| /* |
| * 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; |
| } |
| |
| u64 arch_timer_read_counter(void) |
| { |
| return arch_counter_get_cntvct(); |
| } |
| |
| static cycle_t arch_counter_read(struct clocksource *cs) |
| { |
| return arch_counter_get_cntvct(); |
| } |
| |
| static cycle_t arch_counter_read_cc(const struct cyclecounter *cc) |
| { |
| return arch_counter_get_cntvct(); |
| } |
| |
| 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) |
| { |
| /* |
| * Grab cpu pointer in each case to avoid spurious |
| * preemptible warnings |
| */ |
| switch (action & ~CPU_TASKS_FROZEN) { |
| case CPU_STARTING: |
| arch_timer_setup(this_cpu_ptr(arch_timer_evt)); |
| break; |
| case CPU_DYING: |
| arch_timer_stop(this_cpu_ptr(arch_timer_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_cntvct()); |
| |
| 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 void __init arch_timer_init(struct device_node *np) |
| { |
| u32 freq; |
| int i; |
| |
| if (arch_timer_get_rate()) { |
| pr_warn("arch_timer: multiple nodes in dt, skipping\n"); |
| return; |
| } |
| |
| /* 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; |
| } |
| } |
| |
| arch_timer_register(); |
| arch_timer_arch_init(); |
| } |
| CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init); |
| CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init); |