// SPDX-License-Identifier: GPL-2.0
/*
 * Real Time Clock Driver Test Program
 *
 * Copyright (c) 2018 Alexandre Belloni <alexandre.belloni@bootlin.com>
 */

#include <errno.h>
#include <fcntl.h>
#include <linux/rtc.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>

#include "kselftest_harness.h"

#define NUM_UIE 3
#define ALARM_DELTA 3
#define READ_LOOP_DURATION_SEC 30
#define READ_LOOP_SLEEP_MS 11

static char *rtc_file = "/dev/rtc0";

enum rtc_alarm_state {
        RTC_ALARM_UNKNOWN,
        RTC_ALARM_ENABLED,
        RTC_ALARM_DISABLED,
        RTC_ALARM_RES_MINUTE,
};

FIXTURE(rtc) {
        int fd;
};

FIXTURE_SETUP(rtc) {
        self->fd = open(rtc_file, O_RDONLY);
}

FIXTURE_TEARDOWN(rtc) {
        close(self->fd);
}

TEST_F(rtc, date_read) {
        int rc;
        struct rtc_time rtc_tm;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        /* Read the RTC time/date */
        rc = ioctl(self->fd, RTC_RD_TIME, &rtc_tm);
        ASSERT_NE(-1, rc);

        TH_LOG("Current RTC date/time is %02d/%02d/%02d %02d:%02d:%02d.",
               rtc_tm.tm_mday, rtc_tm.tm_mon + 1, rtc_tm.tm_year + 1900,
               rtc_tm.tm_hour, rtc_tm.tm_min, rtc_tm.tm_sec);
}

static time_t rtc_time_to_timestamp(struct rtc_time *rtc_time)
{
        struct tm tm_time = {
               .tm_sec = rtc_time->tm_sec,
               .tm_min = rtc_time->tm_min,
               .tm_hour = rtc_time->tm_hour,
               .tm_mday = rtc_time->tm_mday,
               .tm_mon = rtc_time->tm_mon,
               .tm_year = rtc_time->tm_year,
        };

        return mktime(&tm_time);
}

static void nanosleep_with_retries(long ns)
{
        struct timespec req = {
                .tv_sec = 0,
                .tv_nsec = ns,
        };
        struct timespec rem;

        while (nanosleep(&req, &rem) != 0) {
                req.tv_sec = rem.tv_sec;
                req.tv_nsec = rem.tv_nsec;
        }
}

static enum rtc_alarm_state get_rtc_alarm_state(int fd, int need_seconds)
{
        struct rtc_param param = { 0 };
        int rc;

        /* Validate kernel reflects unsupported RTC alarm state */
        param.param = RTC_PARAM_FEATURES;
        param.index = 0;
        rc = ioctl(fd, RTC_PARAM_GET, &param);
        if (rc < 0)
                return RTC_ALARM_UNKNOWN;

        if ((param.uvalue & _BITUL(RTC_FEATURE_ALARM)) == 0)
                return RTC_ALARM_DISABLED;

        /* Check if alarm has desired granularity */
        if (need_seconds && (param.uvalue & _BITUL(RTC_FEATURE_ALARM_RES_MINUTE)))
                return RTC_ALARM_RES_MINUTE;

        return RTC_ALARM_ENABLED;
}

TEST_F_TIMEOUT(rtc, date_read_loop, READ_LOOP_DURATION_SEC + 2) {
        int rc;
        long iter_count = 0;
        struct rtc_time rtc_tm;
        time_t start_rtc_read, prev_rtc_read;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        TH_LOG("Continuously reading RTC time for %ds (with %dms breaks after every read).",
               READ_LOOP_DURATION_SEC, READ_LOOP_SLEEP_MS);

        rc = ioctl(self->fd, RTC_RD_TIME, &rtc_tm);
        ASSERT_NE(-1, rc);
        start_rtc_read = rtc_time_to_timestamp(&rtc_tm);
        prev_rtc_read = start_rtc_read;

        do  {
                time_t rtc_read;

                rc = ioctl(self->fd, RTC_RD_TIME, &rtc_tm);
                ASSERT_NE(-1, rc);

                rtc_read = rtc_time_to_timestamp(&rtc_tm);
                /* Time should not go backwards */
                ASSERT_LE(prev_rtc_read, rtc_read);
                /* Time should not increase more then 1s at a time */
                ASSERT_GE(prev_rtc_read + 1, rtc_read);

