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authorLinus Torvalds <torvalds@linux-foundation.org>2013-02-21 15:40:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-02-21 15:40:16 -0800
commit8b5628ab83b671f96ac9f174c1bd51c92589fc82 (patch)
tree8446b0fce80923c3694fe075ffcde7e422bcf818 /drivers/clocksource
parenta8f3740feb12928be1aad19659bf3527ea8d6d96 (diff)
parentfe7dc7202d7d24fe211e0eecf531d8b79b655b3c (diff)
downloadop-kernel-dev-8b5628ab83b671f96ac9f174c1bd51c92589fc82.zip
op-kernel-dev-8b5628ab83b671f96ac9f174c1bd51c92589fc82.tar.gz
Merge tag 'virt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM virtualization changes: "This contains parts of the ARM KVM support that have dependencies on other patches merged through the arm-soc tree. In combination with patches coming through Russell's tree, this will finally add full support for the kernel based virtual machine on ARM, which has been awaited for some time now. Further, we now have a separate platform for virtual machines and qemu booting that is used by both Xen and KVM, separating these from the Versatile Express reference implementation. Obviously, this new platform is multiplatform capable so it can be combined with existing machines in the same kernel." * tag 'virt' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (38 commits) ARM: arch_timer: include linux/errno.h arm: arch_timer: add missing inline in stub function ARM: KVM: arch_timers: Wire the init code and config option ARM: KVM: arch_timers: Add timer world switch ARM: KVM: arch_timers: Add guest timer core support ARM: KVM: Add VGIC configuration option ARM: KVM: VGIC initialisation code ARM: KVM: VGIC control interface world switch ARM: KVM: VGIC interrupt injection ARM: KVM: vgic: retire queued, disabled interrupts ARM: KVM: VGIC virtual CPU interface management ARM: KVM: VGIC distributor handling ARM: KVM: VGIC accept vcpu and dist base addresses from user space ARM: KVM: Initial VGIC infrastructure code ARM: KVM: Keep track of currently running vcpus KVM: ARM: Introduce KVM_ARM_SET_DEVICE_ADDR ioctl ARM: gic: add __ASSEMBLY__ guard to C definitions ARM: gic: define GICH offsets for VGIC support ARM: gic: add missing distributor defintions ARM: mach-virt: fixup machine descriptor after removal of sys_timer ...
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/Kconfig6
-rw-r--r--drivers/clocksource/Makefile2
-rw-r--r--drivers/clocksource/arm_arch_timer.c391
-rw-r--r--drivers/clocksource/arm_generic.c232
4 files changed, 394 insertions, 237 deletions
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 7d978c1..e920cbe 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -60,7 +60,5 @@ config CLKSRC_DBX500_PRCMU_SCHED_CLOCK
help
Use the always on PRCMU Timer as sched_clock
-config CLKSRC_ARM_GENERIC
- def_bool y if ARM64
- help
- This option enables support for the ARM generic timer.
+config ARM_ARCH_TIMER
+ bool
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 596c45c..7d671b8 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -20,4 +20,4 @@ obj-$(CONFIG_SUNXI_TIMER) += sunxi_timer.o
obj-$(CONFIG_ARCH_TEGRA) += tegra20_timer.o
obj-$(CONFIG_VT8500_TIMER) += vt8500_timer.o
-obj-$(CONFIG_CLKSRC_ARM_GENERIC) += arm_generic.o
+obj-$(CONFIG_ARM_ARCH_TIMER) += arm_arch_timer.o
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
new file mode 100644
index 0000000..d7ad425
--- /dev/null
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -0,0 +1,391 @@
+/*
+ * 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 <asm/virt.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", },
+ { .compatible = "arm,armv8-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 HYP mode is available, we know that the physical timer
+ * has been configured to be accessible from PL1. Use it, so
+ * that a guest can use the virtual timer instead.
+ *
+ * If no interrupt provided for virtual timer, we'll have to
+ * stick to the physical timer. It'd better be accessible...
+ */
+ if (is_hyp_mode_available() || !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();
+}
diff --git a/drivers/clocksource/arm_generic.c b/drivers/clocksource/arm_generic.c
deleted file mode 100644
index 8ae1a61..0000000
--- a/drivers/clocksource/arm_generic.c
+++ /dev/null
@@ -1,232 +0,0 @@
-/*
- * Generic timers support
- *
- * Copyright (C) 2012 ARM Ltd.
