SPI: refactored spi_bitbang driver

platform/drivers/SPI/spi_bitbang.c

@@ -21,44 +21,18 @@
 #include <interfaces/delays.h>
 #include "spi_bitbang.h"
 
-typedef uint8_t (*sendRecv_impl)(struct spiConfig *cfg, uint8_t data);
+uint8_t spiBitbang_sendRecv(const void *priv, uint8_t data)
-
-static uint8_t sendRecv_clkRising(struct spiConfig *cfg, uint8_t data)
 {
+    const struct spiConfig *cfg = (const struct spiConfig *) priv;
     uint8_t incoming = 0;
 
     for(uint8_t cnt = 0; cnt < 8; cnt++)
     {
-        // Setup new output towards the peripheral
+        // Clock inactive edge
-        if((data & 0x80) != 0)
+        if((cfg->flags & SPI_FLAG_CPHA) != 0)
-            gpio_setPin(cfg->mosi.port, cfg->mosi.pin);
+            gpio_setPin(cfg->clk.port, cfg->clk.pin);
         else
-            gpio_clearPin(cfg->mosi.port, cfg->mosi.pin);
+            gpio_clearPin(cfg->clk.port, cfg->clk.pin);
-
-        // Sample the current incoming bit from the peripheral
-        data     <<= 1;
-        incoming <<= 1;
-        incoming |= gpio_readPin(cfg->miso.port, cfg->miso.pin);
-
-        // One clock cycle, peripheral reads the new bit and updates its output
-        // bit
-        delayUs(cfg->clkPeriod);
-        gpio_setPin(cfg->clk.port, cfg->clk.pin);
-        delayUs(cfg->clkPeriod);
-        gpio_clearPin(cfg->clk.port, cfg->clk.pin);
-    }
-
-    return incoming;
-}
-
-static uint8_t sendRecv_clkFalling(struct spiConfig *cfg, uint8_t data)
-{
-    uint8_t incoming = 0;
-
-    for(uint8_t cnt = 0; cnt < 8; cnt++)
-    {
-        // Clock rising edge (inactive edge)
-        gpio_setPin(cfg->clk.port, cfg->clk.pin);
 
         // Setup data output
         if((data & 0x80) != 0)
@@ -71,10 +45,14 @@ static uint8_t sendRecv_clkFalling(struct spiConfig *cfg, uint8_t data)
         incoming <<= 1;
         incoming |= gpio_readPin(cfg->miso.port, cfg->miso.pin);
 
-        // Clock falling edge, peripheral reads new data and updates its output
-        // line
         delayUs(cfg->clkPeriod);
-        gpio_clearPin(cfg->clk.port, cfg->clk.pin);
+
+        // Clock active edge
+        if((cfg->flags & SPI_FLAG_CPHA) != 0)
+            gpio_clearPin(cfg->clk.port, cfg->clk.pin);
+        else
+            gpio_setPin(cfg->clk.port, cfg->clk.pin);
+
         delayUs(cfg->clkPeriod);
     }
 
@@ -82,9 +60,12 @@ static uint8_t sendRecv_clkFalling(struct spiConfig *cfg, uint8_t data)
 }
 
 
-int spiBitbang_init(const struct spiDevice* dev)
+int spiBitbang_init(const struct spiCustomDevice *dev)
 {
-    struct spiConfig *cfg = (struct spiConfig *) dev->priv;
+    const struct spiConfig *cfg = (const struct spiConfig *) dev->priv;
+
+    // Basic driver init
+    spi_init((const struct spiDevice *) dev);
 
     // Setup MOSI and clock lines as output, low level
     gpio_setMode(cfg->clk.port,   cfg->clk.pin,  OUTPUT);
@@ -96,84 +77,17 @@ int spiBitbang_init(const struct spiDevice* dev)
     if((cfg->flags & SPI_HALF_DUPLEX) == 0)
         gpio_setMode(cfg->miso.port, cfg->miso.pin, INPUT);
 
-    // Set initial state of clock line to high if requested
-    if((cfg->flags & SPI_FLAG_CPOL) != 0)
-        gpio_clearPin(cfg->clk.port, cfg->clk.pin);
-
-    if(dev->mutex != NULL)
-        pthread_mutex_init((pthread_mutex_t *) dev->mutex, NULL);
-
     return 0;
-
 }
 
-void spiBitbang_terminate(const struct spiDevice* dev)
+void spiBitbang_terminate(const struct spiCustomDevice* dev)
 {
-    struct spiConfig *cfg = (struct spiConfig *) dev->priv;
+    const struct spiConfig *cfg = (const struct spiConfig *) dev->priv;
 
