--- /dev/null
+/* linux/include/linux/clockchips.h
+ *
+ * This file contains the structure definitions for clockchips.
+ *
+ * If you are not a clockchip, or the time of day code, you should
+ * not be including this file!
+ */
+#ifndef _LINUX_CLOCKCHIPS_H
+#define _LINUX_CLOCKCHIPS_H
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+
+#include <linux/clocksource.h>
+#include <linux/cpumask.h>
+#include <linux/ktime.h>
+#include <linux/notifier.h>
+
+struct clock_event_device;
+
+/* Clock event mode commands */
+enum clock_event_mode {
+ CLOCK_EVT_MODE_UNUSED = 0,
+ CLOCK_EVT_MODE_SHUTDOWN,
+ CLOCK_EVT_MODE_PERIODIC,
+ CLOCK_EVT_MODE_ONESHOT,
+};
+
+/* Clock event notification values */
+enum clock_event_nofitiers {
+ CLOCK_EVT_NOTIFY_ADD,
+ CLOCK_EVT_NOTIFY_BROADCAST_ON,
+ CLOCK_EVT_NOTIFY_BROADCAST_OFF,
+ CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
+ CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
+ CLOCK_EVT_NOTIFY_SUSPEND,
+ CLOCK_EVT_NOTIFY_RESUME,
+ CLOCK_EVT_NOTIFY_CPU_DEAD,
+};
+
+/*
+ * Clock event features
+ */
+#define CLOCK_EVT_FEAT_PERIODIC 0x000001
+#define CLOCK_EVT_FEAT_ONESHOT 0x000002
+/*
+ * x86(64) specific misfeatures:
+ *
+ * - Clockevent source stops in C3 State and needs broadcast support.
+ * - Local APIC timer is used as a dummy device.
+ */
+#define CLOCK_EVT_FEAT_C3STOP 0x000004
+#define CLOCK_EVT_FEAT_DUMMY 0x000008
+
+/**
+ * struct clock_event_device - clock event device descriptor
+ * @name: ptr to clock event name
+ * @hints: usage hints
+ * @max_delta_ns: maximum delta value in ns
+ * @min_delta_ns: minimum delta value in ns
+ * @mult: nanosecond to cycles multiplier
+ * @shift: nanoseconds to cycles divisor (power of two)
+ * @rating: variable to rate clock event devices
+ * @irq: irq number (only for non cpu local devices)
+ * @cpumask: cpumask to indicate for which cpus this device works
+ * @set_next_event: set next event
+ * @set_mode: set mode function
+ * @evthandler: Assigned by the framework to be called by the low
+ * level handler of the event source
+ * @broadcast: function to broadcast events
+ * @list: list head for the management code
+ * @mode: operating mode assigned by the management code
+ * @next_event: local storage for the next event in oneshot mode
+ */
+struct clock_event_device {
+ const char *name;
+ unsigned int features;
+ unsigned long max_delta_ns;
+ unsigned long min_delta_ns;
+ unsigned long mult;
+ int shift;
+ int rating;
+ int irq;
+ cpumask_t cpumask;
+ int (*set_next_event)(unsigned long evt,
+ struct clock_event_device *);
+ void (*set_mode)(enum clock_event_mode mode,
+ struct clock_event_device *);
+ void (*event_handler)(struct clock_event_device *);
+ void (*broadcast)(cpumask_t mask);
+ struct list_head list;
+ enum clock_event_mode mode;
+ ktime_t next_event;
+};
+
+/*
+ * Calculate a multiplication factor for scaled math, which is used to convert
+ * nanoseconds based values to clock ticks:
+ *
+ * clock_ticks = (nanoseconds * factor) >> shift.
+ *
+ * div_sc is the rearranged equation to calculate a factor from a given clock
+ * ticks / nanoseconds ratio:
+ *
+ * factor = (clock_ticks << shift) / nanoseconds
+ */
+static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
+ int shift)
+{
+ uint64_t tmp = ((uint64_t)ticks) << shift;
+
+ do_div(tmp, nsec);
+ return (unsigned long) tmp;
+}
+
+/* Clock event layer functions */
+extern unsigned long clockevent_delta2ns(unsigned long latch,
+ struct clock_event_device *evt);
+extern void clockevents_register_device(struct clock_event_device *dev);
+
+extern void clockevents_exchange_device(struct clock_event_device *old,
+ struct clock_event_device *new);
+extern
+struct clock_event_device *clockevents_request_device(unsigned int features,
+ cpumask_t cpumask);
+extern void clockevents_release_device(struct clock_event_device *dev);
+extern void clockevents_set_mode(struct clock_event_device *dev,
+ enum clock_event_mode mode);
+extern int clockevents_register_notifier(struct notifier_block *nb);
+extern void clockevents_unregister_notifier(struct notifier_block *nb);
+extern int clockevents_program_event(struct clock_event_device *dev,
+ ktime_t expires, ktime_t now);
+
+extern void clockevents_notify(unsigned long reason, void *arg);
+
+#else
+
+static inline void clockevents_resume_events(void) { }
+#define clockevents_notify(reason, arg) do { } while (0)
+
+#endif
+
+#endif
--- /dev/null
+/*
+ * linux/kernel/time/clockevents.c
+ *
+ * This file contains functions which manage clock event devices.
