2874c5fd28
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 3029 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
102 lines
2.3 KiB
C
102 lines
2.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* Cirrus Logic CLPS711X clocksource driver
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*
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* Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
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*/
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#include <linux/clk.h>
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#include <linux/clockchips.h>
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#include <linux/clocksource.h>
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#include <linux/interrupt.h>
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#include <linux/io.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 <linux/slab.h>
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enum {
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CLPS711X_CLKSRC_CLOCKSOURCE,
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CLPS711X_CLKSRC_CLOCKEVENT,
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};
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static void __iomem *tcd;
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static u64 notrace clps711x_sched_clock_read(void)
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{
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return ~readw(tcd);
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}
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static void __init clps711x_clksrc_init(struct clk *clock, void __iomem *base)
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{
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unsigned long rate = clk_get_rate(clock);
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tcd = base;
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clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
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clocksource_mmio_readw_down);
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sched_clock_register(clps711x_sched_clock_read, 16, rate);
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}
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static irqreturn_t clps711x_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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evt->event_handler(evt);
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return IRQ_HANDLED;
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}
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static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base,
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unsigned int irq)
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{
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struct clock_event_device *clkevt;
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unsigned long rate;
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clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
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if (!clkevt)
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return -ENOMEM;
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rate = clk_get_rate(clock);
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/* Set Timer prescaler */
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writew(DIV_ROUND_CLOSEST(rate, HZ), base);
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clkevt->name = "clps711x-clockevent";
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clkevt->rating = 300;
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clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP;
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clkevt->cpumask = cpumask_of(0);
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clockevents_config_and_register(clkevt, HZ, 0, 0);
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return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
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"clps711x-timer", clkevt);
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}
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static int __init clps711x_timer_init(struct device_node *np)
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{
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unsigned int irq = irq_of_parse_and_map(np, 0);
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struct clk *clock = of_clk_get(np, 0);
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void __iomem *base = of_iomap(np, 0);
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if (!base)
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return -ENOMEM;
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if (!irq)
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return -EINVAL;
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if (IS_ERR(clock))
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return PTR_ERR(clock);
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switch (of_alias_get_id(np, "timer")) {
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case CLPS711X_CLKSRC_CLOCKSOURCE:
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clps711x_clksrc_init(clock, base);
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break;
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case CLPS711X_CLKSRC_CLOCKEVENT:
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return _clps711x_clkevt_init(clock, base, irq);
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default:
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return -EINVAL;
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}
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return 0;
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}
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TIMER_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);
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