doc: reference: Add GNA API entry

Add an entry for the GNA API.

Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>

doc/reference/peripherals/gna.rst

@@ -0,0 +1,23 @@
+.. _gna_api:
+
+GNA
+###
+
+Overview
+********
+
+The GNA API provides access to Intel's Gaussian Mixture Model and Neural Network
+Accelerator (GNA).
+
+Configuration Options
+*********************
+
+Related configuration options:
+
+* :option:`CONFIG_INTEL_GNA`
+
+API Reference
+*************
+
+.. doxygengroup:: gna_interface
+   :project: Zephyr

doc/reference/peripherals/index.rst

@@ -12,6 +12,7 @@ Peripherals
    eeprom.rst
    entropy.rst
    flash.rst
+   gna.rst
    gpio.rst
    i2c_eeprom_slave.rst
    i2c.rst

include/drivers/gna.h

@@ -9,14 +9,20 @@
 /**
  * @file
  * @brief Public API header file for Intel GNA driver
- *
- * This file contains the driver APIs for Intel's
- * Gaussian Mixture Model and Neural Network Accelerator (GNA)
  */
 
 #ifndef __INCLUDE_GNA__
 #define __INCLUDE_GNA__
 
+/**
+ * @defgroup gna_interface GNA Interface
+ * @ingroup io_interfaces
+ * @{
+ *
+ * This file contains the driver APIs for Intel's
+ * Gaussian Mixture Model and Neural Network Accelerator (GNA)
+ */
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -213,4 +219,8 @@ static inline int gna_infer(struct device *dev, struct gna_inference_req *req,
 }
 #endif
 
+/**
+ * @}
+ */
+
 #endif /* __INCLUDE_GNA__ */