Merge pull request arduino#13 from bcmi-labs/refactor-spi

Refactor SPI module a bit (configuration code especially).

Author: aentinger

libraries/SPI/SPI.cpp

@@ -11,30 +11,51 @@
  * published by the Free Software Foundation.
  */
 
+/**************************************************************************************
+ * INCLUDE
+ **************************************************************************************/
+
 #include "SPI.h"
 
+/**************************************************************************************
+ * NAMESPACE
+ **************************************************************************************/
+
 using namespace arduino;
 
+/**************************************************************************************
+ * EXTERN GLOBAL CONSTANTS
+ **************************************************************************************/
+
 extern const spi_extended_cfg_t g_spi0_ext_cfg;
 extern const spi_extended_cfg_t g_spi1_ext_cfg;
 extern const sci_spi_extended_cfg_t g_spi2_cfg_extend;
 
+/**************************************************************************************
+ * STATIC MEMBER INITIALISATION
+ **************************************************************************************/
+
 uint8_t ArduinoSPI::initialized = 0;
 uint8_t ArduinoSPI::interruptMode = 0;
 uint8_t ArduinoSPI::interruptMask = 0;
 uint8_t ArduinoSPI::interruptSave = 0;
 
+/**************************************************************************************
+ * GLOBAL MEMBER VARIABLES
+ **************************************************************************************/
+
 static spi_event_t _spi_cb_event[13] = {SPI_EVENT_TRANSFER_ABORTED};
 
+/**************************************************************************************
+ * CTOR/DTOR
+ **************************************************************************************/
+
 ArduinoSPI::ArduinoSPI(spi_ctrl_t *g_spi_ctrl
                       ,const spi_cfg_t *g_spi_cfg
                       ,const spi_extended_cfg_t *g_spi_ext_cfg, int ch):
   _g_spi_ctrl(g_spi_ctrl)
 , _g_spi_cfg(g_spi_cfg)
 , _g_spi_ext_cfg(g_spi_ext_cfg)
-, _clk_phase(SPI_CLK_PHASE_EDGE_ODD)
-, _clk_polarity(SPI_CLK_POLARITY_LOW)
-, _bit_order(SPI_BIT_ORDER_MSB_FIRST)
 , _channel(ch)
 , _is_sci(false)
 {
@@ -46,9 +67,6 @@ ArduinoSPI::ArduinoSPI(spi_ctrl_t *g_spi_ctrl
   _g_spi_ctrl(g_spi_ctrl)
 , _g_spi_cfg(g_spi_cfg)
 , _g_sci_spi_ext_cfg(g_spi_ext_cfg)
-, _clk_phase(SPI_CLK_PHASE_EDGE_ODD)
-, _clk_polarity(SPI_CLK_POLARITY_LOW)
-, _bit_order(SPI_BIT_ORDER_MSB_FIRST)
 , _channel(ch)
 , _is_sci(true)
 {
@@ -60,6 +78,10 @@ ArduinoSPI::ArduinoSPI(int ch, bool isSci):
 {
 }
 
+/**************************************************************************************
+ * PUBLIC MEMBER FUNCTIONS
+ **************************************************************************************/
+
 void ArduinoSPI::begin()
 {
   bool isSPIObject = false;
@@ -127,7 +149,7 @@ void ArduinoSPI::begin()
     initialized = true;
   }
 
-  beginTransaction(DEFAULT_SPI_SETTINGS);
+  config(DEFAULT_SPI_SETTINGS);
 }
 
 void ArduinoSPI::end() {
@@ -233,113 +255,137 @@ void ArduinoSPI::transfer(void *buf, size_t count) {
   }
 }
 
-void ArduinoSPI::beginTransaction(arduino::SPISettings settings) {
-  // data mode
-  switch(settings.getDataMode()){
-      case arduino::SPI_MODE0:
-          _clk_polarity = SPI_CLK_POLARITY_LOW;
-          _clk_phase = SPI_CLK_PHASE_EDGE_ODD;
-          break;
-      case arduino::SPI_MODE1:
-          _clk_polarity = SPI_CLK_POLARITY_LOW;
-          _clk_phase = SPI_CLK_PHASE_EDGE_EVEN;
-          break;
-      case arduino::SPI_MODE2:
-          _clk_polarity = SPI_CLK_POLARITY_HIGH;
-          _clk_phase = SPI_CLK_PHASE_EDGE_ODD;
-          break;
-      case arduino::SPI_MODE3:
-          _clk_polarity = SPI_CLK_POLARITY_HIGH;
-          _clk_phase = SPI_CLK_PHASE_EDGE_EVEN;
-          break;
-  }
-  // bit order
-  if(settings.getBitOrder() == LSBFIRST){
-      _bit_order = SPI_BIT_ORDER_LSB_FIRST;
-  } else {
-      _bit_order = SPI_BIT_ORDER_MSB_FIRST;
-  }
+void ArduinoSPI::beginTransaction(arduino::SPISettings settings)
+{
+  config(settings);
+}
 
