1 /* 2 * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 #include <assert.h> 7 #include <debug.h> 8 #include <delay_timer.h> 9 #include <mt8173_def.h> 10 #include <pmic_wrap_init.h> 11 #include <rtc.h> 12 13 /* RTC busy status polling interval and retry count */ 14 enum { 15 RTC_WRTGR_POLLING_DELAY_MS = 10, 16 RTC_WRTGR_POLLING_CNT = 100 17 }; 18 19 static uint16_t RTC_Read(uint32_t addr) 20 { 21 uint32_t rdata = 0; 22 23 pwrap_read((uint32_t)addr, &rdata); 24 return (uint16_t)rdata; 25 } 26 27 static void RTC_Write(uint32_t addr, uint16_t data) 28 { 29 pwrap_write((uint32_t)addr, (uint32_t)data); 30 } 31 32 static inline int32_t rtc_busy_wait(void) 33 { 34 uint64_t retry = RTC_WRTGR_POLLING_CNT; 35 36 do { 37 mdelay(RTC_WRTGR_POLLING_DELAY_MS); 38 if (!(RTC_Read(RTC_BBPU) & RTC_BBPU_CBUSY)) 39 return 1; 40 retry--; 41 } while (retry); 42 43 ERROR("[RTC] rtc cbusy time out!\n"); 44 return 0; 45 } 46 47 static int32_t Write_trigger(void) 48 { 49 RTC_Write(RTC_WRTGR, 1); 50 return rtc_busy_wait(); 51 } 52 53 static int32_t Writeif_unlock(void) 54 { 55 RTC_Write(RTC_PROT, RTC_PROT_UNLOCK1); 56 if (!Write_trigger()) 57 return 0; 58 RTC_Write(RTC_PROT, RTC_PROT_UNLOCK2); 59 if (!Write_trigger()) 60 return 0; 61 62 return 1; 63 } 64 65 void rtc_bbpu_power_down(void) 66 { 67 uint16_t bbpu; 68 69 /* pull PWRBB low */ 70 bbpu = RTC_BBPU_KEY | RTC_BBPU_AUTO | RTC_BBPU_PWREN; 71 if (Writeif_unlock()) { 72 RTC_Write(RTC_BBPU, bbpu); 73 if (!Write_trigger()) 74 assert(0); 75 } else { 76 assert(0); 77 } 78 } 79
