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arm: arch_timer: move core to drivers/clocksource

Browse Source 
The core functionality of the arch_timer driver is not directly tied to
anything under arch/arm, and can be split out.

This patch factors out the core of the arch_timer driver, so it can be
shared with other architectures. A couple of functions are added so
that architecture-specific code can interact with the driver without
needing to touch its internals.

The ARM_ARCH_TIMER config variable is moved out to
drivers/clocksource/Kconfig, existing uses in arch/arm are replaced with
HAVE_ARM_ARCH_TIMER, which selects it.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Mark Rutland 2012-11-12 14:33:44 +00:00
parent b2deabe3ba
commit 8a4da6e36c
8 changed files with 481 additions and 391 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/arm/Kconfig
View File

@ -1572,9 +1572,10 @@ config HAVE_ARM_SCU
help
This option enables support for the ARM system coherency unit
config ARM_ARCH_TIMER
config HAVE_ARM_ARCH_TIMER
bool "Architected timer support"
depends on CPU_V7
select ARM_ARCH_TIMER
help
This option enables support for the ARM architected timer

19
arch/arm/include/asm/arch_timer.h
View File

@ -4,22 +4,14 @@
#include <asm/barrier.h>
#include <asm/errno.h>
#include <linux/clocksource.h>
#include <linux/init.h>
#include <linux/types.h>
#include <clocksource/arm_arch_timer.h>
#ifdef CONFIG_ARM_ARCH_TIMER
int arch_timer_of_register(void);
int arch_timer_sched_clock_init(void);
struct timecounter *arch_timer_get_timecounter(void);
#define ARCH_TIMER_CTRL_ENABLE (1 << 0)
#define ARCH_TIMER_CTRL_IT_MASK (1 << 1)
#define ARCH_TIMER_CTRL_IT_STAT (1 << 2)
#define ARCH_TIMER_REG_CTRL 0
#define ARCH_TIMER_REG_TVAL 1
#define ARCH_TIMER_PHYS_ACCESS 0
#define ARCH_TIMER_VIRT_ACCESS 1
/*
* These register accessors are marked inline so the compiler can
@ -128,11 +120,6 @@ static inline int arch_timer_sched_clock_init(void)
{
return -ENXIO;
}
static inline struct timecounter *arch_timer_get_timecounter(void)
{
return NULL;
}
#endif
#endif

