EFM32: Add IDLE power management hooks. Nothing implemented; just define the hooks

arch/arm/src/armv7-m/up_itm.c

@@ -93,7 +93,7 @@
  *   ch - Character to transmit.
  *
  * Returned Value:
- *      Character to transmit.
+ *   Character to transmit.
  *
  *****************************************************************************/
 
@@ -141,11 +141,12 @@ int32_t itm_receivechar(void)
  * Description:
  *
  * Input Parameters:
- *  The function checks whether a character is pending for reading in the variable g_itm_rxbuffer.
+ *  The function checks whether a character is pending for reading in the
+ *  variable g_itm_rxbuffer.
  *
  * Returned Value:
- *      0  No character available.
+ *   0  No character available.
- *      1  Character available.
+ *   1  Character available.
  *
  *****************************************************************************/
 

arch/arm/src/efm32/efm32_idle.c

@@ -40,6 +40,8 @@
 #include <arch/board/board.h>
 #include <nuttx/config.h>
 
+#include <debug.h>
+
 #include <nuttx/arch.h>
 #include <nuttx/power/pm.h>
 
@@ -47,6 +49,7 @@
 
 #include "chip.h"
 #include "up_internal.h"
+#include "efm32_pm.h"
 
 /****************************************************************************
  * Pre-processor Definitions
@@ -72,6 +75,85 @@
  * Private Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: up_idlepm
+ *
+ * Description:
+ *   Perform IDLE state power management.
+ *
+ *   REVISIT: These power management hooks were taken with no modification
+ *   from the STM32 implementation and need review against EFM32 reduced
+ *   power modes.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_PM
+static void up_idlepm(void)
+{
+  static enum pm_state_e oldstate = PM_NORMAL;
+  enum pm_state_e newstate;
+  irqstate_t flags;
+  int ret;
+
+  /* Decide, which power saving level can be obtained */
+
+  newstate = pm_checkstate();
+
+  /* Check for state changes */
+
+  if (newstate != oldstate)
+    {
+      flags = irqsave();
+
+      /* Perform board-specific, state-dependent logic here */
+
+      llvdbg("newstate= %d oldstate=%d\n", newstate, oldstate);
+
+      /* Then force the global state change */
+
+      ret = pm_changestate(newstate);
+      if (ret < 0)
+        {
+          /* The new state change failed, revert to the preceding state */
+
+          (void)pm_changestate(oldstate);
+        }
+      else
+        {
+          /* Save the new state */
+
+          oldstate = newstate;
+        }
+
+      /* MCU-specific power management logic */
+
+      switch (newstate)
+        {
+        case PM_NORMAL:
+          break;
+
+        case PM_IDLE:
+          break;
+
+        case PM_STANDBY:
+          efm32_pmstop(true);
+          break;
+
+        case PM_SLEEP:
+          (void)efm32_pmstandby();
+          break;
+
+        default:
+          break;
+        }
+
+      irqrestore(flags);
+    }
+}
+#else
+#  define up_idlepm()
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -92,5 +174,12 @@
 void up_idle(void)
 {
   /* Perform IDLE mode power management */
+
+  up_idlepm();
+
   /* Sleep until an interrupt occurs to save power. */
+
+  BEGIN_IDLE();
+  asm("WFI");
+  END_IDLE();
 }