                /* Sleep 11ms to avoid killing / overheating the RTC */
                nanosleep_with_retries(READ_LOOP_SLEEP_MS * 1000000);

                prev_rtc_read = rtc_read;
                iter_count++;
        } while (prev_rtc_read <= start_rtc_read + READ_LOOP_DURATION_SEC);

        TH_LOG("Performed %ld RTC time reads.", iter_count);
}

TEST_F_TIMEOUT(rtc, uie_read, NUM_UIE + 2) {
        int i, rc, irq = 0;
        unsigned long data;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        /* Turn on update interrupts */
        rc = ioctl(self->fd, RTC_UIE_ON, 0);
        if (rc == -1) {
                ASSERT_EQ(EINVAL, errno);
                TH_LOG("skip update IRQs not supported.");
                return;
        }

        for (i = 0; i < NUM_UIE; i++) {
                /* This read will block */
                rc = read(self->fd, &data, sizeof(data));
                ASSERT_NE(-1, rc);
                irq++;
        }

        EXPECT_EQ(NUM_UIE, irq);

        rc = ioctl(self->fd, RTC_UIE_OFF, 0);
        ASSERT_NE(-1, rc);
}

TEST_F(rtc, uie_select) {
        int i, rc, irq = 0;
        unsigned long data;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        /* Turn on update interrupts */
        rc = ioctl(self->fd, RTC_UIE_ON, 0);
        if (rc == -1) {
                ASSERT_EQ(EINVAL, errno);
                TH_LOG("skip update IRQs not supported.");
                return;
        }

        for (i = 0; i < NUM_UIE; i++) {
                struct timeval tv = { .tv_sec = 2 };
                fd_set readfds;

                FD_ZERO(&readfds);
                FD_SET(self->fd, &readfds);
                /* The select will wait until an RTC interrupt happens. */
                rc = select(self->fd + 1, &readfds, NULL, NULL, &tv);
                ASSERT_NE(-1, rc);
                ASSERT_NE(0, rc);

                /* This read won't block */
                rc = read(self->fd, &data, sizeof(unsigned long));
                ASSERT_NE(-1, rc);
                irq++;
        }

        EXPECT_EQ(NUM_UIE, irq);

        rc = ioctl(self->fd, RTC_UIE_OFF, 0);
        ASSERT_NE(-1, rc);
}

TEST_F(rtc, alarm_alm_set) {
        struct timeval tv = { .tv_sec = ALARM_DELTA + 2 };
        unsigned long data;
        struct rtc_time tm;
        fd_set readfds;
        time_t secs, new;
        int rc;
        enum rtc_alarm_state alarm_state = RTC_ALARM_UNKNOWN;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        alarm_state = get_rtc_alarm_state(self->fd, 1);
        if (alarm_state == RTC_ALARM_DISABLED)
                SKIP(return, "Skipping test since alarms are not supported.");
        if (alarm_state == RTC_ALARM_RES_MINUTE)
                SKIP(return, "Skipping test since alarms has only minute granularity.");

        rc = ioctl(self->fd, RTC_RD_TIME, &tm);
        ASSERT_NE(-1, rc);

        secs = timegm((struct tm *)&tm) + ALARM_DELTA;
        gmtime_r(&secs, (struct tm *)&tm);

        rc = ioctl(self->fd, RTC_ALM_SET, &tm);
        if (rc == -1) {
                /*
                 * Report error if rtc alarm was enabled. Fallback to check ioctl
                 * error number if rtc alarm state is unknown.
                 */
                ASSERT_EQ(RTC_ALARM_UNKNOWN, alarm_state);
                ASSERT_EQ(EINVAL, errno);
                TH_LOG("skip alarms are not supported.");
                return;
        }

        rc = ioctl(self->fd, RTC_ALM_READ, &tm);
        ASSERT_NE(-1, rc);

        TH_LOG("Alarm time now set to %02d:%02d:%02d.",
               tm.tm_hour, tm.tm_min, tm.tm_sec);

        /* Enable alarm interrupts */
        rc = ioctl(self->fd, RTC_AIE_ON, 0);
        ASSERT_NE(-1, rc);

        FD_ZERO(&readfds);
        FD_SET(self->fd, &readfds);

        rc = select(self->fd + 1, &readfds, NULL, NULL, &tv);
        ASSERT_NE(-1, rc);
        ASSERT_NE(0, rc);

