arm: arch_timer: move core to drivers/clocksource
authorMark Rutland <mark.rutland@arm.com>
Mon, 12 Nov 2012 14:33:44 +0000 (14:33 +0000)
committerMark Rutland <mark.rutland@arm.com>
Thu, 31 Jan 2013 15:51:49 +0000 (15:51 +0000)
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>
arch/arm/Kconfig
arch/arm/include/asm/arch_timer.h
arch/arm/kernel/arch_timer.c
arch/arm/mach-omap2/Kconfig
drivers/clocksource/Kconfig
drivers/clocksource/Makefile
drivers/clocksource/arm_arch_timer.c [new file with mode: 0644]
include/clocksource/arm_arch_timer.h [new file with mode: 0644]

index 67874b82a4edf318ae3718ae6137393140405586..e1162f52f2b53c286024ef230340c5095ea174c3 100644 (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
 
index 729f6d98df86a6259fafaeb62792646097c3c028..7ade91d8cc6fa4d723016e1e538e16881092f33c 100644 (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
index 94f503394c5c8eac551234858ced13fd1a2e30c1..36ebcf4b516f291be14c7943764a41728a12c912 100644 (file)
  * 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 int arch_timer_ppi[MAX_TIMER_PPI];
-
-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)
-{
-       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)
+static unsigned long arch_timer_read_counter_long(void)
 {
        return arch_timer_read_counter();
 }
 
-static unsigned long arch_timer_read_current_timer(void)
+static u32 arch_timer_read_counter_u32(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 struct delay_timer arch_delay_timer;
 
-static int __init arch_timer_register(void)
+static void __init arch_timer_delay_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;
-
-       np = of_find_matching_node(NULL, arch_timer_of_match);
-       if (!np) {
-               pr_err("arch_timer: can't find DT node\n");
-               return -ENODEV;
-       }
+       int 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;
+       ret = arch_timer_init();
+       if (ret)
+               return ret;
 
-       for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
-               arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
+       arch_timer_delay_timer_register();
 
-       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;
-
-       err = arch_timer_available();
-       if (err)
-               return err;
+       if (arch_timer_get_rate() == 0)
+               return -ENXIO;
 
-       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;
 }
index 41b581fd0213e6a636c921d531463f6979e4af17..9d7909e589806c8d09f8d1679493299cff2ec038 100644 (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
index 7fdcbd3f4da5a7756f2f1fb01a467a11b107092b..dbb085ac64d472ec9d43129c92a871ab47489229 100644 (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
index f93453d0167305d7633495661a5f92d7720aa32a..32f858c8eecc6b90b76389c3922caf0be554805a 100644 (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
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
new file mode 100644 (file)
index 0000000..3e4739d
--- /dev/null
@@ -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();
+}
diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h
new file mode 100644 (file)
index 0000000..b61f996
--- /dev/null
@@ -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