diff options
Diffstat (limited to 'drivers/clocksource/arm_generic.c')
-rw-r--r-- | drivers/clocksource/arm_generic.c | 232 |
1 files changed, 0 insertions, 232 deletions
diff --git a/drivers/clocksource/arm_generic.c b/drivers/clocksource/arm_generic.c deleted file mode 100644 index 8ae1a61523f..00000000000 --- 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; -} |