1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * (C) Copyright 2002
4 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
5 * Marius Groeger <mgroeger@sysgo.de>
6 *
7 * (C) Copyright 2002
8 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
9 * Alex Zuepke <azu@sysgo.de>
10 *
11 * (C) Copyright 2002
12 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
13 *
14 * (C) Copyright 2009
15 * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com>
16 */
17
18 #include <common.h>
19 #include <div64.h>
20 #include <time.h>
21 #include <asm/io.h>
22 #include <asm/arch/imx-regs.h>
23
24 /* General purpose timers bitfields */
25 #define GPTCR_SWR (1 << 15) /* Software reset */
26 #define GPTCR_FRR (1 << 8) /* Freerun / restart */
27 #define GPTCR_CLKSOURCE_32 (4 << 1) /* Clock source */
28 #define GPTCR_TEN 1 /* Timer enable */
29
30 DECLARE_GLOBAL_DATA_PTR;
31
32 #define timestamp (gd->arch.tbl)
33 #define lastinc (gd->arch.lastinc)
34
35 /*
36 * "time" is measured in 1 / CONFIG_SYS_HZ seconds,
37 * "tick" is internal timer period
38 */
39 #ifdef CONFIG_MX27_TIMER_HIGH_PRECISION
40 /* ~0.4% error - measured with stop-watch on 100s boot-delay */
tick_to_time(unsigned long long tick)41 static inline unsigned long long tick_to_time(unsigned long long tick)
42 {
43 tick *= CONFIG_SYS_HZ;
44 do_div(tick, CONFIG_MX27_CLK32);
45 return tick;
46 }
47
time_to_tick(unsigned long long time)48 static inline unsigned long long time_to_tick(unsigned long long time)
49 {
50 time *= CONFIG_MX27_CLK32;
51 do_div(time, CONFIG_SYS_HZ);
52 return time;
53 }
54
us_to_tick(unsigned long long us)55 static inline unsigned long long us_to_tick(unsigned long long us)
56 {
57 us = us * CONFIG_MX27_CLK32 + 999999;
58 do_div(us, 1000000);
59 return us;
60 }
61 #else
62 /* ~2% error */
63 #define TICK_PER_TIME ((CONFIG_MX27_CLK32 + CONFIG_SYS_HZ / 2) / \
64 CONFIG_SYS_HZ)
65 #define US_PER_TICK (1000000 / CONFIG_MX27_CLK32)
66
tick_to_time(unsigned long long tick)67 static inline unsigned long long tick_to_time(unsigned long long tick)
68 {
69 do_div(tick, TICK_PER_TIME);
70 return tick;
71 }
72
time_to_tick(unsigned long long time)73 static inline unsigned long long time_to_tick(unsigned long long time)
74 {
75 return time * TICK_PER_TIME;
76 }
77
us_to_tick(unsigned long long us)78 static inline unsigned long long us_to_tick(unsigned long long us)
79 {
80 us += US_PER_TICK - 1;
81 do_div(us, US_PER_TICK);
82 return us;
83 }
84 #endif
85
86 /* nothing really to do with interrupts, just starts up a counter. */
87 /* The 32768Hz 32-bit timer overruns in 131072 seconds */
timer_init(void)88 int timer_init(void)
89 {
90 int i;
91 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
92 struct pll_regs *pll = (struct pll_regs *)IMX_PLL_BASE;
93
94 /* setup GP Timer 1 */
95 writel(GPTCR_SWR, ®s->gpt_tctl);
96
97 writel(readl(&pll->pccr0) | PCCR0_GPT1_EN, &pll->pccr0);
98 writel(readl(&pll->pccr1) | PCCR1_PERCLK1_EN, &pll->pccr1);
99
100 for (i = 0; i < 100; i++)
101 writel(0, ®s->gpt_tctl); /* We have no udelay by now */
102 writel(0, ®s->gpt_tprer); /* 32Khz */
103 /* Freerun Mode, PERCLK1 input */
104 writel(readl(®s->gpt_tctl) | GPTCR_CLKSOURCE_32 | GPTCR_FRR,
105 ®s->gpt_tctl);
106 writel(readl(®s->gpt_tctl) | GPTCR_TEN, ®s->gpt_tctl);
107
108 return 0;
109 }
110
get_ticks(void)111 unsigned long long get_ticks(void)
112 {
113 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
114 ulong now = readl(®s->gpt_tcn); /* current tick value */
115
116 if (now >= lastinc) {
117 /*
118 * normal mode (non roll)
119 * move stamp forward with absolut diff ticks
120 */
121 timestamp += (now - lastinc);
122 } else {
123 /* we have rollover of incrementer */
124 timestamp += (0xFFFFFFFF - lastinc) + now;
125 }
126 lastinc = now;
127 return timestamp;
128 }
129
get_timer_masked(void)130 static ulong get_timer_masked(void)
131 {
132 /*
133 * get_ticks() returns a long long (64 bit), it wraps in
134 * 2^64 / CONFIG_MX27_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
135 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
136 * 5 * 10^6 days - long enough.
137 */
138 return tick_to_time(get_ticks());
139 }
140
get_timer(ulong base)141 ulong get_timer(ulong base)
142 {
143 return get_timer_masked() - base;
144 }
145
146 /* delay x useconds AND preserve advance timstamp value */
__udelay(unsigned long usec)147 void __udelay(unsigned long usec)
148 {
149 unsigned long long tmp;
150 ulong tmo;
151
152 tmo = us_to_tick(usec);
153 tmp = get_ticks() + tmo; /* get current timestamp */
154
155 while (get_ticks() < tmp) /* loop till event */
156 /*NOP*/;
157 }
158
get_tbclk(void)159 ulong get_tbclk(void)
160 {
161 return CONFIG_MX27_CLK32;
162 }
163