* published by the Free Software Foundation.
*/
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
#include <linux/module.h>
#include <linux/rtc.h>
#include <linux/kdev_t.h>
#include "rtc-core.h"
-static DEFINE_IDR(rtc_idr);
-static DEFINE_MUTEX(idr_lock);
+static DEFINE_IDA(rtc_ida);
struct class *rtc_class;
static void rtc_device_release(struct device *dev)
{
struct rtc_device *rtc = to_rtc_device(dev);
- mutex_lock(&idr_lock);
- idr_remove(&rtc_idr, rtc->id);
- mutex_unlock(&idr_lock);
+ ida_simple_remove(&rtc_ida, rtc->id);
kfree(rtc);
}
-#if defined(CONFIG_PM) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
+#ifdef CONFIG_RTC_HCTOSYS_DEVICE
+/* Result of the last RTC to system clock attempt. */
+int rtc_hctosys_ret = -ENODEV;
+#endif
+#if defined(CONFIG_PM) && defined(CONFIG_RTC_HCTOSYS_DEVICE)
/*
* On suspend(), measure the delta between one RTC and the
* system's wall clock; restore it on resume().
*/
-static time_t oldtime;
-static struct timespec oldts;
+static struct timespec old_rtc, old_system, old_delta;
+
static int rtc_suspend(struct device *dev, pm_message_t mesg)
{
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
+ struct timespec delta, delta_delta;
+
+ if (has_persistent_clock())
+ return 0;
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
+ /* snapshot the current RTC and system time at suspend*/
rtc_read_time(rtc, &tm);
- ktime_get_ts(&oldts);
- rtc_tm_to_time(&tm, &oldtime);
+ getnstimeofday(&old_system);
+ rtc_tm_to_time(&tm, &old_rtc.tv_sec);
+
+
+ /*
+ * To avoid drift caused by repeated suspend/resumes,
+ * which each can add ~1 second drift error,
+ * try to compensate so the difference in system time
+ * and rtc time stays close to constant.
+ */
+ delta = timespec_sub(old_system, old_rtc);
+ delta_delta = timespec_sub(delta, old_delta);
+ if (delta_delta.tv_sec < -2 || delta_delta.tv_sec >= 2) {
+ /*
+ * if delta_delta is too large, assume time correction
+ * has occured and set old_delta to the current delta.
+ */
+ old_delta = delta;
+ } else {
+ /* Otherwise try to adjust old_system to compensate */
+ old_system = timespec_sub(old_system, delta_delta);
+ }
return 0;
}
{
struct rtc_device *rtc = to_rtc_device(dev);
struct rtc_time tm;
- time_t newtime;
- struct timespec time;
- struct timespec newts;
+ struct timespec new_system, new_rtc;
+ struct timespec sleep_time;
+ if (has_persistent_clock())
+ return 0;
+
+ rtc_hctosys_ret = -ENODEV;
if (strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE) != 0)
return 0;
- ktime_get_ts(&newts);
+ /* snapshot the current rtc and system time at resume */
+ getnstimeofday(&new_system);
rtc_read_time(rtc, &tm);
if (rtc_valid_tm(&tm) != 0) {
pr_debug("%s: bogus resume time\n", dev_name(&rtc->dev));
return 0;
}
- rtc_tm_to_time(&tm, &newtime);
- if (newtime <= oldtime) {
- if (newtime < oldtime)
- pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
+ rtc_tm_to_time(&tm, &new_rtc.tv_sec);
+ new_rtc.tv_nsec = 0;
+
+ if (new_rtc.tv_sec < old_rtc.tv_sec) {
+ pr_debug("%s: time travel!\n", dev_name(&rtc->dev));
return 0;
}
- /* calculate the RTC time delta */
- set_normalized_timespec(&time, newtime - oldtime, 0);
- /* subtract kernel time between rtc_suspend to rtc_resume */
- time = timespec_sub(time, timespec_sub(newts, oldts));
-
- timekeeping_inject_sleeptime(&time);
+ /* calculate the RTC time delta (sleep time)*/
+ sleep_time = timespec_sub(new_rtc, old_rtc);
+
+ /*
+ * Since these RTC suspend/resume handlers are not called
+ * at the very end of suspend or the start of resume,
+ * some run-time may pass on either sides of the sleep time
+ * so subtract kernel run-time between rtc_suspend to rtc_resume
+ * to keep things accurate.
