ossc/software/sys_controller_bsp/drivers/src/altera_avalon_timer_sc.c

111 lines
4.7 KiB
C

/******************************************************************************
* *
* License Agreement *
* *
* Copyright (c) 2003 Altera Corporation, San Jose, California, USA. *
* All rights reserved. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a *
* copy of this software and associated documentation files (the "Software"), *
* to deal in the Software without restriction, including without limitation *
* the rights to use, copy, modify, merge, publish, distribute, sublicense, *
* and/or sell copies of the Software, and to permit persons to whom the *
* Software is furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING *
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER *
* DEALINGS IN THE SOFTWARE. *
* *
* This agreement shall be governed in all respects by the laws of the State *
* of California and by the laws of the United States of America. *
* *
* Altera does not recommend, suggest or require that this reference design *
* file be used in conjunction or combination with any other product. *
******************************************************************************/
#include <string.h>
#include "sys/alt_alarm.h"
#include "sys/alt_irq.h"
#include "altera_avalon_timer.h"
#include "altera_avalon_timer_regs.h"
#include "alt_types.h"
#include "sys/alt_log_printf.h"
/*
* alt_avalon_timer_sc_irq() is the interrupt handler used for the system
* clock. This is called periodically when a timer interrupt occurs. The
* function first clears the interrupt condition, and then calls the
* alt_tick() function to notify the system that a timer tick has occurred.
*
* alt_tick() increments the system tick count, and updates any registered
* alarms, see alt_tick.c for further details.
*/
#ifdef ALT_ENHANCED_INTERRUPT_API_PRESENT
static void alt_avalon_timer_sc_irq (void* base)
#else
static void alt_avalon_timer_sc_irq (void* base, alt_u32 id)
#endif
{
alt_irq_context cpu_sr;
/* clear the interrupt */
IOWR_ALTERA_AVALON_TIMER_STATUS (base, 0);
/*
* Dummy read to ensure IRQ is negated before the ISR returns.
* The control register is read because reading the status
* register has side-effects per the register map documentation.
*/
IORD_ALTERA_AVALON_TIMER_CONTROL (base);
/* ALT_LOG - see altera_hal/HAL/inc/sys/alt_log_printf.h */
ALT_LOG_SYS_CLK_HEARTBEAT();
/*
* Notify the system of a clock tick. disable interrupts
* during this time to safely support ISR preemption
*/
cpu_sr = alt_irq_disable_all();
alt_tick ();
alt_irq_enable_all(cpu_sr);
}
/*
* alt_avalon_timer_sc_init() is called to initialise the timer that will be
* used to provide the periodic system clock. This is called from the
* auto-generated alt_sys_init() function.
*/
void alt_avalon_timer_sc_init (void* base, alt_u32 irq_controller_id,
alt_u32 irq, alt_u32 freq)
{
/* set the system clock frequency */
alt_sysclk_init (freq);
/* set to free running mode */
IOWR_ALTERA_AVALON_TIMER_CONTROL (base,
ALTERA_AVALON_TIMER_CONTROL_ITO_MSK |
ALTERA_AVALON_TIMER_CONTROL_CONT_MSK |
ALTERA_AVALON_TIMER_CONTROL_START_MSK);
/* register the interrupt handler, and enable the interrupt */
#ifdef ALT_ENHANCED_INTERRUPT_API_PRESENT
alt_ic_isr_register(irq_controller_id, irq, alt_avalon_timer_sc_irq,
base, NULL);
#else
alt_irq_register (irq, base, alt_avalon_timer_sc_irq);
#endif
}