mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-25 21:40:53 +07:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
102 lines
2.3 KiB
C
102 lines
2.3 KiB
C
/*
|
|
* linux/arch/arm/mach-imx/time.c
|
|
*
|
|
* Copyright (C) 2000-2001 Deep Blue Solutions
|
|
* Copyright (C) 2002 Shane Nay (shane@minirl.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/config.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/init.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/time.h>
|
|
|
|
#include <asm/hardware.h>
|
|
#include <asm/io.h>
|
|
#include <asm/leds.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/mach/time.h>
|
|
|
|
/* Use timer 1 as system timer */
|
|
#define TIMER_BASE IMX_TIM1_BASE
|
|
|
|
/*
|
|
* Returns number of us since last clock interrupt. Note that interrupts
|
|
* will have been disabled by do_gettimeoffset()
|
|
*/
|
|
static unsigned long imx_gettimeoffset(void)
|
|
{
|
|
unsigned long ticks;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
ticks = IMX_TCN(TIMER_BASE);
|
|
|
|
/*
|
|
* Interrupt pending? If so, we've reloaded once already.
|
|
*/
|
|
if (IMX_TSTAT(TIMER_BASE) & TSTAT_COMP)
|
|
ticks += LATCH;
|
|
|
|
/*
|
|
* Convert the ticks to usecs
|
|
*/
|
|
return (1000000 / CLK32) * ticks;
|
|
}
|
|
|
|
/*
|
|
* IRQ handler for the timer
|
|
*/
|
|
static irqreturn_t
|
|
imx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
|
|
{
|
|
write_seqlock(&xtime_lock);
|
|
|
|
/* clear the interrupt */
|
|
if (IMX_TSTAT(TIMER_BASE))
|
|
IMX_TSTAT(TIMER_BASE) = 0;
|
|
|
|
timer_tick(regs);
|
|
write_sequnlock(&xtime_lock);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static struct irqaction imx_timer_irq = {
|
|
.name = "i.MX Timer Tick",
|
|
.flags = SA_INTERRUPT,
|
|
.handler = imx_timer_interrupt
|
|
};
|
|
|
|
/*
|
|
* Set up timer interrupt, and return the current time in seconds.
|
|
*/
|
|
static void __init imx_timer_init(void)
|
|
{
|
|
/*
|
|
* Initialise to a known state (all timers off, and timing reset)
|
|
*/
|
|
IMX_TCTL(TIMER_BASE) = 0;
|
|
IMX_TPRER(TIMER_BASE) = 0;
|
|
IMX_TCMP(TIMER_BASE) = LATCH - 1;
|
|
IMX_TCTL(TIMER_BASE) = TCTL_CLK_32 | TCTL_IRQEN | TCTL_TEN;
|
|
|
|
/*
|
|
* Make irqs happen for the system timer
|
|
*/
|
|
setup_irq(TIM1_INT, &imx_timer_irq);
|
|
}
|
|
|
|
struct sys_timer imx_timer = {
|
|
.init = imx_timer_init,
|
|
.offset = imx_gettimeoffset,
|
|
};
|