+ */
+ sleep_time = timespec_sub(sleep_time,
+ timespec_sub(new_system, old_system));
+
+ if (sleep_time.tv_sec >= 0)
+ timekeeping_inject_sleeptime(&sleep_time);
+ rtc_hctosys_ret = 0;
return 0;
}
struct rtc_wkalrm alrm;
int id, err;
- if (idr_pre_get(&rtc_idr, GFP_KERNEL) == 0) {
- err = -ENOMEM;
+ id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL);
+ if (id < 0) {
+ err = id;
goto exit;
}
-
- mutex_lock(&idr_lock);
- err = idr_get_new(&rtc_idr, NULL, &id);
- mutex_unlock(&idr_lock);
-
- if (err < 0)
- goto exit;
-
- id = id & MAX_ID_MASK;
-
rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL);
if (rtc == NULL) {
err = -ENOMEM;
- goto exit_idr;
+ goto exit_ida;
}
rtc->id = id;
exit_kfree:
kfree(rtc);
-exit_idr:
- mutex_lock(&idr_lock);
- idr_remove(&rtc_idr, id);
- mutex_unlock(&idr_lock);
+exit_ida:
+ ida_simple_remove(&rtc_ida, id);
exit:
dev_err(dev, "rtc core: unable to register %s, err = %d\n",
}
EXPORT_SYMBOL_GPL(rtc_device_unregister);
+static void devm_rtc_device_release(struct device *dev, void *res)
+{
+ struct rtc_device *rtc = *(struct rtc_device **)res;
+
+ rtc_device_unregister(rtc);
+}
+
+static int devm_rtc_device_match(struct device *dev, void *res, void *data)
+{
+ struct rtc **r = res;
+
+ return *r == data;
+}
+
+/**
+ * devm_rtc_device_register - resource managed rtc_device_register()
+ * @dev: the device to register
+ * @name: the name of the device
+ * @ops: the rtc operations structure
+ * @owner: the module owner
+ *
+ * @return a struct rtc on success, or an ERR_PTR on error
+ *
+ * Managed rtc_device_register(). The rtc_device returned from this function
+ * are automatically freed on driver detach. See rtc_device_register()
+ * for more information.
+ */
+
+struct rtc_device *devm_rtc_device_register(struct device *dev,
+ const char *name,
+ const struct rtc_class_ops *ops,
+ struct module *owner)
+{
+ struct rtc_device **ptr, *rtc;
+
+ ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL);
+ if (!ptr)
+ return ERR_PTR(-ENOMEM);
+
+ rtc = rtc_device_register(name, dev, ops, owner);
+ if (!IS_ERR(rtc)) {
+ *ptr = rtc;
+ devres_add(dev, ptr);
+ } else {
+ devres_free(ptr);
+ }
+
+ return rtc;
+}
+EXPORT_SYMBOL_GPL(devm_rtc_device_register);
+
+/**
+ * devm_rtc_device_unregister - resource managed devm_rtc_device_unregister()
+ * @dev: the device to unregister
+ * @rtc: the RTC class device to unregister
+ *
+ * Deallocated a rtc allocated with devm_rtc_device_register(). Normally this
+ * function will not need to be called and the resource management code will
+ * ensure that the resource is freed.
+ */
+void devm_rtc_device_unregister(struct device *dev, struct rtc_device *rtc)
+{
+ int rc;
+
+ rc = devres_release(dev, devm_rtc_device_release,
+ devm_rtc_device_match, rtc);
+ WARN_ON(rc);
+}
+EXPORT_SYMBOL_GPL(devm_rtc_device_unregister);
+
static int __init rtc_init(void)
{
rtc_class = class_create(THIS_MODULE, "rtc");
if (IS_ERR(rtc_class)) {
- printk(KERN_ERR "%s: couldn't create class\n", __FILE__);
+ pr_err("couldn't create class\n");
return PTR_ERR(rtc_class);
}
rtc_class->suspend = rtc_suspend;
{
rtc_dev_exit();
class_destroy(rtc_class);
- idr_destroy(&rtc_idr);
+ ida_destroy(&rtc_ida);
}
subsys_initcall(rtc_init);
projects / firefly-linux-kernel-4.4.55.git / blobdiff