k64f: add RNG HAL implementation

Replaces old mbedtls entropy file, to use new RNG HAL API.

hal/targets.json

@@ -565,7 +565,7 @@
         "inherits": ["Target"],
         "progen": {"target": "frdm-k64f"},
         "detect_code": ["0240"],
-        "device_has": ["ANALOGIN", "ANALOGOUT", "ERROR_RED", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "STORAGE"],
+        "device_has": ["ANALOGIN", "ANALOGOUT", "ERROR_RED", "I2C", "I2CSLAVE", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "STDIO_MESSAGES", "STORAGE", "RNG"],
         "features": ["IPV4", "STORAGE"],
         "release_versions": ["2", "5"]
     },

hal/targets/hal/TARGET_Freescale/TARGET_KSDK2_MCUS/TARGET_MCU_K64F/rng_api.c

@@ -26,6 +26,19 @@
 #include "cmsis.h"
 #include "fsl_common.h"
 #include "fsl_clock.h"
+#include "rng_api.h"
+
+void rng_init(rng_t *obj)
+{
+    CLOCK_EnableClock(kCLOCK_Rnga0);
+    CLOCK_DisableClock(kCLOCK_Rnga0);
+    CLOCK_EnableClock(kCLOCK_Rnga0);
+}
+
+void rng_free(rng_t *obj)
+{
+    CLOCK_DisableClock(kCLOCK_Rnga0);
+}
 
 /*
  * Get one byte of entropy from the RNG, assuming it is up and running.
@@ -43,41 +56,25 @@ static void rng_get_byte( unsigned char *byte )
     }
 }
 
-/*
- * Get len bytes of entropy from the hardware RNG.
- */
-int mbedtls_hardware_poll( void *data,
-                    unsigned char *output, size_t len, size_t *olen )
+int rng_get_numbers(rng_t *obj, uint8_t *output, size_t length, size_t *output_length)
 {
     size_t i;
     int ret;
-    ((void) data);
-
-    CLOCK_EnableClock( kCLOCK_Rnga0 );
-    CLOCK_DisableClock( kCLOCK_Rnga0 );
-    CLOCK_EnableClock( kCLOCK_Rnga0 );
 
     /* Set "Interrupt Mask", "High Assurance" and "Go",
      * unset "Clear interrupt" and "Sleep" */
     RNG->CR = RNG_CR_INTM_MASK | RNG_CR_HA_MASK | RNG_CR_GO_MASK;
 
-    for( i = 0; i < len; i++ )
+    for (i = 0; i < length; i++) {
         rng_get_byte(output + i);
+    }
 
     /* Just be extra sure that we didn't do it wrong */
-    if( ( RNG->SR & RNG_SR_SECV_MASK ) != 0 )
-    {
-        ret = -1;
-        goto cleanup;
+    if ((RNG->SR & RNG_SR_SECV_MASK) != 0) {
+        return -1;
     }
 
-    *olen = len;
-    ret = 0;
+    *output_length = length;
 
-cleanup:
-    /* Disable clock to save power - assume we're the only users of RNG */
-    CLOCK_DisableClock( kCLOCK_Rnga0 );
-
-    return( ret );
+    return 0;
 }
-

hal/targets/hal/TARGET_Freescale/TARGET_KSDK2_MCUS/api/objects.h

@@ -61,6 +61,10 @@ struct dac_s {
     DACName dac;
 };
 
+struct rng_s {
+
+};
+
 #include "gpio_object.h"
 
 #ifdef __cplusplus