221 строка
6.0 KiB
C
221 строка
6.0 KiB
C
/*
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* Amlogic Meson6 SoCs timer handling.
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*
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* Copyright (C) 2014 Carlo Caione <carlo@caione.org>
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*
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* Based on code from Amlogic, Inc
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*
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* This file is licensed under the terms of the GNU General Public
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* License version 2. This program is licensed "as is" without any
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* warranty of any kind, whether express or implied.
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*/
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#include <linux/bitfield.h>
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#include <linux/bitops.h>
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#include <linux/clk.h>
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#include <linux/clockchips.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/irqreturn.h>
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#include <linux/sched_clock.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#ifdef CONFIG_ARM
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#include <linux/delay.h>
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#endif
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#define MESON_ISA_TIMER_MUX 0x00
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#define MESON_ISA_TIMER_MUX_TIMERD_EN BIT(19)
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#define MESON_ISA_TIMER_MUX_TIMERC_EN BIT(18)
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#define MESON_ISA_TIMER_MUX_TIMERB_EN BIT(17)
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#define MESON_ISA_TIMER_MUX_TIMERA_EN BIT(16)
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#define MESON_ISA_TIMER_MUX_TIMERD_MODE BIT(15)
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#define MESON_ISA_TIMER_MUX_TIMERC_MODE BIT(14)
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#define MESON_ISA_TIMER_MUX_TIMERB_MODE BIT(13)
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#define MESON_ISA_TIMER_MUX_TIMERA_MODE BIT(12)
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#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK GENMASK(10, 8)
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#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_SYSTEM_CLOCK 0x0
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#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1US 0x1
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#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_10US 0x2
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#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_100US 0x3
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#define MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1MS 0x4
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#define MESON_ISA_TIMER_MUX_TIMERD_INPUT_CLOCK_MASK GENMASK(7, 6)
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#define MESON_ISA_TIMER_MUX_TIMERC_INPUT_CLOCK_MASK GENMASK(5, 4)
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#define MESON_ISA_TIMER_MUX_TIMERB_INPUT_CLOCK_MASK GENMASK(3, 2)
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#define MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK GENMASK(1, 0)
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#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US 0x0
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#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_10US 0x1
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#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_100US 0x0
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#define MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1MS 0x3
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#define MESON_ISA_TIMERA 0x04
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#define MESON_ISA_TIMERB 0x08
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#define MESON_ISA_TIMERC 0x0c
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#define MESON_ISA_TIMERD 0x10
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#define MESON_ISA_TIMERE 0x14
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static void __iomem *timer_base;
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#ifdef CONFIG_ARM
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static unsigned long meson6_read_current_timer(void)
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{
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return readl_relaxed(timer_base + MESON_ISA_TIMERE);
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}
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static struct delay_timer meson6_delay_timer = {
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.read_current_timer = meson6_read_current_timer,
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.freq = 1000 * 1000,
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};
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#endif
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static u64 notrace meson6_timer_sched_read(void)
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{
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return (u64)readl(timer_base + MESON_ISA_TIMERE);
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}
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static void meson6_clkevt_time_stop(void)
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{
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u32 val = readl(timer_base + MESON_ISA_TIMER_MUX);
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writel(val & ~MESON_ISA_TIMER_MUX_TIMERA_EN,
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timer_base + MESON_ISA_TIMER_MUX);
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}
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static void meson6_clkevt_time_setup(unsigned long delay)
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{
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writel(delay, timer_base + MESON_ISA_TIMERA);
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}
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static void meson6_clkevt_time_start(bool periodic)
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{
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u32 val = readl(timer_base + MESON_ISA_TIMER_MUX);
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if (periodic)
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val |= MESON_ISA_TIMER_MUX_TIMERA_MODE;
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else
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val &= ~MESON_ISA_TIMER_MUX_TIMERA_MODE;
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writel(val | MESON_ISA_TIMER_MUX_TIMERA_EN,
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timer_base + MESON_ISA_TIMER_MUX);
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}
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static int meson6_shutdown(struct clock_event_device *evt)
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{
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meson6_clkevt_time_stop();
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return 0;