-  // Clock settings
-  if (_is_sci) {
+void ArduinoSPI::endTransaction(void) {
 
-    if (initialized) {
-      R_SCI_SPI_Close(_g_spi_ctrl);
-    }
+}
 
-    sci_spi_div_setting_t clk_div = _g_sci_spi_ext_cfg->clk_div;
-    R_SCI_SPI_CalculateBitrate(settings.getClockFreq(), &clk_div, false);
+void ArduinoSPI::attachInterrupt() {
 
-    R_SCI_SPI_Open(_g_spi_ctrl, _g_spi_cfg);
+}
 
-    sci_spi_instance_ctrl_t * p_ctrl = (sci_spi_instance_ctrl_t *)_g_spi_ctrl;
-    uint32_t spmr = p_ctrl->p_reg->SPMR;
-    uint32_t scmr = p_ctrl->p_reg->SCMR;
-    uint32_t smr  = R_SCI0_SMR_CM_Msk;
+void ArduinoSPI::detachInterrupt() {
 
-    /* Configure CPHA setting. */
-    spmr |= (uint32_t) _clk_phase << 7;
+}
 
-    /* Configure CPOL setting. */
-    spmr |= (uint32_t) _clk_polarity << 6;
+/**************************************************************************************
+ * PRIVATE MEMBER FUNCTIONS
+ **************************************************************************************/
 
-    /* Configure Bit Order (MSB,LSB) */
-    scmr |= (uint32_t) _bit_order << 3;
-  
-    /* Select the baud rate generator clock divider. */
-    smr |= (uint32_t) clk_div.cks;
+void ArduinoSPI::config(arduino::SPISettings const & settings)
+{
+  if (_is_sci)
+    configSpiSci(settings);
+  else
+    configSpi(settings);
+}
 
-    // Update settings
-    p_ctrl->p_reg->SMR  = (uint8_t) smr;
-    p_ctrl->p_reg->BRR  = (uint8_t) clk_div.brr;
-    p_ctrl->p_reg->SPMR = spmr;
-    p_ctrl->p_reg->SCMR = scmr;
+void ArduinoSPI::configSpi(arduino::SPISettings const & settings)
+{
+  auto [clk_phase, clk_polarity, bit_order] = toFspSpiConfig(settings);
 
-  } else {
+  if (initialized)
+    R_SPI_Close(_g_spi_ctrl);
 
-    if (initialized) {
-      R_SPI_Close(_g_spi_ctrl);
-    }
+  rspck_div_setting_t spck_div = _g_spi_ext_cfg->spck_div;
+  R_SPI_CalculateBitrate(settings.getClockFreq(), &spck_div);
 
-    rspck_div_setting_t spck_div = _g_spi_ext_cfg->spck_div;
-    R_SPI_CalculateBitrate(settings.getClockFreq(), &spck_div);
+  R_SPI_Open(_g_spi_ctrl, _g_spi_cfg);
 
-    R_SPI_Open(_g_spi_ctrl, _g_spi_cfg);
+  spi_instance_ctrl_t * p_ctrl = (spi_instance_ctrl_t *)_g_spi_ctrl;
+  uint32_t spcmd0 = p_ctrl->p_regs->SPCMD[0];
+  uint32_t spbr = p_ctrl->p_regs->SPBR;
 
-    spi_instance_ctrl_t * p_ctrl = (spi_instance_ctrl_t *)_g_spi_ctrl;
-    uint32_t spcmd0 = p_ctrl->p_regs->SPCMD[0];
-    uint32_t spbr = p_ctrl->p_regs->SPBR;
+  /* Configure CPHA setting. */
+  spcmd0 |= (uint32_t) clk_phase;
 
-    /* Configure CPHA setting. */
-    spcmd0 |= (uint32_t) _clk_phase;
+  /* Configure CPOL setting. */
+  spcmd0 |= (uint32_t) clk_polarity << 1;
 
-    /* Configure CPOL setting. */
-    spcmd0 |= (uint32_t) _clk_polarity << 1;
+  /* Configure Bit Order (MSB,LSB) */
+  spcmd0 |= (uint32_t) bit_order << 12;
 
-    /* Configure Bit Order (MSB,LSB) */
-    spcmd0 |= (uint32_t) _bit_order << 12;
+  /* Configure the Bit Rate Division Setting */
+  spcmd0 &= !(((uint32_t)0xFF) << 2);
+  spcmd0 |= (uint32_t) spck_div.brdv << 2;
 
-    /* Configure the Bit Rate Division Setting */
-    spcmd0 &= !(((uint32_t)0xFF) << 2);
-    spcmd0 |= (uint32_t) spck_div.brdv << 2;
+  /* Update settings. */
+  p_ctrl->p_regs->SPCMD[0] = (uint16_t) spcmd0;
+  p_ctrl->p_regs->SPBR = (uint8_t) spck_div.spbr;
+}
 
