0376148f30
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>
73 lines
2.1 KiB
C
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);
|