linux/drivers/clocksource/timer-atlas7.c
Linus Torvalds 3ddc76dfc7 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer type cleanups from Thomas Gleixner:
 "This series does a tree wide cleanup of types related to
  timers/timekeeping.

   - Get rid of cycles_t and use a plain u64. The type is not really
     helpful and caused more confusion than clarity

   - Get rid of the ktime union. The union has become useless as we use
     the scalar nanoseconds storage unconditionally now. The 32bit
     timespec alike storage got removed due to the Y2038 limitations
     some time ago.

     That leaves the odd union access around for no reason. Clean it up.

  Both changes have been done with coccinelle and a small amount of
  manual mopping up"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  ktime: Get rid of ktime_equal()
  ktime: Cleanup ktime_set() usage
  ktime: Get rid of the union
  clocksource: Use a plain u64 instead of cycle_t
2016-12-25 14:30:04 -08:00

285 lines
8.3 KiB
C

/*
* System timer for CSR SiRFprimaII
*
* Copyright (c) 2011 Cambridge Silicon Radio Limited, a CSR plc group company.
*
* Licensed under GPLv2 or later.
*/
#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 struct irqaction sirfsoc_timer_irq = {
.name = "sirfsoc_timer0",
.flags = IRQF_TIMER | IRQF_NOBALANCING,
.handler = sirfsoc_timer_interrupt,
};
static struct irqaction sirfsoc_timer1_irq = {
.name = "sirfsoc_timer1",
.flags = IRQF_TIMER | IRQF_NOBALANCING,
.handler = sirfsoc_timer_interrupt,
};
static int sirfsoc_local_timer_starting_cpu(unsigned int cpu)
{
struct clock_event_device *ce = per_cpu_ptr(sirfsoc_clockevent, cpu);
struct irqaction *action;
if (cpu == 0)
action = &sirfsoc_timer_irq;
else
action = &sirfsoc_timer1_irq;
ce->irq = action->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->min_delta_ns = clockevent_delta2ns(2, ce);
ce->cpumask = cpumask_of(cpu);
action->dev_id = ce;
BUG_ON(setup_irq(ce->irq, action));
irq_force_affinity(action->irq, cpumask_of(cpu));
clockevents_register_device(ce);
return 0;
}
static int sirfsoc_local_timer_dying_cpu(unsigned int cpu)
{
sirfsoc_timer_count_disable(1);
if (cpu == 0)
remove_irq(sirfsoc_timer_irq.irq, &sirfsoc_timer_irq);
else
remove_irq(sirfsoc_timer1_irq.irq, &sirfsoc_timer1_irq);
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 = irq_of_parse_and_map(np, 0);
if (!sirfsoc_timer_irq.irq) {
pr_err("No irq passed for timer0 via DT\n");
return -EINVAL;
}
sirfsoc_timer1_irq.irq = irq_of_parse_and_map(np, 1);
if (!sirfsoc_timer1_irq.irq) {
pr_err("No irq passed for timer1 via DT\n");
return -EINVAL;
}
return sirfsoc_atlas7_timer_init(np);
}
CLOCKSOURCE_OF_DECLARE(sirfsoc_atlas7_timer, "sirf,atlas7-tick", sirfsoc_of_timer_init);