- * Author: Marc Zyngier <marc.zyngier@arm.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 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/kernel.h>
-#include <linux/delay.h>
-#include <linux/device.h>
-#include <linux/smp.h>
-#include <linux/cpu.h>
-#include <linux/jiffies.h>
-#include <linux/interrupt.h>
-#include <linux/clockchips.h>
-#include <linux/of_irq.h>
-#include <linux/io.h>
-
-#include <clocksource/arm_generic.h>
-
-#include <asm/arm_generic.h>
-
-static u32 arch_timer_rate;
-static u64 sched_clock_mult __read_mostly;
-static DEFINE_PER_CPU(struct clock_event_device, arch_timer_evt);
-static int arch_timer_ppi;
-
-static irqreturn_t arch_timer_handle_irq(int irq, void *dev_id)
-{
- struct clock_event_device *evt = dev_id;
- unsigned long ctrl;
-
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- if (ctrl & ARCH_TIMER_CTRL_ISTATUS) {
- ctrl |= ARCH_TIMER_CTRL_IMASK;
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
- evt->event_handler(evt);
- return IRQ_HANDLED;
- }
-
- return IRQ_NONE;
-}
-
-static void arch_timer_stop(void)
-{
- unsigned long ctrl;
-
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- ctrl &= ~ARCH_TIMER_CTRL_ENABLE;
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-}
-
-static void arch_timer_set_mode(enum clock_event_mode mode,
- struct clock_event_device *clk)
-{
- switch (mode) {
- case CLOCK_EVT_MODE_UNUSED:
- case CLOCK_EVT_MODE_SHUTDOWN:
- arch_timer_stop();
- break;
- default:
- break;
- }
-}
-
-static int arch_timer_set_next_event(unsigned long evt,
- struct clock_event_device *unused)
-{
- unsigned long ctrl;
-
- ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL);
- ctrl |= ARCH_TIMER_CTRL_ENABLE;
- ctrl &= ~ARCH_TIMER_CTRL_IMASK;
-
- arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt);
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl);
-
- return 0;
-}
-
-static void __cpuinit arch_timer_setup(struct clock_event_device *clk)
-{
- /* Let's make sure the timer is off before doing anything else */
- arch_timer_stop();
-
- clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
- clk->name = "arch_sys_timer";
- clk->rating = 400;
- clk->set_mode = arch_timer_set_mode;
- clk->set_next_event = arch_timer_set_next_event;
- clk->irq = arch_timer_ppi;
- clk->cpumask = cpumask_of(smp_processor_id());
-
- clockevents_config_and_register(clk, arch_timer_rate,
- 0xf, 0x7fffffff);
-
- enable_percpu_irq(clk->irq, 0);
-
- /* Ensure the virtual counter is visible to userspace for the vDSO. */
- arch_counter_enable_user_access();
-}
-
-static void __init arch_timer_calibrate(void)
-{
- if (arch_timer_rate == 0) {
- arch_timer_reg_write(ARCH_TIMER_REG_CTRL, 0);
- arch_timer_rate = arch_timer_reg_read(ARCH_TIMER_REG_FREQ);
-
- /* Check the timer frequency. */
- if (arch_timer_rate == 0)
- panic("Architected timer frequency is set to zero.\n"
- "You must set this in your .dts file\n");
- }
-
- /* Cache the sched_clock multiplier to save a divide in the hot path. */
-
- sched_clock_mult = DIV_ROUND_CLOSEST(NSEC_PER_SEC, arch_timer_rate);
-
- pr_info("Architected local timer running at %u.%02uMHz.\n",
- arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100);
-}
-
-static cycle_t arch_counter_read(struct clocksource *cs)
-{
- return arch_counter_get_cntpct();
-}
-
-static struct clocksource clocksource_counter = {
- .name = "arch_sys_counter",
- .rating = 400,
- .read = arch_counter_read,
- .mask = CLOCKSOURCE_MASK(56),
- .flags = (CLOCK_SOURCE_IS_CONTINUOUS | CLOCK_SOURCE_VALID_FOR_HRES),
-};
-
-int read_current_timer(unsigned long *timer_value)
-{
- *timer_value = arch_counter_get_cntpct();
- return 0;
-}
-
-unsigned long long notrace sched_clock(void)
-{
- return arch_counter_get_cntvct() * sched_clock_mult;
-}
-
-static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- int cpu = (long)hcpu;
- struct clock_event_device *clk = per_cpu_ptr(&arch_timer_evt, cpu);
-
- switch(action) {
- case CPU_STARTING:
- case CPU_STARTING_FROZEN:
- arch_timer_setup(clk);
- break;
-
- case CPU_DYING:
- case CPU_DYING_FROZEN:
- pr_debug("arch_timer_teardown disable IRQ%d cpu #%d\n",
- clk->irq, cpu);
- disable_percpu_irq(clk->irq);
- arch_timer_set_mode(CLOCK_EVT_MODE_UNUSED, clk);
- break;
- }
-
- return NOTIFY_OK;
-}
-
-static struct notifier_block __cpuinitdata arch_timer_cpu_nb = {
- .notifier_call = arch_timer_cpu_notify,
-};
-
-static const struct of_device_id arch_timer_of_match[] __initconst = {
- { .compatible = "arm,armv8-timer" },
- {},
-};
-
-int __init arm_generic_timer_init(void)
-{
- struct device_node *np;
- int err;
- u32 freq;
-
- 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;
- arch_timer_calibrate();
-
- arch_timer_ppi = irq_of_parse_and_map(np, 0);
- pr_info("arch_timer: found %s irq %d\n", np->name, arch_timer_ppi);
-
- err = request_percpu_irq(arch_timer_ppi, arch_timer_handle_irq,
- np->name, &arch_timer_evt);
- if (err) {
- pr_err("arch_timer: can't register interrupt %d (%d)\n",
- arch_timer_ppi, err);
- return err;
- }
-
- clocksource_register_hz(&clocksource_counter, arch_timer_rate);
-
- /* Calibrate the delay loop directly */
- lpj_fine = DIV_ROUND_CLOSEST(arch_timer_rate, HZ);
-
- /* Immediately configure the timer on the boot CPU */
- arch_timer_setup(this_cpu_ptr(&arch_timer_evt));
-
- register_cpu_notifier(&arch_timer_cpu_nb);
-
- return 0;
-}
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