wake_zephyr.cpp

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#include "esphome/core/defines.h"
 
#ifdef USE_ZEPHYR
 
#include "esphome/core/hal.h"
#include "esphome/core/wake.h"
 
#include <zephyr/kernel.h>
 
namespace esphome {
 
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
K_SEM_DEFINE(esphome_wake_sem, 0, 1);
 
// === Wake-requested flag storage ===
// Zephyr has preemptive threads and ISRs, so wake_loop_threadsafe() is genuinely
// called cross-context. volatile uint8_t is sufficient because: (1) Cortex-M
// 8-bit aligned store/load is a single non-tearing instruction, and (2) every
// producer pairs the store with k_sem_give() (release barrier) and the consumer
// pairs the load with k_sem_take() (acquire barrier).
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
volatile uint8_t g_wake_requested = 0;
 
void wake_scheduler_threadsafe() { k_sem_give(&esphome_wake_sem); }
 
void wake_loop_threadsafe() {
  wake_request_set();
  wake_scheduler_threadsafe();
}
 
namespace internal {
void wakeable_delay(uint32_t ms) {
  if (ms == 0) [[unlikely]] {
    yield();
    return;
  }
  k_sem_take(&esphome_wake_sem, ms == UINT32_MAX ? K_FOREVER : K_MSEC(ms));
}
}  // namespace internal
 
}  // namespace esphome
 
#endif  // USE_ZEPHYR