zio: Beginning of a better sensor api in ZIO

Add a new sensor device API called zio_dev along with supporting
interface and implmentations needed to better encapsulate a large range
of functionality typical sampled input/output (sensor and signal
generator) type devices commonly provide.

Every device has a set of channels and attributes associated with it.
Channels may be attached to a fifo like interface (zio_buf) which
provides a pollable mechanism for obtaining the raw channel data at
a designated watermark level.

Signed-off-by: Tom Burdick <thomas.burdick@gmail.com>

CODEOWNERS

@@ -253,6 +253,8 @@
 /include/toolchain.h                      @andrewboie @andyross @nashif
 /include/toolchain/                       @andrewboie @andyross
 /include/zephyr.h                         @andrewboie @andyross
+/include/zio.h                            @bfrog
+/include/zio/                             @bfrog
 /kernel/                                  @andrewboie @andyross
 /lib/gui/                                 @vanwinkeljan
 /lib/libc/                                @nashif
@@ -328,6 +330,7 @@
 /subsys/storage/                          @nvlsianpu
 /subsys/testsuite/                        @nashif
 /subsys/usb/                              @jfischer-phytec-iot @finikorg
+/subsys/zio/                              @bfrog
 /tests/                                   @nashif
 /tests/boards/native_posix/               @aescolar
 /tests/boards/intel_s1000_crb/            @dcpleung @sathishkuttan
@@ -351,6 +354,7 @@
 /tests/net/socket/                        @jukkar @tbursztyka @pfalcon
 /tests/subsys/fs/                         @nashif @wentongwu
 /tests/subsys/settings/                   @nvlsianpu
+/tests/subsys/zio/                        @bfrog
 
 # Get all docs reviewed
 *.rst                                     @dbkinder

include/zio.h

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2019  Thomas Burdick <thomas.burdick@gmail.com>
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_ZIO_H_
+#define ZEPHYR_INCLUDE_ZIO_H_
+
+#include <zio/zio_variant.h>
+#include <zio/zio_attr.h>
+#include <zio/zio_fifo.h>
+#include <zio/zio_buf.h>
+#include <zio/zio_fifo_buf.h>
+#include <zio/zio_dev.h>
+
+#endif

include/zio/zio_attr.h

@@ -0,0 +1,61 @@
+/*
+ * Copyright (c) 2019 Thomas Burdick <thomas.burdick@gmail.com>
+ * Copyright (c) 2019 Kevin Townsend
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ * @brief ZIO attribute definitions.
+ */
+
+#ifndef ZEPHYR_INCLUDE_ZIO_ATTR_H_
+#define ZEPHYR_INCLUDE_ZIO_ATTR_H_
+
+#include <zephyr/types.h>
+#include <device.h>
+#include <zio/zio_variant.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief ZIO attribute enum and struct definitions.
+ * @defgroup zio_attributes ZIO attribute definitions
+ * @ingroup zio
+ * @{
+ */
+
+/** @brief ZIO attribute types. */
+enum zio_attr_type {
+	/* samples per second */
+	ZIO_SAMPLE_RATE,
+
+	/* A count of attribute types always begins the user definable range */
+	ZIO_ATTR_TYPES,
+
+	/* enforce a specific enum size allowing for a good number of user
+	 * definable values
+	 */
+	ZIO_ATTR_MAKE_16_BIT = 0xFFFF
+};
+
+/** Attribute record. */
+struct zio_attr {
+	/** Attribute identifier. */
+	enum zio_attr_type type;
+	/** Attribute variant. */
+	struct zio_variant data;
+};
+
+/**
+ * @}
+ */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* ZEPHYR_INCLUDE_ZIO_ATTR_H_ */