pm: fix weak-based default implementations

Instead of using `weak` function definitions, this PR handles
default implementations using `PROVIDES_x` defines, allowing
for cpus/pm realted modules to use their own implementations.

cpu/cortexm_common/include/cpu.h

@@ -50,6 +50,14 @@ extern "C" {
  */
 #define STACK_CANARY_WORD   (0xE7FEE7FEu)
 
+/**
+ * @brief   All Cortex-m-based CPUs provide pm_set_lowest
+ *
+ * The pm_set_lowest is provided either by the pm_layered module if used, or
+ * alternatively as fallback by the cortexm's own implementation.
+ */
+#define PROVIDES_PM_SET_LOWEST
+
 /**
  * @brief   Initialization of the CPU
  */

cpu/cortexm_common/periph/pm.c

@@ -24,7 +24,7 @@
 #include "cpu.h"
 #include "periph/pm.h"
 
-#ifndef FEATURE_PERIPH_PM
+#if !defined(MODULE_PM_LAYERED) && !defined(PROVIDES_PM_SET_LOWEST_CORTEXM)
 void pm_set_lowest(void)
 {
     cortexm_sleep(0);

cpu/lm4f120/include/periph_cpu.h

@@ -21,7 +21,9 @@
 #ifndef PERIPH_CPU_H
 #define PERIPH_CPU_H
 
-#include "cpu_conf.h"
+
+#include "cpu.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif

cpu/lpc1768/include/periph_cpu.h

@@ -19,6 +19,7 @@
 #ifndef PERIPH_CPU_H
 #define PERIPH_CPU_H
 
+#include "cpu.h"
 #include "periph/dev_enums.h"
 
 #ifdef __cplusplus

cpu/mips32r2_common/Makefile.include

@@ -5,6 +5,7 @@ export APP_START=0x80000000
 include $(RIOTMAKE)/arch/mips.inc.mk
 
 export USEMODULE += periph
+export USEMODULE += periph_common
 export USEMODULE += newlib
 
 ifeq ($(USE_UHI_SYSCALLS),1)

cpu/mips32r2_common/include/periph_cpu.h

@@ -16,10 +16,23 @@
  * or no peripherals
  */
 
+#ifndef PERIPH_CPU_H
+#define PERIPH_CPU_H
+
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/**
+ * @name    Power management configuration
+ * @{
+ */
+#define PROVIDES_PM_SET_LOWEST
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif
+
+#endif /* PERIPH_CPU_H */
+/** @} */

cpu/mips32r2_common/periph/pm.c

@@ -22,7 +22,6 @@
 #include <mips/m32c0.h>
 #include "periph/pm.h"
 
-#ifndef FEATURES_PERIPH_PM
 void pm_set_lowest(void)
 {
     /* Dont wait if interrupts are not enabled - we would never return!*/
@@ -30,9 +29,3 @@ void pm_set_lowest(void)
         __asm volatile ("wait");
     }
 }
-#endif
-
-void pm_off(void)
-{
-   /* No Generic Power off Mechanism */
-}

cpu/mips_pic32_common/include/periph_cpu_common.h

@@ -26,7 +26,14 @@
 extern "C" {
 #endif
 
- /**
+/**
+ * @name    Power management configuration
+ * @{
+ */
+#define PROVIDES_PM_SET_LOWEST
+/** @} */
+
+/**
  * @brief   Length of the CPU_ID in bytes
  */
 #define CPUID_LEN           (4U)

cpu/mips_pic32mx/Makefile.include

@@ -8,6 +8,7 @@ export CFLAGS += -march=m4k -DSKIP_COPY_TO_RAM
 
 export USEMODULE += mips_pic32_common
 export USEMODULE += periph
+export USEMODULE += periph_common
 export USEMODULE += newlib
 
 ifeq ($(USE_UHI_SYSCALLS),1)

cpu/mips_pic32mz/Makefile.include

@@ -9,6 +9,7 @@ export CFLAGS += -DMIPS_MICROMIPS
 
 export USEMODULE += mips_pic32_common
 export USEMODULE += periph
+export USEMODULE += periph_common
 export USEMODULE += newlib
 
 ifeq ($(USE_UHI_SYSCALLS),1)

cpu/native/include/periph_cpu.h

@@ -37,6 +37,13 @@ extern "C" {
  */
 #define PERIPH_TIMER_PROVIDES_SET
 
+/**
+ * @name    Power management configuration
+ * @{
+ */
+#define PROVIDES_PM_OFF
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif

cpu/nrf5x_common/include/periph_cpu_common.h

@@ -25,6 +25,13 @@
 extern "C" {
 #endif
 
+/**
+ * @name    Power management configuration
+ * @{
+ */
+#define PROVIDES_PM_OFF
+/** @} */
+
 /**
  * @brief   Starting offset of CPU_ID
  */

cpu/stm32_common/include/periph_cpu_common.h

@@ -50,6 +50,11 @@ extern "C" {
  */
 #define CPUID_LEN           (12U)
 
+/**
+ * @brief   We provide our own pm_off() function for all STM32-based CPUs
+ */
+#define PROVIDES_PM_LAYERED_OFF
+
 /**
  * @brief   All STM timers have 4 capture-compare channels
  */

cpu/x86/include/periph_cpu.h

@@ -32,6 +32,13 @@
 extern "C" {
 #endif
 
+/**
+ * @name    Power management configuration
+ * @{
+ */
+#define PROVIDES_PM_OFF
+/** @} */
+
 #ifdef __cplusplus
 }
 #endif

drivers/include/periph/pm.h

@@ -27,8 +27,12 @@
 #include "assert.h"
 #include "periph_cpu.h"
 
+#ifdef MODULE_PM_LAYERED
+#include "pm_layered.h"
+#endif
+
 #ifdef __cplusplus
- extern "C" {
+extern "C" {
 #endif
 
 /**

drivers/periph_common/pm.c

@@ -24,10 +24,17 @@
 #define ENABLE_DEBUG (0)
 #include "debug.h"
 
-void __attribute__((weak)) pm_set_lowest(void) {}
-
-void __attribute__((weak)) pm_off(void)
+#ifndef PROVIDES_PM_OFF
+void pm_off(void)
 {
     irq_disable();
     while(1) {};
 }
+#endif
+
+#ifndef PROVIDES_PM_SET_LOWEST
+void pm_set_lowest(void)
+{
+    /* don't do anything here */
+}
+#endif

sys/include/pm_layered.h

@@ -35,11 +35,14 @@
 #define PM_LAYERED_H
 
 #include "assert.h"
-#include "periph/pm.h"
 #include "periph_cpu.h"
 
 #ifdef __cplusplus
- extern "C" {
+extern "C" {
+#endif
+
+#ifndef PROVIDES_PM_OFF
+#define PROVIDES_PM_OFF
 #endif
 
 /**

sys/pm_layered/pm.c

@@ -87,9 +87,11 @@ void pm_unblock(unsigned mode)
     irq_restore(state);
 }
 
-void __attribute__((weak)) pm_off(void)
+#ifndef PROVIDES_PM_LAYERED_OFF
+void  pm_off(void)
 {
     pm_blocker.val_u32 = 0;
     pm_set_lowest();
     while(1);
 }
+#endif