396
arch/arm/kernel/arch_timer.c
View File

@ -9,402 +9,52 @@
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/jiffies.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <linux/types.h>
#include <asm/delay.h>
#include <asm/arch_timer.h>
#include <asm/sched_clock.h>
static u32 arch_timer_rate;
#include <clocksource/arm_arch_timer.h>
enum ppi_nr {
PHYS_SECURE_PPI,
PHYS_NONSECURE_PPI,
VIRT_PPI,
HYP_PPI,
MAX_TIMER_PPI
};
static unsigned long arch_timer_read_counter_long(void)
{
return arch_timer_read_counter();
}
static int arch_timer_ppi[MAX_TIMER_PPI];
static u32 arch_timer_read_counter_u32(void)
{
return arch_timer_read_counter();
}
static struct clock_event_device __percpu *arch_timer_evt;
static struct delay_timer arch_delay_timer;
static bool arch_timer_use_virtual = true;
/*
* Architected system timer support.
*/
static irqreturn_t inline timer_handler(const int access,
struct clock_event_device *evt)
static void __init arch_timer_delay_timer_register(void)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
ctrl |= ARCH_TIMER_CTRL_IT_MASK;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
evt->event_handler(evt);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
}
static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
}
static inline void timer_set_mode(const int access, int mode)
{
unsigned long ctrl;
switch (mode) {
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
break;
default:
break;
}
}
static void arch_timer_set_mode_virt(enum clock_event_mode mode,
struct clock_event_device *clk)
{
timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
}
static void arch_timer_set_mode_phys(enum clock_event_mode mode,
struct clock_event_device *clk)
{
timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
}
static inline void set_next_event(const int access, unsigned long evt)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
ctrl |= ARCH_TIMER_CTRL_ENABLE;
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
}
static int arch_timer_set_next_event_virt(unsigned long evt,
struct clock_event_device *unused)
{
set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
return 0;
}
static int arch_timer_set_next_event_phys(unsigned long evt,
struct clock_event_device *unused)
{
set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
return 0;
}
static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
{
clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
clk->name = "arch_sys_timer";
clk->rating = 450;
if (arch_timer_use_virtual) {
clk->irq = arch_timer_ppi[VIRT_PPI];
clk->set_mode = arch_timer_set_mode_virt;
clk->set_next_event = arch_timer_set_next_event_virt;
} else {
clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
clk->set_mode = arch_timer_set_mode_phys;
clk->set_next_event = arch_timer_set_next_event_phys;
}
clk->cpumask = cpumask_of(smp_processor_id());
clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
clockevents_config_and_register(clk, arch_timer_rate,
0xf, 0x7fffffff);
if (arch_timer_use_virtual)
enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
else {
enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
if (arch_timer_ppi[PHYS_NONSECURE_PPI])
enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
}
arch_counter_set_user_access();
return 0;
}
static int arch_timer_available(void)
{
u32 freq;
if (arch_timer_rate == 0) {
freq = arch_timer_get_cntfrq();
/* Check the timer frequency. */
if (freq == 0) {
pr_warn("Architected timer frequency not available\n");
return -EINVAL;
}
arch_timer_rate = freq;
}
pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
(unsigned long)arch_timer_rate / 1000000,
(unsigned long)(arch_timer_rate / 10000) % 100,
arch_timer_use_virtual ? "virt" : "phys");
return 0;
}
/*
* Some external users of arch_timer_read_counter (e.g. sched_clock) may try to
* call it before it has been initialised. Rather than incur a performance
* penalty checking for initialisation, provide a default implementation that
* won't lead to time appearing to jump backwards.
*/
static u64 arch_timer_read_zero(void)
{
return 0;
}
u64 (*arch_timer_read_counter)(void) = arch_timer_read_zero;
static u32 arch_timer_read_counter32(void)
{
return arch_timer_read_counter();
}
static cycle_t arch_counter_read(struct clocksource *cs)
{
return arch_timer_read_counter();
}
static unsigned long arch_timer_read_current_timer(void)
{
return arch_timer_read_counter();
}
static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
{
return arch_timer_read_counter();
}
static struct clocksource clocksource_counter = {
