HAL: ResetReason: Add the get_capabilities function

Add the hal_reset_reason_get_capabilities() to ResetReason HAL API.
Add a default, weak implementation, that every target can override.

hal/mbed_compat.c

@@ -19,6 +19,7 @@
 #include "i2c_api.h"
 #include "spi_api.h"
 #include "gpio_api.h"
+#include "reset_reason_api.h"
 #include "mbed_toolchain.h"
 
 // To be re-implemented in the target layer if required
@@ -90,4 +91,15 @@ MBED_WEAK void spi_get_capabilities(PinName ssel, bool slave, spi_capabilities_t
     }
 }
 
-#endif
+#endif
+
+#if DEVICE_RESET_REASON
+// To be re-implemented in the target layer if required
+MBED_WEAK void hal_reset_reason_get_capabilities(reset_reason_capabilities_t *cap)
+{
+    cap->reasons = (1 << RESET_REASON_PIN_RESET) | (1 << RESET_REASON_SOFTWARE);
+#if DEVICE_WATCHDOG
+    cap->reasons |= 1 << RESET_REASON_WATCHDOG;
+#endif
+}
+#endif

hal/reset_reason_api.h

@@ -41,6 +41,8 @@ extern "C" {
  * some other part of the application may have cleared the value. Therefore,
  * though there may have been a reset reason in the registers when the system
  * started, the reason may not be available when the user comes to check it.
+ * * The function ::hal_reset_reason_get_capabilities fills the given
+ * `reset_reason_capabilities_t` instance.
  *
  * # Undefined behavior
  * * There is no guarantee that the function ::hal_reset_reason_get will
@@ -88,6 +90,12 @@ typedef enum {
     RESET_REASON_UNKNOWN         /**< Unknown or unreadable reset reason **/
 } reset_reason_t;
 
+/** Reset reason capabilities of the platform
+ */
+typedef struct {
+    uint32_t reasons; /**< Supported reset reasons. Each bit represents a corresponding reset_reason_t value.**/
+} reset_reason_capabilities_t;
+
 /** Fetch the reset reason for the last system reset.
  *
  * This function must return the contents of the system reset reason registers
@@ -137,6 +145,10 @@ uint32_t hal_reset_reason_get_raw(void);
  */
 void hal_reset_reason_clear(void);
 
+/** Fill the given reset_reason_capabilities_t instance according to platform capabilities.
+ */
+void hal_reset_reason_get_capabilities(reset_reason_capabilities_t *cap);
+
 /**@}*/
 
 #ifdef __cplusplus