#234 Added support for sharing the deck SPI bus.

Added spiBeginTransaction and spiEndTransaction to lock the bus so it
can be shared. The deck drivers uSD, Loco and Flow were all updated and
can now be used simultainiously.

src/config/config.h

@@ -152,7 +152,7 @@
 #define EXTRX_TASK_STACKSIZE          configMINIMAL_STACK_SIZE
 #define UART_RX_TASK_STACKSIZE        configMINIMAL_STACK_SIZE
 #define VL53_TASK_STACKSIZE           (2 * configMINIMAL_STACK_SIZE)
-#define USDLOG_TASK_STACKSIZE         configMINIMAL_STACK_SIZE
+#define USDLOG_TASK_STACKSIZE         (2 * configMINIMAL_STACK_SIZE)
 #define USDWRITE_TASK_STACKSIZE       (2 * configMINIMAL_STACK_SIZE)
 
 //The radio channel. From 0 to 125

src/deck/api/deck_spi.c

@@ -84,8 +84,10 @@ static bool isInit = false;
 
 static SemaphoreHandle_t txComplete;
 static SemaphoreHandle_t rxComplete;
+static SemaphoreHandle_t spiMutex;
 
 static void spiDMAInit();
+static void spiConfigureWithSpeed(uint16_t baudRatePrescaler);
 
 void spiBegin(void)
 {
@@ -95,6 +97,7 @@ void spiBegin(void)
   // such that the the semaphore must first be 'given' before it can be 'taken'
   txComplete = xSemaphoreCreateBinary();
   rxComplete = xSemaphoreCreateBinary();
+  spiMutex = xSemaphoreCreateMutex();
 
   /*!< Enable the SPI clock */
   SPI_CLK_INIT(SPI_CLK, ENABLE);
@@ -134,12 +137,12 @@ void spiBegin(void)
   spiDMAInit();
 
   /*!< SPI configuration */
-  spiConfigureSlow();
+  spiConfigureWithSpeed(SPI_BAUDRATE_2MHZ);
 
   isInit = true;
 }
 
-void spiDMAInit()
+static void spiDMAInit()
 {
   DMA_InitTypeDef  DMA_InitStructure;
   NVIC_InitTypeDef NVIC_InitStructure;
@@ -183,7 +186,7 @@ void spiDMAInit()
   NVIC_Init(&NVIC_InitStructure);
 }
 
-void spiConfigureSlow()
+static void spiConfigureWithSpeed(uint16_t baudRatePrescaler)
 {
   SPI_InitTypeDef  SPI_InitStructure;
 
@@ -198,26 +201,7 @@ void spiConfigureSlow()
   SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
   SPI_InitStructure.SPI_CRCPolynomial = 0; // Not used
 
-  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_64; //~1.35 MHz
-  SPI_Init(SPI, &SPI_InitStructure);
-}
-
-void spiConfigureFast()
-{
-  SPI_InitTypeDef  SPI_InitStructure;
-
-  SPI_I2S_DeInit(SPI);
-
-  SPI_InitStructure.SPI_Direction = SPI_Direction_2Lines_FullDuplex;
-  SPI_InitStructure.SPI_Mode = SPI_Mode_Master;
-  SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b;
-  SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low;
-  SPI_InitStructure.SPI_CPHA = SPI_CPHA_1Edge;
-  SPI_InitStructure.SPI_NSS = SPI_NSS_Soft;
-  SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB;
-  SPI_InitStructure.SPI_CRCPolynomial = 0; // Not used
-
-  SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_4; //~21 MHz
+  SPI_InitStructure.SPI_BaudRatePrescaler = baudRatePrescaler;
   SPI_Init(SPI, &SPI_InitStructure);
 }
 
@@ -263,6 +247,17 @@ bool spiExchange(size_t length, const uint8_t * data_tx, uint8_t * data_rx)
   return result;
 }
 
+void spiBeginTransaction(uint16_t baudRatePrescaler)
+{
+  xSemaphoreTake(spiMutex, portMAX_DELAY);
+  spiConfigureWithSpeed(baudRatePrescaler);
+}
+
+void spiEndTransaction()
+{
+  xSemaphoreGive(spiMutex);
+}
+
 void __attribute__((used)) SPI_TX_DMA_IRQHandler(void)
 {
   portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;

src/deck/drivers/src/flowdeck.c

@@ -105,6 +105,7 @@ static void registerWrite(uint8_t reg, uint8_t value)
   // Set MSB to 1 for write
   reg |= 0x80u;
 
