1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * (C) Copyright 2007-2011
4 * Allwinner Technology Co., Ltd. <www.allwinnertech.com>
5 * Tom Cubie <tangliang@allwinnertech.com>
6 */
7
8#include <init.h>
9#include <time.h>
10#include <asm/global_data.h>
11#include <asm/io.h>
12#include <asm/arch/cpu.h>
13#include <asm/arch/timer.h>
14#include <linux/delay.h>
15
16DECLARE_GLOBAL_DATA_PTR;
17
18#define TIMER_MODE   (0x0 << 7)	/* continuous mode */
19#define TIMER_DIV    (0x0 << 4)	/* pre scale 1 */
20#define TIMER_SRC    (0x1 << 2)	/* osc24m */
21#define TIMER_RELOAD (0x1 << 1)	/* reload internal value */
22#define TIMER_EN     (0x1 << 0)	/* enable timer */
23
24#define TIMER_CLOCK		(24 * 1000 * 1000)
25#define COUNT_TO_USEC(x)	((x) / 24)
26#define USEC_TO_COUNT(x)	((x) * 24)
27#define TICKS_PER_HZ		(TIMER_CLOCK / CONFIG_SYS_HZ)
28#define TICKS_TO_HZ(x)		((x) / TICKS_PER_HZ)
29
30#define TIMER_LOAD_VAL		0xffffffff
31
32#define TIMER_NUM		0	/* we use timer 0 */
33
34/* read the 32-bit timer */
35static ulong read_timer(void)
36{
37	struct sunxi_timer_reg *timers =
38		(struct sunxi_timer_reg *)SUNXI_TIMER_BASE;
39	struct sunxi_timer *timer = &timers->timer[TIMER_NUM];
40
41	/*
42	 * The hardware timer counts down, therefore we invert to
43	 * produce an incrementing timer.
44	 */
45	return ~readl(&timer->val);
46}
47
48/* init timer register */
49int timer_init(void)
50{
51	struct sunxi_timer_reg *timers =
52		(struct sunxi_timer_reg *)SUNXI_TIMER_BASE;
53	struct sunxi_timer *timer = &timers->timer[TIMER_NUM];
54
55	writel(TIMER_LOAD_VAL, &timer->inter);
56	writel(TIMER_MODE | TIMER_DIV | TIMER_SRC | TIMER_RELOAD | TIMER_EN,
57	       &timer->ctl);
58
59	return 0;
60}
61
62static ulong get_timer_masked(void)
63{
64	/* current tick value */
65	ulong now = TICKS_TO_HZ(read_timer());
66
67	if (now >= gd->arch.lastinc) {	/* normal (non rollover) */
68		gd->arch.tbl += (now - gd->arch.lastinc);
69	} else {
70		/* rollover */
71		gd->arch.tbl += (TICKS_TO_HZ(TIMER_LOAD_VAL)
72				- gd->arch.lastinc) + now;
73	}
74	gd->arch.lastinc = now;
75
76	return gd->arch.tbl;
77}
78
79/* timer without interrupts */
80ulong get_timer(ulong base)
81{
82	return get_timer_masked() - base;
83}
84
85/* delay x useconds */
86void __udelay(unsigned long usec)
87{
88	long tmo = USEC_TO_COUNT(usec);
89	ulong now, last = read_timer();
90
91	while (tmo > 0) {
92		now = read_timer();
93		if (now > last)	/* normal (non rollover) */
94			tmo -= now - last;
95		else		/* rollover */
96			tmo -= TIMER_LOAD_VAL - last + now;
97		last = now;
98	}
99}
100
101/*
102 * This function is derived from PowerPC code (read timebase as long long).
103 * On ARM it just returns the timer value.
104 */
105unsigned long long get_ticks(void)
106{
107	return get_timer(0);
108}
109
110/*
111 * This function is derived from PowerPC code (timebase clock frequency).
112 * On ARM it returns the number of timer ticks per second.
113 */
114ulong get_tbclk(void)
115{
116	return CONFIG_SYS_HZ;
117}
118