kopia lustrzana https://github.com/OpenRTX/OpenRTX
Driver for bitbanged SPI on MCU gpios
Silvano Seva
rodzic
539d1b45f6
commit
b196ce9cbc
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@ -66,7 +66,8 @@ openrtx_src = ['openrtx/src/core/state.c',
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'openrtx/src/protocols/M17/M17Demodulator.cpp',
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'openrtx/src/protocols/M17/M17FrameEncoder.cpp',
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'openrtx/src/protocols/M17/M17FrameDecoder.cpp',
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'openrtx/src/protocols/M17/M17LinkSetupFrame.cpp']
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'openrtx/src/protocols/M17/M17LinkSetupFrame.cpp',
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'platform/drivers/SPI/spi_bitbang.c']
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openrtx_inc = ['openrtx/include',
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'openrtx/include/rtx',
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@ -78,6 +79,7 @@ openrtx_inc = ['openrtx/include',
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'platform/drivers/ADC',
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'platform/drivers/NVM',
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'platform/drivers/GPS',
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'platform/drivers/SPI',
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'platform/drivers/USB',
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'platform/drivers/tones',
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'platform/drivers/baseband',
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@ -0,0 +1,179 @@
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/***************************************************************************
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* Copyright (C) 2024 by Federico Amedeo Izzo IU2NUO, *
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* Niccolò Izzo IU2KIN *
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* Frederik Saraci IU2NRO *
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* Silvano Seva IU2KWO *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, see <http://www.gnu.org/licenses/> *
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***************************************************************************/
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#include <interfaces/delays.h>
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#include "spi_bitbang.h"
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typedef uint8_t (*sendRecv_impl)(struct spiConfig *cfg, uint8_t data);
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static uint8_t sendRecv_clkRising(struct spiConfig *cfg, uint8_t data)
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{
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uint8_t incoming = 0;
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for(uint8_t cnt = 0; cnt < 8; cnt++)
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{
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// Setup new output towards the peripheral
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if((data & 0x80) != 0)
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gpio_setPin(cfg->mosi.port, cfg->mosi.pin);
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else
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gpio_clearPin(cfg->mosi.port, cfg->mosi.pin);
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// Sample the current incoming bit from the peripheral
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data <<= 1;
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incoming <<= 1;
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incoming |= gpio_readPin(cfg->miso.port, cfg->miso.pin);
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// One clock cycle, peripheral reads the new bit and updates its output
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// bit
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delayUs(cfg->clkPeriod);
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gpio_setPin(cfg->clk.port, cfg->clk.pin);
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delayUs(cfg->clkPeriod);
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gpio_clearPin(cfg->clk.port, cfg->clk.pin);
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}
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return incoming;
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}
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static uint8_t sendRecv_clkFalling(struct spiConfig *cfg, uint8_t data)
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{
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uint8_t incoming = 0;
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for(uint8_t cnt = 0; cnt < 8; cnt++)
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{
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// Clock rising edge (inactive edge)
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gpio_setPin(cfg->clk.port, cfg->clk.pin);
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// Setup data output
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if((data & 0x80) != 0)
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gpio_setPin(cfg->mosi.port, cfg->mosi.pin);
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else
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gpio_clearPin(cfg->mosi.port, cfg->mosi.pin);
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// Sample data input
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data <<= 1;
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incoming <<= 1;
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incoming |= gpio_readPin(cfg->miso.port, cfg->miso.pin);
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// Clock falling edge, peripheral reads new data and updates its output
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// line
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delayUs(cfg->clkPeriod);
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gpio_clearPin(cfg->clk.port, cfg->clk.pin);
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delayUs(cfg->clkPeriod);
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}
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return incoming;
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}
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int spiBitbang_init(const struct spiDevice* dev)
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{
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struct spiConfig *cfg = (struct spiConfig *) dev->priv;
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// Setup MOSI and clock lines as output, low level
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gpio_setMode(cfg->clk.port, cfg->clk.pin, OUTPUT);
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gpio_setMode(cfg->mosi.port, cfg->mosi.pin, OUTPUT);
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gpio_clearPin(cfg->mosi.port, cfg->mosi.pin);
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gpio_clearPin(cfg->clk.port, cfg->clk.pin);
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// Set MISO line as input only for full-duplex operation
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if((cfg->flags & SPI_HALF_DUPLEX) == 0)
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gpio_setMode(cfg->miso.port, cfg->miso.pin, INPUT);
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// Set initial state of clock line to high if requested
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if((cfg->flags & SPI_FLAG_CPOL) != 0)
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gpio_clearPin(cfg->clk.port, cfg->clk.pin);
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if(dev->mutex != NULL)
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pthread_mutex_init((pthread_mutex_t *) dev->mutex, NULL);
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return 0;
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}
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void spiBitbang_terminate(const struct spiDevice* dev)
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{
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struct spiConfig *cfg = (struct spiConfig *) dev->priv;
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// Set clock and MOSI back to Hi-Z state
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gpio_setMode(cfg->clk.port, cfg->clk.pin, INPUT);
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gpio_setMode(cfg->mosi.port, cfg->mosi.pin, INPUT);
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if(dev->mutex != NULL)
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pthread_mutex_destroy((pthread_mutex_t *) dev->mutex);
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}
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int spiBitbang_impl(const struct spiDevice *dev, const void *txBuf,
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const size_t txSize, void *rxBuf, const size_t rxSize)
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{