.name = "arch_sys_counter",
.rating = 400,
.read = arch_counter_read,
.mask = CLOCKSOURCE_MASK(56),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct cyclecounter cyclecounter = {
.read = arch_counter_read_cc,
.mask = CLOCKSOURCE_MASK(56),
};
static struct timecounter timecounter;
struct timecounter *arch_timer_get_timecounter(void)
{
return &timecounter;
}
static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
{
pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
clk->irq, smp_processor_id());
if (arch_timer_use_virtual)
disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
else {
disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
if (arch_timer_ppi[PHYS_NONSECURE_PPI])
disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
}
clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
}
static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_STARTING:
arch_timer_setup(evt);
break;
case CPU_DYING:
arch_timer_stop(evt);
break;
}
return NOTIFY_OK;
}
static struct notifier_block arch_timer_cpu_nb __cpuinitdata = {
.notifier_call = arch_timer_cpu_notify,
};
static int __init arch_timer_register(void)
{
int err;
int ppi;
err = arch_timer_available();
if (err)
goto out;
arch_timer_evt = alloc_percpu(struct clock_event_device);
if (!arch_timer_evt) {
err = -ENOMEM;
goto out;
}
clocksource_register_hz(&clocksource_counter, arch_timer_rate);
cyclecounter.mult = clocksource_counter.mult;
cyclecounter.shift = clocksource_counter.shift;
timecounter_init(&timecounter, &cyclecounter,
arch_counter_get_cntpct());
if (arch_timer_use_virtual) {
ppi = arch_timer_ppi[VIRT_PPI];
err = request_percpu_irq(ppi, arch_timer_handler_virt,
"arch_timer", arch_timer_evt);
} else {
ppi = arch_timer_ppi[PHYS_SECURE_PPI];
err = request_percpu_irq(ppi, arch_timer_handler_phys,
"arch_timer", arch_timer_evt);
if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
err = request_percpu_irq(ppi, arch_timer_handler_phys,
"arch_timer", arch_timer_evt);
if (err)
free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
arch_timer_evt);
}
}
if (err) {
pr_err("arch_timer: can't register interrupt %d (%d)\n",
ppi, err);
goto out_free;
}
err = register_cpu_notifier(&arch_timer_cpu_nb);
if (err)
goto out_free_irq;
/* Immediately configure the timer on the boot CPU */
arch_timer_setup(this_cpu_ptr(arch_timer_evt));
/* Use the architected timer for the delay loop. */
arch_delay_timer.read_current_timer = &arch_timer_read_current_timer;
arch_delay_timer.freq = arch_timer_rate;
arch_delay_timer.read_current_timer = arch_timer_read_counter_long;
arch_delay_timer.freq = arch_timer_get_rate();
register_current_timer_delay(&arch_delay_timer);
return 0;
out_free_irq:
if (arch_timer_use_virtual)
free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
else {
free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
arch_timer_evt);
if (arch_timer_ppi[PHYS_NONSECURE_PPI])
free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
arch_timer_evt);
}
out_free:
free_percpu(arch_timer_evt);
out:
return err;
}
static const struct of_device_id arch_timer_of_match[] __initconst = {
{ .compatible = "arm,armv7-timer", },
{},
};
int __init arch_timer_of_register(void)
{
struct device_node *np;
u32 freq;
int i;
int ret;
np = of_find_matching_node(NULL, arch_timer_of_match);
if (!np) {
pr_err("arch_timer: can't find DT node\n");
return -ENODEV;
}
ret = arch_timer_init();
if (ret)
return ret;
/* Try to determine the frequency from the device tree or CNTFRQ */
if (!of_property_read_u32(np, "clock-frequency", &freq))
arch_timer_rate = freq;
arch_timer_delay_timer_register();
for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
of_node_put(np);
/*
* If no interrupt provided for virtual timer, we'll have to
* stick to the physical timer. It'd better be accessible...
*/
if (!arch_timer_ppi[VIRT_PPI]) {
arch_timer_use_virtual = false;
if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
!arch_timer_ppi[PHYS_NONSECURE_PPI]) {
pr_warn("arch_timer: No interrupt available, giving up\n");
return -EINVAL;
}
}
if (arch_timer_use_virtual)
arch_timer_read_counter = arch_counter_get_cntvct;
else
arch_timer_read_counter = arch_counter_get_cntpct;
return arch_timer_register();
return 0;
}
int __init arch_timer_sched_clock_init(void)
{
int err;
if (arch_timer_get_rate() == 0)
return -ENXIO;
err = arch_timer_available();
if (err)
return err;
setup_sched_clock(arch_timer_read_counter32,
32, arch_timer_rate);
setup_sched_clock(arch_timer_read_counter_u32,
32, arch_timer_get_rate());
return 0;
}