+  spiBeginTransaction(SPI_BAUDRATE_2MHZ);
   digitalWrite(NCS_PIN, LOW);
 
   sleepus(50);
@@ -116,6 +117,7 @@ static void registerWrite(uint8_t reg, uint8_t value)
   sleepus(50);
 
   digitalWrite(NCS_PIN, HIGH);
+  spiEndTransaction();
   sleepus(200);
 }
 
@@ -127,6 +129,7 @@ static uint8_t registerRead(uint8_t reg)
   // Set MSB to 0 for read
   reg &= ~0x80u;
 
+  spiBeginTransaction(SPI_BAUDRATE_2MHZ);
   digitalWrite(NCS_PIN, LOW);
 
   sleepus(50);
@@ -138,6 +141,7 @@ static uint8_t registerRead(uint8_t reg)
   sleepus(50);
 
   digitalWrite(NCS_PIN, HIGH);
+  spiEndTransaction();
   sleepus(200);
 
   return data;
@@ -146,13 +150,16 @@ static uint8_t registerRead(uint8_t reg)
 static void readMotion(motionBurst_t * motion)
 {
   uint8_t address = 0x16;
+
+  spiBeginTransaction(SPI_BAUDRATE_2MHZ);
   digitalWrite(NCS_PIN,LOW);
   sleepus(50);
   spiExchange(1, &address, &address);
   sleepus(50);
   spiExchange(sizeof(motionBurst_t), (uint8_t*)motion, (uint8_t*)motion);
   sleepus(50);
   digitalWrite(NCS_PIN, HIGH);
+  spiEndTransaction();
   sleepus(50);
 
   uint16_t realShutter = (motion->shutter >> 8) & 0x0FF;
@@ -312,8 +319,6 @@ static void pamotionInit()
   digitalWrite(NCS_PIN, HIGH);
 
   spiBegin();
-  spiConfigureSlow();
-
   vTaskDelay(M2T(40));
 
   digitalWrite(NCS_PIN, HIGH);

src/deck/drivers/src/locodeck.c

@@ -120,7 +120,6 @@ static uwbAlgorithm_t *algorithm = &uwbTwrTagAlgorithm;
 #endif
 
 static bool isInit = false;
-static xSemaphoreHandle spiSemaphore;
 static SemaphoreHandle_t irqSemaphore;
 static dwDevice_t dwm_device;
 static dwDevice_t *dwm = &dwm_device;
@@ -191,35 +190,32 @@ bool lpsGetLppShort(lpsLppShortPacket_t* shortPacket)
 
 static uint8_t spiTxBuffer[196];
 static uint8_t spiRxBuffer[196];
+static uint16_t spiSpeed = SPI_BAUDRATE_2MHZ;
 
 /************ Low level ops for libdw **********/
 static void spiWrite(dwDevice_t* dev, const void *header, size_t headerLength,
                                       const void* data, size_t dataLength)
 {
-  xSemaphoreTake(spiSemaphore, portMAX_DELAY);
-
+  spiBeginTransaction(spiSpeed);
   digitalWrite(CS_PIN, LOW);
   memcpy(spiTxBuffer, header, headerLength);
   memcpy(spiTxBuffer+headerLength, data, dataLength);
   spiExchange(headerLength+dataLength, spiTxBuffer, spiRxBuffer);
   digitalWrite(CS_PIN, HIGH);
-
-  xSemaphoreGive(spiSemaphore);
+  spiEndTransaction();
 }
 
 static void spiRead(dwDevice_t* dev, const void *header, size_t headerLength,
                                      void* data, size_t dataLength)
 {
-  xSemaphoreTake(spiSemaphore, portMAX_DELAY);
-
+  spiBeginTransaction(spiSpeed);
   digitalWrite(CS_PIN, LOW);
   memcpy(spiTxBuffer, header, headerLength);
   memset(spiTxBuffer+headerLength, 0, dataLength);
   spiExchange(headerLength+dataLength, spiTxBuffer, spiRxBuffer);
   memcpy(data, spiRxBuffer+headerLength, dataLength);
   digitalWrite(CS_PIN, HIGH);
-
-  xSemaphoreGive(spiSemaphore);
+  spiEndTransaction();
 }
 
 void __attribute__((used)) EXTI11_Callback(void)
@@ -240,11 +236,11 @@ static void spiSetSpeed(dwDevice_t* dev, dwSpiSpeed_t speed)
 {
   if (speed == dwSpiSpeedLow)
   {
-    spiConfigureSlow();
+    spiSpeed = SPI_BAUDRATE_2MHZ;
   }
   else if (speed == dwSpiSpeedHigh)
   {
-    spiConfigureFast();
+    spiSpeed = SPI_BAUDRATE_21MHZ;
   }
 }
 
