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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 | // SPDX-License-Identifier: GPL-2.0 #include <linux/kernel.h> #include <linux/time.h> #include <linux/timer.h> #include <linux/init.h> #include <linux/rtc.h> #include <linux/delay.h> #include <linux/ratelimit.h> #include <asm/rtas.h> #include <asm/time.h> #define MAX_RTC_WAIT 5000 /* 5 sec */ time64_t __init rtas_get_boot_time(void) { int ret[8]; int error; unsigned int wait_time; u64 max_wait_tb; max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT; do { error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret); wait_time = rtas_busy_delay_time(error); if (wait_time) { /* This is boot time so we spin. */ udelay(wait_time*1000); } } while (wait_time && (get_tb() < max_wait_tb)); if (error != 0) { printk_ratelimited(KERN_WARNING "error: reading the clock failed (%d)\n", error); return 0; } return mktime64(ret[0], ret[1], ret[2], ret[3], ret[4], ret[5]); } /* NOTE: get_rtc_time will get an error if executed in interrupt context * and if a delay is needed to read the clock. In this case we just * silently return without updating rtc_tm. */ void rtas_get_rtc_time(struct rtc_time *rtc_tm) { int ret[8]; int error; unsigned int wait_time; u64 max_wait_tb; max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT; do { error = rtas_call(rtas_function_token(RTAS_FN_GET_TIME_OF_DAY), 0, 8, ret); wait_time = rtas_busy_delay_time(error); if (wait_time) { if (in_interrupt()) { memset(rtc_tm, 0, sizeof(struct rtc_time)); printk_ratelimited(KERN_WARNING "error: reading clock " "would delay interrupt\n"); return; /* delay not allowed */ } msleep(wait_time); } } while (wait_time && (get_tb() < max_wait_tb)); if (error != 0) { printk_ratelimited(KERN_WARNING "error: reading the clock failed (%d)\n", error); return; } rtc_tm->tm_sec = ret[5]; rtc_tm->tm_min = ret[4]; rtc_tm->tm_hour = ret[3]; rtc_tm->tm_mday = ret[2]; rtc_tm->tm_mon = ret[1] - 1; rtc_tm->tm_year = ret[0] - 1900; } int rtas_set_rtc_time(struct rtc_time *tm) { int error, wait_time; u64 max_wait_tb; max_wait_tb = get_tb() + tb_ticks_per_usec * 1000 * MAX_RTC_WAIT; do { error = rtas_call(rtas_function_token(RTAS_FN_SET_TIME_OF_DAY), 7, 1, NULL, tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec, 0); wait_time = rtas_busy_delay_time(error); if (wait_time) { if (in_interrupt()) return 1; /* probably decrementer */ msleep(wait_time); } } while (wait_time && (get_tb() < max_wait_tb)); if (error != 0) printk_ratelimited(KERN_WARNING "error: setting the clock failed (%d)\n", error); return 0; } |