1628daa8dSBenjamin Herrenschmidt /* 2628daa8dSBenjamin Herrenschmidt * PowerNV Real Time Clock. 3628daa8dSBenjamin Herrenschmidt * 4628daa8dSBenjamin Herrenschmidt * Copyright 2011 IBM Corp. 5628daa8dSBenjamin Herrenschmidt * 6628daa8dSBenjamin Herrenschmidt * This program is free software; you can redistribute it and/or 7628daa8dSBenjamin Herrenschmidt * modify it under the terms of the GNU General Public License 8628daa8dSBenjamin Herrenschmidt * as published by the Free Software Foundation; either version 9628daa8dSBenjamin Herrenschmidt * 2 of the License, or (at your option) any later version. 10628daa8dSBenjamin Herrenschmidt */ 11628daa8dSBenjamin Herrenschmidt 12628daa8dSBenjamin Herrenschmidt 13628daa8dSBenjamin Herrenschmidt #include <linux/kernel.h> 14628daa8dSBenjamin Herrenschmidt #include <linux/time.h> 15628daa8dSBenjamin Herrenschmidt #include <linux/bcd.h> 16628daa8dSBenjamin Herrenschmidt #include <linux/rtc.h> 17628daa8dSBenjamin Herrenschmidt #include <linux/delay.h> 1816b1d26eSNeelesh Gupta #include <linux/platform_device.h> 1916b1d26eSNeelesh Gupta #include <linux/of_platform.h> 20628daa8dSBenjamin Herrenschmidt 21628daa8dSBenjamin Herrenschmidt #include <asm/opal.h> 22628daa8dSBenjamin Herrenschmidt #include <asm/firmware.h> 232c49195bSMichael Neuling #include <asm/machdep.h> 24628daa8dSBenjamin Herrenschmidt 25628daa8dSBenjamin Herrenschmidt static void opal_to_tm(u32 y_m_d, u64 h_m_s_ms, struct rtc_time *tm) 26628daa8dSBenjamin Herrenschmidt { 27628daa8dSBenjamin Herrenschmidt tm->tm_year = ((bcd2bin(y_m_d >> 24) * 100) + 28628daa8dSBenjamin Herrenschmidt bcd2bin((y_m_d >> 16) & 0xff)) - 1900; 29628daa8dSBenjamin Herrenschmidt tm->tm_mon = bcd2bin((y_m_d >> 8) & 0xff) - 1; 30628daa8dSBenjamin Herrenschmidt tm->tm_mday = bcd2bin(y_m_d & 0xff); 31628daa8dSBenjamin Herrenschmidt tm->tm_hour = bcd2bin((h_m_s_ms >> 56) & 0xff); 32628daa8dSBenjamin Herrenschmidt tm->tm_min = bcd2bin((h_m_s_ms >> 48) & 0xff); 33628daa8dSBenjamin Herrenschmidt tm->tm_sec = bcd2bin((h_m_s_ms >> 40) & 0xff); 3400b912b0SDaniel Axtens tm->tm_wday = -1; 35628daa8dSBenjamin Herrenschmidt } 36628daa8dSBenjamin Herrenschmidt 37628daa8dSBenjamin Herrenschmidt unsigned long __init opal_get_boot_time(void) 38628daa8dSBenjamin Herrenschmidt { 39628daa8dSBenjamin Herrenschmidt struct rtc_time tm; 40628daa8dSBenjamin Herrenschmidt u32 y_m_d; 41628daa8dSBenjamin Herrenschmidt u64 h_m_s_ms; 426feff6d4SAnton Blanchard __be32 __y_m_d; 436feff6d4SAnton Blanchard __be64 __h_m_s_ms; 44628daa8dSBenjamin Herrenschmidt long rc = OPAL_BUSY; 45628daa8dSBenjamin Herrenschmidt 46035ed26fSMichael Neuling if (!opal_check_token(OPAL_RTC_READ)) 4716b1d26eSNeelesh Gupta return 0; 48035ed26fSMichael Neuling 49628daa8dSBenjamin Herrenschmidt while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) { 506feff6d4SAnton Blanchard rc = opal_rtc_read(&__y_m_d, &__h_m_s_ms); 51628daa8dSBenjamin Herrenschmidt if (rc == OPAL_BUSY_EVENT) 52628daa8dSBenjamin Herrenschmidt opal_poll_events(NULL); 53628daa8dSBenjamin Herrenschmidt else 54628daa8dSBenjamin Herrenschmidt mdelay(10); 55628daa8dSBenjamin Herrenschmidt } 56035ed26fSMichael Neuling if (rc != OPAL_SUCCESS) 5716b1d26eSNeelesh Gupta return 0; 58035ed26fSMichael Neuling 596feff6d4SAnton Blanchard y_m_d = be32_to_cpu(__y_m_d); 606feff6d4SAnton Blanchard h_m_s_ms = be64_to_cpu(__h_m_s_ms); 61628daa8dSBenjamin Herrenschmidt opal_to_tm(y_m_d, h_m_s_ms, &tm); 62628daa8dSBenjamin Herrenschmidt return mktime(tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, 63628daa8dSBenjamin Herrenschmidt tm.tm_hour, tm.tm_min, tm.tm_sec); 64628daa8dSBenjamin Herrenschmidt } 65628daa8dSBenjamin Herrenschmidt 6616b1d26eSNeelesh Gupta static __init int opal_time_init(void) 67628daa8dSBenjamin Herrenschmidt { 6816b1d26eSNeelesh Gupta struct platform_device *pdev; 6916b1d26eSNeelesh Gupta struct device_node *rtc; 70628daa8dSBenjamin Herrenschmidt 7116b1d26eSNeelesh Gupta rtc = of_find_node_by_path("/ibm,opal/rtc"); 7216b1d26eSNeelesh Gupta if (rtc) { 7316b1d26eSNeelesh Gupta pdev = of_platform_device_create(rtc, "opal-rtc", NULL); 7416b1d26eSNeelesh Gupta of_node_put(rtc); 7516b1d26eSNeelesh Gupta } else { 7616b1d26eSNeelesh Gupta if (opal_check_token(OPAL_RTC_READ) || 7716b1d26eSNeelesh Gupta opal_check_token(OPAL_READ_TPO)) 7816b1d26eSNeelesh Gupta pdev = platform_device_register_simple("opal-rtc", -1, 7916b1d26eSNeelesh Gupta NULL, 0); 80628daa8dSBenjamin Herrenschmidt else 8116b1d26eSNeelesh Gupta return -ENODEV; 82628daa8dSBenjamin Herrenschmidt } 83628daa8dSBenjamin Herrenschmidt 8416b1d26eSNeelesh Gupta return PTR_ERR_OR_ZERO(pdev); 85628daa8dSBenjamin Herrenschmidt } 8616b1d26eSNeelesh Gupta machine_subsys_initcall(powernv, opal_time_init); 87