zircon/kernel/dev/pdev/hw_watchdog/hw_watchdog.cc

// Copyright 2020 The Fuchsia Authors
//
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file or at
// https://opensource.org/licenses/MIT

#include <lib/arch/intrin.h>
#include <zircon/errors.h>
#include <zircon/types.h>

#include <dev/hw_watchdog.h>
#include <pdev/watchdog.h>

static const struct pdev_watchdog_ops default_ops = {
    .pet = []() {},
    .set_enabled = [](bool) -> zx_status_t { return ZX_ERR_NOT_SUPPORTED; },
    .is_enabled = []() -> bool { return false; },
    .get_timeout_nsec = []() -> zx_duration_t { return ZX_TIME_INFINITE; },
    .get_last_pet_time = []() -> zx_time_t { return 0; },
    .suppress_petting = [](bool) {},
    .is_petting_suppressed = []() -> bool { return true; },
};

static const struct pdev_watchdog_ops* watchdog_ops = &default_ops;

bool hw_watchdog_present() { return watchdog_ops != &default_ops; }
void hw_watchdog_pet() { watchdog_ops->pet(); }
zx_status_t hw_watchdog_set_enabled(bool enabled) { return watchdog_ops->set_enabled(enabled); }
bool hw_watchdog_is_enabled() { return watchdog_ops->is_enabled(); }
zx_duration_t hw_watchdog_get_timeout_nsec() { return watchdog_ops->get_timeout_nsec(); }
zx_time_t hw_watchdog_get_last_pet_time() { return watchdog_ops->get_last_pet_time(); }
void hw_watchdog_suppress_petting(bool suppressed) { watchdog_ops->suppress_petting(suppressed); }
bool hw_watchdog_is_petting_suppressed(void) { return watchdog_ops->is_petting_suppressed(); }

void pdev_register_watchdog(const pdev_watchdog_ops_t* ops) {
  watchdog_ops = ops;
  arch::ThreadMemoryBarrier();
}