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/***************************************************************************/
/*
* timers.c - Generic hardware timer support.
*
* Copyright (C) 1993 Hamish Macdonald
* Copyright (C) 1999 D. Jeff Dionne
* Copyright (C) 2001 Georges Menie, Ken Desmet
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file COPYING in the main directory of this archive
* for more details.
*/
/***************************************************************************/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/clocksource.h>
#include <linux/rtc.h>
#include <asm/setup.h>
#include <asm/machdep.h>
#include <asm/MC68VZ328.h>
/***************************************************************************/
#if defined(CONFIG_DRAGEN2)
/* with a 33.16 MHz clock, this will give usec resolution to the time functions */
#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
#define CLOCK_PRE 7
#define TICKS_PER_JIFFY 41450
#elif defined(CONFIG_XCOPILOT_BUGS)
/*
* The only thing I know is that CLK32 is not available on Xcopilot
* I have little idea about what frequency SYSCLK has on Xcopilot.
* The values for prescaler and compare registers were simply
* taken from the original source
*/
#define CLOCK_SOURCE TCTL_CLKSOURCE_SYSCLK
#define CLOCK_PRE 2
#define TICKS_PER_JIFFY 0xd7e4
#else
/* default to using the 32Khz clock */
#define CLOCK_SOURCE TCTL_CLKSOURCE_32KHZ
#define CLOCK_PRE 31
#define TICKS_PER_JIFFY 10
#endif
static u32 m68328_tick_cnt;
static irq_handler_t timer_interrupt;
/***************************************************************************/
static irqreturn_t hw_tick(int irq, void *dummy)
{
/* Reset Timer1 */
TSTAT &= 0;
m68328_tick_cnt += TICKS_PER_JIFFY;
return timer_interrupt(irq, dummy);
}
/***************************************************************************/
static u64 m68328_read_clk(struct clocksource *cs)
{
unsigned long flags;
u32 cycles;
local_irq_save(flags);
cycles = m68328_tick_cnt + TCN;
local_irq_restore(flags);
return cycles;
}
/***************************************************************************/
static struct clocksource m68328_clk = {
.name = "timer",
.rating = 250,
.read = m68328_read_clk,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
/***************************************************************************/
void hw_timer_init(irq_handler_t handler)
{
int ret;
/* disable timer 1 */
TCTL = 0;
/* set ISR */
ret = request_irq(TMR_IRQ_NUM, hw_tick, IRQF_TIMER, "timer", NULL);
if (ret) {
pr_err("Failed to request irq %d (timer): %pe\n", TMR_IRQ_NUM,
ERR_PTR(ret));
}
/* Restart mode, Enable int, Set clock source */
TCTL = TCTL_OM | TCTL_IRQEN | CLOCK_SOURCE;
TPRER = CLOCK_PRE;
TCMP = TICKS_PER_JIFFY;
/* Enable timer 1 */
TCTL |= TCTL_TEN;
clocksource_register_hz(&m68328_clk, TICKS_PER_JIFFY*HZ);
timer_interrupt = handler;
}
/***************************************************************************/
int m68328_hwclk(int set, struct rtc_time *t)
{
if (!set) {
long now = RTCTIME;
t->tm_year = 1;
t->tm_mon = 0;
t->tm_mday = 1;
t->tm_hour = (now >> 24) % 24;
t->tm_min = (now >> 16) % 60;
t->tm_sec = now % 60;
}
return 0;
}
/***************************************************************************/
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