1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2013 Freescale Semiconductor, Inc.
9 #include <asm/arch/imx-regs.h>
10 #include <asm/arch/clock.h>
12 static struct pit_reg *cur_pit = (struct pit_reg *)PIT_BASE_ADDR;
14 DECLARE_GLOBAL_DATA_PTR;
16 #define TIMER_LOAD_VAL 0xffffffff
18 static inline unsigned long long tick_to_time(unsigned long long tick)
20 tick *= CONFIG_SYS_HZ;
21 do_div(tick, mxc_get_clock(MXC_IPG_CLK));
26 static inline unsigned long long us_to_tick(unsigned long long usec)
28 usec = usec * mxc_get_clock(MXC_IPG_CLK) + 999999;
29 do_div(usec, 1000000);
36 __raw_writel(0, &cur_pit->mcr);
38 __raw_writel(TIMER_LOAD_VAL, &cur_pit->ldval1);
39 __raw_writel(0, &cur_pit->tctrl1);
40 __raw_writel(1, &cur_pit->tctrl1);
48 unsigned long long get_ticks(void)
50 ulong now = TIMER_LOAD_VAL - __raw_readl(&cur_pit->cval1);
52 /* increment tbu if tbl has rolled over */
53 if (now < gd->arch.tbl)
57 return (((unsigned long long)gd->arch.tbu) << 32) | gd->arch.tbl;
60 ulong get_timer_masked(void)
62 return tick_to_time(get_ticks());
65 ulong get_timer(ulong base)
67 return get_timer_masked() - base;
70 /* delay x useconds AND preserve advance timstamp value */
71 void __udelay(unsigned long usec)
73 unsigned long long start;
76 start = get_ticks(); /* get current timestamp */
77 tmo = us_to_tick(usec); /* convert usecs to ticks */
78 while ((get_ticks() - start) < tmo)
79 ; /* loop till time has passed */
83 * This function is derived from PowerPC code (timebase clock frequency).
84 * On ARM it returns the number of timer ticks per second.
88 return mxc_get_clock(MXC_IPG_CLK);