[diag] add gpio mode commands (#8391)

This commit adds diag commands for setting the GPIO mode to resolve
the conflict https://github.com/openthread/openthread/issues/8362.

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (261)
+#define OPENTHREAD_API_VERSION (262)
 
 /**
  * @addtogroup api-instance

include/openthread/platform/diag.h

@@ -56,6 +56,16 @@ extern "C" {
  *
  */
 
+/**
+ * This enumeration defines the gpio modes.
+ *
+ */
+typedef enum
+{
+    OT_GPIO_MODE_INPUT  = 0, ///< Input mode without pull resistor.
+    OT_GPIO_MODE_OUTPUT = 1, ///< Output mode.
+} otGpioMode;
+
 /**
  * This function processes a factory diagnostics command line.
  *
@@ -155,6 +165,34 @@ otError otPlatDiagGpioSet(uint32_t aGpio, bool aValue);
  */
 otError otPlatDiagGpioGet(uint32_t aGpio, bool *aValue);
 
+/**
+ * This function sets the gpio mode.
+ *
+ * @param[in]   aGpio   The gpio number.
+ * @param[out]  aMode   The gpio mode.
+ *
+ * @retval OT_ERROR_NONE             Successfully set the gpio mode.
+ * @retval OT_ERROR_INVALID_ARGS     @p aGpio is not supported.
+ * @retval OT_ERROR_NOT_IMPLEMENTED  This function is not implemented on the platform.
+ *
+ */
+otError otPlatDiagGpioSetMode(uint32_t aGpio, otGpioMode aMode);
+
+/**
+ * This function gets the gpio mode.
+ *
+ * @param[in]   aGpio   The gpio number.
+ * @param[out]  aValue  A pointer where to put gpio value.
+ *
+ * @retval OT_ERROR_NONE             Successfully got the gpio value.
+ * @retval OT_ERROR_FAILED           The gpio is neither in input nor output mode. For example, if the gpio is in
+ *                                   analog mode.
+ * @retval OT_ERROR_INVALID_ARGS     @p aGpio is not supported or @p aMode is NULL.
+ * @retval OT_ERROR_NOT_IMPLEMENTED  This function is not implemented on the platform.
+ *
+ */
+otError otPlatDiagGpioGetMode(uint32_t aGpio, otGpioMode *aMode);
+
 /**
  * @}
  *