[deliverable/linux.git] / arch / arm / plat-iop / time.c

/*
 * arch/arm/plat-iop/time.c
 *
 * Timer code for IOP32x and IOP33x based systems
 *
 * Author: Deepak Saxena <dsaxena@mvista.com>
 *
 * Copyright 2002-2003 MontaVista Software Inc.
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/timex.h>
#include <linux/io.h>
#include <mach/hardware.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
#include <asm/mach/irq.h>
#include <asm/mach/time.h>
#include <mach/time.h>

static unsigned long ticks_per_jiffy;
static unsigned long ticks_per_usec;
static unsigned long next_jiffy_time;

unsigned long iop_gettimeoffset(void)
{
	unsigned long offset, temp;

	/* enable cp6, if necessary, to avoid taking the overhead of an
	 * undefined instruction trap
	 */
	asm volatile (
	"mrc	p15, 0, %0, c15, c1, 0\n\t"
	"tst	%0, #(1 << 6)\n\t"
	"orreq	%0, %0, #(1 << 6)\n\t"
	"mcreq	p15, 0, %0, c15, c1, 0\n\t"
#ifdef CONFIG_CPU_XSCALE
	"mrceq	p15, 0, %0, c15, c1, 0\n\t"
	"moveq	%0, %0\n\t"
	"subeq	pc, pc, #4\n\t"
#endif
	: "=r"(temp) : : "cc");

	offset = next_jiffy_time - read_tcr1();

	return offset / ticks_per_usec;
}

static irqreturn_t
iop_timer_interrupt(int irq, void *dev_id)
{
	write_tisr(1);

	while ((signed long)(next_jiffy_time - read_tcr1())
		>= ticks_per_jiffy) {
		timer_tick();
		next_jiffy_time -= ticks_per_jiffy;
	}

	return IRQ_HANDLED;
}

static struct irqaction iop_timer_irq = {
	.name		= "IOP Timer Tick",
	.handler	= iop_timer_interrupt,
	.flags		= IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
};

static unsigned long iop_tick_rate;
unsigned long get_iop_tick_rate(void)
{
	return iop_tick_rate;
}
EXPORT_SYMBOL(get_iop_tick_rate);

void __init iop_init_time(unsigned long tick_rate)
{
	u32 timer_ctl;

	ticks_per_jiffy = (tick_rate + HZ/2) / HZ;
	ticks_per_usec = tick_rate / 1000000;
	next_jiffy_time = 0xffffffff;
	iop_tick_rate = tick_rate;

	timer_ctl = IOP_TMR_EN | IOP_TMR_PRIVILEGED |
			IOP_TMR_RELOAD | IOP_TMR_RATIO_1_1;

	/*
	 * We use timer 0 for our timer interrupt, and timer 1 as
	 * monotonic counter for tracking missed jiffies.
	 */
	write_trr0(ticks_per_jiffy - 1);
	write_tmr0(timer_ctl);
	write_trr1(0xffffffff);
	write_tmr1(timer_ctl);

	setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
}
Commit	Line	Data
48388b2a LB	1	/*
	2	* arch/arm/plat-iop/time.c
	3	*
	4	* Timer code for IOP32x and IOP33x based systems
	5	*
	6	* Author: Deepak Saxena <dsaxena@mvista.com>
	7	*
	8	* Copyright 2002-2003 MontaVista Software Inc.
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License as published by the
	12	* Free Software Foundation; either version 2 of the License, or (at your
	13	* option) any later version.
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/time.h>
	19	#include <linux/init.h>
	20	#include <linux/timex.h>
fced80c7	21	#include <linux/io.h>
a09e64fb	22	#include <mach/hardware.h>
48388b2a LB	23	#include <asm/irq.h>
	24	#include <asm/uaccess.h>
	25	#include <asm/mach/irq.h>
	26	#include <asm/mach/time.h>
a09e64fb	27	#include <mach/time.h>
48388b2a LB	28
	29	static unsigned long ticks_per_jiffy;
	30	static unsigned long ticks_per_usec;
	31	static unsigned long next_jiffy_time;
	32
3668b45d	33	unsigned long iop_gettimeoffset(void)
48388b2a	34	{
8903fcce	35	unsigned long offset, temp;
3668b45d DW	36
	37	/* enable cp6, if necessary, to avoid taking the overhead of an
	38	* undefined instruction trap
	39	*/
	40	asm volatile (
	41	"mrc p15, 0, %0, c15, c1, 0\n\t"
8903fcce	42	"tst %0, #(1 << 6)\n\t"
3668b45d DW	43	"orreq %0, %0, #(1 << 6)\n\t"
3668b45d DW	44	"mcreq p15, 0, %0, c15, c1, 0\n\t"
8903fcce	45	#ifdef CONFIG_CPU_XSCALE
3668b45d DW	46	"mrceq p15, 0, %0, c15, c1, 0\n\t"
	47	"moveq %0, %0\n\t"
	48	"subeq pc, pc, #4\n\t"
	49	#endif
8903fcce	50	: "=r"(temp) : : "cc");
48388b2a	51
3668b45d	52	offset = next_jiffy_time - read_tcr1();
48388b2a LB	53
	54	return offset / ticks_per_usec;
	55	}
	56
	57	static irqreturn_t
3668b45d	58	iop_timer_interrupt(int irq, void *dev_id)
48388b2a	59	{
3668b45d	60	write_tisr(1);
48388b2a	61
3668b45d DW	62	while ((signed long)(next_jiffy_time - read_tcr1())
3668b45d DW	63	>= ticks_per_jiffy) {
0cd61b68	64	timer_tick();
48388b2a LB	65	next_jiffy_time -= ticks_per_jiffy;
	66	}
	67
48388b2a LB	68	return IRQ_HANDLED;
	69	}
	70
3668b45d DW	71	static struct irqaction iop_timer_irq = {
	72	.name = "IOP Timer Tick",
	73	.handler = iop_timer_interrupt,
b30fabad	74	.flags = IRQF_DISABLED \| IRQF_TIMER \| IRQF_IRQPOLL,
48388b2a LB	75	};
48388b2a LB	76
70c14ff0 DW	77	static unsigned long iop_tick_rate;
	78	unsigned long get_iop_tick_rate(void)
	79	{
	80	return iop_tick_rate;
	81	}
	82	EXPORT_SYMBOL(get_iop_tick_rate);
	83
3668b45d	84	void __init iop_init_time(unsigned long tick_rate)
48388b2a LB	85	{
	86	u32 timer_ctl;
	87
	88	ticks_per_jiffy = (tick_rate + HZ/2) / HZ;
	89	ticks_per_usec = tick_rate / 1000000;
	90	next_jiffy_time = 0xffffffff;
70c14ff0	91	iop_tick_rate = tick_rate;
48388b2a	92
3668b45d DW	93	timer_ctl = IOP_TMR_EN \| IOP_TMR_PRIVILEGED \|
3668b45d DW	94	IOP_TMR_RELOAD \| IOP_TMR_RATIO_1_1;
48388b2a LB	95
	96	/*
	97	* We use timer 0 for our timer interrupt, and timer 1 as
	98	* monotonic counter for tracking missed jiffies.
	99	*/
3668b45d DW	100	write_trr0(ticks_per_jiffy - 1);
	101	write_tmr0(timer_ctl);
	102	write_trr1(0xffffffff);
	103	write_tmr1(timer_ctl);
48388b2a	104
3668b45d	105	setup_irq(IRQ_IOP_TIMER0, &iop_timer_irq);
48388b2a	106	}