// SPDX-License-Identifier: GPL-2.0
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#include <linux/kernel.h>
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#include <linux/time.h>
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#include <linux/timer.h>
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#include <linux/init.h>
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#include <linux/rtc.h>
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#include <linux/delay.h>
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#include <linux/ratelimit.h>
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#include <asm/prom.h>
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#include <asm/rtas.h>
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#include <asm/time.h>
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#define MAX_RTC_WAIT 5000 /* 5 sec */
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#define RTAS_CLOCK_BUSY (-2)
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time64_t __init rtas_get_boot_time(void)
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{
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int ret[8];
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int error;
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unsigned int wait_time;
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u64 max_wait_tb;
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max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
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do {
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error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
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wait_time = rtas_busy_delay_time(error);
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if (wait_time) {
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/* This is boot time so we spin. */
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udelay(wait_time*1000);
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}
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} while (wait_time && (get_tb() < max_wait_tb));
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if (error != 0) {
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printk_ratelimited(KERN_WARNING
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"error: reading the clock failed (%d)\n",
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error);
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return 0;
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}
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return mktime64(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]);
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}
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/* NOTE: get_rtc_time will get an error if executed in interrupt context
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* and if a delay is needed to read the clock. In this case we just
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* silently return without updating rtc_tm.
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*/
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void rtas_get_rtc_time(struct rtc_time *rtc_tm)
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{
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int ret[8];
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int error;
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unsigned int wait_time;
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u64 max_wait_tb;
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max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
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do {
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error = rtas_call(rtas_token("get-time-of-day"), 0, 8, ret);
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wait_time = rtas_busy_delay_time(error);
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if (wait_time) {
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if (in_interrupt()) {
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memset(rtc_tm, 0, sizeof(struct rtc_time));
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printk_ratelimited(KERN_WARNING
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"error: reading clock "
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"would delay interrupt\n");
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return; /* delay not allowed */
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}
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msleep(wait_time);
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}
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} while (wait_time && (get_tb() < max_wait_tb));
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if (error != 0) {
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printk_ratelimited(KERN_WARNING
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"error: reading the clock failed (%d)\n",
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error);
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return;
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}
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rtc_tm->tm_sec = ret[5];
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rtc_tm->tm_min = ret[4];
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rtc_tm->tm_hour = ret[3];
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rtc_tm->tm_mday = ret[2];
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rtc_tm->tm_mon = ret[1] - 1;
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rtc_tm->tm_year = ret[0] - 1900;
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}
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int rtas_set_rtc_time(struct rtc_time *tm)
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{
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int error, wait_time;
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u64 max_wait_tb;
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max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT;
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do {
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error = rtas_call(rtas_token("set-time-of-day"), 7, 1, NULL,
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tm->tm_year + 1900, tm->tm_mon + 1,
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tm->tm_mday, tm->tm_hour, tm->tm_min,
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tm->tm_sec, 0);
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wait_time = rtas_busy_delay_time(error);
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if (wait_time) {
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if (in_interrupt())
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return 1; /* probably decrementer */
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msleep(wait_time);
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}
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} while (wait_time && (get_tb() < max_wait_tb));
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if (error != 0)
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printk_ratelimited(KERN_WARNING
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"error: setting the clock failed (%d)\n",
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error);
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return 0;
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}
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