2
arch/arm/mach-omap2/Kconfig
View File

@ -76,12 +76,12 @@ config ARCH_OMAP4
config SOC_OMAP5
bool "TI OMAP5"
select ARM_ARCH_TIMER
select ARM_CPU_SUSPEND if PM
select ARM_GIC
select CPU_V7
select HAVE_SMP
select COMMON_CLK
select HAVE_ARM_ARCH_TIMER
comment "OMAP Core Type"
depends on ARCH_OMAP2

3
drivers/clocksource/Kconfig
View File

@ -58,3 +58,6 @@ config CLKSRC_ARM_GENERIC
def_bool y if ARM64
help
This option enables support for the ARM generic timer.
config ARM_ARCH_TIMER
bool

1
drivers/clocksource/Makefile
View File

@ -18,3 +18,4 @@ obj-$(CONFIG_ARCH_BCM2835) += bcm2835_timer.o
obj-$(CONFIG_SUNXI_TIMER) += sunxi_timer.o
obj-$(CONFIG_CLKSRC_ARM_GENERIC) += arm_generic.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o

385
drivers/clocksource/arm_arch_timer.c Normal file
View File

@ -0,0 +1,385 @@
/*
* linux/drivers/clocksource/arm_arch_timer.c
*
* Copyright (C) 2011 ARM Ltd.
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <linux/clockchips.h>
#include <linux/interrupt.h>
#include <linux/of_irq.h>
#include <linux/io.h>
#include <asm/arch_timer.h>
#include <clocksource/arm_arch_timer.h>
static u32 arch_timer_rate;
enum ppi_nr {
PHYS_SECURE_PPI,
PHYS_NONSECURE_PPI,
VIRT_PPI,
HYP_PPI,
MAX_TIMER_PPI
};
static int arch_timer_ppi[MAX_TIMER_PPI];
static struct clock_event_device __percpu *arch_timer_evt;
static bool arch_timer_use_virtual = true;
/*
* Architected system timer support.
*/
static inline irqreturn_t timer_handler(const int access,
struct clock_event_device *evt)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
if (ctrl & ARCH_TIMER_CTRL_IT_STAT) {
ctrl |= ARCH_TIMER_CTRL_IT_MASK;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
evt->event_handler(evt);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static irqreturn_t arch_timer_handler_virt(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_VIRT_ACCESS, evt);
}
static irqreturn_t arch_timer_handler_phys(int irq, void *dev_id)
{
struct clock_event_device *evt = dev_id;
return timer_handler(ARCH_TIMER_PHYS_ACCESS, evt);
}
static inline void timer_set_mode(const int access, int mode)
{
unsigned long ctrl;
switch (mode) {
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
break;
default:
break;
}
}
static void arch_timer_set_mode_virt(enum clock_event_mode mode,
struct clock_event_device *clk)
{
timer_set_mode(ARCH_TIMER_VIRT_ACCESS, mode);
}
static void arch_timer_set_mode_phys(enum clock_event_mode mode,
struct clock_event_device *clk)
{
timer_set_mode(ARCH_TIMER_PHYS_ACCESS, mode);
}
static inline void set_next_event(const int access, unsigned long evt)
{
unsigned long ctrl;
ctrl = arch_timer_reg_read(access, ARCH_TIMER_REG_CTRL);
ctrl |= ARCH_TIMER_CTRL_ENABLE;
ctrl &= ~ARCH_TIMER_CTRL_IT_MASK;
arch_timer_reg_write(access, ARCH_TIMER_REG_TVAL, evt);
arch_timer_reg_write(access, ARCH_TIMER_REG_CTRL, ctrl);
}
static int arch_timer_set_next_event_virt(unsigned long evt,
struct clock_event_device *unused)
{
set_next_event(ARCH_TIMER_VIRT_ACCESS, evt);
return 0;
}
static int arch_timer_set_next_event_phys(unsigned long evt,
struct clock_event_device *unused)
{
set_next_event(ARCH_TIMER_PHYS_ACCESS, evt);
return 0;
}
static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
{
clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
clk->name = "arch_sys_timer";
clk->rating = 450;
if (arch_timer_use_virtual) {
clk->irq = arch_timer_ppi[VIRT_PPI];
clk->set_mode = arch_timer_set_mode_virt;
clk->set_next_event = arch_timer_set_next_event_virt;
} else {
clk->irq = arch_timer_ppi[PHYS_SECURE_PPI];
clk->set_mode = arch_timer_set_mode_phys;
clk->set_next_event = arch_timer_set_next_event_phys;
}
clk->cpumask = cpumask_of(smp_processor_id());
clk->set_mode(CLOCK_EVT_MODE_SHUTDOWN, NULL);
clockevents_config_and_register(clk, arch_timer_rate,
0xf, 0x7fffffff);
if (arch_timer_use_virtual)
enable_percpu_irq(arch_timer_ppi[VIRT_PPI], 0);
else {
enable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI], 0);
if (arch_timer_ppi[PHYS_NONSECURE_PPI])
enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
}
arch_counter_set_user_access();
return 0;
}
static int arch_timer_available(void)
{
u32 freq;
if (arch_timer_rate == 0) {
freq = arch_timer_get_cntfrq();
/* Check the timer frequency. */
if (freq == 0) {
pr_warn("Architected timer frequency not available\n");
return -EINVAL;
}
arch_timer_rate = freq;
}
pr_info_once("Architected local timer running at %lu.%02luMHz (%s).\n",
(unsigned long)arch_timer_rate / 1000000,
(unsigned long)(arch_timer_rate / 10000) % 100,
arch_timer_use_virtual ? "virt" : "phys");
