zephyr/drivers/timer/sys_clock_init.c

47 lines
1.8 KiB
C

/*
* Copyright (c) 2015 Wind River Systems, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @file
* @brief Initialize system clock driver
*
* Initializing the timer driver is done in this module to reduce code
* duplication. Although both nanokernel and microkernel systems initialize
* the timer driver at the same point, the two systems differ in when the system
* can begin to process system clock ticks. A nanokernel system can process
* system clock ticks once the driver has initialized. However, in a
* microkernel system all system clock ticks are deferred (and stored on the
* kernel server command stack) until the kernel server fiber starts and begins
* processing any queued ticks.
*/
#include <nanokernel.h>
#include <init.h>
#include <drivers/system_timer.h>
/*
* Currently only loapic timer implements device pm ops.
* For other timers, define device_pm_ops with default handers in case
* the app enables CONFIG_DEVICE_POWER_MANAGEMENT.
*/
#ifdef CONFIG_LOAPIC_TIMER
DEFINE_DEVICE_PM_OPS(_sys_clock, _sys_clock_suspend, _sys_clock_resume);
#else
DEFINE_DEVICE_PM_OPS(_sys_clock, device_pm_nop, device_pm_nop);
#endif
SYS_INIT_PM("sys_clock", _sys_clock_driver_init, DEVICE_PM_OPS_GET(_sys_clock),
SECONDARY, CONFIG_SYSTEM_CLOCK_INIT_PRIORITY);