Special IDLE for STM32 will execut WFI to sleep until an interrupt occurs

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@3324 42af7a65-404d-4744-a932-0658087f49c3

arch/arm/src/common/up_idle.c

@@ -62,32 +62,30 @@
  * Name: up_idle
  *
  * Description:
- *   up_idle() is the logic that will be executed when their
+ *   up_idle() is the logic that will be executed when their is no other
- *   is no other ready-to-run task.  This is processor idle
+ *   ready-to-run task.  This is processor idle time and will continue until
- *   time and will continue until some interrupt occurs to
+ *   some interrupt occurs to cause a context switch from the idle task.
- *   cause a context switch from the idle task.
  *
- *   Processing in this state may be processor-specific. e.g.,
+ *   Processing in this state may be processor-specific. e.g., this is where
- *   this is where power management operations might be
+ *   power management operations might be performed.
- *   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,
+  /* If the system is idle and there are no timer interrupts, then process
-   * then process "fake" timer interrupts. Hopefully, something
+   * "fake" timer interrupts. Hopefully, something will wake up.
-   * will wake up.
    */
 
   sched_process_timer();
-#endif
+#else
 
   /* Sleep until an interrupt occurs to save power */
 
 #if 0
   asm("WFI");  /* For example */
 #endif
+#endif
 }
 

arch/arm/src/stm32/Make.defs

@@ -1,7 +1,7 @@
 ############################################################################
 # arch/arm/src/stm32/Make.defs
 #
-#   Copyright (C) 2009 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -38,14 +38,14 @@ HEAD_ASRC	= stm32_vectors.S
 CMN_ASRCS	= up_saveusercontext.S up_fullcontextrestore.S up_switchcontext.S
 CMN_CSRCS	= up_allocateheap.c up_assert.c up_blocktask.c up_copystate.c \
 		  up_createstack.c up_mdelay.c up_udelay.c up_exit.c \
-		  up_idle.c up_initialize.c up_initialstate.c up_interruptcontext.c \
+		  up_initialize.c up_initialstate.c up_interruptcontext.c \
 		  up_modifyreg8.c up_modifyreg16.c up_modifyreg32.c \
 		  up_releasepending.c up_releasestack.c up_reprioritizertr.c \
 		  up_schedulesigaction.c up_sigdeliver.c up_unblocktask.c \
 		  up_usestack.c up_doirq.c up_hardfault.c up_svcall.c
 
 CHIP_ASRCS	= 
-CHIP_CSRCS	= stm32_start.c stm32_rcc.c stm32_gpio.c stm32_irq.c \
+CHIP_CSRCS	= stm32_start.c stm32_rcc.c stm32_gpio.c stm32_idle.c \
-		  stm32_timerisr.c stm32_dma.c stm32_lowputc.c stm32_serial.c \
+		  stm32_irq.c stm32_timerisr.c stm32_dma.c stm32_lowputc.c \
-		  stm32_spi.c stm32_usbdev.c stm32_sdio.c
+		  stm32_serial.c stm32_spi.c stm32_usbdev.c stm32_sdio.c 
 

arch/arm/src/stm32/stm32_idle.c

@@ -0,0 +1,104 @@
+/****************************************************************************
+ *  arch/arm/src/stm32/stm32_idle.c
+ *
+ *   Copyright (C) 2011 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <arch/board/board.h>
+#include <nuttx/config.h>
+
+#include <nuttx/arch.h>
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Does the board support an IDLE LED to indicate that the board is in the
+ * IDLE state?
+ */
+
+#if defined(CONFIG_ARCH_LEDS) && defined(LED_IDLE)
+#  define BEGIN_IDLE() up_ledon(LED_IDLE)
+#  define END_IDLE()   up_ledoff(LED_IDLE)
+#else
+#  define BEGIN_IDLE()
+#  define END_IDLE()
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * 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.
+   */
+
+  sched_process_timer();
+#else
+
+  /* Sleep until an interrupt occurs to save power */
+
+  BEGIN_IDLE();
+  asm("WFI");
+  END_IDLE();
+#endif
+}
+