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SPI: Add half-duplex support #2831

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32 changes: 25 additions & 7 deletions libraries/SPI/src/SPI.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -42,41 +42,59 @@ SPIClass::SPIClass(uint32_t mosi, uint32_t miso, uint32_t sclk, uint32_t ssel)
_spi.pin_mosi = digitalPinToPinName(mosi);
_spi.pin_sclk = digitalPinToPinName(sclk);
_spi.pin_ssel = digitalPinToPinName(ssel);

// Default configuration
_spi.duplex = true;
_spi.direction = SPI_DIRECTION_2LINES;
_spi.mode = SPI_MODE_MASTER;
}

/**
* @brief Initialize the SPI instance.
* @param device: device mode (optional), SPI_MASTER or SPI_SLAVE. Default is master.
*/
void SPIClass::begin(SPIDeviceMode device)
bool SPIClass::begin(SPIDeviceMode device)
{
_spi.handle.State = HAL_SPI_STATE_RESET;
_spiSettings = SPISettings();
_spiSettings.deviceMode = device;
spi_init(&_spi, _spiSettings.clockFreq, _spiSettings.dataMode,
auto error = spi_init(&_spi, _spiSettings.clockFreq, _spiSettings.dataMode,
_spiSettings.bitOrder, _spiSettings.deviceMode);
if (error != SPI_OK) {
Serial.printf("SPI init error: %d\n", error);
}

init = error == SPI_OK;
return init;
}

/**
* @brief This function should be used to configure the SPI instance in case you
* don't use the default parameters set by the begin() function.
* @param settings: SPI settings(clock speed, bit order, data mode, device mode).
*/
void SPIClass::beginTransaction(SPISettings settings)
bool SPIClass::beginTransaction(SPISettings settings)
{
if (_spiSettings != settings) {
_spiSettings = settings;
spi_init(&_spi, _spiSettings.clockFreq, _spiSettings.dataMode,
auto error = spi_init(&_spi, _spiSettings.clockFreq,
_spiSettings.dataMode,
_spiSettings.bitOrder, _spiSettings.deviceMode);
if (error != SPI_OK) {
Serial.printf("SPI init error: %d\n", error);
}
init = error == SPI_OK;
}

return init;
}

/**
* @brief End the transaction after beginTransaction usage
*/
void SPIClass::endTransaction(void)
{

// Nothing to do here
}

/**
Expand Down Expand Up @@ -211,9 +229,9 @@ void SPIClass::transfer(void *buf, size_t count, bool skipReceive)
* the SPI transfer. If NULL, the received data will be discarded.
* @param count: number of bytes to send/receive.
*/
void SPIClass::transfer(const void *tx_buf, void *rx_buf, size_t count)
spi_status_e SPIClass::transfer(const void *tx_buf, void *rx_buf, size_t count)
{
spi_transfer(&_spi, ((const uint8_t *)tx_buf), ((uint8_t *)rx_buf), count);
return spi_transfer(&_spi, ((const uint8_t *)tx_buf), ((uint8_t *)rx_buf), count);
}


Expand Down
21 changes: 18 additions & 3 deletions libraries/SPI/src/SPI.h
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Original file line number Diff line number Diff line change
Expand Up @@ -126,13 +126,27 @@ class SPIClass {
_spi.pin_ssel = (ssel);
};

void begin(SPIDeviceMode device = SPI_MASTER);
void setDirection(uint32_t direction)
{
_spi.direction = direction;
if (direction == SPI_DIRECTION_1LINE)
_spi.duplex = false;
else
_spi.duplex = true;
};

void setDeviceMode(SPIDeviceMode deviceMode)
{
_spiSettings.deviceMode = deviceMode;
};

bool begin(SPIDeviceMode device = SPI_MASTER);
void end(void);

/* This function should be used to configure the SPI instance in case you
* don't use default parameters.
*/
void beginTransaction(SPISettings settings);
bool beginTransaction(SPISettings settings);
void endTransaction(void);

/* Transfer functions: must be called after initialization of the SPI
Expand All @@ -145,7 +159,7 @@ class SPIClass {
/* Expand SPI API
* https://github.com/arduino/ArduinoCore-API/discussions/189
*/
void transfer(const void *tx_buf, void *rx_buf, size_t count);
spi_status_e transfer(const void *tx_buf, void *rx_buf, size_t count);

/* These methods are deprecated and kept for compatibility.
* Use SPISettings with SPI.beginTransaction() to configure SPI parameters.
Expand Down Expand Up @@ -181,6 +195,7 @@ class SPIClass {
protected:
// spi instance
spi_t _spi;
bool init;

private:
/* Current SPISettings */
Expand Down
57 changes: 42 additions & 15 deletions libraries/SPI/src/utility/spi_com.c
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Original file line number Diff line number Diff line change
Expand Up @@ -206,12 +206,15 @@ static uint32_t compute_disable_delay(spi_t *obj)
* @param device : spi device mode: master or slave
* @retval None
*/
void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMode device)
spi_status_e spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMode device)
{
if (obj == NULL) {
return;
return SPI_ERROR;
}

// Set the device mode before any other initialization
obj->mode = device;

SPI_HandleTypeDef *handle = &(obj->handle);
uint32_t spi_freq = 0;
uint32_t pull = 0;
Expand All @@ -226,9 +229,11 @@ void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMo
SPI_TypeDef *spi_ssel = pinmap_peripheral(obj->pin_ssel, PinMap_SPI_SSEL);

