cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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rtc.c (4336B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support
      4 *
      5 *  Copyright (C) 2004  Saito.K & Jeanne(ksaito@interface.co.jp)
      6 *
      7 */
      8
      9#include <linux/init.h>
     10#include <linux/kernel.h>
     11#include <linux/sched.h>
     12#include <linux/time.h>
     13#include <linux/bcd.h>
     14#include <linux/spinlock.h>
     15#include <linux/io.h>
     16#include <linux/rtc.h>
     17#include <linux/platform_device.h>
     18
     19#define RTC_BASE	0xb0000000
     20#define RTC_SEC1	(RTC_BASE + 0)
     21#define RTC_SEC10	(RTC_BASE + 1)
     22#define RTC_MIN1	(RTC_BASE + 2)
     23#define RTC_MIN10	(RTC_BASE + 3)
     24#define RTC_HOU1	(RTC_BASE + 4)
     25#define RTC_HOU10	(RTC_BASE + 5)
     26#define RTC_WEE1	(RTC_BASE + 6)
     27#define RTC_DAY1	(RTC_BASE + 7)
     28#define RTC_DAY10	(RTC_BASE + 8)
     29#define RTC_MON1	(RTC_BASE + 9)
     30#define RTC_MON10	(RTC_BASE + 10)
     31#define RTC_YEA1	(RTC_BASE + 11)
     32#define RTC_YEA10	(RTC_BASE + 12)
     33#define RTC_YEA100	(RTC_BASE + 13)
     34#define RTC_YEA1000	(RTC_BASE + 14)
     35#define RTC_CTL		(RTC_BASE + 15)
     36#define RTC_BUSY	1
     37#define RTC_STOP	2
     38
     39static DEFINE_SPINLOCK(sh03_rtc_lock);
     40
     41static int sh03_rtc_gettimeofday(struct device *dev, struct rtc_time *tm)
     42{
     43	unsigned int year, mon, day, hour, min, sec;
     44
     45	spin_lock(&sh03_rtc_lock);
     46 again:
     47	do {
     48		sec  = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10;
     49		min  = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
     50		hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10;
     51		day  = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10;
     52		mon  = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10;
     53		year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10
     54		     + (__raw_readb(RTC_YEA100 ) & 0xf) * 100
     55		     + (__raw_readb(RTC_YEA1000) & 0xf) * 1000;
     56	} while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10);
     57	if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
     58	    hour > 23 || min > 59 || sec > 59) {
     59		printk(KERN_ERR
     60		       "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
     61		printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
     62		       year, mon, day, hour, min, sec);
     63
     64		__raw_writeb(0, RTC_SEC1); __raw_writeb(0, RTC_SEC10);
     65		__raw_writeb(0, RTC_MIN1); __raw_writeb(0, RTC_MIN10);
     66		__raw_writeb(0, RTC_HOU1); __raw_writeb(0, RTC_HOU10);
     67		__raw_writeb(6, RTC_WEE1);
     68		__raw_writeb(1, RTC_DAY1); __raw_writeb(0, RTC_DAY10);
     69		__raw_writeb(1, RTC_MON1); __raw_writeb(0, RTC_MON10);
     70		__raw_writeb(0, RTC_YEA1); __raw_writeb(0, RTC_YEA10);
     71		__raw_writeb(0, RTC_YEA100);
     72		__raw_writeb(2, RTC_YEA1000);
     73		__raw_writeb(0, RTC_CTL);
     74		goto again;
     75	}
     76
     77	spin_unlock(&sh03_rtc_lock);
     78
     79	tm->tm_sec  = sec;
     80	tm->tm_min  = min;
     81	tm->tm_hour = hour;
     82	tm->tm_mday = day;
     83	tm->tm_mon  = mon;
     84	tm->tm_year = year - 1900;
     85
     86	return 0;
     87}
     88
     89static int set_rtc_mmss(struct rtc_time *tm)
     90{
     91	int retval = 0;
     92	int real_seconds, real_minutes, cmos_minutes;
     93	int i;
     94
     95	/* gets recalled with irq locally disabled */
     96	spin_lock(&sh03_rtc_lock);
     97	for (i = 0 ; i < 1000000 ; i++)	/* may take up to 1 second... */
     98		if (!(__raw_readb(RTC_CTL) & RTC_BUSY))
     99			break;
    100	cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
    101	real_seconds = tm->tm_sec;
    102	real_minutes = tm->tm_min;
    103	if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
    104		real_minutes += 30;		/* correct for half hour time zone */
    105	real_minutes %= 60;
    106
    107	if (abs(real_minutes - cmos_minutes) < 30) {
    108		__raw_writeb(real_seconds % 10, RTC_SEC1);
    109		__raw_writeb(real_seconds / 10, RTC_SEC10);
    110		__raw_writeb(real_minutes % 10, RTC_MIN1);
    111		__raw_writeb(real_minutes / 10, RTC_MIN10);
    112	} else {
    113		printk_once(KERN_NOTICE
    114		       "set_rtc_mmss: can't update from %d to %d\n",
    115		       cmos_minutes, real_minutes);
    116		retval = -EINVAL;
    117	}
    118	spin_unlock(&sh03_rtc_lock);
    119
    120	return retval;
    121}
    122
    123int sh03_rtc_settimeofday(struct device *dev, struct rtc_time *tm)
    124{
    125	return set_rtc_mmss(tm);
    126}
    127
    128static const struct rtc_class_ops rtc_generic_ops = {
    129	.read_time = sh03_rtc_gettimeofday,
    130	.set_time = sh03_rtc_settimeofday,
    131};
    132
    133static int __init sh03_time_init(void)
    134{
    135	struct platform_device *pdev;
    136
    137	pdev = platform_device_register_data(NULL, "rtc-generic", -1,
    138					     &rtc_generic_ops,
    139					     sizeof(rtc_generic_ops));
    140
    141	return PTR_ERR_OR_ZERO(pdev);
    142}
    143arch_initcall(sh03_time_init);