arch/powerpc/platforms/powernv/opal-rtc.c

   1 /*
   2  * PowerNV Real Time Clock.
   3  *
   4  * Copyright 2011 IBM Corp.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12
  13 #include <linux/kernel.h>
  14 #include <linux/time.h>
  15 #include <linux/bcd.h>
  16 #include <linux/rtc.h>
  17 #include <linux/delay.h>
  18
  19 #include <asm/opal.h>
  20 #include <asm/firmware.h>
  21 #include <asm/machdep.h>
  22
  23 static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
  24 {
  25         tm->tm_year     = ((bcd2bin(y_m_d >> 24) * 100) +
  26                            bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
  27         tm->tm_mon      = bcd2bin((y_m_d >> 8) & 0xff) - 1;
  28         tm->tm_mday     = bcd2bin(y_m_d & 0xff);
  29         tm->tm_hour     = bcd2bin((h_m_s_ms >> 56) & 0xff);
  30         tm->tm_min      = bcd2bin((h_m_s_ms >> 48) & 0xff);
  31         tm->tm_sec      = bcd2bin((h_m_s_ms >> 40) & 0xff);
  32
  33         GregorianDay(tm);
  34 }
  35
  36 unsigned long __init opal_get_boot_time(void)
  37 {
  38         struct rtc_time tm;
  39         u32 y_m_d;
  40         u64 h_m_s_ms;
  41         __be32 __y_m_d;
  42         __be64 __h_m_s_ms;
  43         long rc = OPAL_BUSY;
  44
  45         if (!opal_check_token(OPAL_RTC_READ))
  46                 goto out;
  47
  48         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
  49                 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
  50                 if (rc == OPAL_BUSY_EVENT)
  51                         opal_poll_events(NULL);
  52                 else
  53                         mdelay(10);
  54         }
  55         if (rc != OPAL_SUCCESS)
  56                 goto out;
  57
  58         y_m_d = be32_to_cpu(__y_m_d);
  59         h_m_s_ms = be64_to_cpu(__h_m_s_ms);
  60         opal_to_tm(y_m_d, h_m_s_ms, &tm);
  61         return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
  62                       tm.tm_hour, tm.tm_min, tm.tm_sec);
  63 out:
  64         ppc_md.get_rtc_time = NULL;
  65         ppc_md.set_rtc_time = NULL;
  66         return 0;
  67 }
  68
  69 void opal_get_rtc_time(struct rtc_time *tm)
  70 {
  71         long rc = OPAL_BUSY;
  72         u32 y_m_d;
  73         u64 h_m_s_ms;
  74         __be32 __y_m_d;
  75         __be64 __h_m_s_ms;
  76
  77         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
  78                 rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms);
  79                 if (rc == OPAL_BUSY_EVENT)
  80                         opal_poll_events(NULL);
  81                 else
  82                         mdelay(10);
  83         }
  84         if (rc != OPAL_SUCCESS)
  85                 return;
  86         y_m_d = be32_to_cpu(__y_m_d);
  87         h_m_s_ms = be64_to_cpu(__h_m_s_ms);
  88         opal_to_tm(y_m_d, h_m_s_ms, tm);
  89 }
  90
  91 int opal_set_rtc_time(struct rtc_time *tm)
  92 {
  93         long rc = OPAL_BUSY;
  94         u32 y_m_d = 0;
  95         u64 h_m_s_ms = 0;
  96
  97         y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
  98         y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
  99         y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
 100         y_m_d |= ((u32)bin2bcd(tm->tm_mday));
 101
 102         h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
 103         h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
 104         h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
 105
 106         while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
 107                 rc = opal_rtc_write(y_m_d, h_m_s_ms);
 108                 if (rc == OPAL_BUSY_EVENT)
 109                         opal_poll_events(NULL);
 110                 else
 111                         mdelay(10);
 112         }
 113         return rc == OPAL_SUCCESS ? 0 : -EIO;
 114 }