     // Set clock and MOSI back to Hi-Z state
     gpio_setMode(cfg->clk.port,  cfg->clk.pin,  INPUT);
     gpio_setMode(cfg->mosi.port, cfg->mosi.pin, INPUT);
 
-    if(dev->mutex != NULL)
+    // Final driver cleanup
-        pthread_mutex_destroy((pthread_mutex_t *) dev->mutex);
+    spi_terminate((const struct spiDevice *) dev);
-}
-
-int spiBitbang_impl(const struct spiDevice *dev, const void *txBuf,
-                    const size_t txSize, void *rxBuf, const size_t rxSize)
-{
-    struct spiConfig *cfg = (struct spiConfig *) dev->priv;
-    const uint8_t *txData = (const uint8_t *) txBuf;
-    uint8_t       *rxData = (uint8_t *) rxBuf;
-    sendRecv_impl spi_sendRecv;
-
-    if((cfg->flags & SPI_FLAG_CPHA) != 0)
-        spi_sendRecv = &sendRecv_clkFalling;
-    else
-        spi_sendRecv = &sendRecv_clkRising;
-
-    // Send only
-    if((rxBuf == NULL) || (rxSize == 0))
-    {
-        for(size_t i = 0; i < txSize; i++)
-            spi_sendRecv(cfg, txData[i]);
-
-        return 0;
-    }
-
-    // Receive only
-    if((txBuf == NULL) || (txSize == 0))
-    {
-        for(size_t i = 0; i < rxSize; i++)
-            rxData[i] = spi_sendRecv(cfg, 0x00);
-
-        return 0;
-    }
-
-    // Transmit and receive
-    size_t txRxSize = (txSize < rxSize) ? txSize : rxSize;
-    for(size_t i = 0; i < txRxSize; i++)
-        rxData[i] = spi_sendRecv(cfg, txData[i]);
-
-    // Still something to send?
-    if(txSize > txRxSize)
-    {
-        for(size_t i = 0; i < (txSize - txRxSize); i++)
-        {
-            size_t pos = txRxSize + i;
-            spi_sendRecv(cfg, txData[pos]);
-        }
-    }
-
-    // Still something to receive?
-    if(rxSize > txRxSize)
-    {
-        for(size_t i = 0; i < (rxSize - txRxSize); i++)
-        {
-            size_t pos = txRxSize + i;
-            rxData[pos] = spi_sendRecv(cfg, 0x00);
-        }
-    }
-
-    return 0;
 }

platform/drivers/SPI/spi_bitbang.h

@@ -23,6 +23,7 @@
 
 #include <peripherals/gpio.h>
 #include <peripherals/spi.h>
+#include "spi_custom.h"
 
 #ifdef __cplusplus
 extern "C" {
@@ -50,38 +51,33 @@ struct spiConfig
  *  Instantiate an SPI bitbang device.
  *
  * @param name: device name.
- * @param mutx: pointer to mutex, or NULL.
  * @param cfg: driver configuration data.
+ * @param mutx: pointer to mutex, or NULL.
  */
-#define SPI_BITBANG_DEVICE_DEFINE(name, mutx, cfg)                          \
+#define SPI_BITBANG_DEVICE_DEFINE(name, cfg, mutx)           \
-int spiBitbang_impl(const struct spiDevice *dev, const void *txBuf,         \
+uint8_t spiBitbang_sendRecv(const void *priv, uint8_t data); \
-                    const size_t txSize, void *rxBuf, const size_t rxSize); \
+const struct spiCustomDevice name =                          \
-const struct spiDevice name =                                               \
+{                                                            \
-{                                                                           \
+    .transfer = spiCustom_transfer,                          \
-    .transfer = spiBitbang_impl,                                            \
+    .priv     = &cfg,                                        \
-    .priv     = &cfg,                                                       \
+    .mutex    = mutx,                                        \
-    .mutex    = mutx,                                                       \
+    .spiFunc  = spiBitbang_sendRecv                          \
 };
 
 /**
  * Initialise a bitbang SPI driver.
- * Is left to application code to change the operating mode and alternate function
- * mapping of the corresponding gpio lines.
  *
  * @param dev: SPI bitbang device descriptor.
- * @param speed: SPI clock speed.
- * @param flags: SPI configuration flags.
  * @return zero on success, a negative error code otherwise.
  */
-int spiBitbang_init(const struct spiDevice *dev);
+int spiBitbang_init(const struct spiCustomDevice *dev);
 
 /**
  * Shut down a bitbang SPI driver.
  *
  * @param dev: SPI bitbang device descriptor.
  */
-void spiBitbang_terminate(const struct spiDevice *dev);
+void spiBitbang_terminate(const struct spiCustomDevice *dev);
-
 
 #ifdef __cplusplus
 }