1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright (C) 2015 Freescale Semiconductor, Inc.
5 * The file use ls102xa/timer.c as a reference.
12 #include <asm/arch/imx-regs.h>
13 #include <asm/arch/sys_proto.h>
14 #include <asm/mach-imx/syscounter.h>
16 DECLARE_GLOBAL_DATA_PTR;
19 * This function is intended for SHORT delays only.
20 * It will overflow at around 10 seconds @ 400MHz,
21 * or 20 seconds @ 200MHz.
23 unsigned long usec2ticks(unsigned long usec)
28 ticks = ((usec * (get_tbclk()/1000)) + 500) / 1000;
30 ticks = ((usec / 10) * (get_tbclk() / 100000));
35 static inline unsigned long long tick_to_time(unsigned long long tick)
39 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
41 tick *= CONFIG_SYS_HZ;
47 static inline unsigned long long us_to_tick(unsigned long long usec)
51 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));
53 usec = usec * freq + 999999;
54 do_div(usec, 1000000);
59 #ifndef CONFIG_SKIP_LOWLEVEL_INIT
62 struct sctr_regs *sctr = (struct sctr_regs *)SCTR_BASE_ADDR;
63 unsigned long val, freq;
65 freq = CONFIG_SC_TIMER_CLK;
66 asm volatile("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq));
68 writel(freq, &sctr->cntfid0);
70 /* Enable system counter */
71 val = readl(&sctr->cntcr);
72 val &= ~(SC_CNTCR_FREQ0 | SC_CNTCR_FREQ1);
73 val |= SC_CNTCR_FREQ0 | SC_CNTCR_ENABLE | SC_CNTCR_HDBG;
74 writel(val, &sctr->cntcr);
83 unsigned long long get_ticks(void)
85 unsigned long long now;
87 asm volatile("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now));
89 gd->arch.tbl = (unsigned long)(now & 0xffffffff);
90 gd->arch.tbu = (unsigned long)(now >> 32);
95 ulong get_timer(ulong base)
97 return tick_to_time(get_ticks()) - base;
100 void __udelay(unsigned long usec)
102 unsigned long long tmp;
105 tmo = us_to_tick(usec);
106 tmp = get_ticks() + tmo; /* get current timestamp */
108 while (get_ticks() < tmp) /* loop till event */
113 * This function is derived from PowerPC code (timebase clock frequency).
114 * On ARM it returns the number of timer ticks per second.
116 ulong get_tbclk(void)
120 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq));