/* *  /arch/arm/mach-clps711x/timer.c * * (c) 2002 Thomas Gleixner, autronix automation <gleixner@autronix.de> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser 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 * * This is the timer handling for RTAI Real Time Application Interface * COPYRIGHT (C) 2001  Paolo Mantegazza (mantegazza@aero.polimi.it) * * Thanks to Guennadi Liakhovetski, DSA GmbH (gl@dsa-ac.de) for review and  * a helping hand in unterstanding RTAI.  * * TODO's:	Enable profile and leds in Timer interrupt *		Is a call to the original timer handler  *		wrapped in save_flags_cli the easier thing ??? */#include <linux/sched.h>#include <linux/interrupt.h>#include <asm/mach/irq.h>#include <rtai.h>unsigned long rtai_lasttsc;unsigned long rtai_TC2latch;#if DEBUG_LEVEL > 1static	long	dotimercnt = 0;#endif/**	linux_timer_interrupt is the handler, when RTAI is mounted,*	but the timer was not requested by a realtime task*/void linux_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs){	long flags;	rdtsc(); /* update tsc */	D2(if (++dotimercnt == 1000) {		D2(printk("linux_timer_int, jiffies %ul\n",jiffies));		dotimercnt = 0;	});	save_flags_cli(flags);//	do_leds();	do_timer(regs);//	do_profile(regs);	restore_flags(flags);}/**	sotf_timer_interrupt is the handler, when RTAI is mounted,*	the timer is requested by a realtime task and is invoked by*	the scheduler when there is time to do it*/void soft_timer_interrupt(rtai_irq_t irq, void *dev_id, struct pt_regs *regs){	long flags;		rdtsc(); /* update tsc */	D2(if (++dotimercnt == 1000) {		D2(printk("soft_timer_int, jiffies %ul\n",jiffies));		dotimercnt = 0;	});	save_flags_cli(flags);	do_timer(regs);	restore_flags(flags);}/**	rt_request_timer set's the new timer latch value, replaces *	linux_timer_handler with soft_timer_handler, set's the new*	timer latch value and free's + requests the global timer *	irq as realtime interrupt.*/void rt_request_timer(void (*handler)(void), unsigned int tick, int unused){	unsigned long flags;	flags = hard_lock_all();	/* wait for a timer underflow and clear the int. bit */	do {		;	} while ( !(clps_readl(INTSR1) & 0x200) );        clps_writel(0,TC2EOI);	/* set up rt_times structure */	rt_times.linux_tick = LATCH;	rt_times.periodic_tick = (tick > 0 && tick < rt_times.linux_tick) ? tick : rt_times.linux_tick;	rt_times.tick_time  = rdtsc();	rt_times.intr_time  = rt_times.tick_time + (RTIME) rt_times.periodic_tick;	rt_times.linux_time = rt_times.tick_time + (RTIME) rt_times.linux_tick;	/* update Match-register */	D1( if (rt_times.periodic_tick > LATCH)		printk("Periodic tick > LATCH\n");	  );		rt_set_timer_latch((unsigned long)rt_times.periodic_tick);	IRQ_DESC[TIMER_8254_IRQ].action->handler = soft_timer_interrupt;	rt_free_global_irq(TIMER_8254_IRQ);	rt_request_global_irq(TIMER_8254_IRQ, handler);	hard_unlock_all(flags);	return;}/**	Switch back to linux_timer_handler, set the timer latch to*	(linux) LATCH, release global interupt.*/void rt_free_timer(void){	unsigned long flags;	flags = hard_lock_all();	rt_free_global_irq(TIMER_8254_IRQ);	IRQ_DESC[TIMER_8254_IRQ].action->handler = linux_timer_interrupt;	/* wait for a timer underflow and clear the int. bit */	do {		;	} while ( !(clps_readl(INTSR1) & 0x200) );        clps_writel(0,TC2EOI);	/* set up rt_times structure */	rt_times.linux_tick = LATCH;	rt_times.periodic_tick = LATCH;	rt_times.tick_time  = rdtsc();	rt_times.intr_time  = rt_times.tick_time + (RTIME) rt_times.periodic_tick;	rt_times.linux_time = rt_times.tick_time + (RTIME) rt_times.linux_tick;	/* update Match-register */	rt_set_timer_latch((unsigned long)rt_times.periodic_tick);	hard_unlock_all(flags);}