diff options
Diffstat (limited to 'drivers/rtc/class.c')
| -rw-r--r-- | drivers/rtc/class.c | 479 |
1 files changed, 306 insertions, 173 deletions
diff --git a/drivers/rtc/class.c b/drivers/rtc/class.c index 02426812bebc..b1a2be1f9e3b 100644 --- a/drivers/rtc/class.c +++ b/drivers/rtc/class.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0 /* * RTC subsystem, base class * @@ -5,15 +6,12 @@ * Author: Alessandro Zummo <a.zummo@towertech.it> * * class skeleton from drivers/hwmon/hwmon.c - * - * 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. -*/ + */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> +#include <linux/of.h> #include <linux/rtc.h> #include <linux/kdev_t.h> #include <linux/idr.h> @@ -22,20 +20,73 @@ #include "rtc-core.h" - 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); - ida_simple_remove(&rtc_ida, rtc->id); + struct timerqueue_head *head = &rtc->timerqueue; + struct timerqueue_node *node; + + mutex_lock(&rtc->ops_lock); + while ((node = timerqueue_getnext(head))) + timerqueue_del(head, node); + mutex_unlock(&rtc->ops_lock); + + cancel_work_sync(&rtc->irqwork); + + ida_free(&rtc_ida, rtc->id); + mutex_destroy(&rtc->ops_lock); kfree(rtc); } #ifdef CONFIG_RTC_HCTOSYS_DEVICE /* Result of the last RTC to system clock attempt. */ int rtc_hctosys_ret = -ENODEV; + +/* IMPORTANT: the RTC only stores whole seconds. It is arbitrary + * whether it stores the most close value or the value with partial + * seconds truncated. However, it is important that we use it to store + * the truncated value. This is because otherwise it is necessary, + * in an rtc sync function, to read both xtime.tv_sec and + * xtime.tv_nsec. On some processors (i.e. ARM), an atomic read + * of >32bits is not possible. So storing the most close value would + * slow down the sync API. So here we have the truncated value and + * the best guess is to add 0.5s. + */ + +static void rtc_hctosys(struct rtc_device *rtc) +{ + int err; + struct rtc_time tm; + struct timespec64 tv64 = { + .tv_nsec = NSEC_PER_SEC >> 1, + }; + + err = rtc_read_time(rtc, &tm); + if (err) { + dev_err(rtc->dev.parent, + "hctosys: unable to read the hardware clock\n"); + goto err_read; + } + + tv64.tv_sec = rtc_tm_to_time64(&tm); + +#if BITS_PER_LONG == 32 + if (tv64.tv_sec > INT_MAX) { + err = -ERANGE; + goto err_read; + } +#endif + + err = do_settimeofday64(&tv64); + + dev_info(rtc->dev.parent, "setting system clock to %ptR UTC (%lld)\n", + &tm, (long long)tv64.tv_sec); + +err_read: + rtc_hctosys_ret = err; +} #endif #if defined(CONFIG_PM_SLEEP) && defined(CONFIG_RTC_HCTOSYS_DEVICE) @@ -44,26 +95,30 @@ int rtc_hctosys_ret = -ENODEV; * system's wall clock; restore it on resume(). */ -static struct timespec old_rtc, old_system, old_delta; - +static struct timespec64 old_rtc, old_system, old_delta; static int rtc_suspend(struct device *dev) { struct rtc_device *rtc = to_rtc_device(dev); struct rtc_time tm; - struct timespec delta, delta_delta; + struct timespec64 delta, delta_delta; + int err; - if (has_persistent_clock()) + if (timekeeping_rtc_skipsuspend()) 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); - getnstimeofday(&old_system); - rtc_tm_to_time(&tm, &old_rtc.tv_sec); + err = rtc_read_time(rtc, &tm); + if (err < 0) { + pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev)); + return 0; + } + ktime_get_real_ts64(&old_system); + old_rtc.tv_sec = rtc_tm_to_time64(&tm); /* * To avoid drift caused by repeated suspend/resumes, @@ -71,17 +126,17 @@ static int rtc_suspend(struct device *dev) * 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); + delta = timespec64_sub(old_system, old_rtc); + delta_delta = timespec64_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. + * has occurred 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); + old_system = timespec64_sub(old_system, delta_delta); } return 0; @@ -91,10 +146,11 @@ static int rtc_resume(struct device *dev) { struct rtc_device *rtc = to_rtc_device(dev); struct rtc_time tm; - struct timespec new_system, new_rtc; - struct timespec sleep_time; + struct timespec64 new_system, new_rtc; + struct timespec64 sleep_time; + int err; - if (has_persistent_clock()) + if (timekeeping_rtc_skipresume()) return 0; rtc_hctosys_ret = -ENODEV; @@ -102,13 +158,14 @@ static int rtc_resume(struct device *dev) return 0; /* 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)); + ktime_get_real_ts64(&new_system); + err = rtc_read_time(rtc, &tm); + if (err < 0) { + pr_debug("%s: fail to read rtc time\n", dev_name(&rtc->dev)); return 0; } - rtc_tm_to_time(&tm, &new_rtc.tv_sec); + + new_rtc.tv_sec = rtc_tm_to_time64(&tm); new_rtc.tv_nsec = 0; if (new_rtc.tv_sec < old_rtc.tv_sec) { @@ -117,7 +174,7 @@ static int rtc_resume(struct device *dev) } /* calculate the RTC time delta (sleep time)*/ - sleep_time = timespec_sub(new_rtc, old_rtc); + sleep_time = timespec64_sub(new_rtc, old_rtc); /* * Since these RTC suspend/resume handlers are not called @@ -126,11 +183,11 @@ static int rtc_resume(struct device *dev) * 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)); + sleep_time = timespec64_sub(sleep_time, + timespec64_sub(new_system, old_system)); if (sleep_time.tv_sec >= 0) - timekeeping_inject_sleeptime(&sleep_time); + timekeeping_inject_sleeptime64(&sleep_time); rtc_hctosys_ret = 0; return 0; } @@ -141,218 +198,294 @@ static SIMPLE_DEV_PM_OPS(rtc_class_dev_pm_ops, rtc_suspend, rtc_resume); #define RTC_CLASS_DEV_PM_OPS NULL #endif +const struct class rtc_class = { + .name = "rtc", + .pm = RTC_CLASS_DEV_PM_OPS, +}; -/** - * rtc_device_register - register w/ RTC class - * @dev: the device to register - * - * rtc_device_unregister() must be called when the class device is no - * longer needed. - * - * Returns the pointer to the new struct class device. - */ -struct rtc_device *rtc_device_register(const char *name, struct device *dev, - const struct rtc_class_ops *ops, - struct module *owner) +/* Ensure the caller will set the id before releasing the device */ +static struct rtc_device *rtc_allocate_device(void) { struct rtc_device *rtc; - struct rtc_wkalrm alrm; - int id, err; - id = ida_simple_get(&rtc_ida, 0, 0, GFP_KERNEL); - if (id < 0) { - err = id; - goto exit; - } + rtc = kzalloc(sizeof(*rtc), GFP_KERNEL); + if (!rtc) + return NULL; - rtc = kzalloc(sizeof(struct rtc_device), GFP_KERNEL); - if (rtc == NULL) { - err = -ENOMEM; - goto exit_ida; - } + device_initialize(&rtc->dev); + + /* + * Drivers can revise this default after allocating the device. + * The default is what most RTCs do: Increment seconds exactly one + * second after the write happened. This adds a default transport + * time of 5ms which is at least halfways close to reality. + */ + rtc->set_offset_nsec = NSEC_PER_SEC + 5 * NSEC_PER_MSEC; - rtc->id = id; - rtc->ops = ops; - rtc->owner = owner; rtc->irq_freq = 1; rtc->max_user_freq = 64; - rtc->dev.parent = dev; - rtc->dev.class = rtc_class; + rtc->dev.class = &rtc_class; + rtc->dev.groups = rtc_get_dev_attribute_groups(); rtc->dev.release = rtc_device_release; mutex_init(&rtc->ops_lock); spin_lock_init(&rtc->irq_lock); - spin_lock_init(&rtc->irq_task_lock); init_waitqueue_head(&rtc->irq_queue); /* Init timerqueue */ timerqueue_init_head(&rtc->timerqueue); INIT_WORK(&rtc->irqwork, rtc_timer_do_work); /* Init aie timer */ - rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, (void *)rtc); + rtc_timer_init(&rtc->aie_timer, rtc_aie_update_irq, rtc); /* Init uie timer */ - rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, (void *)rtc); + rtc_timer_init(&rtc->uie_rtctimer, rtc_uie_update_irq, rtc); /* Init pie timer */ - hrtimer_init(&rtc->pie_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rtc->pie_timer.function = rtc_pie_update_irq; + hrtimer_setup(&rtc->pie_timer, rtc_pie_update_irq, CLOCK_MONOTONIC, HRTIMER_MODE_REL); rtc->pie_enabled = 0; - /* Check to see if there is an ALARM already set in hw */ - err = __rtc_read_alarm(rtc, &alrm); + set_bit(RTC_FEATURE_ALARM, rtc->features); + set_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features); - if (!err && !rtc_valid_tm(&alrm.time)) - rtc_initialize_alarm(rtc, &alrm); + return rtc; +} - strlcpy(rtc->name, name, RTC_DEVICE_NAME_SIZE); - dev_set_name(&rtc->dev, "rtc%d", id); +static int rtc_device_get_id(struct device *dev) +{ + int of_id = -1, id = -1; - rtc_dev_prepare(rtc); + if (dev->of_node) + of_id = of_alias_get_id(dev->of_node, "rtc"); + else if (dev->parent && dev->parent->of_node) + of_id = of_alias_get_id(dev->parent->of_node, "rtc"); - err = device_register(&rtc->dev); - if (err) { - put_device(&rtc->dev); - goto exit_kfree; + if (of_id >= 0) { + id = ida_alloc_range(&rtc_ida, of_id, of_id, GFP_KERNEL); + if (id < 0) + dev_warn(dev, "/aliases ID %d not available\n", of_id); } - rtc_dev_add_device(rtc); - rtc_sysfs_add_device(rtc); - rtc_proc_add_device(rtc); + if (id < 0) + id = ida_alloc(&rtc_ida, GFP_KERNEL); - dev_info(dev, "rtc core: registered %s as %s\n", - rtc->name, dev_name(&rtc->dev)); + return id; +} - return rtc; +static void rtc_device_get_offset(struct rtc_device *rtc) +{ + time64_t range_secs; + u32 start_year; + int ret; -exit_kfree: - kfree(rtc); + /* + * If RTC driver did not implement the range of RTC hardware device, + * then we can not expand the RTC range by adding or subtracting one + * offset. + */ + if (rtc->range_min == rtc->range_max) + return; + + ret = device_property_read_u32(rtc->dev.parent, "start-year", + &start_year); + if (!ret) { + rtc->start_secs = mktime64(start_year, 1, 1, 0, 0, 0); + rtc->set_start_time = true; + } + + /* + * If user did not implement the start time for RTC driver, then no + * need to expand the RTC range. + */ + if (!rtc->set_start_time) + return; -exit_ida: - ida_simple_remove(&rtc_ida, id); + range_secs = rtc->range_max - rtc->range_min + 1; -exit: - dev_err(dev, "rtc core: unable to register %s, err = %d\n", - name, err); - return ERR_PTR(err); + /* + * If the start_secs is larger than the maximum seconds (rtc->range_max) + * supported by RTC hardware or the maximum seconds of new expanded + * range (start_secs + rtc->range_max - rtc->range_min) is less than + * rtc->range_min, which means the minimum seconds (rtc->range_min) of + * RTC hardware will be mapped to start_secs by adding one offset, so + * the offset seconds calculation formula should be: + * rtc->offset_secs = rtc->start_secs - rtc->range_min; + * + * If the start_secs is larger than the minimum seconds (rtc->range_min) + * supported by RTC hardware, then there is one region is overlapped + * between the original RTC hardware range and the new expanded range, + * and this overlapped region do not need to be mapped into the new + * expanded range due to it is valid for RTC device. So the minimum + * seconds of RTC hardware (rtc->range_min) should be mapped to + * rtc->range_max + 1, then the offset seconds formula should be: + * rtc->offset_secs = rtc->range_max - rtc->range_min + 1; + * + * If the start_secs is less than the minimum seconds (rtc->range_min), + * which is similar to case 2. So the start_secs should be mapped to + * start_secs + rtc->range_max - rtc->range_min + 1, then the + * offset seconds formula should be: + * rtc->offset_secs = -(rtc->range_max - rtc->range_min + 1); + * + * Otherwise the offset seconds should be 0. + */ + if ((rtc->start_secs >= 0 && rtc->start_secs > rtc->range_max) || + rtc->start_secs + range_secs - 1 < rtc->range_min) + rtc->offset_secs = rtc->start_secs - rtc->range_min; + else if (rtc->start_secs > rtc->range_min) + rtc->offset_secs = range_secs; + else if (rtc->start_secs < rtc->range_min) + rtc->offset_secs = -range_secs; + else + rtc->offset_secs = 0; } -EXPORT_SYMBOL_GPL(rtc_device_register); +static void devm_rtc_unregister_device(void *data) +{ + struct rtc_device *rtc = data; -/** - * rtc_device_unregister - removes the previously registered RTC class device - * - * @rtc: the RTC class device to destroy - */ -void rtc_device_unregister(struct rtc_device *rtc) + mutex_lock(&rtc->ops_lock); + /* + * Remove innards of this RTC, then disable it, before + * letting any rtc_class_open() users access it again + */ + rtc_proc_del_device(rtc); + if (!test_bit(RTC_NO_CDEV, &rtc->flags)) + cdev_device_del(&rtc->char_dev, &rtc->dev); + rtc->ops = NULL; + mutex_unlock(&rtc->ops_lock); +} + +static void devm_rtc_release_device(void *res) { - if (get_device(&rtc->dev) != NULL) { - mutex_lock(&rtc->ops_lock); - /* remove innards of this RTC, then disable it, before - * letting any rtc_class_open() users access it again - */ - rtc_sysfs_del_device(rtc); - rtc_dev_del_device(rtc); - rtc_proc_del_device(rtc); - device_unregister(&rtc->dev); - rtc->ops = NULL; - mutex_unlock(&rtc->ops_lock); - put_device(&rtc->dev); - } + struct rtc_device *rtc = res; + + put_device(&rtc->dev); } -EXPORT_SYMBOL_GPL(rtc_device_unregister); -static void devm_rtc_device_release(struct device *dev, void *res) +struct rtc_device *devm_rtc_allocate_device(struct device *dev) { - struct rtc_device *rtc = *(struct rtc_device **)res; + struct rtc_device *rtc; + int id, err; + + id = rtc_device_get_id(dev); + if (id < 0) + return ERR_PTR(id); + + rtc = rtc_allocate_device(); + if (!rtc) { + ida_free(&rtc_ida, id); + return ERR_PTR(-ENOMEM); + } - rtc_device_unregister(rtc); + rtc->id = id; + rtc->dev.parent = dev; + err = devm_add_action_or_reset(dev, devm_rtc_release_device, rtc); + if (err) + return ERR_PTR(err); + + err = dev_set_name(&rtc->dev, "rtc%d", id); + if (err) + return ERR_PTR(err); + + return rtc; } +EXPORT_SYMBOL_GPL(devm_rtc_allocate_device); -static int devm_rtc_device_match(struct