-    // Update settings
-    p_ctrl->p_regs->SPCMD[0] = (uint16_t) spcmd0;
-    p_ctrl->p_regs->SPBR = (uint8_t) spck_div.spbr;
+void ArduinoSPI::configSpiSci(arduino::SPISettings const & settings)
+{
+  auto [clk_phase, clk_polarity, bit_order] = toFspSpiConfig(settings);
 
-  }
-}
+  if (initialized)
+    R_SCI_SPI_Close(_g_spi_ctrl);
 
-void ArduinoSPI::endTransaction(void) {
+  sci_spi_div_setting_t clk_div = _g_sci_spi_ext_cfg->clk_div;
+  R_SCI_SPI_CalculateBitrate(settings.getClockFreq(), &clk_div, false);
 
-}
+  R_SCI_SPI_Open(_g_spi_ctrl, _g_spi_cfg);
 
-void ArduinoSPI::attachInterrupt() {
+  sci_spi_instance_ctrl_t * p_ctrl = (sci_spi_instance_ctrl_t *)_g_spi_ctrl;
+  uint32_t spmr = p_ctrl->p_reg->SPMR;
+  uint32_t scmr = p_ctrl->p_reg->SCMR;
+  uint32_t smr  = R_SCI0_SMR_CM_Msk;
+
+  /* Configure CPHA setting. */
+  spmr |= (uint32_t) clk_phase << 7;
+
+  /* Configure CPOL setting. */
+  spmr |= (uint32_t) clk_polarity << 6;
+
+  /* Configure Bit Order (MSB,LSB) */
+  scmr |= (uint32_t) bit_order << 3;
+
+  /* Select the baud rate generator clock divider. */
+  smr |= (uint32_t) clk_div.cks;
 
+  /* Update settings. */
+  p_ctrl->p_reg->SMR  = (uint8_t) smr;
+  p_ctrl->p_reg->BRR  = (uint8_t) clk_div.brr;
+  p_ctrl->p_reg->SPMR = spmr;
+  p_ctrl->p_reg->SCMR = scmr;
 }
 
-void ArduinoSPI::detachInterrupt() {
+std::tuple<spi_clk_phase_t, spi_clk_polarity_t, spi_bit_order_t> ArduinoSPI::toFspSpiConfig(arduino::SPISettings const & settings)
+{
+  spi_clk_phase_t clk_phase = SPI_CLK_PHASE_EDGE_ODD;
+  spi_clk_polarity_t clk_polarity = SPI_CLK_POLARITY_LOW;
+  spi_bit_order_t bit_order = SPI_BIT_ORDER_MSB_FIRST;
 
+  switch(settings.getDataMode())
+  {
+    case arduino::SPI_MODE0:
+      clk_polarity = SPI_CLK_POLARITY_LOW;
+      clk_phase = SPI_CLK_PHASE_EDGE_ODD;
+    break;
+    case arduino::SPI_MODE1:
+     clk_polarity = SPI_CLK_POLARITY_LOW;
+     clk_phase = SPI_CLK_PHASE_EDGE_EVEN;
+    break;
+    case arduino::SPI_MODE2:
+      clk_polarity = SPI_CLK_POLARITY_HIGH;
+      clk_phase = SPI_CLK_PHASE_EDGE_ODD;
+    break;
+    case arduino::SPI_MODE3:
+      clk_polarity = SPI_CLK_POLARITY_HIGH;
+      clk_phase = SPI_CLK_PHASE_EDGE_EVEN;
+    break;
+  }
+
+  if(settings.getBitOrder() == LSBFIRST)
+    bit_order = SPI_BIT_ORDER_LSB_FIRST;
+  else
+    bit_order = SPI_BIT_ORDER_MSB_FIRST;
+
+  return std::make_tuple(clk_phase, clk_polarity, bit_order);
 }
 
 void ArduinoSPI::enableSciSpiIrqs() {
@@ -423,6 +469,10 @@ void ArduinoSPI::enableSciSpiIrqs() {
 
 }
 
+/**************************************************************************************
+ * CALLBACKS FOR FSP FRAMEWORK
+ **************************************************************************************/
+
 void spi_callback(spi_callback_args_t *p_args) {
   if (SPI_EVENT_TRANSFER_COMPLETE == p_args->event) {
     _spi_cb_event[p_args->channel] = SPI_EVENT_TRANSFER_COMPLETE;
@@ -444,10 +494,14 @@ void sci_spi_callback(spi_callback_args_t *p_args) {
   }
 }
 
+/**************************************************************************************
+ * OBJECT INSTANTIATION
+ **************************************************************************************/
+
 #if SPI_HOWMANY > 0
 ArduinoSPI SPI(SPI_CHANNEL, (bool)IS_SPI_SCI);
 #endif
 
 #if SPI_HOWMANY > 1
 ArduinoSPI SPI1(SPI1_CHANNEL, (bool)IS_SPI1_SCI);
-#endif
+#endif