pw_chrono_freertos: Add CMake support

Change-Id: I2dd197f7701ff47e13adf386422e7596df5f306c
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/79727
Pigweed-Auto-Submit: Ewout van Bekkum <ewout@google.com>
Reviewed-by: Wyatt Hepler <hepler@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed.google.com.iam.gserviceaccount.com>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 547e24b..f1a4e60 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -29,9 +29,10 @@
 add_subdirectory(pw_build EXCLUDE_FROM_ALL)
 add_subdirectory(pw_bytes EXCLUDE_FROM_ALL)
 add_subdirectory(pw_checksum EXCLUDE_FROM_ALL)
-add_subdirectory(pw_chrono_zephyr EXCLUDE_FROM_ALL)
 add_subdirectory(pw_chrono EXCLUDE_FROM_ALL)
+add_subdirectory(pw_chrono_freertos EXCLUDE_FROM_ALL)
 add_subdirectory(pw_chrono_stl EXCLUDE_FROM_ALL)
+add_subdirectory(pw_chrono_zephyr EXCLUDE_FROM_ALL)
 add_subdirectory(pw_containers EXCLUDE_FROM_ALL)
 add_subdirectory(pw_cpu_exception EXCLUDE_FROM_ALL)
 add_subdirectory(pw_cpu_exception_cortex_m EXCLUDE_FROM_ALL)
diff --git a/pw_chrono_freertos/CMakeLists.txt b/pw_chrono_freertos/CMakeLists.txt
new file mode 100644
index 0000000..391f2e3
--- /dev/null
+++ b/pw_chrono_freertos/CMakeLists.txt
@@ -0,0 +1,71 @@
+# Copyright 2022 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.
+
+include($ENV{PW_ROOT}/pw_build/pigweed.cmake)
+
+pw_add_module_config(pw_chrono_freertos_CONFIG)
+
+pw_add_module_library(pw_chrono_freertos.config
+  HEADERS
+    public/pw_chrono_freertos/config.h
+  PUBLIC_INCLUDES
+    public
+  PUBLIC_DEPS
+    pw_third_party.freertos
+    ${pw_chrono_freertos_CONFIG}
+)
+
+# This target provides the backend for pw::chrono::SystemClock.
+pw_add_module_library(pw_chrono_freertos.system_clock
+  IMPLEMENTS_FACADES
+    pw_chrono.system_clock
+  HEADERS
+    public/pw_chrono_freertos/system_clock_config.h
+    public/pw_chrono_freertos/system_clock_constants.h
+    public_overrides/pw_chrono_backend/system_clock_config.h
+  PUBLIC_INCLUDES
+    public
+    public_overrides
+  PUBLIC_DEPS
+    pw_chrono_freertos.config
+    pw_chrono.epoch
+    pw_third_party.freertos
+  SOURCES
+    system_clock.cc
+  PRIVATE_DEPS
+    pw_interrupt.context
+    pw_sync.interrupt_spin_lock
+)
+
+# This target provides the backend for pw::chrono::SystemTimer.
+pw_add_module_library(pw_chrono_freertos.system_timer
+  IMPLEMENTS_FACADES
+    pw_chrono.system_timer
+  HEADERS
+    public/pw_chrono_freertos/system_timer_inline.h
+    public/pw_chrono_freertos/system_timer_native.h
+    public_overrides/pw_chrono_backend/system_timer_inline.h
+    public_overrides/pw_chrono_backend/system_timer_native.h
+  PUBLIC_INCLUDES
+    public
+    public_overrides
+  PUBLIC_DEPS
+    pw_chrono.system_clock
+    pw_third_party.freertos
+  SOURCES
+    system_timer.cc
+  PRIVATE_DEPS
+    pw_assert
+    pw_chrono_freertos.system_clock
+)