Add CRC configuration options to HAL API

Author: Steven Cartmell

drivers/MbedCRC.h

@@ -201,7 +201,14 @@ class MbedCRC
 
 #ifdef DEVICE_CRC
         if (_mode == HARDWARE) {
-          hal_crc_compute_partial_start(polynomial);
+            crc_mbed_config_t config;
+            config.polynomial  = polynomial;
+            config.initial_xor = _initial_value;
+            config.final_xor   = _final_xor;
+            config.reflect_in  = _reflect_data;
+            config.reflect_out = _reflect_remainder;
+
+            hal_crc_compute_partial_start(&config);
         }
 #endif // DEVICE_CRC
 
@@ -431,7 +438,14 @@ class MbedCRC
         _mode = (_crc_table == NULL) ? TABLE : BITWISE;
 
 #ifdef DEVICE_CRC
-        if (hal_crc_is_supported(polynomial)) {
+        crc_mbed_config_t config;
+        config.polynomial  = polynomial;
+        config.initial_xor = _initial_value;
+        config.final_xor   = _final_xor;
+        config.reflect_in  = _reflect_data;
+        config.reflect_out = _reflect_remainder;
+
+        if (hal_crc_is_supported(&config)) {
             _mode = HARDWARE;
         }
 #endif

hal/crc_api.h

@@ -35,6 +35,19 @@ typedef enum crc_polynomial {
     POLY_32BIT_ANSI  = 0x04C11DB7, // x32+x26+x23+x22+x16+x12+x11+x10+x8+x7+x5+x4+x2+x+1
 } crc_polynomial_t;
 
+typedef struct crc_mbed_config {
+    /// CRC Polynomial. Example polynomial: 0x21 = 0010_0011 = x^5+x+1
+    uint32_t polynomial;
+    /// Initial seed value for the computation.
+    uint32_t initial_xor;
+    /// Final xor value for the computation.
+    uint32_t final_xor;
+    /// Reflect bits on input.
+    bool reflect_in;
+    /// Reflect bits in final result before returning.
+    bool reflect_out;
+} crc_mbed_config_t;
+
 #ifdef DEVICE_CRC
 
 #ifdef __cplusplus
@@ -70,7 +83,7 @@ extern "C" {
  *
  * \return  True if running if the polynomial is supported, false if not.
  */
-bool hal_crc_is_supported(const uint32_t polynomial);
+bool hal_crc_is_supported(const crc_mbed_config_t* polynomial);
 
 /** Initialise the hardware CRC module with the given polynomial
  *
@@ -100,7 +113,7 @@ bool hal_crc_is_supported(const uint32_t polynomial);
  *
  * \param polynomial CRC Polynomial. Example polynomial: 0x1021 = x^12+x^5+1
  */
-void hal_crc_compute_partial_start(const uint32_t polynomial);
+void hal_crc_compute_partial_start(const crc_mbed_config_t* polynomial);
 
 /** Writes data to the current CRC module.
  *

targets/TARGET_Freescale/TARGET_MCUXpresso_MCUS/TARGET_MCU_K64F/mbed_crc_api.c

@@ -7,77 +7,34 @@
 
 static crc_bits_t width;
 
-bool hal_crc_is_supported(const uint32_t polynomial)
+bool hal_crc_is_supported(const crc_mbed_config_t* config)
 {
-  switch (polynomial)
-  {
-    case POLY_16BIT_CCITT:
-    case POLY_16BIT_IBM:
-    case POLY_32BIT_ANSI:
-      return true;
-    case POLY_8BIT_CCITT:
-    case POLY_7BIT_SD:
-      return false;
-    default:
-      return false;
-  }
-}
-
-void hal_crc_compute_partial_start(const uint32_t polynomial)
-{
-  crc_config_t config;
-
-  switch (polynomial)
-  {
-    case POLY_32BIT_ANSI:
-    {
-      width = kCrcBits32;
+  if (config == NULL)
+    return false;
 
-      config.polynomial         = polynomial;
-      config.seed               = 0xFFFFFFFFU;
-      config.reflectIn          = true;
-      config.reflectOut         = true;
-      config.complementChecksum = true;
-      config.crcBits            = width;
-      config.crcResult          = kCrcFinalChecksum;
+  if ((config->polynomial & 0x80008000) == 0)
+    return false;
 
-      break;
-    }
-    case POLY_16BIT_IBM:
-    {
-      width = kCrcBits16;
-
-      config.polynomial         = polynomial;
-      config.seed               = 0;
-      config.reflectIn          = true;
-      config.reflectOut         = true;
-      config.complementChecksum = false;
-      config.crcBits            = width;
-      config.crcResult          = kCrcFinalChecksum;
-
-      break;
-    }
-    case POLY_16BIT_CCITT:
-    {
-      width = kCrcBits16;
+  return true;
+}
 
-      config.polynomial         = polynomial;
-      config.seed               = 0xFFFFFFFFU;
-      config.reflectIn          = false;
-      config.reflectOut         = false;
-      config.complementChecksum = false;
-      config.crcBits            = width;
-      config.crcResult          = kCrcFinalChecksum;
+void hal_crc_compute_partial_start(const crc_mbed_config_t* config)
+{
+  if (config == NULL)
+    return;
 
-      break;
-    }
-    default:
-      MBED_ASSERT("Configuring Mbed CRC with unsupported polynomial");
+  width = ((config->polynomial & 0xFFFF0000U) != 0) ? kCrcBits32 : kCrcBits16;
 
-      return;
-  }
+  crc_config_t platform_config;
+  platform_config.polynomial         = config->polynomial;
+  platform_config.seed               = config->initial_xor;
+  platform_config.reflectIn          = config->reflect_in;
+  platform_config.reflectOut         = config->reflect_out;
+  platform_config.complementChecksum = true;
+  platform_config.crcBits            = width;
+  platform_config.crcResult          = kCrcFinalChecksum;
 
-  CRC_Init(CRC0, &config);
+  CRC_Init(CRC0, &platform_config);
 }
 
 void hal_crc_compute_partial(const uint8_t *data, const size_t size)