return 0;
}
u32 arch_timer_get_rate(void)
{
return arch_timer_rate;
}
/*
* Some external users of arch_timer_read_counter (e.g. sched_clock) may try to
* call it before it has been initialised. Rather than incur a performance
* penalty checking for initialisation, provide a default implementation that
* won't lead to time appearing to jump backwards.
*/
static u64 arch_timer_read_zero(void)
{
return 0;
}
u64 (*arch_timer_read_counter)(void) = arch_timer_read_zero;
static cycle_t arch_counter_read(struct clocksource *cs)
{
return arch_timer_read_counter();
}
static cycle_t arch_counter_read_cc(const struct cyclecounter *cc)
{
return arch_timer_read_counter();
}
static struct clocksource clocksource_counter = {
.name = "arch_sys_counter",
.rating = 400,
.read = arch_counter_read,
.mask = CLOCKSOURCE_MASK(56),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static struct cyclecounter cyclecounter = {
.read = arch_counter_read_cc,
.mask = CLOCKSOURCE_MASK(56),
};
static struct timecounter timecounter;
struct timecounter *arch_timer_get_timecounter(void)
{
return &timecounter;
}
static void __cpuinit arch_timer_stop(struct clock_event_device *clk)
{
pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
clk->irq, smp_processor_id());
if (arch_timer_use_virtual)
disable_percpu_irq(arch_timer_ppi[VIRT_PPI]);
else {
disable_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI]);
if (arch_timer_ppi[PHYS_NONSECURE_PPI])
disable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI]);
}
clk->set_mode(CLOCK_EVT_MODE_UNUSED, clk);
}
static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt);
switch (action & ~CPU_TASKS_FROZEN) {
case CPU_STARTING:
arch_timer_setup(evt);
break;
case CPU_DYING:
arch_timer_stop(evt);
break;
}
return NOTIFY_OK;
}
static struct notifier_block arch_timer_cpu_nb __cpuinitdata = {
.notifier_call = arch_timer_cpu_notify,
};
static int __init arch_timer_register(void)
{
int err;
int ppi;
err = arch_timer_available();
if (err)
goto out;
arch_timer_evt = alloc_percpu(struct clock_event_device);
if (!arch_timer_evt) {
err = -ENOMEM;
goto out;
}
clocksource_register_hz(&clocksource_counter, arch_timer_rate);
cyclecounter.mult = clocksource_counter.mult;
cyclecounter.shift = clocksource_counter.shift;
timecounter_init(&timecounter, &cyclecounter,
arch_counter_get_cntpct());
if (arch_timer_use_virtual) {
ppi = arch_timer_ppi[VIRT_PPI];
err = request_percpu_irq(ppi, arch_timer_handler_virt,
"arch_timer", arch_timer_evt);
} else {
ppi = arch_timer_ppi[PHYS_SECURE_PPI];
err = request_percpu_irq(ppi, arch_timer_handler_phys,
"arch_timer", arch_timer_evt);
if (!err && arch_timer_ppi[PHYS_NONSECURE_PPI]) {
ppi = arch_timer_ppi[PHYS_NONSECURE_PPI];
err = request_percpu_irq(ppi, arch_timer_handler_phys,
"arch_timer", arch_timer_evt);
if (err)
free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
arch_timer_evt);
}
}
if (err) {
pr_err("arch_timer: can't register interrupt %d (%d)\n",
ppi, err);
goto out_free;
}
err = register_cpu_notifier(&arch_timer_cpu_nb);
if (err)
goto out_free_irq;
/* Immediately configure the timer on the boot CPU */
arch_timer_setup(this_cpu_ptr(arch_timer_evt));
return 0;
out_free_irq:
if (arch_timer_use_virtual)
free_percpu_irq(arch_timer_ppi[VIRT_PPI], arch_timer_evt);
else {
free_percpu_irq(arch_timer_ppi[PHYS_SECURE_PPI],
arch_timer_evt);
if (arch_timer_ppi[PHYS_NONSECURE_PPI])
free_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI],
arch_timer_evt);
}
out_free:
free_percpu(arch_timer_evt);
out:
return err;
}
static const struct of_device_id arch_timer_of_match[] __initconst = {
{ .compatible = "arm,armv7-timer", },
{},
};
int __init arch_timer_init(void)
{
struct device_node *np;
u32 freq;
int i;
np = of_find_matching_node(NULL, arch_timer_of_match);
if (!np) {
pr_err("arch_timer: can't find DT node\n");
return -ENODEV;
}
/* Try to determine the frequency from the device tree or CNTFRQ */
if (!of_property_read_u32(np, "clock-frequency", &freq))
arch_timer_rate = freq;
for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
of_node_put(np);
/*
* If no interrupt provided for virtual timer, we'll have to
* stick to the physical timer. It'd better be accessible...
*/
if (!arch_timer_ppi[VIRT_PPI]) {
arch_timer_use_virtual = false;
if (!arch_timer_ppi[PHYS_SECURE_PPI] ||
!arch_timer_ppi[PHYS_NONSECURE_PPI]) {
pr_warn("arch_timer: No interrupt available, giving up\n");
return -EINVAL;
}
}
if (arch_timer_use_virtual)
arch_timer_read_counter = arch_counter_get_cntvct;
else
arch_timer_read_counter = arch_counter_get_cntpct;
return arch_timer_register();
}

