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/*
* timer.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/irq.h>
#include <asm/system.h>
#include <asm/io.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
#include <mach/time.h>
#include <plat/ast-scu.h>
#define ASPEED_TIMER0_VA_BASE (IO_ADDRESS(AST_TIMER_BASE)+ASPEED_TIMER0_OFFSET)
#define ASPEED_TIMER1_VA_BASE (IO_ADDRESS(AST_TIMER_BASE)+ASPEED_TIMER1_OFFSET)
#define ASPEED_TIMER2_VA_BASE (IO_ADDRESS(AST_TIMER_BASE)+ASPEED_TIMER2_OFFSET)
#define ASPEED_TIMERC_VA_BASE (IO_ADDRESS(AST_TIMER_BASE)+ASPEED_TIMERRC_OFFSET)
/*
* Returns number of ms since last clock interrupt. Note that interrupts
* will have been disabled by do_gettimeoffset()
*/
static unsigned long ast_gettimeoffset(void)
{
volatile TimerStruct_t *timer0 = (TimerStruct_t *) ASPEED_TIMER0_VA_BASE;
unsigned long ticks1, ticks2;//, status;
/*
* Get the current number of ticks. Note that there is a race
* condition between us reading the timer and checking for
* an interrupt. We get around this by ensuring that the
* counter has not reloaded between our two reads.
*/
ticks2 = timer0->TimerValue;
do {
ticks1 = ticks2;
// status = readl(AST_RAW_STS(0));// __raw_readl(IO_ADDRESS(ASPEED_VIC_BASE) + ASPEED_VIC_RAW_STATUS_OFFSET);
ticks2 = timer0->TimerValue;
} while (ticks2 > ticks1);
/*
* Number of ticks since last interrupt.
*/
ticks1 = TIMER_RELOAD - ticks2;
/*
* Interrupt pending? If so, we've reloaded once already.
*/
// if (status & (1 << IRQ_TIMER0))
// ticks1 += TIMER_RELOAD;
/*
* Convert the ticks to usecs
*/
return TICKS2USECS(ticks1);
}
/*
* IRQ handler for the timer
*/
static irqreturn_t
ast_timer_interrupt(int irq, void *dev_id)
{
// write_seqlock(&xtime_lock);
/*
* clear the interrupt in Irq.c
*/
// IRQ_EDGE_CLEAR(0,IRQ_TIMER0);
timer_tick();
// write_sequnlock(&xtime_lock);
return IRQ_HANDLED;
}
static struct irqaction ast_timer_irq = {
.name = "ast timer",
.flags = IRQF_DISABLED | IRQF_TIMER,
.handler = ast_timer_interrupt,
};
/*
* Set up timer interrupt, and return the current time in seconds.
*/
static void __init ast_setup_timer(void)
{
volatile TimerStruct_t *timer0 = (volatile TimerStruct_t *) ASPEED_TIMER0_VA_BASE;
volatile __u32 *timerc = (volatile __u32*) ASPEED_TIMERC_VA_BASE;
/*
* Initialise to a known state (all timers off)
*/
*timerc = 0;
timer0->TimerLoad = TIMER_RELOAD - 1;
timer0->TimerValue = TIMER_RELOAD - 1;
*timerc = TIMER0_ENABLE | TIMER0_RefExt;
/*
* Make irqs happen for the system timer
*/
ast_scu_show_system_info();
setup_irq(IRQ_TIMER0, &ast_timer_irq);
}
struct sys_timer ast_timer = {
.init = ast_setup_timer,
// .offset = ast_gettimeoffset,
};
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