162 lines
4 KiB
C
162 lines
4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 1991, 1992, 1995 Linus Torvalds
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*
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* Adapted for PowerPC (PReP) by Gary Thomas
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* Modified by Cort Dougan (cort@cs.nmt.edu).
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* Copied and modified from arch/i386/kernel/time.c
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*
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*/
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/param.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/time.h>
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#include <linux/timex.h>
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#include <linux/kernel_stat.h>
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#include <linux/mc146818rtc.h>
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#include <linux/init.h>
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#include <linux/bcd.h>
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#include <linux/ioport.h>
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#include <asm/io.h>
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#include <asm/nvram.h>
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#include <asm/prom.h>
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#include <asm/sections.h>
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#include <asm/time.h>
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#include <platforms/chrp/chrp.h>
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extern spinlock_t rtc_lock;
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#define NVRAM_AS0 0x74
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#define NVRAM_AS1 0x75
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#define NVRAM_DATA 0x77
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static int nvram_as1 = NVRAM_AS1;
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static int nvram_as0 = NVRAM_AS0;
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static int nvram_data = NVRAM_DATA;
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long __init chrp_time_init(void)
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{
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struct device_node *rtcs;
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struct resource r;
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int base;
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rtcs = of_find_compatible_node(NULL, "rtc", "pnpPNP,b00");
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if (rtcs == NULL)
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rtcs = of_find_compatible_node(NULL, "rtc", "ds1385-rtc");
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if (rtcs == NULL)
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return 0;
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if (of_address_to_resource(rtcs, 0, &r)) {
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of_node_put(rtcs);
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return 0;
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}
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of_node_put(rtcs);
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base = r.start;
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nvram_as1 = 0;
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nvram_as0 = base;
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nvram_data = base + 1;
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return 0;
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}
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static int chrp_cmos_clock_read(int addr)
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{
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if (nvram_as1 != 0)
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outb(addr>>8, nvram_as1);
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outb(addr, nvram_as0);
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return (inb(nvram_data));
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}
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static void chrp_cmos_clock_write(unsigned long val, int addr)
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{
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if (nvram_as1 != 0)
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outb(addr>>8, nvram_as1);
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outb(addr, nvram_as0);
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outb(val, nvram_data);
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return;
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}
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/*
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* Set the hardware clock. -- Cort
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*/
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int chrp_set_rtc_time(struct rtc_time *tmarg)
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{
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unsigned char save_control, save_freq_select;
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struct rtc_time tm = *tmarg;
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spin_lock(&rtc_lock);
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save_control = chrp_cmos_clock_read(RTC_CONTROL); /* tell the clock it's being set */
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chrp_cmos_clock_write((save_control|RTC_SET), RTC_CONTROL);
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save_freq_select = chrp_cmos_clock_read(RTC_FREQ_SELECT); /* stop and reset prescaler */
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chrp_cmos_clock_write((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);
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if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
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tm.tm_sec = bin2bcd(tm.tm_sec);
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tm.tm_min = bin2bcd(tm.tm_min);
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tm.tm_hour = bin2bcd(tm.tm_hour);
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tm.tm_mon = bin2bcd(tm.tm_mon);
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tm.tm_mday = bin2bcd(tm.tm_mday);
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tm.tm_year = bin2bcd(tm.tm_year);
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}
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chrp_cmos_clock_write(tm.tm_sec,RTC_SECONDS);
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chrp_cmos_clock_write(tm.tm_min,RTC_MINUTES);
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chrp_cmos_clock_write(tm.tm_hour,RTC_HOURS);
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chrp_cmos_clock_write(tm.tm_mon,RTC_MONTH);
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chrp_cmos_clock_write(tm.tm_mday,RTC_DAY_OF_MONTH);
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chrp_cmos_clock_write(tm.tm_year,RTC_YEAR);
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/* The following flags have to be released exactly in this order,
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* otherwise the DS12887 (popular MC146818A clone with integrated
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* battery and quartz) will not reset the oscillator and will not
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* update precisely 500 ms later. You won't find this mentioned in
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* the Dallas Semiconductor data sheets, but who believes data
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* sheets anyway ... -- Markus Kuhn
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*/
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chrp_cmos_clock_write(save_control, RTC_CONTROL);
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chrp_cmos_clock_write(save_freq_select, RTC_FREQ_SELECT);
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spin_unlock(&rtc_lock);
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return 0;
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}
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void chrp_get_rtc_time(struct rtc_time *tm)
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{
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unsigned int year, mon, day, hour, min, sec;
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do {
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sec = chrp_cmos_clock_read(RTC_SECONDS);
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min = chrp_cmos_clock_read(RTC_MINUTES);
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hour = chrp_cmos_clock_read(RTC_HOURS);
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day = chrp_cmos_clock_read(RTC_DAY_OF_MONTH);
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mon = chrp_cmos_clock_read(RTC_MONTH);
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year = chrp_cmos_clock_read(RTC_YEAR);
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} while (sec != chrp_cmos_clock_read(RTC_SECONDS));
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if (!(chrp_cmos_clock_read(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
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sec = bcd2bin(sec);
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min = bcd2bin(min);
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hour = bcd2bin(hour);
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day = bcd2bin(day);
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mon = bcd2bin(mon);
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year = bcd2bin(year);
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}
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if (year < 70)
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year += 100;
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tm->tm_sec = sec;
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tm->tm_min = min;
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tm->tm_hour = hour;
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tm->tm_mday = day;
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tm->tm_mon = mon;
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tm->tm_year = year;
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}
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