[deliverable/linux.git] / arch / mips / sibyte / bcm1480 / time.c

/*
 * Copyright (C) 2000,2001,2004 Broadcom Corporation
 *
 * 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.
 */

/*
 * These are routines to set up and handle interrupts from the
 * bcm1480 general purpose timer 0.  We're using the timer as a
 * system clock, so we set it up to run at 100 Hz.  On every
 * interrupt, we update our idea of what the time of day is,
 * then call do_timer() in the architecture-independent kernel
 * code to do general bookkeeping (e.g. update jiffies, run
 * bottom halves, etc.)
 */
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>

#include <asm/irq.h>
#include <asm/ptrace.h>
#include <asm/addrspace.h>
#include <asm/time.h>
#include <asm/io.h>

#include <asm/sibyte/bcm1480_regs.h>
#include <asm/sibyte/sb1250_regs.h>
#include <asm/sibyte/bcm1480_int.h>
#include <asm/sibyte/bcm1480_scd.h>

#include <asm/sibyte/sb1250.h>


#define IMR_IP2_VAL	K_BCM1480_INT_MAP_I0
#define IMR_IP3_VAL	K_BCM1480_INT_MAP_I1
#define IMR_IP4_VAL	K_BCM1480_INT_MAP_I2

extern int bcm1480_steal_irq(int irq);

void bcm1480_time_init(void)
{
	int cpu = smp_processor_id();
	int irq = K_BCM1480_INT_TIMER_0+cpu;

	/* Only have 4 general purpose timers */
	if (cpu > 3) {
		BUG();
	}

	if (!cpu) {
		/* Use our own gettimeoffset() routine */
		do_gettimeoffset = bcm1480_gettimeoffset;
	}

	bcm1480_mask_irq(cpu, irq);

	/* Map the timer interrupt to ip[4] of this cpu */
	__raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)
	      + (irq<<3)));

	/* the general purpose timer ticks at 1 Mhz independent of the rest of the system */
	/* Disable the timer and set up the count */
	__raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
	__raw_writeq(
#ifndef CONFIG_SIMULATION
		1000000/HZ
#else
		50000/HZ
#endif
		, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));

	/* Set the timer running */
	__raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
	      IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));

	bcm1480_unmask_irq(cpu, irq);
	bcm1480_steal_irq(irq);
	/*
	 * This interrupt is "special" in that it doesn't use the request_irq
	 * way to hook the irq line.  The timer interrupt is initialized early
	 * enough to make this a major pain, and it's also firing enough to
	 * warrant a bit of special case code.  bcm1480_timer_interrupt is
	 * called directly from irq_handler.S when IP[4] is set during an
	 * interrupt
	 */
}

#include <asm/sibyte/sb1250.h>

void bcm1480_timer_interrupt(void)
{
	int cpu = smp_processor_id();
	int irq = K_BCM1480_INT_TIMER_0 + cpu;

	/* Reset the timer */
	__raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
	      IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));

	if (cpu == 0) {
		/*
		 * CPU 0 handles the global timer interrupt job
		 */
		ll_timer_interrupt(irq);
	}
	else {
		/*
		 * other CPUs should just do profiling and process accounting
		 */
		ll_local_timer_interrupt(irq);
	}
}

/*
 * We use our own do_gettimeoffset() instead of the generic one,
 * because the generic one does not work for SMP case.
 * In addition, since we use general timer 0 for system time,
 * we can get accurate intra-jiffy offset without calibration.
 */
unsigned long bcm1480_gettimeoffset(void)
{
	unsigned long count =
		__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));