63
include/clocksource/arm_arch_timer.h Normal file
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@ -0,0 +1,63 @@
/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 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/>.
*/
#ifndef __CLKSOURCE_ARM_ARCH_TIMER_H
#define __CLKSOURCE_ARM_ARCH_TIMER_H
#include <linux/clocksource.h>
#include <linux/types.h>
#define ARCH_TIMER_CTRL_ENABLE (1 << 0)
#define ARCH_TIMER_CTRL_IT_MASK (1 << 1)
#define ARCH_TIMER_CTRL_IT_STAT (1 << 2)
#define ARCH_TIMER_REG_CTRL 0
#define ARCH_TIMER_REG_TVAL 1
#define ARCH_TIMER_PHYS_ACCESS 0
#define ARCH_TIMER_VIRT_ACCESS 1
#ifdef CONFIG_ARM_ARCH_TIMER
extern int arch_timer_init(void);
extern u32 arch_timer_get_rate(void);
extern u64 (*arch_timer_read_counter)(void);
extern struct timecounter *arch_timer_get_timecounter(void);
#else
static inline int arch_timer_init(void)
{
return -ENXIO;
}
static inline u32 arch_timer_get_rate(void)
{
return 0;
}
static inline u64 arch_timer_read_counter(void)
{
return 0;
}
static struct timecounter *arch_timer_get_timecounter(void)
{
return NULL;
}
#endif
#endif