diff options
Diffstat (limited to 'arch/um/drivers/rtc_kern.c')
| -rw-r--r-- | arch/um/drivers/rtc_kern.c | 211 |
1 files changed, 211 insertions, 0 deletions
diff --git a/arch/um/drivers/rtc_kern.c b/arch/um/drivers/rtc_kern.c new file mode 100644 index 000000000..97ceb205c --- /dev/null +++ b/arch/um/drivers/rtc_kern.c @@ -0,0 +1,211 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Intel Corporation + * Author: Johannes Berg <johannes@sipsolutions.net> + */ +#include <linux/platform_device.h> +#include <linux/time-internal.h> +#include <linux/suspend.h> +#include <linux/err.h> +#include <linux/rtc.h> +#include <kern_util.h> +#include <irq_kern.h> +#include <os.h> +#include "rtc.h" + +static time64_t uml_rtc_alarm_time; +static bool uml_rtc_alarm_enabled; +static struct rtc_device *uml_rtc; +static int uml_rtc_irq_fd, uml_rtc_irq; + +#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT + +static void uml_rtc_time_travel_alarm(struct time_travel_event *ev) +{ + uml_rtc_send_timetravel_alarm(); +} + +static struct time_travel_event uml_rtc_alarm_event = { + .fn = uml_rtc_time_travel_alarm, +}; +#endif + +static int uml_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct timespec64 ts; + + /* Use this to get correct time in time-travel mode */ + read_persistent_clock64(&ts); + rtc_time64_to_tm(timespec64_to_ktime(ts) / NSEC_PER_SEC, tm); + + return 0; +} + +static int uml_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + rtc_time64_to_tm(uml_rtc_alarm_time, &alrm->time); + alrm->enabled = uml_rtc_alarm_enabled; + + return 0; +} + +static int uml_rtc_alarm_irq_enable(struct device *dev, unsigned int enable) +{ + unsigned long long secs; + + if (!enable && !uml_rtc_alarm_enabled) + return 0; + + uml_rtc_alarm_enabled = enable; + + secs = uml_rtc_alarm_time - ktime_get_real_seconds(); + + if (time_travel_mode == TT_MODE_OFF) { + if (!enable) { + uml_rtc_disable_alarm(); + return 0; + } + + /* enable or update */ + return uml_rtc_enable_alarm(secs); + } else { + time_travel_del_event(¨_rtc_alarm_event); + + if (enable) + time_travel_add_event_rel(¨_rtc_alarm_event, + secs * NSEC_PER_SEC); + } + + return 0; +} + +static int uml_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) +{ + uml_rtc_alarm_irq_enable(dev, 0); + uml_rtc_alarm_time = rtc_tm_to_time64(&alrm->time); + uml_rtc_alarm_irq_enable(dev, alrm->enabled); + + return 0; +} + +static const struct rtc_class_ops uml_rtc_ops = { + .read_time = uml_rtc_read_time, + .read_alarm = uml_rtc_read_alarm, + .alarm_irq_enable = uml_rtc_alarm_irq_enable, + .set_alarm = uml_rtc_set_alarm, +}; + +static irqreturn_t uml_rtc_interrupt(int irq, void *data) +{ + unsigned long long c = 0; + + /* alarm triggered, it's now off */ + uml_rtc_alarm_enabled = false; + + os_read_file(uml_rtc_irq_fd, &c, sizeof(c)); + WARN_ON(c == 0); + + pm_system_wakeup(); + rtc_update_irq(uml_rtc, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static int uml_rtc_setup(void) +{ + int err; + + err = uml_rtc_start(time_travel_mode != TT_MODE_OFF); + if (WARN(err < 0, "err = %d\n", err)) + return err; + + uml_rtc_irq_fd = err; + + err = um_request_irq(UM_IRQ_ALLOC, uml_rtc_irq_fd, IRQ_READ, + uml_rtc_interrupt, 0, "rtc", NULL); + if (err < 0) { + uml_rtc_stop(time_travel_mode != TT_MODE_OFF); + return err; + } + + irq_set_irq_wake(err, 1); + + uml_rtc_irq = err; + return 0; +} + +static void uml_rtc_cleanup(void) +{ + um_free_irq(uml_rtc_irq, NULL); + uml_rtc_stop(time_travel_mode != TT_MODE_OFF); +} + +static int uml_rtc_probe(struct platform_device *pdev) +{ + int err; + + err = uml_rtc_setup(); + if (err) + return err; + + uml_rtc = devm_rtc_allocate_device(&pdev->dev); + if (IS_ERR(uml_rtc)) { + err = PTR_ERR(uml_rtc); + goto cleanup; + } + + uml_rtc->ops = ¨_rtc_ops; + + device_init_wakeup(&pdev->dev, 1); + + err = devm_rtc_register_device(uml_rtc); + if (err) + goto cleanup; + + return 0; +cleanup: + uml_rtc_cleanup(); + return err; +} + +static int uml_rtc_remove(struct platform_device *pdev) +{ + device_init_wakeup(&pdev->dev, 0); + uml_rtc_cleanup(); + return 0; +} + +static struct platform_driver uml_rtc_driver = { + .probe = uml_rtc_probe, + .remove = uml_rtc_remove, + .driver = { + .name = "uml-rtc", + }, +}; + +static int __init uml_rtc_init(void) +{ + struct platform_device *pdev; + int err; + + err = platform_driver_register(¨_rtc_driver); + if (err) + return err; + + pdev = platform_device_alloc("uml-rtc", 0); + if (!pdev) { + err = -ENOMEM; + goto unregister; + } + + err = platform_device_add(pdev); + if (err) + goto unregister; + return 0; + +unregister: + platform_device_put(pdev); + platform_driver_unregister(¨_rtc_driver); + return err; +} +device_initcall(uml_rtc_init); |