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e2bf3e6eca
The EP93xx is registering a clocksource of 40 bits with
clocksource_mmio_init() but this is not working because of this
artificial limitation. It works fine to lift the uppe limit to
64 bits, and since cycle_t is u64, it should intuitively have been
like that from the beginning.
Fixes: 000bc17817 "ARM: ep93xx: switch to GENERIC_CLOCKEVENTS"
Reported-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: http://lkml.kernel.org/r/1449768101-6879-1-git-send-email-linus.walleij@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
74 lines
1.9 KiB
C
74 lines
1.9 KiB
C
/*
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* Generic MMIO clocksource support
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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 version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/clocksource.h>
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#include <linux/errno.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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struct clocksource_mmio {
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void __iomem *reg;
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struct clocksource clksrc;
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};
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static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
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{
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return container_of(c, struct clocksource_mmio, clksrc);
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}
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cycle_t clocksource_mmio_readl_up(struct clocksource *c)
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{
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return (cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg);
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}
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cycle_t clocksource_mmio_readl_down(struct clocksource *c)
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{
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return ~(cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
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}
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cycle_t clocksource_mmio_readw_up(struct clocksource *c)
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{
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return (cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg);
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}
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cycle_t clocksource_mmio_readw_down(struct clocksource *c)
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{
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return ~(cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
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}
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/**
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* clocksource_mmio_init - Initialize a simple mmio based clocksource
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* @base: Virtual address of the clock readout register
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* @name: Name of the clocksource
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* @hz: Frequency of the clocksource in Hz
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* @rating: Rating of the clocksource
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* @bits: Number of valid bits
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* @read: One of clocksource_mmio_read*() above
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*/
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int __init clocksource_mmio_init(void __iomem *base, const char *name,
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unsigned long hz, int rating, unsigned bits,
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cycle_t (*read)(struct clocksource *))
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{
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struct clocksource_mmio *cs;
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if (bits > 64 || bits < 16)
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return -EINVAL;
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cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
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if (!cs)
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return -ENOMEM;
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cs->reg = base;
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cs->clksrc.name = name;
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cs->clksrc.rating = rating;
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cs->clksrc.read = read;
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cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
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cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
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return clocksource_register_hz(&cs->clksrc, hz);
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}
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