+ *
+ * Copyright(C) 2005-2006, Thomas Gleixner <tglx@linutronix.de>
+ * Copyright(C) 2005-2007, Red Hat, Inc., Ingo Molnar
+ * Copyright(C) 2006-2007, Timesys Corp., Thomas Gleixner
+ *
+ * This code is licenced under the GPL version 2. For details see
+ * kernel-base/COPYING.
+ */
+
+#include <linux/clockchips.h>
+#include <linux/hrtimer.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/smp.h>
+#include <linux/sysdev.h>
+
+/* The registered clock event devices */
+static LIST_HEAD(clockevent_devices);
+static LIST_HEAD(clockevents_released);
+
+/* Notification for clock events */
+static RAW_NOTIFIER_HEAD(clockevents_chain);
+
+/* Protection for the above */
+static DEFINE_SPINLOCK(clockevents_lock);
+
+/**
+ * clockevents_delta2ns - Convert a latch value (device ticks) to nanoseconds
+ * @latch: value to convert
+ * @evt: pointer to clock event device descriptor
+ *
+ * Math helper, returns latch value converted to nanoseconds (bound checked)
+ */
+unsigned long clockevent_delta2ns(unsigned long latch,
+ struct clock_event_device *evt)
+{
+ u64 clc = ((u64) latch << evt->shift);
+
+ do_div(clc, evt->mult);
+ if (clc < 1000)
+ clc = 1000;
+ if (clc > LONG_MAX)
+ clc = LONG_MAX;
+
+ return (unsigned long) clc;
+}
+
+/**
+ * clockevents_set_mode - set the operating mode of a clock event device
+ * @dev: device to modify
+ * @mode: new mode
+ *
+ * Must be called with interrupts disabled !
+ */
+void clockevents_set_mode(struct clock_event_device *dev,
+ enum clock_event_mode mode)
+{
+ if (dev->mode != mode) {
+ dev->set_mode(mode, dev);
+ dev->mode = mode;
+ }
+}
+
+/**
+ * clockevents_program_event - Reprogram the clock event device.
+ * @expires: absolute expiry time (monotonic clock)
+ *
+ * Returns 0 on success, -ETIME when the event is in the past.
+ */
+int clockevents_program_event(struct clock_event_device *dev, ktime_t expires,
+ ktime_t now)
+{
+ unsigned long long clc;
+ int64_t delta;
+
+ delta = ktime_to_ns(ktime_sub(expires, now));
+
+ if (delta <= 0)
+ return -ETIME;
+
+ dev->next_event = expires;
+
+ if (dev->mode == CLOCK_EVT_MODE_SHUTDOWN)
+ return 0;
+
+ if (delta > dev->max_delta_ns)
+ delta = dev->max_delta_ns;
+ if (delta < dev->min_delta_ns)
+ delta = dev->min_delta_ns;
+
+ clc = delta * dev->mult;
+ clc >>= dev->shift;
+
+ return dev->set_next_event((unsigned long) clc, dev);
+}
+
+/**
+ * clockevents_register_notifier - register a clock events change listener
+ */
+int clockevents_register_notifier(struct notifier_block *nb)
+{
+ int ret;
+
+ spin_lock(&clockevents_lock);
+ ret = raw_notifier_chain_register(&clockevents_chain, nb);
+ spin_unlock(&clockevents_lock);
+
+ return ret;
+}
+
+/**
+ * clockevents_unregister_notifier - unregister a clock events change listener
+ */
+void clockevents_unregister_notifier(struct notifier_block *nb)
+{
+ spin_lock(&clockevents_lock);
+ raw_notifier_chain_unregister(&clockevents_chain, nb);
+ spin_unlock(&clockevents_lock);
+}
+
+/*
+ * Notify about a clock event change. Called with clockevents_lock
+ * held.
+ */
+static void clockevents_do_notify(unsigned long reason, void *dev)
+{
+ raw_notifier_call_chain(&clockevents_chain, reason, dev);
+}
+
+/*
+ * Called after a notify add to make devices availble which were
+ * released from the notifier call.
+ */
+static void clockevents_notify_released(void)
+{
+ struct clock_event_device *dev;
+
+ while (!list_empty(&clockevents_released)) {
+ dev = list_entry(clockevents_released.next,
+ struct clock_event_device, list);
+ list_del(&dev->list);
+ list_add(&dev->list, &clockevent_devices);
+ clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+ }
+}
+
+/**
+ * clockevents_register_device - register a clock event device
+ * @dev: device to register
+ */
+void clockevents_register_device(struct clock_event_device *dev)
+{
+ BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED);
+
+ spin_lock(&clockevents_lock);
+
+ list_add(&dev->list, &clockevent_devices);
+ clockevents_do_notify(CLOCK_EVT_NOTIFY_ADD, dev);
+ clockevents_notify_released();
+
+ spin_unlock(&clockevents_lock);
+}
+
+/*
+ * Noop handler when we shut down an event device
+ */
+static void clockevents_handle_noop(struct clock_event_device *dev)
+{
+}
+
+/**
+ * clockevents_exchange_device - release and request clock devices
+ * @old: device to release (can be NULL)
+ * @new: device to request (can be NULL)
+ *
+ * Called from the notifier chain. clockevents_lock is held already
+ */
+void clockevents_exchange_device(struct clock_event_device *old,
+ struct clock_event_device *new)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ /*
+ * Caller releases a clock event device. We queue it into the
+ * released list and do a notify add later.
