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 <init.h>
21 #include <time.h>
22 #include <asm/global_data.h>
23 #include <asm/io.h>
24 #include <asm/arch/imx-regs.h>
25 #include <asm/ptrace.h>
26 #include <linux/delay.h>
27
28 /* General purpose timers bitfields */
29 #define GPTCR_SWR (1 << 15) /* Software reset */
30 #define GPTCR_FRR (1 << 8) /* Freerun / restart */
31 #define GPTCR_CLKSOURCE_32 (4 << 1) /* Clock source */
32 #define GPTCR_TEN 1 /* Timer enable */
33
34 DECLARE_GLOBAL_DATA_PTR;
35
36 #define timestamp (gd->arch.tbl)
37 #define lastinc (gd->arch.lastinc)
38
39 /*
40 * "time" is measured in 1 / CONFIG_SYS_HZ seconds,
41 * "tick" is internal timer period
42 */
43 #ifdef CONFIG_MX27_TIMER_HIGH_PRECISION
44 /* ~0.4% error - measured with stop-watch on 100s boot-delay */
tick_to_time(unsigned long long tick)45 static inline unsigned long long tick_to_time(unsigned long long tick)
46 {
47 tick *= CONFIG_SYS_HZ;
48 do_div(tick, CONFIG_MX27_CLK32);
49 return tick;
50 }
51
time_to_tick(unsigned long long time)52 static inline unsigned long long time_to_tick(unsigned long long time)
53 {
54 time *= CONFIG_MX27_CLK32;
55 do_div(time, CONFIG_SYS_HZ);
56 return time;
57 }
58
us_to_tick(unsigned long long us)59 static inline unsigned long long us_to_tick(unsigned long long us)
60 {
61 us = us * CONFIG_MX27_CLK32 + 999999;
62 do_div(us, 1000000);
63 return us;
64 }
65 #else
66 /* ~2% error */
67 #define TICK_PER_TIME ((CONFIG_MX27_CLK32 + CONFIG_SYS_HZ / 2) / \
68 CONFIG_SYS_HZ)
69 #define US_PER_TICK (1000000 / CONFIG_MX27_CLK32)
70
tick_to_time(unsigned long long tick)71 static inline unsigned long long tick_to_time(unsigned long long tick)
72 {
73 do_div(tick, TICK_PER_TIME);
74 return tick;
75 }
76
time_to_tick(unsigned long long time)77 static inline unsigned long long time_to_tick(unsigned long long time)
78 {
79 return time * TICK_PER_TIME;
80 }
81
us_to_tick(unsigned long long us)82 static inline unsigned long long us_to_tick(unsigned long long us)
83 {
84 us += US_PER_TICK - 1;
85 do_div(us, US_PER_TICK);
86 return us;
87 }
88 #endif
89
90 /* nothing really to do with interrupts, just starts up a counter. */
91 /* The 32768Hz 32-bit timer overruns in 131072 seconds */
timer_init(void)92 int timer_init(void)
93 {
94 int i;
95 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
96 struct pll_regs *pll = (struct pll_regs *)IMX_PLL_BASE;
97
98 /* setup GP Timer 1 */
99 writel(GPTCR_SWR, ®s->gpt_tctl);
100
101 writel(readl(&pll->pccr0) | PCCR0_GPT1_EN, &pll->pccr0);
102 writel(readl(&pll->pccr1) | PCCR1_PERCLK1_EN, &pll->pccr1);
103
104 for (i = 0; i < 100; i++)
105 writel(0, ®s->gpt_tctl); /* We have no udelay by now */
106 writel(0, ®s->gpt_tprer); /* 32Khz */
107 /* Freerun Mode, PERCLK1 input */
108 writel(readl(®s->gpt_tctl) | GPTCR_CLKSOURCE_32 | GPTCR_FRR,
109 ®s->gpt_tctl);
110 writel(readl(®s->gpt_tctl) | GPTCR_TEN, ®s->gpt_tctl);
111
112 return 0;
113 }
114
get_ticks(void)115 unsigned long long get_ticks(void)
116 {
117 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
118 ulong now = readl(®s->gpt_tcn); /* current tick value */
119
120 if (now >= lastinc) {
121 /*
122 * normal mode (non roll)
123 * move stamp forward with absolut diff ticks
124 */
125 timestamp += (now - lastinc);
126 } else {
127 /* we have rollover of incrementer */
128 timestamp += (0xFFFFFFFF - lastinc) + now;
129 }
130 lastinc = now;
131 return timestamp;
132 }
133
get_timer_masked(void)134 static ulong get_timer_masked(void)
135 {
136 /*
137 * get_ticks() returns a long long (64 bit), it wraps in
138 * 2^64 / CONFIG_MX27_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
139 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
140 * 5 * 10^6 days - long enough.
141 */
142 return tick_to_time(get_ticks());
143 }
144
get_timer(ulong base)145 ulong get_timer(ulong base)
146 {
147 return get_timer_masked() - base;
148 }
149
150 /* delay x useconds AND preserve advance timstamp value */
__udelay(unsigned long usec)151 void __udelay(unsigned long usec)
152 {
153 unsigned long long tmp;
154 ulong tmo;
155
156 tmo = us_to_tick(usec);
157 tmp = get_ticks() + tmo; /* get current timestamp */
158
159 while (get_ticks() < tmp) /* loop till event */
160 /*NOP*/;
161 }
162
get_tbclk(void)163 ulong get_tbclk(void)
164 {
165 return CONFIG_MX27_CLK32;
166 }
167