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