linux/drivers/clocksource/timer-atlas7.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wherever that has been found, it too has been replaced by free_irq().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

282 lines
8.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* System timer for CSR SiRFprimaII
*
* Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
*/
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/clockchips.h>
#include <linux/clocksource.h>
#include <linux/cpu.h>
#include <linux/bitops.h>
#include <linux/irq.h>
#include <linux/clk.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <linux/sched_clock.h>
#define SIRFSOC_TIMER_32COUNTER_0_CTRL 0x0000
#define SIRFSOC_TIMER_32COUNTER_1_CTRL 0x0004
#define SIRFSOC_TIMER_MATCH_0 0x0018
#define SIRFSOC_TIMER_MATCH_1 0x001c
#define SIRFSOC_TIMER_COUNTER_0 0x0048
#define SIRFSOC_TIMER_COUNTER_1 0x004c
#define SIRFSOC_TIMER_INTR_STATUS 0x0060
#define SIRFSOC_TIMER_WATCHDOG_EN 0x0064
#define SIRFSOC_TIMER_64COUNTER_CTRL 0x0068
#define SIRFSOC_TIMER_64COUNTER_LO 0x006c
#define SIRFSOC_TIMER_64COUNTER_HI 0x0070
#define SIRFSOC_TIMER_64COUNTER_LOAD_LO 0x0074
#define SIRFSOC_TIMER_64COUNTER_LOAD_HI 0x0078
#define SIRFSOC_TIMER_64COUNTER_RLATCHED_LO 0x007c
#define SIRFSOC_TIMER_64COUNTER_RLATCHED_HI 0x0080
#define SIRFSOC_TIMER_REG_CNT 6
static unsigned long atlas7_timer_rate;
static const u32 sirfsoc_timer_reg_list[SIRFSOC_TIMER_REG_CNT] = {
SIRFSOC_TIMER_WATCHDOG_EN,
SIRFSOC_TIMER_32COUNTER_0_CTRL,
SIRFSOC_TIMER_32COUNTER_1_CTRL,
SIRFSOC_TIMER_64COUNTER_CTRL,
SIRFSOC_TIMER_64COUNTER_RLATCHED_LO,
SIRFSOC_TIMER_64COUNTER_RLATCHED_HI,
};
static u32 sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT];
static void __iomem *sirfsoc_timer_base;
/* disable count and interrupt */
static inline void sirfsoc_timer_count_disable(int idx)
{
writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) & ~0x7,
sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx);
}
/* enable count and interrupt */
static inline void sirfsoc_timer_count_enable(int idx)
{
writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx) | 0x3,
sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL + 4 * idx);
}
/* timer interrupt handler */
static irqreturn_t sirfsoc_timer_interrupt(int irq, void *dev_id)
{
struct clock_event_device *ce = dev_id;
int cpu = smp_processor_id();
/* clear timer interrupt */
writel_relaxed(BIT(cpu), sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
if (clockevent_state_oneshot(ce))
sirfsoc_timer_count_disable(cpu);
ce->event_handler(ce);
return IRQ_HANDLED;
}
/* read 64-bit timer counter */
static u64 sirfsoc_timer_read(struct clocksource *cs)
{
u64 cycles;
writel_relaxed((readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
BIT(0)) & ~BIT(1), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
cycles = readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_HI);
cycles = (cycles << 32) | readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_RLATCHED_LO);
return cycles;
}
static int sirfsoc_timer_set_next_event(unsigned long delta,
struct clock_event_device *ce)
{
int cpu = smp_processor_id();
/* disable timer first, then modify the related registers */
sirfsoc_timer_count_disable(cpu);
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0 +
4 * cpu);
writel_relaxed(delta, sirfsoc_timer_base + SIRFSOC_TIMER_MATCH_0 +
4 * cpu);
/* enable the tick */
sirfsoc_timer_count_enable(cpu);
return 0;
}
/* Oneshot is enabled in set_next_event */
static int sirfsoc_timer_shutdown(struct clock_event_device *evt)
{
sirfsoc_timer_count_disable(smp_processor_id());
return 0;
}
static void sirfsoc_clocksource_suspend(struct clocksource *cs)
{
int i;
for (i = 0; i < SIRFSOC_TIMER_REG_CNT; i++)
sirfsoc_timer_reg_val[i] = readl_relaxed(sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
}
static void sirfsoc_clocksource_resume(struct clocksource *cs)
{
int i;
for (i = 0; i < SIRFSOC_TIMER_REG_CNT - 2; i++)
writel_relaxed(sirfsoc_timer_reg_val[i], sirfsoc_timer_base + sirfsoc_timer_reg_list[i]);
writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 2],
sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO);
writel_relaxed(sirfsoc_timer_reg_val[SIRFSOC_TIMER_REG_CNT - 1],
sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI);
writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
}
static struct clock_event_device __percpu *sirfsoc_clockevent;
static struct clocksource sirfsoc_clocksource = {
.name = "sirfsoc_clocksource",
.rating = 200,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.read = sirfsoc_timer_read,
.suspend = sirfsoc_clocksource_suspend,
.resume = sirfsoc_clocksource_resume,
};
static unsigned int sirfsoc_timer_irq, sirfsoc_timer1_irq;
static int sirfsoc_local_timer_starting_cpu(unsigned int cpu)
{
struct clock_event_device *ce = per_cpu_ptr(sirfsoc_clockevent, cpu);
unsigned int irq;
const char *name;
if (cpu == 0) {
irq = sirfsoc_timer_irq;
name = "sirfsoc_timer0";
} else {
irq = sirfsoc_timer1_irq;
name = "sirfsoc_timer1";
}
ce->irq = irq;
ce->name = "local_timer";
ce->features = CLOCK_EVT_FEAT_ONESHOT;
ce->rating = 200;
ce->set_state_shutdown = sirfsoc_timer_shutdown;
ce->set_state_oneshot = sirfsoc_timer_shutdown;
ce->tick_resume = sirfsoc_timer_shutdown;
ce->set_next_event = sirfsoc_timer_set_next_event;
clockevents_calc_mult_shift(ce, atlas7_timer_rate, 60);
ce->max_delta_ns = clockevent_delta2ns(-2, ce);
ce->max_delta_ticks = (unsigned long)-2;
ce->min_delta_ns = clockevent_delta2ns(2, ce);
ce->min_delta_ticks = 2;
ce->cpumask = cpumask_of(cpu);
BUG_ON(request_irq(ce->irq, sirfsoc_timer_interrupt,
IRQF_TIMER | IRQF_NOBALANCING, name, ce));
irq_force_affinity(ce->irq, cpumask_of(cpu));
clockevents_register_device(ce);
return 0;
}
static int sirfsoc_local_timer_dying_cpu(unsigned int cpu)
{
struct clock_event_device *ce = per_cpu_ptr(sirfsoc_clockevent, cpu);
sirfsoc_timer_count_disable(1);
if (cpu == 0)
free_irq(sirfsoc_timer_irq, ce);
else
free_irq(sirfsoc_timer1_irq, ce);
return 0;
}
static int __init sirfsoc_clockevent_init(void)
{
sirfsoc_clockevent = alloc_percpu(struct clock_event_device);
BUG_ON(!sirfsoc_clockevent);
/* Install and invoke hotplug callbacks */
return cpuhp_setup_state(CPUHP_AP_MARCO_TIMER_STARTING,
"clockevents/marco:starting",
sirfsoc_local_timer_starting_cpu,
sirfsoc_local_timer_dying_cpu);
}
/* initialize the kernel jiffy timer source */
static int __init sirfsoc_atlas7_timer_init(struct device_node *np)
{
struct clk *clk;
clk = of_clk_get(np, 0);
BUG_ON(IS_ERR(clk));
BUG_ON(clk_prepare_enable(clk));
atlas7_timer_rate = clk_get_rate(clk);
/* timer dividers: 0, not divided */
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_0_CTRL);
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_32COUNTER_1_CTRL);
/* Initialize timer counters to 0 */
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_LO);
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_LOAD_HI);
writel_relaxed(readl_relaxed(sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL) |
BIT(1) | BIT(0), sirfsoc_timer_base + SIRFSOC_TIMER_64COUNTER_CTRL);
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_0);
writel_relaxed(0, sirfsoc_timer_base + SIRFSOC_TIMER_COUNTER_1);
/* Clear all interrupts */
writel_relaxed(0xFFFF, sirfsoc_timer_base + SIRFSOC_TIMER_INTR_STATUS);
BUG_ON(clocksource_register_hz(&sirfsoc_clocksource, atlas7_timer_rate));
return sirfsoc_clockevent_init();
}
static int __init sirfsoc_of_timer_init(struct device_node *np)
{
sirfsoc_timer_base = of_iomap(np, 0);
if (!sirfsoc_timer_base) {
pr_err("unable to map timer cpu registers\n");
return -ENXIO;
}
sirfsoc_timer_irq = irq_of_parse_and_map(np, 0);
if (!sirfsoc_timer_irq) {
pr_err("No irq passed for timer0 via DT\n");
return -EINVAL;
}
sirfsoc_timer1_irq = irq_of_parse_and_map(np, 1);
if (!sirfsoc_timer1_irq) {
pr_err("No irq passed for timer1 via DT\n");
return -EINVAL;
}
return sirfsoc_atlas7_timer_init(np);
}
TIMER_OF_DECLARE(sirfsoc_atlas7_timer, "sirf,atlas7-tick", sirfsoc_of_timer_init);