// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/sched_clock.h>
#include <linux/cpu.h>
#include <linux/of_irq.h>
#include <asm/reg_ops.h>
#include "timer-of.h"
#define PTIM_CCVR "cr<3, 14>"
#define PTIM_CTLR "cr<0, 14>"
#define PTIM_LVR "cr<6, 14>"
#define PTIM_TSR "cr<1, 14>"
static int csky_mptimer_irq;
static int csky_mptimer_set_next_event(unsigned long delta,
struct clock_event_device *ce)
{
mtcr(PTIM_LVR, delta);
return 0;
}
static int csky_mptimer_shutdown(struct clock_event_device *ce)
{
mtcr(PTIM_CTLR, 0);
return 0;
}
static int csky_mptimer_oneshot(struct clock_event_device *ce)
{
mtcr(PTIM_CTLR, 1);
return 0;
}
static int csky_mptimer_oneshot_stopped(struct clock_event_device *ce)
{
mtcr(PTIM_CTLR, 0);
return 0;
}
static DEFINE_PER_CPU(struct timer_of, csky_to) = {
.flags = TIMER_OF_CLOCK,
.clkevt = {
.rating = 300,
.features = CLOCK_EVT_FEAT_PERCPU |
CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = csky_mptimer_shutdown,
.set_state_oneshot = csky_mptimer_oneshot,
.set_state_oneshot_stopped = csky_mptimer_oneshot_stopped,
.set_next_event = csky_mptimer_set_next_event,
},
};
static irqreturn_t csky_timer_interrupt(int irq, void *dev)
{
struct timer_of *to = this_cpu_ptr(&csky_to);
mtcr(PTIM_TSR, 0);
to->clkevt.event_handler(&to->clkevt);
return IRQ_HANDLED;
}
/*
* clock event for percpu
*/
static int csky_mptimer_starting_cpu(unsigned int cpu)
{
struct timer_of *to = per_cpu_ptr(&csky_to, cpu);
to->clkevt.cpumask = cpumask_of(cpu);
enable_percpu_irq(csky_mptimer_irq, 0);
clockevents_config_and_register(&to->clkevt, timer_of_rate(to),
2, ULONG_MAX);
return 0;
}
static int csky_mptimer_dying_cpu(unsigned int cpu)
{
disable_percpu_irq(csky_mptimer_irq);
return 0;
}
/*
* clock source
*/
static u64 notrace sched_clock_read(void)
{
return (u64)mfcr(PTIM_CCVR);
}
static u64 clksrc_read(struct clocksource *c)
{
return (u64)mfcr(PTIM_CCVR);
}
struct clocksource csky_clocksource = {
.name = "csky",
.rating = 400,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.read = clksrc_read,
};
static int __init csky_mptimer_init(struct device_node *np)
{
int ret, cpu, cpu_rollback;
struct timer_of *to = NULL;
/*
* Csky_mptimer is designed for C-SKY SMP multi-processors and
* every core has it's own private irq and regs for clkevt and
* clksrc.
*
* The regs is accessed by cpu instruction: mfcr/mtcr instead of
* mmio map style. So we needn't mmio-address in dts, but we still
* need to give clk and irq number.
*
* We use private irq for the mptimer and irq number is the same
* for every core. So we use request_percpu_irq() in timer_of_init.
*/
csky_mptimer_irq = irq_of_parse_and_map(np, 0);
if (csky_mptimer_irq <= 0)
return -EINVAL;
ret = request_percpu_irq(csky_mptimer_irq, csky_timer_interrupt,
"csky_mp_timer", &csky_to);
if (ret)
return -EINVAL;
for_each_possible_cpu(cpu) {
to = per_cpu_ptr(&csky_to, cpu);
ret = timer_of_init(np, to);
if (ret)
goto rollback;
}
clocksource_register_hz(&csky_clocksource, timer_of_rate(to));
sched_clock_register(sched_clock_read, 32, timer_of_rate(to));
ret = cpuhp_setup_state(CPUHP_AP_CSKY_TIMER_STARTING,
"clockevents/csky/timer:starting",
csky_mptimer_starting_cpu,
csky_mptimer_dying_cpu);
if (ret)
return -EINVAL;
return 0;
rollback:
for_each_possible_cpu(cpu_rollback) {
if (cpu_rollback == cpu)
break;
to = per_cpu_ptr(&csky_to, cpu_rollback);
timer_of_cleanup(to);
}
return -EINVAL;
}
TIMER_OF_DECLARE(csky_mptimer, "csky,mptimer", csky_mptimer_init);
