linux/drivers/clocksource/clksrc-dbx500-prcmu.c
Thomas Gleixner 0376148f30 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 197
Based on 1 normalized pattern(s):

  license terms gnu general public license v2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 37 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170027.724130665@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:22 -07:00

73 lines
2.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) ST-Ericsson SA 2011
*
* Author: Mattias Wallin <mattias.wallin@stericsson.com> for ST-Ericsson
* Author: Sundar Iyer for ST-Ericsson
* sched_clock implementation is based on:
* plat-nomadik/timer.c Linus Walleij <linus.walleij@stericsson.com>
*
* DBx500-PRCMU Timer
* The PRCMU has 5 timers which are available in a always-on
* power domain. We use the Timer 4 for our always-on clock
* source on DB8500.
*/
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/clockchips.h>
#define RATE_32K 32768
#define TIMER_MODE_CONTINOUS 0x1
#define TIMER_DOWNCOUNT_VAL 0xffffffff
#define PRCMU_TIMER_REF 0
#define PRCMU_TIMER_DOWNCOUNT 0x4
#define PRCMU_TIMER_MODE 0x8
static void __iomem *clksrc_dbx500_timer_base;
static u64 notrace clksrc_dbx500_prcmu_read(struct clocksource *cs)
{
void __iomem *base = clksrc_dbx500_timer_base;
u32 count, count2;
do {
count = readl_relaxed(base + PRCMU_TIMER_DOWNCOUNT);
count2 = readl_relaxed(base + PRCMU_TIMER_DOWNCOUNT);
} while (count2 != count);
/* Negate because the timer is a decrementing counter */
return ~count;
}
static struct clocksource clocksource_dbx500_prcmu = {
.name = "dbx500-prcmu-timer",
.rating = 100,
.read = clksrc_dbx500_prcmu_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_SUSPEND_NONSTOP,
};
static int __init clksrc_dbx500_prcmu_init(struct device_node *node)
{
clksrc_dbx500_timer_base = of_iomap(node, 0);
/*
* The A9 sub system expects the timer to be configured as
* a continous looping timer.
* The PRCMU should configure it but if it for some reason
* don't we do it here.
*/
if (readl(clksrc_dbx500_timer_base + PRCMU_TIMER_MODE) !=
TIMER_MODE_CONTINOUS) {
writel(TIMER_MODE_CONTINOUS,
clksrc_dbx500_timer_base + PRCMU_TIMER_MODE);
writel(TIMER_DOWNCOUNT_VAL,
clksrc_dbx500_timer_base + PRCMU_TIMER_REF);
}
return clocksource_register_hz(&clocksource_dbx500_prcmu, RATE_32K);
}
TIMER_OF_DECLARE(dbx500_prcmu, "stericsson,db8500-prcmu-timer-4",
clksrc_dbx500_prcmu_init);