        /* Disable alarm interrupts */
        rc = ioctl(self->fd, RTC_AIE_OFF, 0);
        ASSERT_NE(-1, rc);

        rc = read(self->fd, &data, sizeof(unsigned long));
        ASSERT_NE(-1, rc);
        TH_LOG("data: %lx", data);

        rc = ioctl(self->fd, RTC_RD_TIME, &tm);
        ASSERT_NE(-1, rc);

        new = timegm((struct tm *)&tm);
        ASSERT_EQ(new, secs);
}

TEST_F(rtc, alarm_wkalm_set) {
        struct timeval tv = { .tv_sec = ALARM_DELTA + 2 };
        struct rtc_wkalrm alarm = { 0 };
        struct rtc_time tm;
        unsigned long data;
        fd_set readfds;
        time_t secs, new;
        int rc;
        enum rtc_alarm_state alarm_state = RTC_ALARM_UNKNOWN;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        alarm_state = get_rtc_alarm_state(self->fd, 1);
        if (alarm_state == RTC_ALARM_DISABLED)
                SKIP(return, "Skipping test since alarms are not supported.");
        if (alarm_state == RTC_ALARM_RES_MINUTE)
                SKIP(return, "Skipping test since alarms has only minute granularity.");

        rc = ioctl(self->fd, RTC_RD_TIME, &alarm.time);
        ASSERT_NE(-1, rc);

        secs = timegm((struct tm *)&alarm.time) + ALARM_DELTA;
        gmtime_r(&secs, (struct tm *)&alarm.time);

        alarm.enabled = 1;

        rc = ioctl(self->fd, RTC_WKALM_SET, &alarm);
        if (rc == -1) {
                /*
                 * Report error if rtc alarm was enabled. Fallback to check ioctl
                 * error number if rtc alarm state is unknown.
                 */
                ASSERT_EQ(RTC_ALARM_UNKNOWN, alarm_state);
                ASSERT_EQ(EINVAL, errno);
                TH_LOG("skip alarms are not supported.");
                return;
        }

        rc = ioctl(self->fd, RTC_WKALM_RD, &alarm);
        ASSERT_NE(-1, rc);

        TH_LOG("Alarm time now set to %02d/%02d/%02d %02d:%02d:%02d.",
               alarm.time.tm_mday, alarm.time.tm_mon + 1,
               alarm.time.tm_year + 1900, alarm.time.tm_hour,
               alarm.time.tm_min, alarm.time.tm_sec);

        FD_ZERO(&readfds);
        FD_SET(self->fd, &readfds);

        rc = select(self->fd + 1, &readfds, NULL, NULL, &tv);
        ASSERT_NE(-1, rc);
        ASSERT_NE(0, rc);

        rc = read(self->fd, &data, sizeof(unsigned long));
        ASSERT_NE(-1, rc);

        rc = ioctl(self->fd, RTC_RD_TIME, &tm);
        ASSERT_NE(-1, rc);

        new = timegm((struct tm *)&tm);
        ASSERT_EQ(new, secs);
}

TEST_F_TIMEOUT(rtc, alarm_alm_set_minute, 65) {
        struct timeval tv = { .tv_sec = 62 };
        unsigned long data;
        struct rtc_time tm;
        fd_set readfds;
        time_t secs, new;
        int rc;
        enum rtc_alarm_state alarm_state = RTC_ALARM_UNKNOWN;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        alarm_state = get_rtc_alarm_state(self->fd, 0);
        if (alarm_state == RTC_ALARM_DISABLED)
                SKIP(return, "Skipping test since alarms are not supported.");

        rc = ioctl(self->fd, RTC_RD_TIME, &tm);
        ASSERT_NE(-1, rc);

        secs = timegm((struct tm *)&tm) + 60 - tm.tm_sec;
        gmtime_r(&secs, (struct tm *)&tm);

        rc = ioctl(self->fd, RTC_ALM_SET, &tm);
        if (rc == -1) {
                /*
                 * Report error if rtc alarm was enabled. Fallback to check ioctl
                 * error number if rtc alarm state is unknown.
                 */
                ASSERT_EQ(RTC_ALARM_UNKNOWN, alarm_state);
                ASSERT_EQ(EINVAL, errno);
                TH_LOG("skip alarms are not supported.");
                return;
        }

        rc = ioctl(self->fd, RTC_ALM_READ, &tm);
        ASSERT_NE(-1, rc);

