LXR linux/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
  22static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm)
  23{
  24        tm->tm_year     = ((bcd2bin(y_m_d >> 24) * 100) +
  25                           bcd2bin((y_m_d >> 16) & 0xff)) - 1900;
  26        tm->tm_mon      = bcd2bin((y_m_d >> 8) & 0xff) - 1;
  27        tm->tm_mday     = bcd2bin(y_m_d & 0xff);
  28        tm->tm_hour     = bcd2bin((h_m_s_ms >> 56) & 0xff);
  29        tm->tm_min      = bcd2bin((h_m_s_ms >> 48) & 0xff);
  30        tm->tm_sec      = bcd2bin((h_m_s_ms >> 40) & 0xff);
  31
  32        GregorianDay(tm);
  33}
  34
  35unsigned long __init opal_get_boot_time(void)
  36{
  37        struct rtc_time tm;
  38        u32 y_m_d;
  39        u64 h_m_s_ms;
  40        long rc = OPAL_BUSY;
  41
  42        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
  43                rc = opal_rtc_read(&y_m_d, &h_m_s_ms);
  44                if (rc == OPAL_BUSY_EVENT)
  45                        opal_poll_events(NULL);
  46                else
  47                        mdelay(10);
  48        }
  49        if (rc != OPAL_SUCCESS)
  50                return 0;
  51        opal_to_tm(y_m_d, h_m_s_ms, &tm);
  52        return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
  53                      tm.tm_hour, tm.tm_min, tm.tm_sec);
  54}
  55
  56void opal_get_rtc_time(struct rtc_time *tm)
  57{
  58        long rc = OPAL_BUSY;
  59        u32 y_m_d;
  60        u64 h_m_s_ms;
  61
  62        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
  63                rc = opal_rtc_read(&y_m_d, &h_m_s_ms);
  64                if (rc == OPAL_BUSY_EVENT)
  65                        opal_poll_events(NULL);
  66                else
  67                        mdelay(10);
  68        }
  69        if (rc != OPAL_SUCCESS)
  70                return;
  71        opal_to_tm(y_m_d, h_m_s_ms, tm);
  72}
  73
  74int opal_set_rtc_time(struct rtc_time *tm)
  75{
  76        long rc = OPAL_BUSY;
  77        u32 y_m_d = 0;
  78        u64 h_m_s_ms = 0;
  79
  80        y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) / 100)) << 24;
  81        y_m_d |= ((u32)bin2bcd((tm->tm_year + 1900) % 100)) << 16;
  82        y_m_d |= ((u32)bin2bcd((tm->tm_mon + 1))) << 8;
  83        y_m_d |= ((u32)bin2bcd(tm->tm_mday));
  84
  85        h_m_s_ms |= ((u64)bin2bcd(tm->tm_hour)) << 56;
  86        h_m_s_ms |= ((u64)bin2bcd(tm->tm_min)) << 48;
  87        h_m_s_ms |= ((u64)bin2bcd(tm->tm_sec)) << 40;
  88
  89        while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
  90                rc = opal_rtc_write(y_m_d, h_m_s_ms);
  91                if (rc == OPAL_BUSY_EVENT)
  92                        opal_poll_events(NULL);
  93                else
  94                        mdelay(10);
  95        }
  96        return rc == OPAL_SUCCESS ? 0 : -EIO;
  97}
  98