// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Support for OLPC XO-1 Real Time Clock (RTC)
 *
 * Copyright (C) 2011 One Laptop per Child
 */

#include <linux/mc146818rtc.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>
#include <linux/of.h>

#include <asm/msr.h>
#include <asm/olpc.h>
#include <asm/x86_init.h>

static void rtc_wake_on(struct device *dev)
{
        olpc_xo1_pm_wakeup_set(CS5536_PM_RTC);
}

static void rtc_wake_off(struct device *dev)
{
        olpc_xo1_pm_wakeup_clear(CS5536_PM_RTC);
}

static struct resource rtc_platform_resource[] = {
        [0] = {
                .start  = RTC_PORT(0),
                .end    = RTC_PORT(1),
                .flags  = IORESOURCE_IO,
        },
        [1] = {
                .start  = RTC_IRQ,
                .end    = RTC_IRQ,
                .flags  = IORESOURCE_IRQ,
        }
};

static struct cmos_rtc_board_info rtc_info = {
        .rtc_day_alarm = 0,
        .rtc_mon_alarm = 0,
        .rtc_century = 0,
        .wake_on = rtc_wake_on,
        .wake_off = rtc_wake_off,
};

static struct platform_device xo1_rtc_device = {
        .name = "rtc_cmos",
        .id = -1,
        .num_resources = ARRAY_SIZE(rtc_platform_resource),
        .dev.platform_data = &rtc_info,
        .resource = rtc_platform_resource,
};

static int __init xo1_rtc_init(void)
{
        int r;
        struct device_node *node;

        node = of_find_compatible_node(NULL, NULL, "olpc,xo1-rtc");
        if (!node)
                return 0;
        of_node_put(node);

        pr_info("olpc-xo1-rtc: Initializing OLPC XO-1 RTC\n");
        rdmsrq(MSR_RTC_DOMA_OFFSET, rtc_info.rtc_day_alarm);
        rdmsrq(MSR_RTC_MONA_OFFSET, rtc_info.rtc_mon_alarm);
        rdmsrq(MSR_RTC_CEN_OFFSET, rtc_info.rtc_century);

        r = platform_device_register(&xo1_rtc_device);
        if (r)
                return r;

        x86_platform.legacy.rtc = 0;

        device_init_wakeup(&xo1_rtc_device.dev, 1);
        return 0;
}
arch_initcall(xo1_rtc_init);