arch/arm/src/efm32/efm32_pm.h

@@ -0,0 +1,155 @@
+/************************************************************************************
+ * arch/arm/src/efm32/efm32_pm.h
+ *
+ *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
+ *
+ * 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.
+ *
+ ************************************************************************************/
+
+#ifndef __ARCH_ARM_SRC_EFM32_EFM32_PM_H
+#define __ARCH_ARM_SRC_EFM32_EFM32_PM_H
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdbool.h>
+
+#include "chip.h"
+#include "up_internal.h"
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Types
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+ #ifndef __ASSEMBLY__
+#ifdef __cplusplus
+#define EXTERN extern "C"
+extern "C"
+{
+#else
+#define EXTERN extern
+#endif
+
+/****************************************************************************
+ * Public Function Prototypes
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: efm32_pmstop
+ *
+ * Description:
+ *   Enter STOP mode.
+ *
+ *   REVISIT: This power management interface was taken with no modification
+ *   from the STM32 implementation and needs to be reviewed against EFM32
+ *   reduced power modes.  Comments here apply to the STM32!
+ *
+ * Input Parameters:
+ *   lpds - true: To further reduce power consumption in Stop mode, put the
+ *          internal voltage regulator in low-power mode using the LPDS bit
+ *          of the Power control register (PWR_CR).
+ *
+ * Returned Value:
+ *   Zero means that the STOP was successfully entered and the system has
+ *   been re-awakened.  The internal voltage regulator is back to its
+ *   original state.  Otherwise, STOP mode did not occur and a negated
+ *   errno value is returned to indicate the cause of the failure.
+ *
+ ****************************************************************************/
+
+int efm32_pmstop(bool lpds);
+
+/****************************************************************************
+ * Name: efm32_pmstandby
+ *
+ * Description:
+ *   Enter STANDBY mode.
+ *
+ *   REVISIT: This power management interface was taken with no modification
+ *   from the STM32 implementation and needs to be reviewed against EFM32
+ *   reduced power modes.  Comments here apply to the STM32!
+ *
+ * Input Parameters:
+ *   None
+ *
+ * Returned Value.
+ *   On success, this function will not return (STANDBY mode can only be
+ *   terminated with a reset event).  Otherwise, STANDBY mode did not occur
+ *   and a negated errno value is returned to indicate the cause of the
+ *   failure.
+ *
+ ****************************************************************************/
+
+int efm32_pmstandby(void);
+
+/****************************************************************************
+ * Name: efm32_pmsleep
+ *
+ * Description:
+ *   Enter SLEEP mode.
+ *
+ *   REVISIT: This power management interface was taken with no modification
+ *   from the STM32 implementation and needs to be reviewed against EFM32
+ *   reduced power modes.  Comments here apply to the STM32!
+ *
+ * Input Parameters:
+ *   sleeponexit - true:  SLEEPONEXIT bit is set when the WFI instruction is
+ *                        executed, the MCU enters Sleep mode as soon as it
+ *                        exits the lowest priority ISR.
+ *               - false: SLEEPONEXIT bit is cleared, the MCU enters Sleep mode
+ *                        as soon as WFI or WFE instruction is executed.
+ * Returned Value:
+ *   Zero means that the STOP was successfully entered and the system has
+ *   been re-awakened.  The internal voltage regulator is back to its
+ *   original state.  Otherwise, STOP mode did not occur and a negated
+ *   errno value is returned to indicate the cause of the failure.
+ *
+ ****************************************************************************/
+
+void efm32_pmsleep(bool sleeponexit);
+
+#undef EXTERN
+#ifdef __cplusplus
+}
+#endif
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ARCH_ARM_SRC_EFM32_EFM32_PM_H */

arch/arm/src/stm32/stm32_idle.c

@@ -211,4 +211,3 @@ void up_idle(void)
 #endif
 #endif
 }
-

arch/arm/src/stm32/stm32_pm.h

@@ -62,7 +62,8 @@
  #ifndef __ASSEMBLY__
 #ifdef __cplusplus
 #define EXTERN extern "C"
-extern "C" {
+extern "C"
+{
 #else
 #define EXTERN extern
 #endif
@@ -84,13 +85,13 @@ extern "C" {
  *
  * Returned Value:
  *   Zero means that the STOP was successfully entered and the system has
- *   been re-awakened.  The internal volatage regulator is back to its
+ *   been re-awakened.  The internal voltage regulator is back to its
  *   original state.  Otherwise, STOP mode did not occur and a negated
  *   errno value is returned to indicate the cause of the failure.
  *
  ****************************************************************************/
 
-EXTERN int stm32_pmstop(bool lpds);
+int stm32_pmstop(bool lpds);
 
 /****************************************************************************
  * Name: stm32_pmstandby
@@ -109,7 +110,7 @@ EXTERN int stm32_pmstop(bool lpds);
  *
  ****************************************************************************/
 
-EXTERN int stm32_pmstandby(void);
+int stm32_pmstandby(void);
 
 /****************************************************************************
  * Name: stm32_pmsleep
@@ -125,13 +126,13 @@ EXTERN int stm32_pmstandby(void);
  *                        as soon as WFI or WFE instruction is executed.
  * Returned Value:
  *   Zero means that the STOP was successfully entered and the system has
- *   been re-awakened.  The internal volatage regulator is back to its
+ *   been re-awakened.  The internal voltage regulator is back to its
  *   original state.  Otherwise, STOP mode did not occur and a negated
  *   errno value is returned to indicate the cause of the failure.
  *
  ****************************************************************************/
 
-EXTERN void stm32_pmsleep(bool sleeponexit);
+void stm32_pmsleep(bool sleeponexit);
 
 #undef EXTERN
 #ifdef __cplusplus

drivers/power/battery.c

@@ -249,6 +249,7 @@ int battery_register(FAR const char *devpath, FAR struct battery_dev_s *dev)
     {
       dbg("Failed to register driver: %d\n", ret);
     }
+
   return ret;
 }
 #endif /* CONFIG_BATTERY */