@@ -301,9 +297,6 @@ static void dwm1000Init(DeckInfo *info)
   GPIO_WriteBit(GPIOC, GPIO_Pin_10, 1);
   vTaskDelay(M2T(10));
 
-  // Semaphore that protect the SPI communication
-  spiSemaphore = xSemaphoreCreateMutex();
-
   // Initialize the driver
   dwInit(dwm, &dwOps);       // Init libdw
 

src/deck/drivers/src/usddeck.c

@@ -76,6 +76,8 @@ static crc crcTable[256];
 static usdLogConfig_t usdLogConfig;
 
 static BYTE exchangeBuff[512];
+static uint16_t spiSpeed;
+
 #ifdef USD_RUN_DISKIO_FUNCTION_TESTS
 DWORD workBuff[512];  /* 2048 byte working buffer */
 #endif
@@ -125,20 +127,22 @@ static DISKIO_LowLevelDriver_t fatDrv =
 static void initSpi(void)
 {
   spiBegin();   /* Enable SPI function */
+  spiSpeed = SPI_BAUDRATE_2MHZ;
+
   pinMode(USD_CS_PIN, OUTPUT);
-  csHigh();
+  digitalWrite(USD_CS_PIN, 1);
 
   // FIXME: DELAY of 10ms?
 }
 
 static void setSlowSpiMode(void)
 {
-  spiConfigureSlow();
+  spiSpeed = SPI_BAUDRATE_2MHZ;
 }
 
 static void setFastSpiMode(void)
 {
-  spiConfigureFast();
+  spiSpeed = SPI_BAUDRATE_21MHZ;
 }
 
 /* Exchange a byte */
@@ -166,10 +170,17 @@ static void xmitSpiMulti(const BYTE *buff, UINT btx)
 static void csHigh(void)
 {
   digitalWrite(USD_CS_PIN, 1);
+
+  // Dummy clock (force DO hi-z for multiple slave SPI)
+  // Moved here from fatfs_sd.c to handle bus release
+  xchgSpi(0xFF);
+
+  spiEndTransaction();
 }
 
 static void csLow(void)
 {
+  spiBeginTransaction(spiSpeed);
   digitalWrite(USD_CS_PIN, 0);
 }
 

src/deck/interface/deck_spi.h

@@ -30,12 +30,19 @@
 #include <stdbool.h>
 #include <string.h>
 
+// Based on 84MHz peripheral clock
+#define SPI_BAUDRATE_21MHZ  SPI_BaudRatePrescaler_4     // 21MHz
+#define SPI_BAUDRATE_12MHZ  SPI_BaudRatePrescaler_8     // 11.5MHz
+#define SPI_BAUDRATE_6MHZ   SPI_BaudRatePrescaler_16    // 5.25MHz
+#define SPI_BAUDRATE_3MHZ   SPI_BaudRatePrescaler_32    // 2.625MHz
+#define SPI_BAUDRATE_2MHZ   SPI_BaudRatePrescaler_64    // 1.3125MHz
+
 /**
  * Initialize the SPI.
  */
 void spiBegin(void);
-void spiConfigureSlow(void);
-void spiConfigureFast(void);
+void spiBeginTransaction(uint16_t baudRatePrescaler);
+void spiEndTransaction();
 
 /* Send the data_tx buffer and receive into the data_rx buffer */
 bool spiExchange(size_t length, const uint8_t *data_tx, uint8_t *data_rx);

src/drivers/src/fatfs_sd.c

@@ -58,7 +58,8 @@ static void deselect(sdSpiContext_t *context) {
   context->csHigh();
 
   // Dummy clock (force DO hi-z for multiple slave SPI)
-  context->xchgSpi(0xFF);
+  // which has been moved to higher layer.
+  //context->xchgSpi(0xFF);
 }