blob: 79011a263aa6b26c2227c44e064a4a4cf3f2ad66 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PowerNV Real Time Clock.
*
* Copyright 2011 IBM Corp.
*/
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <asm/opal.h>
#include <asm/firmware.h>
#include <asm/machdep.h>
static void __init opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
{
tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) +
bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1;
tm->tm_mday = bcd2bin(y_m_d & 0xff);
tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff);
tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff);
tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff);
tm->tm_wday = -1;
}
time64_t __init opal_get_boot_time(void)
{
struct rtc_time tm;
u32 y_m_d;
u64 h_m_s_ms;
__be32 __y_m_d;
__be64 __h_m_s_ms;
long rc = OPAL_BUSY;
if (!opal_check_token(OPAL_RTC_READ))
return 0;
while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
if (rc == OPAL_BUSY_EVENT) {
mdelay(OPAL_BUSY_DELAY_MS);
opal_poll_events(NULL);
} else if (rc == OPAL_BUSY) {
mdelay(OPAL_BUSY_DELAY_MS);
}
}
if (rc != OPAL_SUCCESS)
return 0;
y_m_d = be32_to_cpu(__y_m_d);
h_m_s_ms = be64_to_cpu(__h_m_s_ms);
opal_to_tm(y_m_d, h_m_s_ms, &tm);
return rtc_tm_to_time64(&tm);
}
static __init int opal_time_init(void)
{
struct platform_device *pdev;
struct device_node *rtc;
rtc = of_find_node_by_path("/ibm,opal/rtc");
if (rtc) {
pdev = of_platform_device_create(rtc, "opal-rtc", NULL);
of_node_put(rtc);
} else {
if (opal_check_token(OPAL_RTC_READ) ||
opal_check_token(OPAL_READ_TPO))
pdev = platform_device_register_simple("opal-rtc", -1,
NULL, 0);
else
return -ENODEV;
}
return PTR_ERR_OR_ZERO(pdev);
}
machine_subsys_initcall(powernv, opal_time_init);