linux/drivers/clocksource/timer-vt8500.c
afzal mohammed cc2550b421 clocksource: Replace setup_irq() by request_irq()
request_irq() is preferred over setup_irq(). The early boot setup_irq()
invocations happen either via 'init_IRQ()' or 'time_init()', while
memory allocators are ready by 'mm_init()'.

Per tglx[1], setup_irq() existed in olden days when allocators were not
ready by the time early interrupts were initialized.

Hence replace setup_irq() by request_irq().

Seldom remove_irq() usage has been observed coupled with setup_irq(),
wherever that has been found, it too has been replaced by free_irq().

A build error that was reported by kbuild test robot <lkp@intel.com>
in the previous version of the patch also has been fixed.

[1] https://lkml.kernel.org/r/alpine.DEB.2.20.1710191609480.1971@nanos

Signed-off-by: afzal mohammed <afzal.mohd.ma@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/91961c77c1cf93d41523f5e1ac52043f32f97077.1582799709.git.afzal.mohd.ma@gmail.com
2020-02-27 12:15:24 +01:00

151 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* arch/arm/mach-vt8500/timer.c
*
* Copyright (C) 2012 Tony Prisk <linux@prisktech.co.nz>
* Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
*/
/*
* This file is copied and modified from the original timer.c provided by
* Alexey Charkov. Minor changes have been made for Device Tree Support.
*/
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#define VT8500_TIMER_OFFSET 0x0100
#define VT8500_TIMER_HZ 3000000
#define TIMER_MATCH_VAL 0x0000
#define TIMER_COUNT_VAL 0x0010
#define TIMER_STATUS_VAL 0x0014
#define TIMER_IER_VAL 0x001c /* interrupt enable */
#define TIMER_CTRL_VAL 0x0020
#define TIMER_AS_VAL 0x0024 /* access status */
#define TIMER_COUNT_R_ACTIVE (1 << 5) /* not ready for read */
#define TIMER_COUNT_W_ACTIVE (1 << 4) /* not ready for write */
#define TIMER_MATCH_W_ACTIVE (1 << 0) /* not ready for write */
#define msecs_to_loops(t) (loops_per_jiffy / 1000 * HZ * t)
#define MIN_OSCR_DELTA 16
static void __iomem *regbase;
static u64 vt8500_timer_read(struct clocksource *cs)
{
int loops = msecs_to_loops(10);
writel(3, regbase + TIMER_CTRL_VAL);
while ((readl((regbase + TIMER_AS_VAL)) & TIMER_COUNT_R_ACTIVE)
&& --loops)
cpu_relax();
return readl(regbase + TIMER_COUNT_VAL);
}
static struct clocksource clocksource = {
.name = "vt8500_timer",
.rating = 200,
.read = vt8500_timer_read,
.mask = CLOCKSOURCE_MASK(32),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static int vt8500_timer_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
int loops = msecs_to_loops(10);
u64 alarm = clocksource.read(&clocksource) + cycles;
while ((readl(regbase + TIMER_AS_VAL) & TIMER_MATCH_W_ACTIVE)
&& --loops)
cpu_relax();
writel((unsigned long)alarm, regbase + TIMER_MATCH_VAL);
if ((signed)(alarm - clocksource.read(&clocksource)) <= MIN_OSCR_DELTA)
return -ETIME;
writel(1, regbase + TIMER_IER_VAL);
return 0;
}
static int vt8500_shutdown(struct clock_event_device *evt)
{
writel(readl(regbase + TIMER_CTRL_VAL) | 1, regbase + TIMER_CTRL_VAL);
writel(0, regbase + TIMER_IER_VAL);
return 0;
}
static struct clock_event_device clockevent = {
.name = "vt8500_timer",
.features = CLOCK_EVT_FEAT_ONESHOT,
.rating = 200,
.set_next_event = vt8500_timer_set_next_event,
.set_state_shutdown = vt8500_shutdown,
.set_state_oneshot = vt8500_shutdown,
};
static irqreturn_t vt8500_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
writel(0xf, regbase + TIMER_STATUS_VAL);
evt->event_handler(evt);
return IRQ_HANDLED;
}
static int __init vt8500_timer_init(struct device_node *np)
{
int timer_irq, ret;
regbase = of_iomap(np, 0);
if (!regbase) {
pr_err("%s: Missing iobase description in Device Tree\n",
__func__);
return -ENXIO;
}
timer_irq = irq_of_parse_and_map(np, 0);
if (!timer_irq) {
pr_err("%s: Missing irq description in Device Tree\n",
__func__);
return -EINVAL;
}
writel(1, regbase + TIMER_CTRL_VAL);
writel(0xf, regbase + TIMER_STATUS_VAL);
writel(~0, regbase + TIMER_MATCH_VAL);
ret = clocksource_register_hz(&clocksource, VT8500_TIMER_HZ);
if (ret) {
pr_err("%s: clocksource_register failed for %s\n",
__func__, clocksource.name);
return ret;
}
clockevent.cpumask = cpumask_of(0);
ret = request_irq(timer_irq, vt8500_timer_interrupt,
IRQF_TIMER | IRQF_IRQPOLL, "vt8500_timer",
&clockevent);
if (ret) {
pr_err("%s: setup_irq failed for %s\n", __func__,
clockevent.name);
return ret;
}
clockevents_config_and_register(&clockevent, VT8500_TIMER_HZ,
MIN_OSCR_DELTA * 2, 0xf0000000);
return 0;
}
TIMER_OF_DECLARE(vt8500, "via,vt8500-timer", vt8500_timer_init);