	return 1000000/HZ - count;
}
Commit	Line	Data
f137e463 AI	1	/*
	2	* Copyright (C) 2000,2001,2004 Broadcom Corporation
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version 2
	7	* of the License, or (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*/
	18
	19	/*
	20	* These are routines to set up and handle interrupts from the
	21	* bcm1480 general purpose timer 0. We're using the timer as a
	22	* system clock, so we set it up to run at 100 Hz. On every
	23	* interrupt, we update our idea of what the time of day is,
	24	* then call do_timer() in the architecture-independent kernel
	25	* code to do general bookkeeping (e.g. update jiffies, run
	26	* bottom halves, etc.)
	27	*/
f137e463 AI	28	#include <linux/interrupt.h>
	29	#include <linux/sched.h>
	30	#include <linux/spinlock.h>
	31	#include <linux/kernel_stat.h>
	32
	33	#include <asm/irq.h>
	34	#include <asm/ptrace.h>
	35	#include <asm/addrspace.h>
	36	#include <asm/time.h>
	37	#include <asm/io.h>
	38
	39	#include <asm/sibyte/bcm1480_regs.h>
	40	#include <asm/sibyte/sb1250_regs.h>
	41	#include <asm/sibyte/bcm1480_int.h>
	42	#include <asm/sibyte/bcm1480_scd.h>
	43
	44	#include <asm/sibyte/sb1250.h>
	45
	46
	47	#define IMR_IP2_VAL K_BCM1480_INT_MAP_I0
	48	#define IMR_IP3_VAL K_BCM1480_INT_MAP_I1
	49	#define IMR_IP4_VAL K_BCM1480_INT_MAP_I2
	50
	51	extern int bcm1480_steal_irq(int irq);
	52
	53	void bcm1480_time_init(void)
	54	{
	55	int cpu = smp_processor_id();
	56	int irq = K_BCM1480_INT_TIMER_0+cpu;
	57
	58	/* Only have 4 general purpose timers */
	59	if (cpu > 3) {
	60	BUG();
	61	}
	62
	63	if (!cpu) {
	64	/* Use our own gettimeoffset() routine */
	65	do_gettimeoffset = bcm1480_gettimeoffset;
	66	}
	67
	68	bcm1480_mask_irq(cpu, irq);
	69
	70	/* Map the timer interrupt to ip[4] of this cpu */
	71	__raw_writeq(IMR_IP4_VAL, IOADDR(A_BCM1480_IMR_REGISTER(cpu, R_BCM1480_IMR_INTERRUPT_MAP_BASE_H)
	72	+ (irq<<3)));
	73
	74	/* the general purpose timer ticks at 1 Mhz independent of the rest of the system */
	75	/* Disable the timer and set up the count */
	76	__raw_writeq(0, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
	77	__raw_writeq(
	78	#ifndef CONFIG_SIMULATION
	79	1000000/HZ
	80	#else
	81	50000/HZ
	82	#endif
	83	, IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT)));
	84
	85	/* Set the timer running */
	86	__raw_writeq(M_SCD_TIMER_ENABLE\|M_SCD_TIMER_MODE_CONTINUOUS,
	87	IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
	88
	89	bcm1480_unmask_irq(cpu, irq);
	90	bcm1480_steal_irq(irq);
	91	/*
92	* This interrupt is "special" in that it doesn't use the request_irq
93	* way to hook the irq line. The timer interrupt is initialized early
94	* enough to make this a major pain, and it's also firing enough to
95	* warrant a bit of special case code. bcm1480_timer_interrupt is
96	* called directly from irq_handler.S when IP[4] is set during an
97	* interrupt
98	*/
99	}
100
101	#include <asm/sibyte/sb1250.h>
102
937a8015	103	void bcm1480_timer_interrupt(void)
f137e463 AI	104	{
f137e463 AI	105	int cpu = smp_processor_id();
937a8015	106	int irq = K_BCM1480_INT_TIMER_0 + cpu;
f137e463 AI	107
	108	/* Reset the timer */
	109	__raw_writeq(M_SCD_TIMER_ENABLE\|M_SCD_TIMER_MODE_CONTINUOUS,
	110	IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
	111
f137e463	112	if (cpu == 0) {
e1701fb2 MJW	113	/*
	114	* CPU 0 handles the global timer interrupt job
	115	*/
937a8015	116	ll_timer_interrupt(irq);
f137e463	117	}
e1701fb2 MJW	118	else {
	119	/*
	120	* other CPUs should just do profiling and process accounting
	121	*/
937a8015	122	ll_local_timer_interrupt(irq);
e1701fb2	123	}
f137e463 AI	124	}
	125
	126	/*
	127	* We use our own do_gettimeoffset() instead of the generic one,
	128	* because the generic one does not work for SMP case.
	129	* In addition, since we use general timer 0 for system time,
	130	* we can get accurate intra-jiffy offset without calibration.
	131	*/
	132	unsigned long bcm1480_gettimeoffset(void)
	133	{
	134	unsigned long count =
	135	__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
	136
	137	return 1000000/HZ - count;
	138	}