linux/arch/powerpc/platforms/powernv/opal-rtc.c
Neelesh Gupta 16b1d26e77 rtc/tpo: Driver to support rtc and wakeup on PowerNV platform
The patch implements the OPAL rtc driver that binds with the rtc
driver subsystem. The driver uses the platform device infrastructure
to probe the rtc device and register it to rtc class framework. The
'wakeup' is supported depending upon the property 'has-tpo' present
in the OF node. It provides a way to load the generic rtc driver in
in the absence of an OPAL driver.

The patch also moves the existing OPAL rtc get/set time interfaces to the
new driver and exposes the necessary OPAL calls using EXPORT_SYMBOL_GPL.

Test results:
-------------
Host:
[root@tul169p1 ~]# ls -l /sys/class/rtc/
total 0
lrwxrwxrwx 1 root root 0 Oct 14 03:07 rtc0 -> ../../devices/opal-rtc/rtc/rtc0
[root@tul169p1 ~]# cat /sys/devices/opal-rtc/rtc/rtc0/time
08:10:07
[root@tul169p1 ~]# echo `date '+%s' -d '+ 2 minutes'` > /sys/class/rtc/rtc0/wakealarm
[root@tul169p1 ~]# cat /sys/class/rtc/rtc0/wakealarm
1413274345
[root@tul169p1 ~]#

FSP:
$ smgr mfgState
standby
$ rtim timeofday

System time is valid: 2014/10/14 08:12:04.225115

$ smgr mfgState
ipling
$

CC: devicetree@vger.kernel.org
CC: tglx@linutronix.de
CC: rtc-linux@googlegroups.com
CC: a.zummo@towertech.it
Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2014-11-17 18:04:01 +11:00

88 lines
2.1 KiB
C

/*
* PowerNV Real Time Clock.
*
* Copyright 2011 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/of_platform.h>
#include <asm/opal.h>
#include <asm/firmware.h>
#include <asm/machdep.h>
static void 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);
GregorianDay(tm);
}
unsigned long __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)
opal_poll_events(NULL);
else
mdelay(10);
}
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 mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec);
}
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);