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