Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  *  linux/arch/alpha/kernel/rtc.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *  Copyright (C) 1991, 1992, 1995, 1999, 2000  Linus Torvalds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * This file contains date handling.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/param.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/mc146818rtc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/bcd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/rtc.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/platform_device.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include "proto.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  * Support for the RTC device.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)  * We don't want to use the rtc-cmos driver, because we don't want to support
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  * alarms, as that would be indistinguishable from timer interrupts.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28)  * Further, generic code is really, really tied to a 1900 epoch.  This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29)  * true in __get_rtc_time as well as the users of struct rtc_time e.g.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30)  * rtc_tm_to_time.  Thankfully all of the other epochs in use are later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31)  * than 1900, and so it's easy to adjust.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) static unsigned long rtc_epoch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) static int __init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) specifiy_epoch(char *str)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 	unsigned long epoch = simple_strtoul(str, NULL, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 	if (epoch < 1900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 		printk("Ignoring invalid user specified epoch %lu\n", epoch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		rtc_epoch = epoch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) __setup("epoch=", specifiy_epoch);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) static void __init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) init_rtc_epoch(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	int epoch, year, ctrl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 	if (rtc_epoch != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		/* The epoch was specified on the command-line.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 	/* Detect the epoch in use on this computer.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 	ctrl = CMOS_READ(RTC_CONTROL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	year = CMOS_READ(RTC_YEAR);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 	if (!(ctrl & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 		year = bcd2bin(year);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	/* PC-like is standard; used for year >= 70 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	epoch = 1900;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	if (year < 20) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 		epoch = 2000;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	} else if (year >= 20 && year < 48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 		/* NT epoch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 		epoch = 1980;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	} else if (year >= 48 && year < 70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 		/* Digital UNIX epoch */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		epoch = 1952;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	rtc_epoch = epoch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	printk(KERN_INFO "Using epoch %d for rtc year %d\n", epoch, year);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) alpha_rtc_read_time(struct device *dev, struct rtc_time *tm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	mc146818_get_time(tm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	/* Adjust for non-default epochs.  It's easier to depend on the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	   generic __get_rtc_time and adjust the epoch here than create
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	   a copy of __get_rtc_time with the edits we need.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	if (rtc_epoch != 1900) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		int year = tm->tm_year;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		/* Undo the century adjustment made in __get_rtc_time.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		if (year >= 100)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 			year -= 100;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		year += rtc_epoch - 1900;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		/* Redo the century adjustment with the epoch in place.  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 		if (year <= 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 			year += 100;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		tm->tm_year = year;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) alpha_rtc_set_time(struct device *dev, struct rtc_time *tm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 	struct rtc_time xtm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	if (rtc_epoch != 1900) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 		xtm = *tm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		xtm.tm_year -= rtc_epoch - 1900;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		tm = &xtm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	return mc146818_set_time(tm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) alpha_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 	switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	case RTC_EPOCH_READ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 		return put_user(rtc_epoch, (unsigned long __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	case RTC_EPOCH_SET:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 		if (arg < 1900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 			return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		rtc_epoch = arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 		return -ENOIOCTLCMD;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) static const struct rtc_class_ops alpha_rtc_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	.read_time = alpha_rtc_read_time,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	.set_time = alpha_rtc_set_time,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	.ioctl = alpha_rtc_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140)  * Similarly, except do the actual CMOS access on the boot cpu only.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)  * This requires marshalling the data across an interprocessor call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) #if defined(CONFIG_SMP) && \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)     (defined(CONFIG_ALPHA_GENERIC) || defined(CONFIG_ALPHA_MARVEL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) # define HAVE_REMOTE_RTC 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) union remote_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	struct rtc_time *tm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 	long retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) do_remote_read(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	union remote_data *x = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	x->retval = alpha_rtc_read_time(NULL, x->tm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) remote_read_time(struct device *dev, struct rtc_time *tm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	union remote_data x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	if (smp_processor_id() != boot_cpuid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		x.tm = tm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 		smp_call_function_single(boot_cpuid, do_remote_read, &x, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 		return x.retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	return alpha_rtc_read_time(NULL, tm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) static void
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) do_remote_set(void *data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	union remote_data *x = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	x->retval = alpha_rtc_set_time(NULL, x->tm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) static int
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) remote_set_time(struct device *dev, struct rtc_time *tm)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	union remote_data x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	if (smp_processor_id() != boot_cpuid) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		x.tm = tm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		smp_call_function_single(boot_cpuid, do_remote_set, &x, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		return x.retval;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	return alpha_rtc_set_time(NULL, tm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) static const struct rtc_class_ops remote_rtc_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	.read_time = remote_read_time,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) 	.set_time = remote_set_time,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	.ioctl = alpha_rtc_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) static int __init
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) alpha_rtc_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	struct platform_device *pdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	struct rtc_device *rtc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	init_rtc_epoch();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	pdev = platform_device_register_simple("rtc-alpha", -1, NULL, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	rtc = devm_rtc_allocate_device(&pdev->dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	if (IS_ERR(rtc))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 		return PTR_ERR(rtc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	platform_set_drvdata(pdev, rtc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	rtc->ops = &alpha_rtc_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) #ifdef HAVE_REMOTE_RTC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	if (alpha_mv.rtc_boot_cpu_only)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 		rtc->ops = &remote_rtc_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	return rtc_register_device(rtc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) device_initcall(alpha_rtc_init);