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- // 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);
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