blob: 91606411d2e08b2ca0c5938829fb2ca5b088cbda [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* (c) Copyright 2004 Benjamin Herrenschmidt (benh@kernel.crashing.org),
* IBM Corp.
*/
#undef DEBUG
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/time.h>
#include <linux/adb.h>
#include <linux/pmu.h>
#include <linux/interrupt.h>
#include <linux/mc146818rtc.h>
#include <linux/bcd.h>
#include <linux/of_address.h>
#include <asm/sections.h>
#include <asm/io.h>
#include <asm/machdep.h>
#include <asm/time.h>
#include "maple.h"
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
static int maple_rtc_addr;
static int maple_clock_read(int addr)
{
outb_p(addr, maple_rtc_addr);
return inb_p(maple_rtc_addr+1);
}
static void maple_clock_write(unsigned long val, int addr)
{
outb_p(addr, maple_rtc_addr);
outb_p(val, maple_rtc_addr+1);
}
void maple_get_rtc_time(struct rtc_time *tm)
{
do {
tm->tm_sec = maple_clock_read(RTC_SECONDS);
tm->tm_min = maple_clock_read(RTC_MINUTES);
tm->tm_hour = maple_clock_read(RTC_HOURS);
tm->tm_mday = maple_clock_read(RTC_DAY_OF_MONTH);
tm->tm_mon = maple_clock_read(RTC_MONTH);
tm->tm_year = maple_clock_read(RTC_YEAR);
} while (tm->tm_sec != maple_clock_read(RTC_SECONDS));
if (!(maple_clock_read(RTC_CONTROL) & RTC_DM_BINARY)
|| RTC_ALWAYS_BCD) {
tm->tm_sec = bcd2bin(tm->tm_sec);
tm->tm_min = bcd2bin(tm->tm_min);
tm->tm_hour = bcd2bin(tm->tm_hour);
tm->tm_mday = bcd2bin(tm->tm_mday);
tm->tm_mon = bcd2bin(tm->tm_mon);
tm->tm_year = bcd2bin(tm->tm_year);
}
if ((tm->tm_year + 1900) < 1970)
tm->tm_year += 100;
tm->tm_wday = -1;
}
int maple_set_rtc_time(struct rtc_time *tm)
{
unsigned char save_control, save_freq_select;
int sec, min, hour, mon, mday, year;
spin_lock(&rtc_lock);
save_control = maple_clock_read(RTC_CONTROL); /* tell the clock it's being set */
maple_clock_write((save_control|RTC_SET), RTC_CONTROL);
save_freq_select = maple_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
maple_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
sec = tm->tm_sec;
min = tm->tm_min;
hour = tm->tm_hour;
mon = tm->tm_mon;
mday = tm->tm_mday;
year = tm->tm_year;
if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
sec = bin2bcd(sec);
min = bin2bcd(min);
hour = bin2bcd(hour);
mon = bin2bcd(mon);
mday = bin2bcd(mday);
year = bin2bcd(year);
}
maple_clock_write(sec, RTC_SECONDS);
maple_clock_write(min, RTC_MINUTES);
maple_clock_write(hour, RTC_HOURS);
maple_clock_write(mon, RTC_MONTH);
maple_clock_write(mday, RTC_DAY_OF_MONTH);
maple_clock_write(year, RTC_YEAR);
/* The following flags have to be released exactly in this order,
* otherwise the DS12887 (popular MC146818A clone with integrated
* battery and quartz) will not reset the oscillator and will not
* update precisely 500 ms later. You won't find this mentioned in
* the Dallas Semiconductor data sheets, but who believes data
* sheets anyway ... -- Markus Kuhn
*/
maple_clock_write(save_control, RTC_CONTROL);
maple_clock_write(save_freq_select, RTC_FREQ_SELECT);
spin_unlock(&rtc_lock);
return 0;
}
static struct resource rtc_iores = {
.name = "rtc",
.flags = IORESOURCE_IO | IORESOURCE_BUSY,
};
time64_t __init maple_get_boot_time(void)
{
struct rtc_time tm;
struct device_node *rtcs;
rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
if (rtcs) {
struct resource r;
if (of_address_to_resource(rtcs, 0, &r)) {
printk(KERN_EMERG "Maple: Unable to translate RTC"
" address\n");
goto bail;
}
if (!(r.flags & IORESOURCE_IO)) {
printk(KERN_EMERG "Maple: RTC address isn't PIO!\n");
goto bail;
}
maple_rtc_addr = r.start;
printk(KERN_INFO "Maple: Found RTC at IO 0x%x\n",
maple_rtc_addr);
}
bail:
of_node_put(rtcs);
if (maple_rtc_addr == 0) {
maple_rtc_addr = RTC_PORT(0); /* legacy address */
printk(KERN_INFO "Maple: No device node for RTC, assuming "
"legacy address (0x%x)\n", maple_rtc_addr);
}
rtc_iores.start = maple_rtc_addr;
rtc_iores.end = maple_rtc_addr + 7;
request_resource(&ioport_resource, &rtc_iores);
maple_get_rtc_time(&tm);
return rtc_tm_to_time64(&tm);
}