diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-05-04 12:04:11 +0100 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-05-04 12:04:11 +0100 |
commit | 5693188a6e888603afa9564974145e5e6e2c623c (patch) | |
tree | d092580bb003f34fb630d62916214a045ba078f1 | |
parent | e423c0c30c76fc850a443102a2965ec397ba6e21 (diff) | |
parent | fb8a99f9f6bdc908cbbd2284cee80c709d9f7c03 (diff) |
Merge branch 'timers-v3.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable
-rw-r--r-- | Documentation/devicetree/bindings/arm/arch_timer.txt | 27 | ||||
-rw-r--r-- | arch/arm/Kconfig | 6 | ||||
-rw-r--r-- | arch/arm/include/asm/arch_timer.h | 19 | ||||
-rw-r--r-- | arch/arm/kernel/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/kernel/arch_timer.c | 350 | ||||
-rw-r--r-- | arch/arm/kernel/smp.c | 3 | ||||
-rw-r--r-- | arch/arm/mach-vexpress/v2m.c | 8 |
7 files changed, 413 insertions, 1 deletions
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt new file mode 100644 index 000000000000..52478c83d0cc --- /dev/null +++ b/Documentation/devicetree/bindings/arm/arch_timer.txt @@ -0,0 +1,27 @@ +* ARM architected timer + +ARM Cortex-A7 and Cortex-A15 have a per-core architected timer, which +provides per-cpu timers. + +The timer is attached to a GIC to deliver its per-processor interrupts. + +** Timer node properties: + +- compatible : Should at least contain "arm,armv7-timer". + +- interrupts : Interrupt list for secure, non-secure, virtual and + hypervisor timers, in that order. + +- clock-frequency : The frequency of the main counter, in Hz. Optional. + +Example: + + timer { + compatible = "arm,cortex-a15-timer", + "arm,armv7-timer"; + interrupts = <1 13 0xf08>, + <1 14 0xf08>, + <1 11 0xf08>, + <1 10 0xf08>; + clock-frequency = <100000000>; + }; diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index cf006d40342c..4faabbade2e9 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1543,6 +1543,12 @@ config HAVE_ARM_SCU help This option enables support for the ARM system coherency unit +config ARM_ARCH_TIMER + bool "Architected timer support" + depends on CPU_V7 + help + This option enables support for the ARM architected timer + config HAVE_ARM_TWD bool depends on SMP diff --git a/arch/arm/include/asm/arch_timer.h b/arch/arm/include/asm/arch_timer.h new file mode 100644 index 000000000000..ed2e95d46e29 --- /dev/null +++ b/arch/arm/include/asm/arch_timer.h @@ -0,0 +1,19 @@ +#ifndef __ASMARM_ARCH_TIMER_H +#define __ASMARM_ARCH_TIMER_H + +#ifdef CONFIG_ARM_ARCH_TIMER +int arch_timer_of_register(void); +int arch_timer_sched_clock_init(void); +#else +static inline int arch_timer_of_register(void) +{ + return -ENXIO; +} + +static inline int arch_timer_sched_clock_init(void) +{ + return -ENXIO; +} +#endif + +#endif diff --git a/arch/arm/kernel/Makefile b/arch/arm/kernel/Makefile index 7b787d642af4..22b0f1e255f0 100644 --- a/arch/arm/kernel/Makefile +++ b/arch/arm/kernel/Makefile @@ -34,6 +34,7 @@ obj-$(CONFIG_ARM_CPU_SUSPEND) += sleep.o suspend.o obj-$(CONFIG_SMP) += smp.o smp_tlb.o obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o obj-$(CONFIG_HAVE_ARM_TWD) += smp_twd.o +obj-$(CONFIG_ARM_ARCH_TIMER) += arch_timer.