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/*
* 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/clockchips.h>
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/kernel_stat.h>
#include <asm/irq.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
#ifdef CONFIG_SIMULATION
#define BCM1480_HPT_VALUE 50000
#else
#define BCM1480_HPT_VALUE 1000000
#endif
extern int bcm1480_steal_irq(int irq);
void __init plat_time_init(void)
{
unsigned int cpu = smp_processor_id();
unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
BUG_ON(cpu > 3); /* Only have 4 general purpose timers */
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)));
bcm1480_unmask_irq(cpu, irq);
bcm1480_steal_irq(irq);
}
/*
* The general purpose timer ticks at 1 Mhz independent if
* the rest of the system
*/
static void sibyte_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
void __iomem *timer_cfg, *timer_init;
timer_cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
timer_init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
__raw_writeq(0, timer_cfg);
__raw_writeq(BCM1480_HPT_VALUE / HZ - 1, timer_init);
__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS,
timer_cfg);
break;
case CLOCK_EVT_MODE_ONESHOT:
/* Stop the timer until we actually program a shot */
case CLOCK_EVT_MODE_SHUTDOWN:
__raw_writeq(0, timer_cfg);
break;
case CLOCK_EVT_MODE_UNUSED: /* shuddup gcc */
;
}
}
struct clock_event_device sibyte_hpt_clockevent = {
.name = "bcm1480-counter",
.features = CLOCK_EVT_FEAT_PERIODIC,
.set_mode = sibyte_set_mode,
.shift = 32,
.irq = 0,
};
static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
{
struct clock_event_device *cd = &sibyte_hpt_clockevent;
unsigned int cpu = smp_processor_id();
/* Reset the timer */
__raw_writeq(M_SCD_TIMER_ENABLE|M_SCD_TIMER_MODE_CONTINUOUS,
IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG)));
cd->event_handler(cd);
return IRQ_HANDLED;
}
static struct irqaction sibyte_counter_irqaction = {
.handler = sibyte_counter_handler,
.flags = IRQF_DISABLED | IRQF_PERCPU,
.name = "timer",
};
/*
* 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
*/
static void __init sb1480_clockevent_init(void)
{
unsigned int cpu = smp_processor_id();
unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
setup_irq(irq, &sibyte_counter_irqaction);
}
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)));
ll_timer_interrupt(irq);
}
static cycle_t bcm1480_hpt_read(void)
{
/* We assume this function is called xtime_lock held. */
unsigned long count =
__raw_readq(IOADDR(A_SCD_TIMER_REGISTER(0, R_SCD_TIMER_CNT)));
return (jiffies + 1) * (BCM1480_HPT_VALUE / HZ) - count;
}
void __init bcm1480_hpt_setup(void)
{
clocksource_mips.read = bcm1480_hpt_read;
mips_hpt_frequency = BCM1480_HPT_VALUE;
sb1480_clockevent_init();
}
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