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![Daniel Lezcano](/assets/img/avatar_default.png)
The CLOCKSOURCE_OF_DECLARE macro is used widely for the timers to declare the clocksource at early stage. However, this macro is also used to initialize the clockevent if any, or the clockevent only. It was originally suggested to declare another macro to initialize a clockevent, so in order to separate the two entities even they belong to the same IP. This was not accepted because of the impact on the DT where splitting a clocksource/clockevent definition does not make sense as it is a Linux concept not a hardware description. On the other side, the clocksource has not interrupt declared while the clockevent has, so it is easy from the driver to know if the description is for a clockevent or a clocksource, IOW it could be implemented at the driver level. So instead of dealing with a named clocksource macro, let's use a more generic one: TIMER_OF_DECLARE. The patch has not functional changes. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Heiko Stuebner <heiko@sntech.de> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Matthias Brugger <matthias.bgg@gmail.com> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
258 lines
6.4 KiB
C
258 lines
6.4 KiB
C
/*
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*
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* Copyright (C) 2007 Google, Inc.
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* Copyright (c) 2009-2012,2014, The Linux Foundation. All rights reserved.
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*
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* This software is licensed under the terms of the GNU General Public
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* License version 2, as published by the Free Software Foundation, and
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* may be copied, distributed, and modified under those terms.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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*/
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#include <linux/clocksource.h>
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#include <linux/clockchips.h>
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#include <linux/cpu.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/irq.h>
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#include <linux/io.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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#include <linux/sched_clock.h>
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#include <asm/delay.h>
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#define TIMER_MATCH_VAL 0x0000
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#define TIMER_COUNT_VAL 0x0004
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#define TIMER_ENABLE 0x0008
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#define TIMER_ENABLE_CLR_ON_MATCH_EN BIT(1)
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#define TIMER_ENABLE_EN BIT(0)
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#define TIMER_CLEAR 0x000C
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#define DGT_CLK_CTL 0x10
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#define DGT_CLK_CTL_DIV_4 0x3
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#define TIMER_STS_GPT0_CLR_PEND BIT(10)
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#define GPT_HZ 32768
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static void __iomem *event_base;
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static void __iomem *sts_base;
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static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *evt = dev_id;
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/* Stop the timer tick */
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if (clockevent_state_oneshot(evt)) {
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u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
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ctrl &= ~TIMER_ENABLE_EN;
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writel_relaxed(ctrl, event_base + TIMER_ENABLE);
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}
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evt->event_handler(evt);
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return IRQ_HANDLED;
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}
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static int msm_timer_set_next_event(unsigned long cycles,
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struct clock_event_device *evt)
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{
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u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
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ctrl &= ~TIMER_ENABLE_EN;
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writel_relaxed(ctrl, event_base + TIMER_ENABLE);
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writel_relaxed(ctrl, event_base + TIMER_CLEAR);
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writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
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if (sts_base)
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while (readl_relaxed(sts_base) & TIMER_STS_GPT0_CLR_PEND)
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cpu_relax();
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writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
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return 0;
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}
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static int msm_timer_shutdown(struct clock_event_device *evt)
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{
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u32 ctrl;
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ctrl = readl_relaxed(event_base + TIMER_ENABLE);
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ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
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writel_relaxed(ctrl, event_base + TIMER_ENABLE);
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return 0;
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}
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static struct clock_event_device __percpu *msm_evt;
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static void __iomem *source_base;
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static notrace u64 msm_read_timer_count(struct clocksource *cs)
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{
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return readl_relaxed(source_base + TIMER_COUNT_VAL);
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}
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static struct clocksource msm_clocksource = {
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.name = "dg_timer",
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.rating = 300,
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.read = msm_read_timer_count,
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.mask = CLOCKSOURCE_MASK(32),
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.flags = CLOCK_SOURCE_IS_CONTINUOUS,
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};
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static int msm_timer_irq;
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static int msm_timer_has_ppi;
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static int msm_local_timer_starting_cpu(unsigned int cpu)
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{
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struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
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int err;
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evt->irq = msm_timer_irq;
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evt->name = "msm_timer";
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evt->features = CLOCK_EVT_FEAT_ONESHOT;
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evt->rating = 200;
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evt->set_state_shutdown = msm_timer_shutdown;
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evt->set_state_oneshot = msm_timer_shutdown;
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evt->tick_resume = msm_timer_shutdown;
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evt->set_next_event = msm_timer_set_next_event;
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evt->cpumask = cpumask_of(cpu);
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clockevents_config_and_register(evt, GPT_HZ, 4, 0xffffffff);
