forked from mirrors/linux
a5a1d1c291
There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org>
128 lines
3.6 KiB
C
128 lines
3.6 KiB
C
/**
|
|
* timer-ti-32k.c - OMAP2 32k Timer Support
|
|
*
|
|
* Copyright (C) 2009 Nokia Corporation
|
|
*
|
|
* Update to use new clocksource/clockevent layers
|
|
* Author: Kevin Hilman, MontaVista Software, Inc. <source@mvista.com>
|
|
* Copyright (C) 2007 MontaVista Software, Inc.
|
|
*
|
|
* Original driver:
|
|
* Copyright (C) 2005 Nokia Corporation
|
|
* Author: Paul Mundt <paul.mundt@nokia.com>
|
|
* Juha Yrjölä <juha.yrjola@nokia.com>
|
|
* OMAP Dual-mode timer framework support by Timo Teras
|
|
*
|
|
* Some parts based off of TI's 24xx code:
|
|
*
|
|
* Copyright (C) 2004-2009 Texas Instruments, Inc.
|
|
*
|
|
* Roughly modelled after the OMAP1 MPU timer code.
|
|
* Added OMAP4 support - Santosh Shilimkar <santosh.shilimkar@ti.com>
|
|
*
|
|
* Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 of
|
|
* the License as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/time.h>
|
|
#include <linux/sched_clock.h>
|
|
#include <linux/clocksource.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_address.h>
|
|
|
|
/*
|
|
* 32KHz clocksource ... always available, on pretty most chips except
|
|
* OMAP 730 and 1510. Other timers could be used as clocksources, with
|
|
* higher resolution in free-running counter modes (e.g. 12 MHz xtal),
|
|
* but systems won't necessarily want to spend resources that way.
|
|
*/
|
|
|
|
#define OMAP2_32KSYNCNT_REV_OFF 0x0
|
|
#define OMAP2_32KSYNCNT_REV_SCHEME (0x3 << 30)
|
|
#define OMAP2_32KSYNCNT_CR_OFF_LOW 0x10
|
|
#define OMAP2_32KSYNCNT_CR_OFF_HIGH 0x30
|
|
|
|
struct ti_32k {
|
|
void __iomem *base;
|
|
void __iomem *counter;
|
|
struct clocksource cs;
|
|
};
|
|
|
|
static inline struct ti_32k *to_ti_32k(struct clocksource *cs)
|
|
{
|
|
return container_of(cs, struct ti_32k, cs);
|
|
}
|
|
|
|
static u64 notrace ti_32k_read_cycles(struct clocksource *cs)
|
|
{
|
|
struct ti_32k *ti = to_ti_32k(cs);
|
|
|
|
return (u64)readl_relaxed(ti->counter);
|
|
}
|
|
|
|
static struct ti_32k ti_32k_timer = {
|
|
.cs = {
|
|
.name = "32k_counter",
|
|
.rating = 250,
|
|
.read = ti_32k_read_cycles,
|
|
.mask = CLOCKSOURCE_MASK(32),
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS |
|
|
CLOCK_SOURCE_SUSPEND_NONSTOP,
|
|
},
|
|
};
|
|
|
|
static u64 notrace omap_32k_read_sched_clock(void)
|
|
{
|
|
return ti_32k_read_cycles(&ti_32k_timer.cs);
|
|
}
|
|
|
|
static int __init ti_32k_timer_init(struct device_node *np)
|
|
{
|
|
int ret;
|
|
|
|
ti_32k_timer.base = of_iomap(np, 0);
|
|
if (!ti_32k_timer.base) {
|
|
pr_err("Can't ioremap 32k timer base\n");
|
|
return -ENXIO;
|
|
}
|
|
|
|
ti_32k_timer.counter = ti_32k_timer.base;
|
|
|
|
/*
|
|
* 32k sync Counter IP register offsets vary between the highlander
|
|
* version and the legacy ones.
|
|
*
|
|
* The 'SCHEME' bits(30-31) of the revision register is used to identify
|
|
* the version.
|
|
*/
|
|
if (readl_relaxed(ti_32k_timer.base + OMAP2_32KSYNCNT_REV_OFF) &
|
|
OMAP2_32KSYNCNT_REV_SCHEME)
|
|
ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_HIGH;
|
|
else
|
|
ti_32k_timer.counter += OMAP2_32KSYNCNT_CR_OFF_LOW;
|
|
|
|
ret = clocksource_register_hz(&ti_32k_timer.cs, 32768);
|
|
if (ret) {
|
|
pr_err("32k_counter: can't register clocksource\n");
|
|
return ret;
|
|
}
|
|
|
|
sched_clock_register(omap_32k_read_sched_clock, 32, 32768);
|
|
pr_info("OMAP clocksource: 32k_counter at 32768 Hz\n");
|
|
|
|
return 0;
|
|
}
|
|
CLOCKSOURCE_OF_DECLARE(ti_32k_timer, "ti,omap-counter32k",
|
|
ti_32k_timer_init);
|