        TH_LOG("Alarm time now set to %02d:%02d:%02d.",
               tm.tm_hour, tm.tm_min, tm.tm_sec);

        /* Enable alarm interrupts */
        rc = ioctl(self->fd, RTC_AIE_ON, 0);
        ASSERT_NE(-1, rc);

        FD_ZERO(&readfds);
        FD_SET(self->fd, &readfds);

        rc = select(self->fd + 1, &readfds, NULL, NULL, &tv);
        ASSERT_NE(-1, rc);
        ASSERT_NE(0, rc);

        /* Disable alarm interrupts */
        rc = ioctl(self->fd, RTC_AIE_OFF, 0);
        ASSERT_NE(-1, rc);

        rc = read(self->fd, &data, sizeof(unsigned long));
        ASSERT_NE(-1, rc);
        TH_LOG("data: %lx", data);

        rc = ioctl(self->fd, RTC_RD_TIME, &tm);
        ASSERT_NE(-1, rc);

        new = timegm((struct tm *)&tm);
        ASSERT_EQ(new, secs);
}

TEST_F_TIMEOUT(rtc, alarm_wkalm_set_minute, 65) {
        struct timeval tv = { .tv_sec = 62 };
        struct rtc_wkalrm alarm = { 0 };
        struct rtc_time tm;
        unsigned long data;
        fd_set readfds;
        time_t secs, new;
        int rc;
        enum rtc_alarm_state alarm_state = RTC_ALARM_UNKNOWN;

        if (self->fd == -1 && errno == ENOENT)
                SKIP(return, "Skipping test since %s does not exist", rtc_file);
        ASSERT_NE(-1, self->fd);

        alarm_state = get_rtc_alarm_state(self->fd, 0);
        if (alarm_state == RTC_ALARM_DISABLED)
                SKIP(return, "Skipping test since alarms are not supported.");

        rc = ioctl(self->fd, RTC_RD_TIME, &alarm.time);
        ASSERT_NE(-1, rc);

        secs = timegm((struct tm *)&alarm.time) + 60 - alarm.time.tm_sec;
        gmtime_r(&secs, (struct tm *)&alarm.time);

        alarm.enabled = 1;

        rc = ioctl(self->fd, RTC_WKALM_SET, &alarm);
        if (rc == -1) {
                /*
                 * Report error if rtc alarm was enabled. Fallback to check ioctl
                 * error number if rtc alarm state is unknown.
                 */
                ASSERT_EQ(RTC_ALARM_UNKNOWN, alarm_state);
                ASSERT_EQ(EINVAL, errno);
                TH_LOG("skip alarms are not supported.");
                return;
        }

        rc = ioctl(self->fd, RTC_WKALM_RD, &alarm);
        ASSERT_NE(-1, rc);

        TH_LOG("Alarm time now set to %02d/%02d/%02d %02d:%02d:%02d.",
               alarm.time.tm_mday, alarm.time.tm_mon + 1,
               alarm.time.tm_year + 1900, alarm.time.tm_hour,
               alarm.time.tm_min, alarm.time.tm_sec);

        FD_ZERO(&readfds);
        FD_SET(self->fd, &readfds);

        rc = select(self->fd + 1, &readfds, NULL, NULL, &tv);
        ASSERT_NE(-1, rc);
        ASSERT_NE(0, rc);

        rc = read(self->fd, &data, sizeof(unsigned long));
        ASSERT_NE(-1, rc);

        rc = ioctl(self->fd, RTC_RD_TIME, &tm);
        ASSERT_NE(-1, rc);

        new = timegm((struct tm *)&tm);
        ASSERT_EQ(new, secs);
}

int main(int argc, char **argv)
{
        int ret = -1;

        switch (argc) {
        case 2:
                rtc_file = argv[1];
                /* FALLTHROUGH */
        case 1:
                break;
        default:
                fprintf(stderr, "usage: %s [rtcdev]\n", argv[0]);
                return 1;
        }

        /* Run the test if rtc_file is accessible */
        if (access(rtc_file, R_OK) == 0)
                ret = test_harness_run(argc, argv);
        else
                ksft_exit_skip("[SKIP]: Cannot access rtc file %s - Exiting\n",
                                                rtc_file);

        return ret;
}