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[MIPS] Clockevent driver for BCM1480

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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle 2007-10-11 23:46:10 +01:00
parent 9b9ea2202f
commit e9f874b6f7
1 changed files with 81 additions and 26 deletions
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107
arch/mips/sibyte/bcm1480/time.c
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@ -25,6 +25,7 @@
* 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>
@ -55,15 +56,12 @@
extern int bcm1480_steal_irq(int irq);
void bcm1480_time_init(void)
void __init plat_time_init(void)
{
int cpu = smp_processor_id();
int irq = K_BCM1480_INT_TIMER_0+cpu;
unsigned int cpu = smp_processor_id();
unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
/* Only have 4 general purpose timers */
if (cpu > 3) {
BUG();
}
BUG_ON(cpu > 3); /* Only have 4 general purpose timers */
bcm1480_mask_irq(cpu, irq);
@ -71,27 +69,83 @@ void bcm1480_time_init(void)
__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(
BCM1480_HPT_VALUE/HZ
, 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
*/
}
/*
* 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_CFG));
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)
@ -118,4 +172,5 @@ void __init bcm1480_hpt_setup(void)
{
clocksource_mips.read = bcm1480_hpt_read;
mips_hpt_frequency = BCM1480_HPT_VALUE;
sb1480_clockevent_init();
}