/* Pins MOSI/MISO/SCLK must not be NP. ssel can be NP. */
if (spi_mosi == NP || spi_miso == NP || spi_sclk == NP) {
core_debug("ERROR: at least one SPI pin has no peripheral\n");
return;
if (spi_mosi == NP || spi_miso == NP || spi_sclk == NP || spi_ssel == NP) {
if (spi_miso == NP && obj->duplex) {
core_debug("ERROR: at least one SPI pin has no peripheral\n");
return SPI_ERROR;
}
}

SPI_TypeDef *spi_data = pinmap_merge_peripheral(spi_mosi, spi_miso);
Expand All @@ -239,27 +244,31 @@ void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMo
// Are all pins connected to the same SPI instance?
if (spi_data == NP || spi_cntl == NP || obj->spi == NP) {
core_debug("ERROR: SPI pins mismatch\n");
return;
return SPI_ERROR;
}
#if defined(SUBGHZSPI_BASE)
} else {
if (obj->pin_mosi != NC || obj->pin_miso != NC || obj->pin_sclk != NC || obj->pin_ssel != NC) {
core_debug("ERROR: SUBGHZ_SPI cannot define custom pins\n");
return;
return SPI_ERROR;
}
}
#endif

// Configure the SPI pins
if (obj->pin_ssel != NC) {
handle->Init.NSS = SPI_NSS_HARD_OUTPUT;
if (obj->mode == SPI_MODE_SLAVE) {
handle->Init.NSS = SPI_NSS_HARD_INPUT;
} else {
handle->Init.NSS = SPI_NSS_HARD_OUTPUT;
}
} else {
handle->Init.NSS = SPI_NSS_SOFT;
}

/* Fill default value */
handle->Instance = obj->spi;
handle->Init.Mode = (device == SPI_MASTER) ? SPI_MODE_MASTER : SPI_MODE_SLAVE;
handle->Instance = obj->spi;
handle->Init.Mode = obj->mode;

spi_freq = spi_getClkFreqInst(obj->spi);
/* For SUBGHZSPI, 'SPI_BAUDRATEPRESCALER_*' == 'SUBGHZSPI_BAUDRATEPRESCALER_*' */
Expand Down Expand Up @@ -290,7 +299,7 @@ void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMo
obj->disable_delay = compute_disable_delay(obj);
#endif

handle->Init.Direction = SPI_DIRECTION_2LINES;
handle->Init.Direction = obj->direction;

if ((mode == SPI_MODE0) || (mode == SPI_MODE2)) {
handle->Init.CLKPhase = SPI_PHASE_1EDGE;
Expand Down Expand Up @@ -325,9 +334,22 @@ void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMo
#if defined(SUBGHZSPI_BASE)
if (handle->Instance != SUBGHZSPI) {
#endif
/* Configure SPI GPIO pins */
pinmap_pinout(obj->pin_mosi, PinMap_SPI_MOSI);
pinmap_pinout(obj->pin_miso, PinMap_SPI_MISO);
/* Configure SPI GPIO pins based on device mode and duplex setting */
if (obj->mode == SPI_MODE_MASTER) {
/* Master mode: configure MOSI for output */
pinmap_pinout(obj->pin_mosi, PinMap_SPI_MOSI);
/* Configure MISO for input if duplex is enabled */
if (obj->duplex) {
pinmap_pinout(obj->pin_miso, PinMap_SPI_MISO);
}
} else {
/* Slave mode: configure MISO for output */
pinmap_pinout(obj->pin_miso, PinMap_SPI_MISO);
/* Configure MOSI for input if duplex is enabled */
if (obj->duplex) {
pinmap_pinout(obj->pin_mosi, PinMap_SPI_MOSI);
}
}
pinmap_pinout(obj->pin_sclk, PinMap_SPI_SCLK);
/*
* According the STM32 Datasheet for SPI peripheral we need to PULLDOWN
Expand Down Expand Up @@ -396,10 +418,15 @@ void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMo
}
#endif

HAL_SPI_Init(handle);
HAL_StatusTypeDef status = HAL_SPI_Init(handle);
if (status != HAL_OK) {
core_debug("ERROR: HAL_SPI_Init failed\n");
return SPI_ERROR;
}

/* In order to set correctly the SPI polarity we need to enable the peripheral */
__HAL_SPI_ENABLE(handle);
return SPI_OK;
}

/**
Expand Down
6 changes: 4 additions & 2 deletions libraries/SPI/src/utility/spi_com.h
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,9 @@ struct spi_s {
PinName pin_mosi;
PinName pin_sclk;
PinName pin_ssel;
bool duplex;
uint32_t direction;
uint32_t mode;
#if defined(SPI_IFCR_EOTC)
// Delay before disabling SPI.
// See https://github.com/stm32duino/Arduino_Core_STM32/issues/1294
Expand All @@ -39,7 +42,6 @@ struct spi_s {

typedef struct spi_s spi_t;


///@brief specifies the SPI speed bus in HZ.
#define SPI_SPEED_CLOCK_DEFAULT 4000000

Expand Down Expand Up @@ -88,7 +90,7 @@ typedef enum {
} spi_status_e;

/* Exported functions ------------------------------------------------------- */
void spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMode device);
spi_status_e spi_init(spi_t *obj, uint32_t speed, SPIMode mode, uint8_t msb, SPIDeviceMode device_mode);
void spi_deinit(spi_t *obj);
spi_status_e spi_transfer(spi_t *obj, const uint8_t *tx_buffer, uint8_t *rx_buffer, uint16_t len);
uint32_t spi_getClkFreq(spi_t *obj);
Expand Down