linux-imx

/* rtc-sun4v.c: Hypervisor based RTC for SUN4V systems.

 *

 * Author: David S. Miller

 * License: GPL

 *

 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>

 */

​

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

​

#include <linux/kernel.h>

#include <linux/delay.h>

#include <linux/init.h>

#include <linux/rtc.h>

#include <linux/platform_device.h>

​

#include <asm/hypervisor.h>

​

static unsigned long hypervisor_get_time(void)

{

    unsigned long ret, time;

    int retries = 10000;

​

retry:

    ret = sun4v_tod_get(&time);

    if (ret == HV_EOK)

        return time;

    if (ret == HV_EWOULDBLOCK) {

        if (--retries > 0) {

            udelay(100);

            goto retry;

        }

        pr_warn("tod_get() timed out.\n");

        return 0;

    }

    pr_warn("tod_get() not supported.\n");

    return 0;

}

​

static int sun4v_read_time(struct device *dev, struct rtc_time *tm)

{

    rtc_time_to_tm(hypervisor_get_time(), tm);

    return 0;

}

​

static int hypervisor_set_time(unsigned long secs)

{

    unsigned long ret;

    int retries = 10000;

​

retry:

    ret = sun4v_tod_set(secs);

    if (ret == HV_EOK)

        return 0;

    if (ret == HV_EWOULDBLOCK) {

        if (--retries > 0) {

            udelay(100);

            goto retry;

        }

        pr_warn("tod_set() timed out.\n");

        return -EAGAIN;

    }

    pr_warn("tod_set() not supported.\n");