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git.ipfire.org Git - people/ms/u-boot.git/blob - arch/arm/mach-imx/syscounter.c
2 * Copyright (C) 2015 Freescale Semiconductor, Inc.
4 * SPDX-License-Identifier: GPL-2.0+
6 * 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);
61 struct sctr_regs
*sctr
= (struct sctr_regs
*)SCTR_BASE_ADDR
;
62 unsigned long val
, freq
;
64 freq
= CONFIG_SC_TIMER_CLK
;
65 asm("mcr p15, 0, %0, c14, c0, 0" : : "r" (freq
));
67 writel(freq
, &sctr
->cntfid0
);
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
);
81 unsigned long long get_ticks(void)
83 unsigned long long now
;
85 asm("mrrc p15, 0, %Q0, %R0, c14" : "=r" (now
));
87 gd
->arch
.tbl
= (unsigned long)(now
& 0xffffffff);
88 gd
->arch
.tbu
= (unsigned long)(now
>> 32);
93 ulong
get_timer_masked(void)
95 return tick_to_time(get_ticks());
98 ulong
get_timer(ulong base
)
100 return get_timer_masked() - base
;
103 void __udelay(unsigned long usec
)
105 unsigned long long tmp
;
108 tmo
= us_to_tick(usec
);
109 tmp
= get_ticks() + tmo
; /* get current timestamp */
111 while (get_ticks() < tmp
) /* loop till event */
116 * This function is derived from PowerPC code (timebase clock frequency).
117 * On ARM it returns the number of timer ticks per second.
119 ulong
get_tbclk(void)
123 asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (freq
));