cevt-bcm1480.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2000,2001,2004 Broadcom Corporation
*/
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/irq.h>
#include <asm/addrspace.h>
#include <asm/io.h>
#include <asm/time.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
/*
* The general purpose timer ticks at 1MHz independent if
* the rest of the system
*/
static int sibyte_set_periodic(struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
void __iomem *cfg, *init;
cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
__raw_writeq(0, cfg);
__raw_writeq((V_SCD_TIMER_FREQ / HZ) - 1, init);
__raw_writeq(M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS, cfg);
return 0;
}
static int sibyte_shutdown(struct clock_event_device *evt)
{
unsigned int cpu = smp_processor_id();
void __iomem *cfg;
cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
/* Stop the timer until we actually program a shot */
__raw_writeq(0, cfg);
return 0;
}
static int sibyte_next_event(unsigned long delta, struct clock_event_device *cd)
{
unsigned int cpu = smp_processor_id();
void __iomem *cfg, *init;
cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
init = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_INIT));
__raw_writeq(0, cfg);
__raw_writeq(delta - 1, init);
__raw_writeq(M_SCD_TIMER_ENABLE, cfg);
return 0;
}
static irqreturn_t sibyte_counter_handler(int irq, void *dev_id)
{
unsigned int cpu = smp_processor_id();
struct clock_event_device *cd = dev_id;
void __iomem *cfg;
unsigned long tmode;
if (clockevent_state_periodic(cd))
tmode = M_SCD_TIMER_ENABLE | M_SCD_TIMER_MODE_CONTINUOUS;
else
tmode = 0;
/* ACK interrupt */
cfg = IOADDR(A_SCD_TIMER_REGISTER(cpu, R_SCD_TIMER_CFG));
____raw_writeq(tmode, cfg);
cd->event_handler(cd);
return IRQ_HANDLED;
}
static DEFINE_PER_CPU(struct clock_event_device, sibyte_hpt_clockevent);
static DEFINE_PER_CPU(struct irqaction, sibyte_hpt_irqaction);
static DEFINE_PER_CPU(char [18], sibyte_hpt_name);
void sb1480_clockevent_init(void)
{
unsigned int cpu = smp_processor_id();
unsigned int irq = K_BCM1480_INT_TIMER_0 + cpu;
struct irqaction *action = &per_cpu(sibyte_hpt_irqaction, cpu);
struct clock_event_device *cd = &per_cpu(sibyte_hpt_clockevent, cpu);
unsigned char *name = per_cpu(sibyte_hpt_name, cpu);
BUG_ON(cpu > 3); /* Only have 4 general purpose timers */
sprintf(name, "bcm1480-counter-%d", cpu);
cd->name = name;
cd->features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT;
clockevent_set_clock(cd, V_SCD_TIMER_FREQ);
cd->max_delta_ns = clockevent_delta2ns(0x7fffff, cd);
cd->max_delta_ticks = 0x7fffff;
cd->min_delta_ns = clockevent_delta2ns(2, cd);
cd->min_delta_ticks = 2;
cd->rating = 200;
cd->irq = irq;
cd->cpumask = cpumask_of(cpu);
cd->set_next_event = sibyte_next_event;
cd->set_state_shutdown = sibyte_shutdown;
cd->set_state_periodic = sibyte_set_periodic;
cd->set_state_oneshot = sibyte_shutdown;
clockevents_register_device(cd);
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);
action->handler = sibyte_counter_handler;
action->flags = IRQF_PERCPU | IRQF_TIMER;
action->name = name;
action->dev_id = cd;
irq_set_affinity(irq, cpumask_of(cpu));
setup_irq(irq, action);
}