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
/*
|
|
* Generic MMIO clocksource support
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/clocksource.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/init.h>
|
|
#include <linux/slab.h>
|
|
|
|
struct clocksource_mmio {
|
|
void __iomem *reg;
|
|
struct clocksource clksrc;
|
|
};
|
|
|
|
static inline struct clocksource_mmio *to_mmio_clksrc(struct clocksource *c)
|
|
{
|
|
return container_of(c, struct clocksource_mmio, clksrc);
|
|
}
|
|
|
|
cycle_t clocksource_mmio_readl_up(struct clocksource *c)
|
|
{
|
|
return (cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg);
|
|
}
|
|
|
|
cycle_t clocksource_mmio_readl_down(struct clocksource *c)
|
|
{
|
|
return ~(cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
|
|
}
|
|
|
|
cycle_t clocksource_mmio_readw_up(struct clocksource *c)
|
|
{
|
|
return (cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg);
|
|
}
|
|
|
|
cycle_t clocksource_mmio_readw_down(struct clocksource *c)
|
|
{
|
|
return ~(cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
|
|
}
|
|
|
|
/**
|
|
* clocksource_mmio_init - Initialize a simple mmio based clocksource
|
|
* @base: Virtual address of the clock readout register
|
|
* @name: Name of the clocksource
|
|
* @hz: Frequency of the clocksource in Hz
|
|
* @rating: Rating of the clocksource
|
|
* @bits: Number of valid bits
|
|
* @read: One of clocksource_mmio_read*() above
|
|
*/
|
|
int __init clocksource_mmio_init(void __iomem *base, const char *name,
|
|
unsigned long hz, int rating, unsigned bits,
|
|
cycle_t (*read)(struct clocksource *))
|
|
{
|
|
struct clocksource_mmio *cs;
|
|
|
|
if (bits > 64 || bits < 16)
|
|
return -EINVAL;
|
|
|
|
cs = kzalloc(sizeof(struct clocksource_mmio), GFP_KERNEL);
|
|
if (!cs)
|
|
return -ENOMEM;
|
|
|
|
cs->reg = base;
|
|
cs->clksrc.name = name;
|
|
cs->clksrc.rating = rating;
|
|
cs->clksrc.read = read;
|
|
cs->clksrc.mask = CLOCKSOURCE_MASK(bits);
|
|
cs->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
|
|
|
|
return clocksource_register_hz(&cs->clksrc, hz);
|
|
}
|