1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Copyright (C) 2015 Freescale Semiconductor, Inc. 4 * 5 * The file use ls102xa/timer.c as a reference. 6 */ 7 8 #include <common.h> 9 #include <asm/io.h> 10 #include <div64.h> 11 #include <asm/arch/imx-regs.h> 12 #include <asm/arch/sys_proto.h> 13 #include <asm/mach-imx/syscounter.h> 14 15 DECLARE_GLOBAL_DATA_PTR; 16 17 /* 18 * This function is intended for SHORT delays only. 19 * It will overflow at around 10 seconds @ 400MHz, 20 * or 20 seconds @ 200MHz. 21 */ 22 unsigned long usec2ticks(unsigned long usec) 23 { 24 ulong ticks; 25 26 if (usec < 1000) 27 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000; 28 else 29 ticks = ((usec / 10) * (get_tbclk() / 100000)); 30 31 return ticks; 32 } 33 34 static inline unsigned long long tick_to_time(unsigned long long tick) 35 { 36 unsigned long freq; 37 38 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 39 40 tick *= CONFIG_SYS_HZ; 41 do_div(tick, freq); 42 43 return tick; 44 } 45 46 static inline unsigned long long us_to_tick(unsigned long long usec) 47 { 48 unsigned long freq; 49 50 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq)); 51 52 usec = usec * freq + 999999; 53 do_div(usec, 1000000); 54 55 return usec; 56 } 57 58 #ifndef CONFIG_SKIP_LOWLEVEL_INIT 59 int timer_init(void) 60 { 61 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR; 62 unsigned long val, freq; 63 64 freq = CONFIG_SC_TIMER_CLK; 65 asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq)); 66 67 writel(freq, &sctr->cntfid0); 68 69 /* Enable system counter */ 70 val = readl(&sctr->cntcr); 71 val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1); 72 val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG; 73 writel(val, &sctr->cntcr); 74 75 gd->arch.tbl = 0; 76 gd->arch.tbu = 0; 77 78 return 0; 79 } 80 #endif 81 82 unsigned long long get_ticks(void) 83 { 84 unsigned long long now; 85 86 asm volatile("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 ulong get_timer(ulong base) 95 { 96 return tick_to_time(get_ticks()) - base; 97 } 98 99 void __udelay(unsigned long usec) 100 { 101 unsigned long long tmp; 102 ulong tmo; 103 104 tmo = us_to_tick(usec); 105 tmp = get_ticks() + tmo; /* get current timestamp */ 106 107 while (get_ticks() < tmp) /* loop till event */ 108 /*NOP*/; 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 ulong 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