mirror of https://github.com/hsoft/collapseos.git
40 lines
812 B
C
40 lines
812 B
C
#include "sms_spi.h"
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void spi_init(SPI *spi, Tristate *TH, Tristate *TR, EXCH spixfn)
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{
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spi->TH = TH;
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spi->TR = TR;
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spi->lastTH = *TH;
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spi->bitcnt = 0;
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spi->bit = false;
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spi->rx = 0;
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spi->tx = 0xff;
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spi->spixfn = spixfn;
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}
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byte spi_rd(SPI *spi)
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{
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return (byte)spi->bit; // return in bit 0
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}
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void spi_pulse(SPI *spi)
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{
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if (*spi->TH != spi->lastTH) {
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spi->lastTH = *spi->TH;
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if (spi->lastTH == TRI_HIGH) {
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spi->rx <<= 1;
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if (*spi->TR == TRI_HIGH) {
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spi->rx++;
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}
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spi->bit = spi->tx >> 7;
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spi->tx <<= 1;
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spi->bitcnt++;
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if (spi->bitcnt == 8) {
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spi->tx = spi->spixfn(spi->rx);
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spi->bitcnt = 0;
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}
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}
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}
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}
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