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}
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static int meson6_set_oneshot(struct clock_event_device *evt)
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{
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meson6_clkevt_time_stop();
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meson6_clkevt_time_start(false);
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return 0;
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}
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static int meson6_set_periodic(struct clock_event_device *evt)
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{
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meson6_clkevt_time_stop();
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meson6_clkevt_time_setup(USEC_PER_SEC / HZ - 1);
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meson6_clkevt_time_start(true);
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return 0;
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}
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static int meson6_clkevt_next_event(unsigned long evt,
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struct clock_event_device *unused)
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{
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meson6_clkevt_time_stop();
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meson6_clkevt_time_setup(evt);
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meson6_clkevt_time_start(false);
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return 0;
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}
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static struct clock_event_device meson6_clockevent = {
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.name = "meson6_tick",
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.rating = 400,
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.features = CLOCK_EVT_FEAT_PERIODIC |
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CLOCK_EVT_FEAT_ONESHOT,
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.set_state_shutdown = meson6_shutdown,
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.set_state_periodic = meson6_set_periodic,
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.set_state_oneshot = meson6_set_oneshot,
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.tick_resume = meson6_shutdown,
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.set_next_event = meson6_clkevt_next_event,
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};
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static irqreturn_t meson6_timer_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *evt = (struct clock_event_device *)dev_id;
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evt->event_handler(evt);
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return IRQ_HANDLED;
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}
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static struct irqaction meson6_timer_irq = {
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.name = "meson6_timer",
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.flags = IRQF_TIMER | IRQF_IRQPOLL,
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.handler = meson6_timer_interrupt,
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.dev_id = &meson6_clockevent,
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};
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static int __init meson6_timer_init(struct device_node *node)
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{
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u32 val;
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int ret, irq;
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timer_base = of_io_request_and_map(node, 0, "meson6-timer");
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if (IS_ERR(timer_base)) {
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pr_err("Can't map registers\n");
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return -ENXIO;
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}
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irq = irq_of_parse_and_map(node, 0);
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if (irq <= 0) {
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pr_err("Can't parse IRQ\n");
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return -EINVAL;
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}
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/* Set 1us for timer E */
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val = readl(timer_base + MESON_ISA_TIMER_MUX);
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val &= ~MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK;
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val |= FIELD_PREP(MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_MASK,
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MESON_ISA_TIMER_MUX_TIMERE_INPUT_CLOCK_1US);
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writel(val, timer_base + MESON_ISA_TIMER_MUX);
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sched_clock_register(meson6_timer_sched_read, 32, USEC_PER_SEC);
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clocksource_mmio_init(timer_base + MESON_ISA_TIMERE, node->name,
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1000 * 1000, 300, 32, clocksource_mmio_readl_up);
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/* Timer A base 1us */
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val &= ~MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK;
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val |= FIELD_PREP(MESON_ISA_TIMER_MUX_TIMERA_INPUT_CLOCK_MASK,
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MESON_ISA_TIMER_MUX_TIMERABCD_INPUT_CLOCK_1US);
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writel(val, timer_base + MESON_ISA_TIMER_MUX);
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/* Stop the timer A */
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meson6_clkevt_time_stop();
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ret = setup_irq(irq, &meson6_timer_irq);
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if (ret) {
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pr_warn("failed to setup irq %d\n", irq);
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return ret;
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}
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meson6_clockevent.cpumask = cpu_possible_mask;
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meson6_clockevent.irq = irq;
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clockevents_config_and_register(&meson6_clockevent, USEC_PER_SEC,
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1, 0xfffe);
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#ifdef CONFIG_ARM
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/* Also use MESON_ISA_TIMERE for delays */
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register_current_timer_delay(&meson6_delay_timer);
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#endif
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return 0;
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}
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TIMER_OF_DECLARE(meson6, "amlogic,meson6-timer",
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meson6_timer_init);
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