rtc-test.c
// SPDX-License-Identifier: GPL-2.0
/*
* An RTC test device/driver
* Copyright (C) 2005 Tower Technologies
* Author: Alessandro Zummo <a.zummo@towertech.it>
*/
#include <linux/module.h>
#include <linux/err.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#define MAX_RTC_TEST 3
struct rtc_test_data {
struct rtc_device *rtc;
time64_t offset;
struct timer_list alarm;
bool alarm_en;
};
static struct platform_device *pdev[MAX_RTC_TEST];
static int test_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_test_data *rtd = dev_get_drvdata(dev);
time64_t alarm;
alarm = (rtd->alarm.expires - jiffies) / HZ;
alarm += ktime_get_real_seconds() + rtd->offset;
rtc_time64_to_tm(alarm, &alrm->time);
alrm->enabled = rtd->alarm_en;
return 0;
}
static int test_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
struct rtc_test_data *rtd = dev_get_drvdata(dev);
ktime_t timeout;
u64 expires;
timeout = rtc_tm_to_time64(&alrm->time) - ktime_get_real_seconds();
timeout -= rtd->offset;
del_timer(&rtd->alarm);
expires = jiffies + timeout * HZ;
if (expires > U32_MAX)
expires = U32_MAX;
pr_err("ABE: %s +%d %s\n", __FILE__, __LINE__, __func__);
rtd->alarm.expires = expires;
if (alrm->enabled)
add_timer(&rtd->alarm);
rtd->alarm_en = alrm->enabled;
return 0;
}
static int test_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
struct rtc_test_data *rtd = dev_get_drvdata(dev);
rtc_time64_to_tm(ktime_get_real_seconds() + rtd->offset, tm);
return 0;
}
static int test_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
struct rtc_test_data *rtd = dev_get_drvdata(dev);
rtd->offset = rtc_tm_to_time64(tm) - ktime_get_real_seconds();
return 0;
}
static int test_rtc_alarm_irq_enable(struct device *dev, unsigned int enable)
{
struct rtc_test_data *rtd = dev_get_drvdata(dev);
rtd->alarm_en = enable;
if (enable)
add_timer(&rtd->alarm);
else
del_timer(&rtd->alarm);
return 0;
}
static const struct rtc_class_ops test_rtc_ops_noalm = {
.read_time = test_rtc_read_time,
.set_time = test_rtc_set_time,
.alarm_irq_enable = test_rtc_alarm_irq_enable,
};
static const struct rtc_class_ops test_rtc_ops = {
.read_time = test_rtc_read_time,
.set_time = test_rtc_set_time,
.read_alarm = test_rtc_read_alarm,
.set_alarm = test_rtc_set_alarm,
.alarm_irq_enable = test_rtc_alarm_irq_enable,
};
static void test_rtc_alarm_handler(struct timer_list *t)
{
struct rtc_test_data *rtd = from_timer(rtd, t, alarm);
rtc_update_irq(rtd->rtc, 1, RTC_AF | RTC_IRQF);
}
static int test_probe(struct platform_device *plat_dev)
{
struct rtc_test_data *rtd;
rtd = devm_kzalloc(&plat_dev->dev, sizeof(*rtd), GFP_KERNEL);
if (!rtd)
return -ENOMEM;
platform_set_drvdata(plat_dev, rtd);
rtd->rtc = devm_rtc_allocate_device(&plat_dev->dev);
if (IS_ERR(rtd->rtc))
return PTR_ERR(rtd->rtc);
switch (plat_dev->id) {
case 0:
rtd->rtc->ops = &test_rtc_ops_noalm;
break;
default:
rtd->rtc->ops = &test_rtc_ops;
}
timer_setup(&rtd->alarm, test_rtc_alarm_handler, 0);
rtd->alarm.expires = 0;
return rtc_register_device(rtd->rtc);
}
static struct platform_driver test_driver = {
.probe = test_probe,
.driver = {
.name = "rtc-test",
},
};
static int __init test_init(void)
{
int i, err;
err = platform_driver_register(&test_driver);
if (err)
return err;
err = -ENOMEM;
for (i = 0; i < MAX_RTC_TEST; i++) {
pdev[i] = platform_device_alloc("rtc-test", i);
if (!pdev[i])
goto exit_free_mem;
}
for (i = 0; i < MAX_RTC_TEST; i++) {
err = platform_device_add(pdev[i]);
if (err)
goto exit_device_del;
}
return 0;
exit_device_del:
for (; i > 0; i--)
platform_device_del(pdev[i - 1]);
exit_free_mem:
for (i = 0; i < MAX_RTC_TEST; i++)
platform_device_put(pdev[i]);
platform_driver_unregister(&test_driver);
return err;
}
static void __exit test_exit(void)
{
int i;
for (i = 0; i < MAX_RTC_TEST; i++)
platform_device_unregister(pdev[i]);
platform_driver_unregister(&test_driver);
}
MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
MODULE_DESCRIPTION("RTC test driver/device");
MODULE_LICENSE("GPL v2");
module_init(test_init);
module_exit(test_exit);