device *dev, void *res, void *data) +int __devm_rtc_register_device(struct module *owner, struct rtc_device *rtc) { - struct rtc **r = res; + struct rtc_wkalrm alrm; + int err; + + if (!rtc->ops) { + dev_dbg(&rtc->dev, "no ops set\n"); + return -EINVAL; + } + + if (!rtc->ops->set_alarm) + clear_bit(RTC_FEATURE_ALARM, rtc->features); + + if (rtc->ops->set_offset) + set_bit(RTC_FEATURE_CORRECTION, rtc->features); - return *r == data; + rtc->owner = owner; + rtc_device_get_offset(rtc); + + /* Check to see if there is an ALARM already set in hw */ + err = __rtc_read_alarm(rtc, &alrm); + if (!err && !rtc_valid_tm(&alrm.time)) + rtc_initialize_alarm(rtc, &alrm); + + rtc_dev_prepare(rtc); + + err = cdev_device_add(&rtc->char_dev, &rtc->dev); + if (err) { + set_bit(RTC_NO_CDEV, &rtc->flags); + dev_warn(rtc->dev.parent, "failed to add char device %d:%d\n", + MAJOR(rtc->dev.devt), rtc->id); + } else { + dev_dbg(rtc->dev.parent, "char device (%d:%d)\n", + MAJOR(rtc->dev.devt), rtc->id); + } + + rtc_proc_add_device(rtc); + + dev_info(rtc->dev.parent, "registered as %s\n", + dev_name(&rtc->dev)); + +#ifdef CONFIG_RTC_HCTOSYS_DEVICE + if (!strcmp(dev_name(&rtc->dev), CONFIG_RTC_HCTOSYS_DEVICE)) + rtc_hctosys(rtc); +#endif + + return devm_add_action_or_reset(rtc->dev.parent, + devm_rtc_unregister_device, rtc); } +EXPORT_SYMBOL_GPL(__devm_rtc_register_device); /** * devm_rtc_device_register - resource managed rtc_device_register() * @dev: the device to register - * @name: the name of the device + * @name: the name of the device (unused) * @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. + * are automatically freed on driver detach. + * This function is deprecated, use devm_rtc_allocate_device and + * rtc_register_device instead */ - struct rtc_device *devm_rtc_device_register(struct device *dev, - const char *name, - const struct rtc_class_ops *ops, - struct module *owner) + const char *name, + const struct rtc_class_ops *ops, + struct module *owner) { - struct rtc_device **ptr, *rtc; + struct rtc_device *rtc; + int err; - ptr = devres_alloc(devm_rtc_device_release, sizeof(*ptr), GFP_KERNEL); - if (!ptr) - return ERR_PTR(-ENOMEM); + rtc = devm_rtc_allocate_device(dev); + if (IS_ERR(rtc)) + return rtc; - rtc = rtc_device_register(name, dev, ops, owner); - if (!IS_ERR(rtc)) { - *ptr = rtc; - devres_add(dev, ptr); - } else { - devres_free(ptr); - } + rtc->ops = ops; + + err = __devm_rtc_register_device(owner, rtc); + if (err) + return ERR_PTR(err); 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) +static int __init rtc_init(void) { - int rc; + int err; - rc = devres_release(dev, devm_rtc_device_release, - devm_rtc_device_match, rtc); - WARN_ON(rc); -} -EXPORT_SYMBOL_GPL(devm_rtc_device_unregister); + err = class_register(&rtc_class); + if (err) + return err; -static int __init rtc_init(void) -{ - rtc_class = class_create(THIS_MODULE, "rtc"); - if (IS_ERR(rtc_class)) { - pr_err("couldn't create class\n"); - return PTR_ERR(rtc_class); - } - rtc_class->pm = RTC_CLASS_DEV_PM_OPS; rtc_dev_init(); - rtc_sysfs_init(rtc_class); - return 0; -} -static void __exit rtc_exit(void) -{ - rtc_dev_exit(); - class_destroy(rtc_class); - ida_destroy(&rtc_ida); + return 0; } - subsys_initcall(rtc_init); -module_exit(rtc_exit); - -MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>"); -MODULE_DESCRIPTION("RTC class support"); -MODULE_LICENSE("GPL"); |