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c new file mode 100644 index 000000000000..dd58035621f7 --- /dev/null +++ b/arch/arm/kernel/arch_timer.c @@ -0,0 +1,350 @@ +/* + * linux/arch/arm/kernel/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/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 <asm/cputype.h> +#include <asm/localtimer.h> +#include <asm/arch_timer.h> +#include <asm/system_info.h> +#include <asm/sched_clock.h> + +static unsigned long arch_timer_rate; +static int arch_timer_ppi; +static int arch_timer_ppi2; + +static struct clock_event_device __percpu **arch_timer_evt; + +/* + * Architected system timer support. + */ + +#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_FREQ 1 +#define ARCH_TIMER_REG_TVAL 2 + +static void arch_timer_reg_write(int reg, u32 val) +{ + switch (reg) { + case ARCH_TIMER_REG_CTRL: + asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val)); + break; + case ARCH_TIMER_REG_TVAL: + asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val)); + break; + } + + isb(); +} + +static u32 arch_timer_reg_read(int reg) +{ + u32 val; + + switch (reg) { + case ARCH_TIMER_REG_CTRL: + asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val)); + break; + case ARCH_TIMER_REG_FREQ: + asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val)); + break; + case ARCH_TIMER_REG_TVAL: + asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val)); + break; + default: + BUG(); + } + + return val; +} + +static irqreturn_t arch_timer_handler(int irq, void *dev_id) +{ + struct clock_event_device *evt = *(struct clock_event_device **)dev_id; + unsigned long ctrl; + + ctrl = arch_timer_reg_read(ARCH_TIMER_REG_CTRL); + if (ctrl & ARCH_TIMER_CTRL_IT_STAT) { + ctrl |= ARCH_TIMER_CTRL_IT_MASK; + arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl); + evt->event_handler(evt); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static void arch_timer_disable(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_disable(); + 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_IT_MASK; + + arch_timer_reg_write(ARCH_TIMER_REG_TVAL, evt); + arch_timer_reg_write(ARCH_TIMER_REG_CTRL, ctrl); + + return 0; +} + +static int __cpuinit arch_timer_setup(struct clock_event_device *clk) +{ + /* Be safe... */ + arch_timer_disable(); + + clk->features = CLOCK_EVT_FEAT_ONESHOT; + clk->name = "arch_sys_timer"; + clk->rating = 450; + clk->set_mode = arch_timer_set_mode; + clk->set_next_event = arch_timer_set_next_event; + clk->irq = arch_timer_ppi; + + clockevents_config_and_register(clk, arch_timer_rate, + 0xf, 0x7fffffff); + + *__this_cpu_ptr(arch_timer_evt) = clk; + + enable_percpu_irq(clk->irq, 0); + if (arch_timer_ppi2) + enable_percpu_irq(arch_timer_ppi2, 0); + + return 0; +} + +/* Is the optional system timer available? */ +static int local_timer_is_architected(void) +{ + return (cpu_architecture() >= CPU_ARCH_ARMv7) && + ((read_cpuid_ext(CPUID_EXT_PFR1) >> 16) & 0xf) == 1; +} + +static int arch_timer_available(void) +{ + unsigned long freq; + + if (!local_timer_is_architected()) + return -ENXIO; + + if (arch_timer_rate == 0) { + arch_timer_reg_write(ARCH_TIMER_REG_CTRL, 0); + freq = arch_timer_reg_read(ARCH_TIMER_REG_FREQ); + + /* 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.\n", + arch_timer_rate / 1000000, (arch_timer_rate / 10000) % 100); + return 0; +} + +static inline cycle_t arch_counter_get_cntpct(void) +{ + u32 cvall, cvalh; + + asm volatile("mrrc p15, 0, %0, %1, c14" : "=r" (cvall), "=r" (cvalh)); + + return ((cycle_t) cvalh << 32) | cvall; +} + +static inline cycle_t arch_counter_get_cntvct(void) +{ + u32 cvall, cvalh; + + asm volatile("mrrc p15, 1, %0, %1, c14" : "=r" (cvall), "=r" (cvalh)); + + return ((cycle_t) cvalh << 32) | cvall; +} + +static u32 notrace arch_counter_get_cntvct32(void) +{ + cycle_t cntvct = arch_counter_get_cntvct(); + + /* + * The sched_clock infrastructure only knows about counters + * with at most 32bits. Forget about the upper 24 bits for the + * time being... + */ + return (u32)(cntvct & (u32)~0); +} + +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, +}; + +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()); + disable_percpu_irq(clk->irq); + if (arch_timer_ppi2) + disable_percpu_irq(arch_timer_ppi2); + arch_timer_set_mode(CLOCK_EVT_MODE_UNUSED, clk); +} + +static struct local_timer_ops arch_timer_ops __cpuinitdata = { + .setup = arch_timer_setup, + .stop = arch_timer_stop, +}; + +static struct clock_event_device arch_timer_global_evt; + +static int __init arch_timer_register(void) +{ + int err; + + err = arch_timer_available(); + if (err) + return err; + + arch_timer_evt = alloc_percpu(struct clock_event_device *); + if (!arch_timer_evt) + return -ENOMEM; + + clocksource_register_hz(&clocksource_counter, arch_timer_rate); + + err = request_percpu_irq(arch_timer_ppi, arch_timer_handler, + "arch_timer", arch_timer_evt); + if (err) { + pr_err("arch_timer: can't register interrupt %d (%d)\n", + arch_timer_ppi, err); + goto out_free; + } + + if (arch_timer_ppi2) { + err = request_percpu_irq(arch_timer_ppi2, arch_timer_handler, + "arch_timer", arch_timer_evt); + if (err) { + pr_err("arch_timer: can't register interrupt %d (%d)\n", + arch_timer_ppi2, err); + arch_timer_ppi2 = 0; + goto out_free_irq; + } + } + + err = local_timer_register(&arch_timer_ops); + if (err) { + /* + * We couldn't register as a local timer (could be + * because we're on a UP platform, or because some + * other local timer is already present...). Try as a + * global timer instead. + */ + arch_timer_global_evt.cpumask = cpumask_of(0); + err = arch_timer_setup(&arch_timer_global_evt); + } + + if (err) + goto out_free_irq; + + return 0; + +out_free_irq: + free_percpu_irq(arch_timer_ppi, arch_timer_evt); + if (arch_timer_ppi2) + free_percpu_irq(arch_timer_ppi2, arch_timer_evt); + +out_free: + free_percpu(arch_timer_evt); + + 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; + + 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_ppi = irq_of_parse_and_map(np, 0); + arch_timer_ppi2 = irq_of_parse_and_map(np, 1); + pr_info("arch_timer: found %s irqs %d %d\n", + np->name, arch_timer_ppi, arch_timer_ppi2); + + return arch_timer_register(); +} + +int __init arch_timer_sched_clock_init(void) +{ + int err; + + err = arch_timer_available(); + if (err) + return err; + + setup_sched_clock(arch_counter_get_cntvct32, 32, arch_timer_rate); + return 0; +} diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index addbbe8028c2..11c4148b8abb 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -454,6 +454,9 @@ static struct local_timer_ops *lt_ops; #ifdef CONFIG_LOCAL_TIMERS int local_timer_register(struct local_timer_ops *ops) { + if (!is_smp() || !setup_max_cpus) + return -ENXIO; + if (lt_ops) return -EBUSY; diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c index 47cdcca5a7e7..04dd092211b8 100644 --- a/arch/arm/mach-vexpress/v2m.c +++ b/arch/arm/mach-vexpress/v2m.c @@ -19,8 +19,10 @@ #include <linux/clkdev.h> #include <linux/mtd/physmap.h> +#include <asm/arch_timer.h> #include <asm/mach-types.h> #include <asm/sizes.h> +#include <asm/smp_twd.h> #include <asm/mach/arch.h> #include <asm/mach/map.h> #include <asm/mach/time.h> @@ -616,7 +618,6 @@ void __init v2m_dt_init_early(void) } clkdev_add_table(v2m_dt_lookups, ARRAY_SIZE(v2m_dt_lookups)); - versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ, 24000000); } static struct of_device_id vexpress_irq_match[] __initdata = { @@ -643,6 +644,11 @@ static void __init v2m_dt_timer_init(void) return; node = of_find_node_by_path(path); v2m_sp804_init(of_iomap(node, 0), irq_of_parse_and_map(node, 0)); + if (arch_timer_of_register() != 0) + twd_local_timer_of_register(); + + if (arch_timer_sched_clock_init() != 0) + versatile_sched_clock_init(v2m_sysreg_base + V2M_SYS_24MHZ, 24000000); } static struct sys_timer v2m_dt_timer = { |