From 8a4da6e36c582ff746191eca85b6c1c068dbfbd6 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Mon, 12 Nov 2012 14:33:44 +0000 Subject: arm: arch_timer: move core to drivers/clocksource 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 Acked-by: Catalin Marinas Acked-by: Marc Zyngier diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 67874b8..e1162f5 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -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 diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h index 729f6d9..7ade91d 100644 --- a/arch/arm/include/asm/arch_timer.h +++ b/arch/arm/include/asm/arch_timer.h @@ -4,22 +4,14 @@ #include #include #include +#include #include +#include + #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 diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index 94f5033..36ebcf4 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -9,402 +9,52 @@ * published by the Free Software Foundation. */ #include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include +#include #include -#include #include -static u32 arch_timer_rate; +#include -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; } diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig index 41b581f..9d7909e 100644 --- a/arch/arm/mach-omap2/Kconfig +++ b/arch/arm/mach-omap2/Kconfig @@ -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 diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig index 7fdcbd3..dbb085a 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -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 diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index f93453d..32f858c 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -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 index 0000000..3e4739d --- /dev/null +++ b/drivers/clocksource/arm_arch_timer.c @@ -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 +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include + +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 index 0000000..b61f996 --- /dev/null +++ b/include/clocksource/arm_arch_timer.h @@ -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 . + */ +#ifndef __CLKSOURCE_ARM_ARCH_TIMER_H +#define __CLKSOURCE_ARM_ARCH_TIMER_H + +#include +#include + +#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 -- cgit v0.10.2