forked from Minki/linux
1b3f828760
Pull clocksource/clockevent updates from Daniel Lezcano:
* Axel Lin removed an unused structure defining the ids for the
bcm kona driver.
* Ezequiel Garcia enabled the timer divider only when the 25MHz
timer is not used for the armada 370 XP.
* Jingoo Han removed a pointless platform data initialization for
the sh_mtu and sh_mtu2.
* Laurent Pinchart added the clk_prepare/clk_unprepare for sh_cmt.
* Linus Walleij added a useful warning in clk_of when no clocks
are found while the old behavior was to silently hang at boot time.
* Maxime Ripard added the high speed timer drivers for the
Allwinner SoCs (A10, A13, A20). He increased the rating, shared the
irq across all available cpus and fixed the clockevent's irq
initialization for the sun4i.
* Michael Opdenacker removed the usage of the IRQF_DISABLED for the
all the timers driver located in drivers/clocksource.
* Stephen Boyd switched to sched_clock_register for the
arm_global_timer, cadence_ttc, sun4i and orion timers.
Conflicts:
drivers/clocksource/clksrc-of.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
319 lines
7.9 KiB
C
319 lines
7.9 KiB
C
/*
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* Marvell Armada 370/XP SoC timer handling.
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*
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* Copyright (C) 2012 Marvell
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*
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* Lior Amsalem <alior@marvell.com>
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* Gregory CLEMENT <gregory.clement@free-electrons.com>
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* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
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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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* Timer 0 is used as free-running clocksource, while timer 1 is
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* used as clock_event_device.
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*
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* ---
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* Clocksource driver for Armada 370 and Armada XP SoC.
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* This driver implements one compatible string for each SoC, given
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* each has its own characteristics:
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*
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* * Armada 370 has no 25 MHz fixed timer.
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*
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* * Armada XP cannot work properly without such 25 MHz fixed timer as
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* doing otherwise leads to using a clocksource whose frequency varies
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* when doing cpufreq frequency changes.
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*
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* See Documentation/devicetree/bindings/timer/marvell,armada-370-xp-timer.txt
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*/
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/kernel.h>
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#include <linux/clk.h>
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#include <linux/cpu.h>
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#include <linux/timer.h>
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#include <linux/clockchips.h>
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#include <linux/interrupt.h>
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#include <linux/of.h>
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#include <linux/of_irq.h>
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#include <linux/of_address.h>
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#include <linux/irq.h>
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#include <linux/module.h>
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#include <linux/sched_clock.h>
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#include <linux/percpu.h>
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/*
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* Timer block registers.
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*/
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#define TIMER_CTRL_OFF 0x0000
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#define TIMER0_EN BIT(0)
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#define TIMER0_RELOAD_EN BIT(1)
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#define TIMER0_25MHZ BIT(11)
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#define TIMER0_DIV(div) ((div) << 19)
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#define TIMER1_EN BIT(2)
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#define TIMER1_RELOAD_EN BIT(3)
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#define TIMER1_25MHZ BIT(12)
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#define TIMER1_DIV(div) ((div) << 22)
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#define TIMER_EVENTS_STATUS 0x0004
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#define TIMER0_CLR_MASK (~0x1)
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#define TIMER1_CLR_MASK (~0x100)
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#define TIMER0_RELOAD_OFF 0x0010
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#define TIMER0_VAL_OFF 0x0014
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#define TIMER1_RELOAD_OFF 0x0018
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#define TIMER1_VAL_OFF 0x001c
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#define LCL_TIMER_EVENTS_STATUS 0x0028
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/* Global timers are connected to the coherency fabric clock, and the
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below divider reduces their incrementing frequency. */
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#define TIMER_DIVIDER_SHIFT 5
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#define TIMER_DIVIDER (1 << TIMER_DIVIDER_SHIFT)
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/*
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* SoC-specific data.
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*/
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static void __iomem *timer_base, *local_base;
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static unsigned int timer_clk;
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static bool timer25Mhz = true;
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static u32 enable_mask;
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/*
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* Number of timer ticks per jiffy.
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*/
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static u32 ticks_per_jiffy;
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static struct clock_event_device __percpu *armada_370_xp_evt;
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static void timer_ctrl_clrset(u32 clr, u32 set)
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{
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writel((readl(timer_base + TIMER_CTRL_OFF) & ~clr) | set,
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timer_base + TIMER_CTRL_OFF);
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}
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static void local_timer_ctrl_clrset(u32 clr, u32 set)
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{
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writel((readl(local_base + TIMER_CTRL_OFF) & ~clr) | set,
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local_base + TIMER_CTRL_OFF);
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}
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static u64 notrace armada_370_xp_read_sched_clock(void)
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{
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return ~readl(timer_base + TIMER0_VAL_OFF);
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}
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/*
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* Clockevent handling.
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*/
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static int
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armada_370_xp_clkevt_next_event(unsigned long delta,
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struct clock_event_device *dev)
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{
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/*
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* Clear clockevent timer interrupt.
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*/
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writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
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/*
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* Setup new clockevent timer value.
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*/
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writel(delta, local_base + TIMER0_VAL_OFF);
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/*
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* Enable the timer.
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*/
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local_timer_ctrl_clrset(TIMER0_RELOAD_EN, enable_mask);
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return 0;
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}
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static void
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armada_370_xp_clkevt_mode(enum clock_event_mode mode,
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struct clock_event_device *dev)
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{
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if (mode == CLOCK_EVT_MODE_PERIODIC) {
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/*
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* Setup timer to fire at 1/HZ intervals.
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*/
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writel(ticks_per_jiffy - 1, local_base + TIMER0_RELOAD_OFF);
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writel(ticks_per_jiffy - 1, local_base + TIMER0_VAL_OFF);
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/*
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* Enable timer.
