1 /* 2 * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 #include <assert.h> 31 #include <debug.h> 32 #include <delay_timer.h> 33 #include <mt8173_def.h> 34 #include <pmic_wrap_init.h> 35 #include <rtc.h> 36 37 /* RTC busy status polling interval and retry count */ 38 enum { 39 RTC_WRTGR_POLLING_DELAY_MS = 10, 40 RTC_WRTGR_POLLING_CNT = 100 41 }; 42 43 static uint16_t RTC_Read(uint32_t addr) 44 { 45 uint32_t rdata = 0; 46 47 pwrap_read((uint32_t)addr, &rdata); 48 return (uint16_t)rdata; 49 } 50 51 static void RTC_Write(uint32_t addr, uint16_t data) 52 { 53 pwrap_write((uint32_t)addr, (uint32_t)data); 54 } 55 56 static inline int32_t rtc_busy_wait(void) 57 { 58 uint64_t retry = RTC_WRTGR_POLLING_CNT; 59 60 do { 61 mdelay(RTC_WRTGR_POLLING_DELAY_MS); 62 if (!(RTC_Read(RTC_BBPU) & RTC_BBPU_CBUSY)) 63 return 1; 64 retry--; 65 } while (retry); 66 67 ERROR("[RTC] rtc cbusy time out!\n"); 68 return 0; 69 } 70 71 static int32_t Write_trigger(void) 72 { 73 RTC_Write(RTC_WRTGR, 1); 74 return rtc_busy_wait(); 75 } 76 77 static int32_t Writeif_unlock(void) 78 { 79 RTC_Write(RTC_PROT, RTC_PROT_UNLOCK1); 80 if (!Write_trigger()) 81 return 0; 82 RTC_Write(RTC_PROT, RTC_PROT_UNLOCK2); 83 if (!Write_trigger()) 84 return 0; 85 86 return 1; 87 } 88 89 void rtc_bbpu_power_down(void) 90 { 91 uint16_t bbpu; 92 93 /* pull PWRBB low */ 94 bbpu = RTC_BBPU_KEY | RTC_BBPU_AUTO | RTC_BBPU_PWREN; 95 if (Writeif_unlock()) { 96 RTC_Write(RTC_BBPU, bbpu); 97 if (!Write_trigger()) 98 assert(0); 99 } else { 100 assert(0); 101 } 102 } 103