1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * Copyright 2014 Freescale Semiconductor, Inc. 4 */ 5 6#include <common.h> 7#include <init.h> 8#include <time.h> 9#include <asm/global_data.h> 10#include <asm/io.h> 11#include <div64.h> 12#include <asm/arch/immap_ls102xa.h> 13#include <asm/arch/clock.h> 14#include <linux/delay.h> 15 16DECLARE_GLOBAL_DATA_PTR; 17 18/* 19 * This function is intended for SHORT delays only. 20 * It will overflow at around 10 seconds @ 400MHz, 21 * or 20 seconds @ 200MHz. 22 */ 23unsigned long usec2ticks(unsigned long usec) 24{ 25 ulong ticks; 26 27 if (usec < 1000) 28 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000; 29 else 30 ticks = ((usec / 10) * (get_tbclk() / 100000)); 31 32 return ticks; 33} 34 35static inline unsigned long long tick_to_time(unsigned long long tick) 36{ 37 unsigned long freq; 38 39 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 40 41 tick *= CONFIG_SYS_HZ; 42 do_div(tick, freq); 43 44 return tick; 45} 46 47static inline unsigned long long us_to_tick(unsigned long long usec) 48{ 49 unsigned long freq; 50 51 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 52 53 usec = usec * freq + 999999; 54 do_div(usec, 1000000); 55 56 return usec; 57} 58 59int timer_init(void) 60{ 61 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR; 62 unsigned long ctrl, freq; 63 unsigned long long val; 64 65 /* Enable System Counter */ 66 writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr); 67 68 freq = CONFIG_COUNTER_FREQUENCY; 69 asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq)); 70 71 /* Set PL1 Physical Timer Ctrl */ 72 ctrl = ARCH_TIMER_CTRL_ENABLE; 73 asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl)); 74 75 /* Set PL1 Physical Comp Value */ 76 val = TIMER_COMP_VAL; 77 asm("mcrr p15, 2, %Q0, %R0, c14" : : "r" (val)); 78 79 gd->arch.tbl = 0; 80 gd->arch.tbu = 0; 81 82 return 0; 83} 84 85unsigned long long get_ticks(void) 86{ 87 unsigned long long now; 88 89 asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now)); 90 91 gd->arch.tbl = (unsigned long)(now & 0xffffffff); 92 gd->arch.tbu = (unsigned long)(now >> 32); 93 94 return now; 95} 96 97unsigned long get_timer(ulong base) 98{ 99 return tick_to_time(get_ticks()) - base; 100} 101 102/* delay x useconds and preserve advance timstamp value */ 103void __udelay(unsigned long usec) 104{ 105 unsigned long long start; 106 unsigned long tmo; 107 108 start = get_ticks(); /* get current timestamp */ 109 tmo = us_to_tick(usec); /* convert usecs to ticks */ 110 111 while ((get_ticks() - start) < tmo) 112 ; /* loop till time has passed */ 113} 114 115/* 116 * This function is derived from PowerPC code (timebase clock frequency). 117 * On ARM it returns the number of timer ticks per second. 118 */ 119unsigned long get_tbclk(void) 120{ 121 unsigned long freq; 122 123 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 124 125 return freq; 126} 127