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/* -*- c++ -*- */
/*
* Copyright 2008 Free Software Foundation, Inc.
*
* 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 3 of the License, or
* (at your option) 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, see <http://www.gnu.org/licenses/>.
*/
#include "lsadc.h"
#include "spi.h"
#include "memory_map.h"
// AD9712 or AD7922 1 MS/s, 10-/12-bit ADCs
//#define SPI_SS_DEBUG SPI_SS_RX_DB
#define SPI_SS_DEBUG 0
void
lsadc_init(void)
{
// nop
}
/*
* The ADC's are pipelined. That is, you have to tell them
* which of the two inputs you want one cycle ahead of time.
* We could optimize and keep track of which one we used last
* time, but for simplicity we'll always tell it which
* one we want. This takes 2 16-bit xfers, one to set the
* input and one to read the one we want.
*/
int
_lsadc_read(int which_adc, int slave_select)
{
uint32_t r;
int channel = which_adc & 0x1;
// Set CHN and STY equal to channel number. We don't want "daisy chain mode"
uint16_t cmd = (channel << 13) | (channel << 12);
spi_transact(SPI_TXONLY, slave_select | SPI_SS_DEBUG,
cmd, 16, SPIF_PUSH_RISE | SPIF_LATCH_RISE);
r = spi_transact(SPI_TXRX, slave_select | SPI_SS_DEBUG,
cmd, 16, SPIF_PUSH_RISE | SPIF_LATCH_RISE);
return r & 0x0fff;
}
int
lsadc_read_rx(int which_adc)
{
return _lsadc_read(which_adc, SPI_SS_RX_ADC);
}
int
lsadc_read_tx(int which_adc)
{
return _lsadc_read(which_adc, SPI_SS_TX_ADC);
}
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