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