pw_i2c: Add endianness utility functions
- Add enum class IntSize, which will be used in I2cRegisterDevice
- Add GetEndian and ConvertToEndian
Change-Id: If0b0886538005f437c0847192269125af4d6f876
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/15667
Reviewed-by: Keir Mierle <keir@google.com>
diff --git a/pw_bytes/BUILD b/pw_bytes/BUILD
index baa3389..1e71763 100644
--- a/pw_bytes/BUILD
+++ b/pw_bytes/BUILD
@@ -30,6 +30,7 @@
hdrs = [
"public/pw_bytes/byte_builder.h",
"public/pw_bytes/span.h",
+ "public/pw_bytes/endianness.h",
],
includes = ["public"],
deps = [
diff --git a/pw_bytes/BUILD.gn b/pw_bytes/BUILD.gn
index ab0ca28..d211198 100644
--- a/pw_bytes/BUILD.gn
+++ b/pw_bytes/BUILD.gn
@@ -29,6 +29,7 @@
public = [
"public/pw_bytes/byte_builder.h",
"public/pw_bytes/span.h",
+ "public/pw_bytes/endianness.h",
]
sources = [ "byte_builder.cc" ]
public_deps = [
diff --git a/pw_bytes/public/pw_bytes/endianness.h b/pw_bytes/public/pw_bytes/endianness.h
new file mode 100644
index 0000000..69da843
--- /dev/null
+++ b/pw_bytes/public/pw_bytes/endianness.h
@@ -0,0 +1,98 @@
+// Copyright 2020 The Pigweed Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may not
+// use this file except in compliance with the License. You may obtain a copy of
+// the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+// License for the specific language governing permissions and limitations under
+// the License.
+#pragma once
+
+#include <cstddef>
+#include <cstring>
+#include <span>
+
+#include "pw_bytes/byte_builder.h"
+
+namespace pw {
+
+enum class IntSize { kUint8, kUint16, kUint32, kUint64 };
+
+size_t GetIntSize(IntSize int_size) {
+ if (int_size == IntSize::kUint8) {
+ return sizeof(uint8_t);
+ } else if (int_size == IntSize::kUint16) {
+ return sizeof(uint16_t);
+ } else if (int_size == IntSize::kUint32) {
+ return sizeof(uint32_t);
+ } else if (int_size == IntSize::kUint64){
+ return sizeof(uint64_t);
+ } else {
+ return 0; // Indicate an error
+ }
+}
+
+void GetEndian(ConstByteSpan bytes,
+ void* value,
+ IntSize int_size,
+ ByteOrder kEndianness) {
+ if (int_size == IntSize::kUint8) {
+ ByteBuffer<1> bb;
+ bb.append(bytes);
+ auto it = bb.begin();
+ *static_cast<uint8_t*>(value) = it.ReadUint8();
+ } else if (int_size == IntSize::kUint16) {
+ ByteBuffer<2> bb;
+ bb.append(bytes);
+ auto it = bb.begin();
+ *static_cast<uint16_t*>(value) = it.ReadUint16(kEndianness);
+ } else if (int_size == IntSize::kUint32) {
+ ByteBuffer<4> bb;
+ bb.append(bytes);
+ auto it = bb.begin();
+ *static_cast<uint32_t*>(value) = it.ReadUint32(kEndianness);
+ } else if (int_size == IntSize::kUint64) {
+ ByteBuffer<8> bb;
+ bb.append(bytes);
+ auto it = bb.begin();
+ *static_cast<uint64_t*>(value) = it.ReadUint64(kEndianness);
+ }
+}
+
+void ConvertToEndian(void* value,
+ ByteSpan bytes,
+ IntSize int_size,
+ ByteOrder kEndianness) {
+ if (int_size == IntSize::kUint8) {
+ ByteBuffer<1> bb;
+ bb.append(value, 1);
+ auto it = bb.begin();
+ uint8_t value_converted = it.ReadUint8();
+ std::memcpy(bytes.data(), &value_converted, sizeof(uint8_t));
+ } else if (int_size == IntSize::kUint16) {
+ ByteBuffer<2> bb;
+ bb.append(value, 2);
+ auto it = bb.begin();
+ uint16_t value_converted = it.ReadUint16(kEndianness);
+ std::memcpy(bytes.data(), &value_converted, sizeof(uint16_t));
+ } else if (int_size == IntSize::kUint32) {
+ ByteBuffer<4> bb;
+ bb.append(value, 4);
+ auto it = bb.begin();
+ uint32_t value_converted = it.ReadUint32(kEndianness);
+ std::memcpy(bytes.data(), &value_converted, sizeof(uint32_t));
+ } else if (int_size == IntSize::kUint64) {
+ ByteBuffer<8> bb;
+ bb.append(value, 8);
+ auto it = bb.begin();
+ uint64_t value_converted = it.ReadUint64(kEndianness);
+ std::memcpy(bytes.data(), &value_converted, sizeof(uint64_t));
+ }
+}
+
+} // namespace pw
\ No newline at end of file