+ */
+ if (old) {
+ old->event_handler = clockevents_handle_noop;
+ clockevents_set_mode(old, CLOCK_EVT_MODE_UNUSED);
+ list_del(&old->list);
+ list_add(&old->list, &clockevents_released);
+ }
+
+ if (new) {
+ BUG_ON(new->mode != CLOCK_EVT_MODE_UNUSED);
+ clockevents_set_mode(new, CLOCK_EVT_MODE_SHUTDOWN);
+ }
+ local_irq_restore(flags);
+}
+
+/**
+ * clockevents_request_device
+ */
+struct clock_event_device *clockevents_request_device(unsigned int features,
+ cpumask_t cpumask)
+{
+ struct clock_event_device *cur, *dev = NULL;
+ struct list_head *tmp;
+
+ spin_lock(&clockevents_lock);
+
+ list_for_each(tmp, &clockevent_devices) {
+ cur = list_entry(tmp, struct clock_event_device, list);
+
+ if ((cur->features & features) == features &&
+ cpus_equal(cpumask, cur->cpumask)) {
+ if (!dev || dev->rating < cur->rating)
+ dev = cur;
+ }
+ }
+
+ clockevents_exchange_device(NULL, dev);
+
+ spin_unlock(&clockevents_lock);
+
+ return dev;
+}
+
+/**
+ * clockevents_release_device
+ */
+void clockevents_release_device(struct clock_event_device *dev)
+{
+ spin_lock(&clockevents_lock);
+
+ clockevents_exchange_device(dev, NULL);
+ clockevents_notify_released();
+
+ spin_unlock(&clockevents_lock);
+}
+
+/**
+ * clockevents_notify - notification about relevant events
+ */
+void clockevents_notify(unsigned long reason, void *arg)
+{
+ spin_lock(&clockevents_lock);
+ clockevents_do_notify(reason, arg);
+
+ switch (reason) {
+ case CLOCK_EVT_NOTIFY_CPU_DEAD:
+ /*
+ * Unregister the clock event devices which were
+ * released from the users in the notify chain.
+ */
+ while (!list_empty(&clockevents_released)) {
+ struct clock_event_device *dev;
+
+ dev = list_entry(clockevents_released.next,
+ struct clock_event_device, list);
+ list_del(&dev->list);
+ }
+ break;
+ default:
+ break;
+ }
+ spin_unlock(&clockevents_lock);
+}
+EXPORT_SYMBOL_GPL(clockevents_notify);
+
+#ifdef CONFIG_SYSFS
+
+/**
+ * clockevents_show_registered - sysfs interface for listing clockevents
+ * @dev: unused
+ * @buf: char buffer to be filled with clock events list
+ *
+ * Provides sysfs interface for listing registered clock event devices
+ */
+static ssize_t clockevents_show_registered(struct sys_device *dev, char *buf)
+{
+ struct list_head *tmp;
+ char *p = buf;
+ int cpu;
+
+ spin_lock(&clockevents_lock);
+
+ list_for_each(tmp, &clockevent_devices) {
+ struct clock_event_device *ce;
+
+ ce = list_entry(tmp, struct clock_event_device, list);
+ p += sprintf(p, "%-20s F:%04x M:%d", ce->name,
+ ce->features, ce->mode);
+ p += sprintf(p, " C:");
+ if (!cpus_equal(ce->cpumask, cpu_possible_map)) {
+ for_each_cpu_mask(cpu, ce->cpumask)
+ p += sprintf(p, " %d", cpu);
+ } else {
+ /*
+ * FIXME: Add the cpu which is handling this sucker
+ */
+ }
+ p += sprintf(p, "\n");
+ }
+
+ spin_unlock(&clockevents_lock);
+
+ return p - buf;
+}
+
+/*
+ * Sysfs setup bits:
+ */
+static SYSDEV_ATTR(registered, 0600,
+ clockevents_show_registered, NULL);
+
+static struct sysdev_class clockevents_sysclass = {
+ set_kset_name("clockevents"),
+};
+
+static struct sys_device clockevents_sys_device = {
+ .id = 0,
+ .cls = &clockevents_sysclass,
+};
+
+static int __init clockevents_sysfs_init(void)
+{
+ int error = sysdev_class_register(&clockevents_sysclass);
+
+ if (!error)
+ error = sysdev_register(&clockevents_sys_device);
+ if (!error)
+ error = sysdev_create_file(
+ &clockevents_sys_device,
+ &attr_registered);
+ return error;
+}
+device_initcall(clockevents_sysfs_init);
+#endif
projects / linux-drm-fsl-dcu.git / commitdiff