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*/
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local_timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask);
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} else {
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/*
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* Disable timer.
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*/
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local_timer_ctrl_clrset(TIMER0_EN, 0);
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/*
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* ACK pending timer interrupt.
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*/
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writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
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}
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}
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static int armada_370_xp_clkevt_irq;
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static irqreturn_t armada_370_xp_timer_interrupt(int irq, void *dev_id)
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{
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/*
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* ACK timer interrupt and call event handler.
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*/
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struct clock_event_device *evt = dev_id;
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writel(TIMER0_CLR_MASK, local_base + LCL_TIMER_EVENTS_STATUS);
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evt->event_handler(evt);
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return IRQ_HANDLED;
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}
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/*
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* Setup the local clock events for a CPU.
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*/
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static int armada_370_xp_timer_setup(struct clock_event_device *evt)
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{
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u32 clr = 0, set = 0;
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int cpu = smp_processor_id();
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if (timer25Mhz)
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set = TIMER0_25MHZ;
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else
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clr = TIMER0_25MHZ;
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local_timer_ctrl_clrset(clr, set);
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evt->name = "armada_370_xp_per_cpu_tick",
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evt->features = CLOCK_EVT_FEAT_ONESHOT |
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CLOCK_EVT_FEAT_PERIODIC;
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evt->shift = 32,
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evt->rating = 300,
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evt->set_next_event = armada_370_xp_clkevt_next_event,
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evt->set_mode = armada_370_xp_clkevt_mode,
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evt->irq = armada_370_xp_clkevt_irq;
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evt->cpumask = cpumask_of(cpu);
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clockevents_config_and_register(evt, timer_clk, 1, 0xfffffffe);
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enable_percpu_irq(evt->irq, 0);
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return 0;
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}
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static void armada_370_xp_timer_stop(struct clock_event_device *evt)
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{
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evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
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disable_percpu_irq(evt->irq);
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}
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static int armada_370_xp_timer_cpu_notify(struct notifier_block *self,
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unsigned long action, void *hcpu)
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{
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/*
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* Grab cpu pointer in each case to avoid spurious
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* preemptible warnings
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*/
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switch (action & ~CPU_TASKS_FROZEN) {
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case CPU_STARTING:
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armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
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break;
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case CPU_DYING:
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armada_370_xp_timer_stop(this_cpu_ptr(armada_370_xp_evt));
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break;
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}
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return NOTIFY_OK;
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}
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static struct notifier_block armada_370_xp_timer_cpu_nb = {
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.notifier_call = armada_370_xp_timer_cpu_notify,
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};
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static void __init armada_370_xp_timer_common_init(struct device_node *np)
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{
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u32 clr = 0, set = 0;
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int res;
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timer_base = of_iomap(np, 0);
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WARN_ON(!timer_base);
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local_base = of_iomap(np, 1);
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if (timer25Mhz) {
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set = TIMER0_25MHZ;
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enable_mask = TIMER0_EN;
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} else {
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clr = TIMER0_25MHZ;
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enable_mask = TIMER0_EN | TIMER0_DIV(TIMER_DIVIDER_SHIFT);
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}
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timer_ctrl_clrset(clr, set);
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local_timer_ctrl_clrset(clr, set);
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/*
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* We use timer 0 as clocksource, and private(local) timer 0
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* for clockevents
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*/
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armada_370_xp_clkevt_irq = irq_of_parse_and_map(np, 4);
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ticks_per_jiffy = (timer_clk + HZ / 2) / HZ;
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/*
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* Setup free-running clocksource timer (interrupts
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* disabled).
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*/
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writel(0xffffffff, timer_base + TIMER0_VAL_OFF);
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writel(0xffffffff, timer_base + TIMER0_RELOAD_OFF);
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timer_ctrl_clrset(0, TIMER0_RELOAD_EN | enable_mask);
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/*
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* Set scale and timer for sched_clock.
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*/
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sched_clock_register(armada_370_xp_read_sched_clock, 32, timer_clk);
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clocksource_mmio_init(timer_base + TIMER0_VAL_OFF,
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"armada_370_xp_clocksource",
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timer_clk, 300, 32, clocksource_mmio_readl_down);
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register_cpu_notifier(&armada_370_xp_timer_cpu_nb);
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armada_370_xp_evt = alloc_percpu(struct clock_event_device);
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/*
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* Setup clockevent timer (interrupt-driven).
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*/
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res = request_percpu_irq(armada_370_xp_clkevt_irq,
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armada_370_xp_timer_interrupt,
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"armada_370_xp_per_cpu_tick",
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armada_370_xp_evt);
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/* Immediately configure the timer on the boot CPU */
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if (!res)
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armada_370_xp_timer_setup(this_cpu_ptr(armada_370_xp_evt));
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}
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static void __init armada_xp_timer_init(struct device_node *np)
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{
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struct clk *clk = of_clk_get_by_name(np, "fixed");
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/* The 25Mhz fixed clock is mandatory, and must always be available */
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BUG_ON(IS_ERR(clk));
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timer_clk = clk_get_rate(clk);
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armada_370_xp_timer_common_init(np);
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}
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CLOCKSOURCE_OF_DECLARE(armada_xp, "marvell,armada-xp-timer",
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armada_xp_timer_init);
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static void __init armada_370_timer_init(struct device_node *np)
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{
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struct clk *clk = of_clk_get(np, 0);
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BUG_ON(IS_ERR(clk));
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timer_clk = clk_get_rate(clk) / TIMER_DIVIDER;
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timer25Mhz = false;
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armada_370_xp_timer_common_init(np);
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}
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CLOCKSOURCE_OF_DECLARE(armada_370, "marvell,armada-370-timer",
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armada_370_timer_init);
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