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drivers: add layered power modes module

pr/spi.typo
Kaspar Schleiser 6 years ago
parent
commit
92f6fc6888
  1. 75
      sys/include/pm_layered.h
  2. 1
      sys/pm_layered/Makefile
  3. 95
      sys/pm_layered/pm.c

75
sys/include/pm_layered.h

@ -0,0 +1,75 @@
/*
* Copyright (C) 2017 Kaspar Schleiser <kaspar@schleiser.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_periph_pm
* @{
*
* This module provides a base infrastructure that MCU's may use to implement
* periph/pm.
*
* This simple power management interface is based on the following assumptions:
*
* - CPUs define up to 4 power modes (from zero, the lowest power mode, to
* PM_NUM_MODES-1, the highest)
* - there is an implicit extra idle mode (which has the number PM_NUM_MODES)
* - individual power modes can be blocked/unblocked, e.g., by peripherals
* - if a mode is blocked, so are implicitly all lower modes
* - the idle thread automatically selects and sets the lowest unblocked mode
*
* In order to use this module, you'll need to implement pm_set().
*
* @file
* @brief Layered low power mode infrastructure
*
* @author Kaspar Schleiser <kaspar@schleiser.de>
*/
#ifndef PM_LAYERED_H_
#define PM_LAYERED_H_
#include "assert.h"
#include "periph/pm.h"
#include "periph_cpu.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Block a power mode
*
* @param[in] mode power mode to block
*/
void pm_block(unsigned mode);
/**
* @brief Unblock a power mode
*
* @param[in] mode power mode to unblock
*/
void pm_unblock(unsigned mode);
/**
* @brief Switches the MCU to a new power mode
*
* This function will be called by @ref pm_set_lowest() after determining the
* lowest non-blocked mode.
*
* It needs to be implemented for each MCU using this module.
*
* @param[in] mode Target power mode
*/
void pm_set(unsigned mode);
#ifdef __cplusplus
}
#endif
#endif /* __PM_LAYERED_H_ */
/** @} */

1
sys/pm_layered/Makefile

@ -0,0 +1 @@
include $(RIOTBASE)/Makefile.base

95
sys/pm_layered/pm.c

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/*
* Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup drivers_periph_pm
* @{
*
* @file
* @brief Platform-independent power management code
*
* @author Kaspar Schleiser <kaspar@schleiser.de>
*
* @}
*/
#include "irq.h"
#include "periph/pm.h"
#include "pm_layered.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
#ifndef PM_NUM_MODES
#error PM_NUM_MODES must be defined in periph_cpu.h!
#endif
#ifndef PM_BLOCKER_INITIAL
#define PM_BLOCKER_INITIAL { .val_u32=0x01010101 }
#endif
/**
* @brief Power Management mode typedef
*/
typedef union {
uint32_t val_u32;
uint8_t val_u8[PM_NUM_MODES];
} pm_blocker_t;
/**
* @brief Global variable for keeping track of blocked modes
*/
volatile pm_blocker_t pm_blocker = PM_BLOCKER_INITIAL;
void pm_set_lowest(void)
{
pm_blocker_t blocker = (pm_blocker_t) pm_blocker;
unsigned mode = PM_NUM_MODES;
while (mode) {
if (blocker.val_u8[mode-1]) {
break;
}
mode--;
}
/* set lowest mode if blocker is still the same */
unsigned state = irq_disable();
if (blocker.val_u32 == pm_blocker.val_u32) {
DEBUG("pm: setting mode %u\n", mode);
pm_set(mode);
}
else {
DEBUG("pm: mode block changed\n");
}
irq_restore(state);
}
void pm_block(unsigned mode)
{
assert(pm_blocker.val_u8[mode] != 255);
unsigned state = irq_disable();
pm_blocker.val_u8[mode]++;
irq_restore(state);
}
void pm_unblock(unsigned mode)
{
assert(pm_blocker.val_u8[mode] > 0);
unsigned state = irq_disable();
pm_blocker.val_u8[mode]--;
irq_restore(state);
}
void __attribute__((weak)) pm_off(void)
{
pm_blocker.val_u32 = 0;
pm_set_lowest();
while(1);
}
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