From 6ccf08a778534a3b057a00920d457521fa10491b Mon Sep 17 00:00:00 2001
From: Masayuki Ishikawa <masayuki.ishikawa@gmail.com>
Date: Thu, 20 Feb 2020 09:35:32 +0900
Subject: [PATCH] arch: imx6: Add imx_idle.c

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
---
 arch/arm/src/imx6/Make.defs  |  2 +-
 arch/arm/src/imx6/imx_idle.c | 61 ++++++++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 arch/arm/src/imx6/imx_idle.c

diff --git a/arch/arm/src/imx6/Make.defs b/arch/arm/src/imx6/Make.defs
index 34c9e1aaf3..ae9e98df5b 100644
--- a/arch/arm/src/imx6/Make.defs
+++ b/arch/arm/src/imx6/Make.defs
@@ -76,7 +76,7 @@ CMN_CSRCS += arm_schedulesigaction.c arm_sigdeliver.c arm_syscall.c
 CMN_CSRCS += arm_unblocktask.c arm_undefinedinsn.c
 
 ifneq ($(CONFIG_ARCH_IDLE_CUSTOM),y)
-CMN_CSRCS += up_idle.c
+CMN_CSRCS += imx_idle.c
 endif
 
 ifeq ($(CONFIG_SMP),y)
diff --git a/arch/arm/src/imx6/imx_idle.c b/arch/arm/src/imx6/imx_idle.c
new file mode 100644
index 0000000000..afdc1f511a
--- /dev/null
+++ b/arch/arm/src/imx6/imx_idle.c
@@ -0,0 +1,61 @@
+/****************************************************************************
+ *  arch/arm/src/imx6/imx_idle.c
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.  The
+ * ASF licenses this file to you 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.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <nuttx/arch.h>
+#include "up_internal.h"
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_idle
+ *
+ * Description:
+ *   up_idle() is the logic that will be executed when their is no other
+ *   ready-to-run task.  This is processor idle time and will continue until
+ *   some interrupt occurs to cause a context switch from the idle task.
+ *
+ *   Processing in this state may be processor-specific. e.g., this is where
+ *   power management operations might be performed.
+ *
+ ****************************************************************************/
+
+void up_idle(void)
+{
+#if defined(CONFIG_SUPPRESS_INTERRUPTS) || defined(CONFIG_SUPPRESS_TIMER_INTS)
+  /* If the system is idle and there are no timer interrupts, then process
+   * "fake" timer interrupts. Hopefully, something will wake up.
+   */
+
+  nxsched_process_timer();
+#else
+
+  /* Sleep until an interrupt occurs to save power */
+
+  asm("WFI");
+#endif
+}