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1727339590
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>
123 lines
2.9 KiB
C
123 lines
2.9 KiB
C
/*
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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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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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 int __init _clps711x_clksrc_init(struct clk *clock, void __iomem *base)
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{
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unsigned long rate;
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if (!base)
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return -ENOMEM;
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if (IS_ERR(clock))
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return PTR_ERR(clock);
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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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return 0;
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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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if (!irq)
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return -EINVAL;
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if (!base)
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return -ENOMEM;
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if (IS_ERR(clock))
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return PTR_ERR(clock);
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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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void __init clps711x_clksrc_init(void __iomem *tc1_base, void __iomem *tc2_base,
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unsigned int irq)
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{
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struct clk *tc1 = clk_get_sys("clps711x-timer.0", NULL);
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struct clk *tc2 = clk_get_sys("clps711x-timer.1", NULL);
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BUG_ON(_clps711x_clksrc_init(tc1, tc1_base));
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BUG_ON(_clps711x_clkevt_init(tc2, tc2_base, irq));
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}
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#ifdef CONFIG_CLKSRC_OF
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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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switch (of_alias_get_id(np, "timer")) {
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case CLPS711X_CLKSRC_CLOCKSOURCE:
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return _clps711x_clksrc_init(clock, base);
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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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}
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TIMER_OF_DECLARE(clps711x, "cirrus,ep7209-timer", clps711x_timer_init);
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#endif
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