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struct spiConfig *cfg = (struct spiConfig *) dev->priv;
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const uint8_t *txData = (const uint8_t *) txBuf;
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uint8_t *rxData = (uint8_t *) rxBuf;
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sendRecv_impl spi_sendRecv;
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if((cfg->flags & SPI_FLAG_CPHA) != 0)
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spi_sendRecv = &sendRecv_clkFalling;
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else
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spi_sendRecv = &sendRecv_clkRising;
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// Send only
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if((rxBuf == NULL) || (rxSize == 0))
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{
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for(size_t i = 0; i < txSize; i++)
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spi_sendRecv(cfg, txData[i]);
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return 0;
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}
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// Receive only
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if((txBuf == NULL) || (txSize == 0))
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{
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for(size_t i = 0; i < rxSize; i++)
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rxData[i] = spi_sendRecv(cfg, 0x00);
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return 0;
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}
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// Transmit and receive
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size_t txRxSize = (txSize < rxSize) ? txSize : rxSize;
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for(size_t i = 0; i < txRxSize; i++)
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rxData[i] = spi_sendRecv(cfg, txData[i]);
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// Still something to send?
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if(txSize > txRxSize)
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{
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for(size_t i = 0; i < (txSize - txRxSize); i++)
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{
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size_t pos = txRxSize + i;
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spi_sendRecv(cfg, txData[pos]);
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}
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}
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// Still something to receive?
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if(rxSize > txRxSize)
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{
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for(size_t i = 0; i < (rxSize - txRxSize); i++)
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{
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size_t pos = txRxSize + i;
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rxData[pos] = spi_sendRecv(cfg, 0x00);
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}
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}
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return 0;
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}
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@ -0,0 +1,90 @@
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/***************************************************************************
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* Copyright (C) 2024 by Federico Amedeo Izzo IU2NUO, *
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* Niccolò Izzo IU2KIN *
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* Frederik Saraci IU2NRO *
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* Silvano Seva IU2KWO *
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 3 of the License, or *
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* (at your option) any later version. *
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* *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, see <http://www.gnu.org/licenses/> *
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***************************************************************************/
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#ifndef SPI_BITBANG_H
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#define SPI_BITBANG_H
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#include <peripherals/gpio.h>
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#include <peripherals/spi.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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#define SCK_PERIOD_FROM_FREQ(x) (1000000/x)
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/**
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* Data structure collecting the configuration data for the SPI bitbang driver.
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*
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* The driver uses the MCU native gpio driver for two reasons:
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* 1) the faster the gpios are driver, the faster the SPI bitbang can work
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* 2) using an external port expander to do SPI bitbang does not make sense...
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*/
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struct spiConfig
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{
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const struct gpio clk; ///< SPI clock
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const struct gpio mosi; ///< SPI data from MCU to peripherals
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const struct gpio miso; ///< SPI data from peripherals to MCU
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const uint32_t clkPeriod; ///< Clock period, in us
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const uint8_t flags; ///< SPI configuration flags
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};
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/**
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* Instantiate an SPI bitbang device.
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*
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* @param name: device name.
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* @param mutx: pointer to mutex, or NULL.
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* @param cfg: driver configuration data.
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*/
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#define SPI_BITBANG_DEVICE_DEFINE(name, mutx, cfg) \
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int spiBitbang_impl(const struct spiDevice *dev, const void *txBuf, \
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const size_t txSize, void *rxBuf, const size_t rxSize); \
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const struct spiDevice name = \
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{ \
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.transfer = spiBitbang_impl, \
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.priv = &cfg, \
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.mutex = mutx, \
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};
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/**
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* Initialise a bitbang SPI driver.
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* Is left to application code to change the operating mode and alternate function
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* mapping of the corresponding gpio lines.
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*
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* @param dev: SPI bitbang device descriptor.
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* @param speed: SPI clock speed.
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* @param flags: SPI configuration flags.
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* @return zero on success, a negative error code otherwise.
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*/
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int spiBitbang_init(const struct spiDevice *dev);
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/**
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* Shut down a bitbang SPI driver.
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*
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* @param dev: SPI bitbang device descriptor.
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*/
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void spiBitbang_terminate(const struct spiDevice *dev);
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#ifdef __cplusplus
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}
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#endif
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#endif /* SPI_BITBANG_H */
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