forked from Minki/linux
067bc91447
The Spreadtrum SC9860 platform will use the architected timers as local clock events, but we also need a broadcast timer device to wake up the CPUs when the CPUs are in sleep mode. The Spreadtrum timer can support 32-bit or 64-bit counters, as well as supporting period mode or one-shot mode. Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Philippe Ombredanne <pombredanne@nexb.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1515418139-23276-8-git-send-email-daniel.lezcano@linaro.org [ Minor readability edits. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
160 lines
3.6 KiB
C
160 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2017 Spreadtrum Communications Inc.
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*/
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include "timer-of.h"
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#define TIMER_NAME "sprd_timer"
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#define TIMER_LOAD_LO 0x0
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#define TIMER_LOAD_HI 0x4
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#define TIMER_VALUE_LO 0x8
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#define TIMER_VALUE_HI 0xc
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#define TIMER_CTL 0x10
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#define TIMER_CTL_PERIOD_MODE BIT(0)
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#define TIMER_CTL_ENABLE BIT(1)
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#define TIMER_CTL_64BIT_WIDTH BIT(16)
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#define TIMER_INT 0x14
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#define TIMER_INT_EN BIT(0)
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#define TIMER_INT_RAW_STS BIT(1)
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#define TIMER_INT_MASK_STS BIT(2)
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#define TIMER_INT_CLR BIT(3)
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#define TIMER_VALUE_SHDW_LO 0x18
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#define TIMER_VALUE_SHDW_HI 0x1c
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#define TIMER_VALUE_LO_MASK GENMASK(31, 0)
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static void sprd_timer_enable(void __iomem *base, u32 flag)
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{
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u32 val = readl_relaxed(base + TIMER_CTL);
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val |= TIMER_CTL_ENABLE;
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if (flag & TIMER_CTL_64BIT_WIDTH)
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val |= TIMER_CTL_64BIT_WIDTH;
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else
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val &= ~TIMER_CTL_64BIT_WIDTH;
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if (flag & TIMER_CTL_PERIOD_MODE)
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val |= TIMER_CTL_PERIOD_MODE;
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else
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val &= ~TIMER_CTL_PERIOD_MODE;
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writel_relaxed(val, base + TIMER_CTL);
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}
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static void sprd_timer_disable(void __iomem *base)
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{
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u32 val = readl_relaxed(base + TIMER_CTL);
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val &= ~TIMER_CTL_ENABLE;
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writel_relaxed(val, base + TIMER_CTL);
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}
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static void sprd_timer_update_counter(void __iomem *base, unsigned long cycles)
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{
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writel_relaxed(cycles & TIMER_VALUE_LO_MASK, base + TIMER_LOAD_LO);
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writel_relaxed(0, base + TIMER_LOAD_HI);
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}
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static void sprd_timer_enable_interrupt(void __iomem *base)
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{
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writel_relaxed(TIMER_INT_EN, base + TIMER_INT);
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}
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static void sprd_timer_clear_interrupt(void __iomem *base)
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{
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u32 val = readl_relaxed(base + TIMER_INT);
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val |= TIMER_INT_CLR;
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writel_relaxed(val, base + TIMER_INT);
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}
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static int sprd_timer_set_next_event(unsigned long cycles,
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struct clock_event_device *ce)
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{
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struct timer_of *to = to_timer_of(ce);
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sprd_timer_disable(timer_of_base(to));
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sprd_timer_update_counter(timer_of_base(to), cycles);
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sprd_timer_enable(timer_of_base(to), 0);
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return 0;
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}
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static int sprd_timer_set_periodic(struct clock_event_device *ce)
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{
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struct timer_of *to = to_timer_of(ce);
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sprd_timer_disable(timer_of_base(to));
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sprd_timer_update_counter(timer_of_base(to), timer_of_period(to));
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sprd_timer_enable(timer_of_base(to), TIMER_CTL_PERIOD_MODE);
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return 0;
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}
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static int sprd_timer_shutdown(struct clock_event_device *ce)
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{
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struct timer_of *to = to_timer_of(ce);
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sprd_timer_disable(timer_of_base(to));
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return 0;
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}
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static irqreturn_t sprd_timer_interrupt(int irq, void *dev_id)
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{
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struct clock_event_device *ce = (struct clock_event_device *)dev_id;
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struct timer_of *to = to_timer_of(ce);
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sprd_timer_clear_interrupt(timer_of_base(to));
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if (clockevent_state_oneshot(ce))
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sprd_timer_disable(timer_of_base(to));
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ce->event_handler(ce);
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return IRQ_HANDLED;
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}
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static struct timer_of to = {
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.flags = TIMER_OF_IRQ | TIMER_OF_BASE | TIMER_OF_CLOCK,
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.clkevt = {
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.name = TIMER_NAME,
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.rating = 300,
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.features = CLOCK_EVT_FEAT_DYNIRQ | CLOCK_EVT_FEAT_PERIODIC |
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CLOCK_EVT_FEAT_ONESHOT,
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.set_state_shutdown = sprd_timer_shutdown,
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.set_state_periodic = sprd_timer_set_periodic,
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.set_next_event = sprd_timer_set_next_event,
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.cpumask = cpu_possible_mask,
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},
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.of_irq = {
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.handler = sprd_timer_interrupt,
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.flags = IRQF_TIMER | IRQF_IRQPOLL,
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},
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};
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static int __init sprd_timer_init(struct device_node *np)
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{
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int ret;
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ret = timer_of_init(np, &to);
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if (ret)
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return ret;
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sprd_timer_enable_interrupt(timer_of_base(&to));
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clockevents_config_and_register(&to.clkevt, timer_of_rate(&to),
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1, UINT_MAX);
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return 0;
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}
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TIMER_OF_DECLARE(sc9860_timer, "sprd,sc9860-timer", sprd_timer_init);
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