1 /* 2 * Copyright 2014 Freescale Semiconductor, Inc. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <asm/io.h> 9 #include <div64.h> 10 #include <asm/arch/immap_ls102xa.h> 11 #include <asm/arch/clock.h> 12 13 DECLARE_GLOBAL_DATA_PTR; 14 15 /* 16 * This function is intended for SHORT delays only. 17 * It will overflow at around 10 seconds @ 400MHz, 18 * or 20 seconds @ 200MHz. 19 */ 20 unsigned long usec2ticks(unsigned long usec) 21 { 22 ulong ticks; 23 24 if (usec < 1000) 25 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000; 26 else 27 ticks = ((usec / 10) * (get_tbclk() / 100000)); 28 29 return ticks; 30 } 31 32 static inline unsigned long long tick_to_time(unsigned long long tick) 33 { 34 unsigned long freq; 35 36 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 37 38 tick *= CONFIG_SYS_HZ; 39 do_div(tick, freq); 40 41 return tick; 42 } 43 44 static inline unsigned long long us_to_tick(unsigned long long usec) 45 { 46 unsigned long freq; 47 48 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 49 50 usec = usec * freq + 999999; 51 do_div(usec, 1000000); 52 53 return usec; 54 } 55 56 int timer_init(void) 57 { 58 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR; 59 unsigned long ctrl, freq; 60 unsigned long long val; 61 62 /* Enable System Counter */ 63 writel(SYS_COUNTER_CTRL_ENABLE, &sctr->cntcr); 64 65 freq = GENERIC_TIMER_CLK; 66 asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq)); 67 68 /* Set PL1 Physical Timer Ctrl */ 69 ctrl = ARCH_TIMER_CTRL_ENABLE; 70 asm("mcr p15, 0, %0, c14, c2, 1" : : "r" (ctrl)); 71 72 /* Set PL1 Physical Comp Value */ 73 val = TIMER_COMP_VAL; 74 asm("mcrr p15, 2, %Q0, %R0, c14" : : "r" (val)); 75 76 gd->arch.tbl = 0; 77 gd->arch.tbu = 0; 78 79 return 0; 80 } 81 82 unsigned long long get_ticks(void) 83 { 84 unsigned long long now; 85 86 asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now)); 87 88 gd->arch.tbl = (unsigned long)(now & 0xffffffff); 89 gd->arch.tbu = (unsigned long)(now >> 32); 90 91 return now; 92 } 93 94 unsigned long get_timer_masked(void) 95 { 96 return tick_to_time(get_ticks()); 97 } 98 99 unsigned long get_timer(ulong base) 100 { 101 return get_timer_masked() - base; 102 } 103 104 /* delay x useconds and preserve advance timstamp value */ 105 void __udelay(unsigned long usec) 106 { 107 unsigned long long start; 108 unsigned long tmo; 109 110 start = get_ticks(); /* get current timestamp */ 111 tmo = us_to_tick(usec); /* convert usecs to ticks */ 112 113 while ((get_ticks() - start) < tmo) 114 ; /* loop till time has passed */ 115 } 116 117 /* 118 * This function is derived from PowerPC code (timebase clock frequency). 119 * On ARM it returns the number of timer ticks per second. 120 */ 121 unsigned long get_tbclk(void) 122 { 123 unsigned long freq; 124 125 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 126 127 return freq; 128 } 129