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if (msm_timer_has_ppi) {
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enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
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} else {
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err = request_irq(evt->irq, msm_timer_interrupt,
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IRQF_TIMER | IRQF_NOBALANCING |
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IRQF_TRIGGER_RISING, "gp_timer", evt);
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if (err)
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pr_err("request_irq failed\n");
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}
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return 0;
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}
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static int msm_local_timer_dying_cpu(unsigned int cpu)
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{
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struct clock_event_device *evt = per_cpu_ptr(msm_evt, cpu);
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evt->set_state_shutdown(evt);
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disable_percpu_irq(evt->irq);
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return 0;
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}
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static u64 notrace msm_sched_clock_read(void)
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{
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return msm_clocksource.read(&msm_clocksource);
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}
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static unsigned long msm_read_current_timer(void)
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{
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return msm_clocksource.read(&msm_clocksource);
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}
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static struct delay_timer msm_delay_timer = {
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.read_current_timer = msm_read_current_timer,
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};
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static int __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
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bool percpu)
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{
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struct clocksource *cs = &msm_clocksource;
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int res = 0;
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msm_timer_irq = irq;
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msm_timer_has_ppi = percpu;
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msm_evt = alloc_percpu(struct clock_event_device);
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if (!msm_evt) {
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pr_err("memory allocation failed for clockevents\n");
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goto err;
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}
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if (percpu)
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res = request_percpu_irq(irq, msm_timer_interrupt,
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"gp_timer", msm_evt);
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if (res) {
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pr_err("request_percpu_irq failed\n");
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} else {
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/* Install and invoke hotplug callbacks */
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res = cpuhp_setup_state(CPUHP_AP_QCOM_TIMER_STARTING,
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"clockevents/qcom/timer:starting",
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msm_local_timer_starting_cpu,
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msm_local_timer_dying_cpu);
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if (res) {
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free_percpu_irq(irq, msm_evt);
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goto err;
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}
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}
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err:
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writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
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res = clocksource_register_hz(cs, dgt_hz);
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if (res)
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pr_err("clocksource_register failed\n");
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sched_clock_register(msm_sched_clock_read, sched_bits, dgt_hz);
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msm_delay_timer.freq = dgt_hz;
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register_current_timer_delay(&msm_delay_timer);
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return res;
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}
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static int __init msm_dt_timer_init(struct device_node *np)
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{
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u32 freq;
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int irq, ret;
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struct resource res;
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u32 percpu_offset;
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void __iomem *base;
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void __iomem *cpu0_base;
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base = of_iomap(np, 0);
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if (!base) {
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pr_err("Failed to map event base\n");
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return -ENXIO;
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}
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/* We use GPT0 for the clockevent */
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irq = irq_of_parse_and_map(np, 1);
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if (irq <= 0) {
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pr_err("Can't get irq\n");
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return -EINVAL;
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}
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/* We use CPU0's DGT for the clocksource */
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if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
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percpu_offset = 0;
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ret = of_address_to_resource(np, 0, &res);
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if (ret) {
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pr_err("Failed to parse DGT resource\n");
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return ret;
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}
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cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res));
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if (!cpu0_base) {
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pr_err("Failed to map source base\n");
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return -EINVAL;
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}
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if (of_property_read_u32(np, "clock-frequency", &freq)) {
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pr_err("Unknown frequency\n");
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return -EINVAL;
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}
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event_base = base + 0x4;
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sts_base = base + 0x88;
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source_base = cpu0_base + 0x24;
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freq /= 4;
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writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL);
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return msm_timer_init(freq, 32, irq, !!percpu_offset);
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}
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TIMER_OF_DECLARE(kpss_timer, "qcom,kpss-timer", msm_dt_timer_init);
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TIMER_OF_DECLARE(scss_timer, "qcom,scss-timer", msm_dt_timer_init);
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