)) count++;
if (v & (1 << 4)) count++;
if (v & (1 << 5)) count++;
if (v & (1 << 6)) count++;
if (v & (1 << 7)) count++;
return count;
}
#endif
static void
write_byte_msb (unsigned char v);
unsigned char
transact_byte_msb (unsigned char v);
static void
write_bytes_msb (const xdata unsigned char *buf, unsigned char len);
static void
read_bytes_msb (xdata unsigned char *buf, unsigned char len);
static void
transact_bytes_msb (xdata unsigned char *buf, unsigned char len);
// returns non-zero if successful, else 0
unsigned char
spi_read (unsigned char header_hi, unsigned char header_lo,
unsigned char enables, unsigned char format,
xdata unsigned char *buf, unsigned char len)
{
if (count_bits8 (enables) > 1)
return 0; // error, too many enables set
setup_enables (enables);
if (format & SPI_FMT_LSB){ // order: LSB
#if 1
return 0; // error, not implemented
#else
switch (format & SPI_FMR_HDR_MASK){
case SPI_FMT_HDR_0:
break;
case SPI_FMT_HDR_1:
write_byte_lsb (header_lo);
break;
case SPI_FMT_HDR_2:
write_byte_lsb (header_lo);
write_byte_lsb (header_hi);
break;
default:
return 0; // error
}
if (len != 0)
read_bytes_lsb (buf, len);
#endif
}
else { // order: MSB
switch (format & SPI_FMT_HDR_MASK){
case SPI_FMT_HDR_0:
break;
case SPI_FMT_HDR_1:
write_byte_msb (header_lo);
break;
case SPI_FMT_HDR_2:
write_byte_msb (header_hi);
write_byte_msb (header_lo);
break;
default:
return 0; // error
}
if (len != 0)
read_bytes_msb (buf, len);
}
disable_all ();
return 1; // success
}
// returns non-zero if successful, else 0
unsigned char
spi_write (unsigned char header_hi, unsigned char header_lo,
unsigned char enables, unsigned char format,
const xdata unsigned char *buf, unsigned char len)
{
setup_enables (enables);
if (format & SPI_FMT_LSB){ // order: LSB
#if 1
return 0; // error, not implemented
#else
switch (format & SPI_FMR_HDR_MASK){
case SPI_FMT_HDR_0:
break;
case SPI_FMT_HDR_1:
write_byte_lsb (header_lo);
break;
case SPI_FMT_HDR_2:
write_byte_lsb (header_lo);
write_byte_lsb (header_hi);
break;
default:
return 0; // error
}
if (len != 0)
write_bytes_lsb (buf, len);
#endif
}
else { // order: MSB
switch (format & SPI_FMT_HDR_MASK){
case SPI_FMT_HDR_0:
break;
case SPI_FMT_HDR_1:
write_byte_msb (header_lo);
break;
case SPI_FMT_HDR_2:
write_byte_msb (header_hi);
write_byte_msb (header_lo);
break;
default:
return 0; // error
}
if (len != 0)
write_bytes_msb (buf, len);
}
disable_all ();
return 1; // success
}
unsigned char
spi_transact (unsigned char data0, unsigned char data1,
unsigned char data2, unsigned char data3,
unsigned char enables, xdata unsigned char *buf,
unsigned char len)
{
if (count_bits8 (enables) > 1)
return 0; // error, too many enables set
if (len > 4)
return 0;
setup_enables (enables);
buf[0] = data0;
buf[1] = data1;
buf[2] = data2;
buf[3] = data3;
if (len != 0)
transact_bytes_msb(buf, len);
disable_all ();
return 1; // success
}
static unsigned char
transact_byte_msb (unsigned char v)
{
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN; // read into bottom bit
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = (v << 1) | (v >> 7);
bitS_OUT = v & 0x1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
return v;
}
static void
transact_bytes_msb (xdata unsigned char *buf, unsigned char len)
{
while (len-- != 0){
*buf++ = transact_byte_msb (*buf);
}
}
static void
write_byte_msb (unsigned char v)
{
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
v = (v << 1) | (v >> 7); // rotate left (MSB into bottom bit)
bitS_OUT = v & 0x1;
bitS_CLK = 1;
bitS_CLK = 0;
}
static void
write_bytes_msb (const xdata unsigned char *buf, unsigned char len)
{
while (len-- != 0){
write_byte_msb (*buf++);
}
}
#if 0
/*
* This is incorrectly compiled by SDCC 2.4.0
*/
static unsigned char
read_byte_msb (void)
{
unsigned char v = 0;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
v = v << 1;
bitS_CLK = 1;
v |= bitS_IN;
bitS_CLK = 0;
return v;
}
#else
static unsigned char
read_byte_msb (void) _naked
{
_asm
clr a
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
setb _bitS_CLK
mov c, _bitS_IN
rlc a
clr _bitS_CLK
mov dpl,a
ret
_endasm;
}
#endif
static void
read_bytes_msb (xdata unsigned char *buf, unsigned char len)
{
while (len-- != 0){
*buf++ = read_byte_msb ();
}
}
|
