Initial version of the MCU HAL

Change-Id: Ic88da7e825b67ed64cde4eed3055022daabe9830
diff --git a/include/hardware/mcu.h b/include/hardware/mcu.h
new file mode 100644
index 0000000..6fe2cfe
--- /dev/null
+++ b/include/hardware/mcu.h
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://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.
+ */
+
+#ifndef ANDROID_INCLUDE_HARDWARE_MCU_H
+#define ANDROID_INCLUDE_HARDWARE_MCU_H
+
+#include <stdint.h>
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+#include <hardware/hardware.h>
+
+__BEGIN_DECLS
+
+#define MCU_MODULE_API_VERSION_0_1  HARDWARE_MODULE_API_VERSION(0, 1)
+
+/*
+ * The id of this module
+ */
+#define MCU_HARDWARE_MODULE_ID "mcu"
+
+/*
+ * MCU message keys passed to (*sendMessage)
+ */
+#define MCU_PARAMETER_MSG_ENABLE_MCU "enable_mcu"
+
+/*
+ * MCU message values passed to (*sendMessage)
+ */
+#define MCU_PARAMETER_ARG_ON "on"
+#define MCU_PARAMETER_ARG_OFF "off"
+
+/*
+ * Every hardware module must have a data structure named HAL_MODULE_INFO_SYM
+ * and the fields of this data structure must begin with hw_module_t
+ * followed by module specific information.
+ */
+typedef struct mcu_module {
+    struct hw_module_t common;
+
+    /*
+     * (*init)() performs MCU module setup actions at runtime startup, such
+     * as to initialize an external MCU. This is called only by the MCU HAL
+     * instance loaded by PowerManagerService.
+     *
+     * Returns 0 on success or -errno on error.
+     */
+    int (*init)(struct mcu_module *module);
+
+    /*
+     * (*sendMessage)() passes a message/argument pair to the MCU to execute
+     * a function. msg is NULL-terminated. If arg is text, then arg_len must
+     * reflect the string length. result is a heap-allocated buffer that the
+     * caller must free. If there is no result, then *result will be NULL and
+     * *result_len will be 0.
+     *
+     * Returns 0 on success or -errno in case of error (for example, if the
+     * MCU does not support the specified message.)
+     *
+     */
+    int (*sendMessage)(struct mcu_module *module, const char *msg,
+                        const void *arg, size_t arg_len, void **result,
+                        size_t *result_len);
+
+} mcu_module_t;
+
+__END_DECLS
+
+#endif  // ANDROID_INCLUDE_HARDWARE_MCU_H
diff --git a/modules/Android.mk b/modules/Android.mk
index 07fa5ee..f1a6c1c 100644
--- a/modules/Android.mk
+++ b/modules/Android.mk
@@ -1,3 +1,4 @@
 hardware_modules := gralloc hwcomposer audio nfc nfc-nci local_time \
-	power usbaudio audio_remote_submix camera consumerir sensors vibrator
+	power usbaudio audio_remote_submix camera consumerir sensors vibrator \
+	mcu
 include $(call all-named-subdir-makefiles,$(hardware_modules))
diff --git a/modules/mcu/Android.mk b/modules/mcu/Android.mk
new file mode 100644
index 0000000..ec40e3a
--- /dev/null
+++ b/modules/mcu/Android.mk
@@ -0,0 +1,25 @@
+# Copyright (C) 2014 The Android Open Source Project
+#
+# 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
+#
+#      http://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.
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := mcu.default
+LOCAL_MODULE_RELATIVE_PATH := hw
+LOCAL_SRC_FILES := mcu.c
+LOCAL_SHARED_LIBRARIES := liblog
+LOCAL_MODULE_TAGS := optional
+
+include $(BUILD_SHARED_LIBRARY)
diff --git a/modules/mcu/mcu.c b/modules/mcu/mcu.c
new file mode 100644
index 0000000..47300f9
--- /dev/null
+++ b/modules/mcu/mcu.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * 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
+ *
+ *      http://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 <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#define LOG_TAG "Legacy MCU HAL"
+#include <utils/Log.h>
+
+#include <hardware/hardware.h>
+#include <hardware/mcu.h>
+
+static int mcu_init(struct mcu_module *module)
+{
+    return 0;
+}
+
+static int mcu_send_message(struct mcu_module *module, const char *msg,
+                            const void *arg, size_t arg_len, void **result,
+                            size_t *result_len)
+{
+    return 0;
+}
+
+static struct hw_module_methods_t mcu_module_methods = {
+    .open = NULL,
+};
+
+struct mcu_module HAL_MODULE_INFO_SYM = {
+    .common = {
+        .tag = HARDWARE_MODULE_TAG,
+        .module_api_version = MCU_MODULE_API_VERSION_0_1,
+        .hal_api_version = HARDWARE_HAL_API_VERSION,
+        .id = MCU_HARDWARE_MODULE_ID,
+        .name = "Default MCU HAL",
+        .author = "The Android Open Source Project",
+        .methods = &mcu_module_methods,
+    },
+
+    .init = mcu_init,
+    .sendMessage = mcu_send_message,
+};