1 /* 2 * (C) Copyright 2009 Faraday Technology 3 * Po-Yu Chuang <ratbert@faraday-tech.com> 4 * 5 * Copyright (C) 2011 Andes Technology Corporation 6 * Shawn Lin, Andes Technology Corporation <nobuhiro@andestech.com> 7 * Macpaul Lin, Andes Technology Corporation <macpaul@andestech.com> 8 * 9 * SPDX-License-Identifier: GPL-2.0+ 10 */ 11 12 #include <common.h> 13 #include <asm/io.h> 14 #include <faraday/fttmr010.h> 15 16 static ulong timestamp; 17 static ulong lastdec; 18 19 int timer_init(void) 20 { 21 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE; 22 unsigned int cr; 23 24 debug("%s()\n", __func__); 25 26 /* disable timers */ 27 writel(0, &tmr->cr); 28 29 #ifdef CONFIG_FTTMR010_EXT_CLK 30 /* use 32768Hz oscillator for RTC, WDT, TIMER */ 31 ftpmu010_32768osc_enable(); 32 #endif 33 34 /* setup timer */ 35 writel(TIMER_LOAD_VAL, &tmr->timer3_load); 36 writel(TIMER_LOAD_VAL, &tmr->timer3_counter); 37 writel(0, &tmr->timer3_match1); 38 writel(0, &tmr->timer3_match2); 39 40 /* we don't want timer to issue interrupts */ 41 writel(FTTMR010_TM3_MATCH1 | 42 FTTMR010_TM3_MATCH2 | 43 FTTMR010_TM3_OVERFLOW, 44 &tmr->interrupt_mask); 45 46 cr = readl(&tmr->cr); 47 #ifdef CONFIG_FTTMR010_EXT_CLK 48 cr |= FTTMR010_TM3_CLOCK; /* use external clock */ 49 #endif 50 cr |= FTTMR010_TM3_ENABLE; 51 writel(cr, &tmr->cr); 52 53 /* init the timestamp and lastdec value */ 54 reset_timer_masked(); 55 56 return 0; 57 } 58 59 /* 60 * timer without interrupts 61 */ 62 63 /* 64 * reset time 65 */ 66 void reset_timer_masked(void) 67 { 68 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE; 69 70 /* capure current decrementer value time */ 71 #ifdef CONFIG_FTTMR010_EXT_CLK 72 lastdec = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ); 73 #else 74 lastdec = readl(&tmr->timer3_counter) / (CONFIG_SYS_CLK_FREQ / 2); 75 #endif 76 timestamp = 0; /* start "advancing" time stamp from 0 */ 77 78 debug("%s(): lastdec = %lx\n", __func__, lastdec); 79 } 80 81 void reset_timer(void) 82 { 83 debug("%s()\n", __func__); 84 reset_timer_masked(); 85 } 86 87 /* 88 * return timer ticks 89 */ 90 ulong get_timer_masked(void) 91 { 92 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE; 93 94 /* current tick value */ 95 #ifdef CONFIG_FTTMR010_EXT_CLK 96 ulong now = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ); 97 #else 98 ulong now = readl(&tmr->timer3_counter) / \ 99 (CONFIG_SYS_CLK_FREQ / 2 / 1024); 100 #endif 101 102 debug("%s(): now = %lx, lastdec = %lx\n", __func__, now, lastdec); 103 104 if (lastdec >= now) { 105 /* 106 * normal mode (non roll) 107 * move stamp fordward with absoulte diff ticks 108 */ 109 timestamp += lastdec - now; 110 } else { 111 /* 112 * we have overflow of the count down timer 113 * 114 * nts = ts + ld + (TLV - now) 115 * ts=old stamp, ld=time that passed before passing through -1 116 * (TLV-now) amount of time after passing though -1 117 * nts = new "advancing time stamp"...it could also roll and 118 * cause problems. 119 */ 120 timestamp += lastdec + TIMER_LOAD_VAL - now; 121 } 122 123 lastdec = now; 124 125 debug("%s() returns %lx\n", __func__, timestamp); 126 127 return timestamp; 128 } 129 130 /* 131 * return difference between timer ticks and base 132 */ 133 ulong get_timer(ulong base) 134 { 135 debug("%s(%lx)\n", __func__, base); 136 return get_timer_masked() - base; 137 } 138 139 void set_timer(ulong t) 140 { 141 debug("%s(%lx)\n", __func__, t); 142 timestamp = t; 143 } 144 145 /* delay x useconds AND preserve advance timestamp value */ 146 void __udelay(unsigned long usec) 147 { 148 struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE; 149 150 #ifdef CONFIG_FTTMR010_EXT_CLK 151 long tmo = usec * (TIMER_CLOCK / 1000) / 1000; 152 #else 153 long tmo = usec * ((CONFIG_SYS_CLK_FREQ / 2) / 1000) / 1000; 154 #endif 155 unsigned long now, last = readl(&tmr->timer3_counter); 156 157 debug("%s(%lu)\n", __func__, usec); 158 while (tmo > 0) { 159 now = readl(&tmr->timer3_counter); 160 if (now > last) /* count down timer overflow */ 161 tmo -= TIMER_LOAD_VAL + last - now; 162 else 163 tmo -= last - now; 164 last = now; 165 } 166 } 167 168 /* 169 * This function is derived from PowerPC code (read timebase as long long). 170 * On ARM it just returns the timer value. 171 */ 172 unsigned long long get_ticks(void) 173 { 174 debug("%s()\n", __func__); 175 return get_timer(0); 176 } 177 178 /* 179 * This function is derived from PowerPC code (timebase clock frequency). 180 * On ARM it returns the number of timer ticks per second. 181 */ 182 ulong get_tbclk(void) 183 { 184 debug("%s()\n", __func__); 185 #ifdef CONFIG_FTTMR010_EXT_CLK 186 return CONFIG_SYS_HZ; 187 #else 188 return CONFIG_SYS_CLK_FREQ; 189 #endif 190 } 191