blob: 8f1d47bba775716ec21afd2a5e662c617b7a24d4 [file] [log] [blame]
Ilya Yanok1dc4da72009-06-08 04:12:45 +04001/*
2 * (C) Copyright 2002
3 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
4 * Marius Groeger <mgroeger@sysgo.de>
5 *
6 * (C) Copyright 2002
7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
8 * Alex Zuepke <azu@sysgo.de>
9 *
10 * (C) Copyright 2002
11 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
12 *
13 * (C) Copyright 2009
14 * Ilya Yanok, Emcraft Systems Ltd, <yanok@emcraft.com>
15 *
16 * See file CREDITS for list of people who contributed to this
17 * project.
18 *
19 * This program is free software; you can redistribute it and/or
20 * modify it under the terms of the GNU General Public License as
21 * published by the Free Software Foundation; either version 2 of
22 * the License, or (at your option) any later version.
23 *
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with this program; if not, write to the Free Software
31 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
32 * MA 02111-1307 USA
33 */
34
35#include <common.h>
36#include <div64.h>
37#include <asm/io.h>
38#include <asm/arch/imx-regs.h>
39
40/* General purpose timers bitfields */
41#define GPTCR_SWR (1 << 15) /* Software reset */
42#define GPTCR_FRR (1 << 8) /* Freerun / restart */
43#define GPTCR_CLKSOURCE_32 (4 << 1) /* Clock source */
44#define GPTCR_TEN 1 /* Timer enable */
45
46static ulong timestamp;
47static ulong lastinc;
48
49/*
50 * "time" is measured in 1 / CONFIG_SYS_HZ seconds,
51 * "tick" is internal timer period
52 */
53#ifdef CONFIG_MX27_TIMER_HIGH_PRECISION
54/* ~0.4% error - measured with stop-watch on 100s boot-delay */
55static inline unsigned long long tick_to_time(unsigned long long tick)
56{
57 tick *= CONFIG_SYS_HZ;
58 do_div(tick, CONFIG_MX27_CLK32);
59 return tick;
60}
61
62static inline unsigned long long time_to_tick(unsigned long long time)
63{
64 time *= CONFIG_MX27_CLK32;
65 do_div(time, CONFIG_SYS_HZ);
66 return time;
67}
68
69static inline unsigned long long us_to_tick(unsigned long long us)
70{
71 us = us * CONFIG_MX27_CLK32 + 999999;
72 do_div(us, 1000000);
73 return us;
74}
75#else
76/* ~2% error */
77#define TICK_PER_TIME ((CONFIG_MX27_CLK32 + CONFIG_SYS_HZ / 2) / \
78 CONFIG_SYS_HZ)
79#define US_PER_TICK (1000000 / CONFIG_MX27_CLK32)
80
81static inline unsigned long long tick_to_time(unsigned long long tick)
82{
83 do_div(tick, TICK_PER_TIME);
84 return tick;
85}
86
87static inline unsigned long long time_to_tick(unsigned long long time)
88{
89 return time * TICK_PER_TIME;
90}
91
92static inline unsigned long long us_to_tick(unsigned long long us)
93{
94 us += US_PER_TICK - 1;
95 do_div(us, US_PER_TICK);
96 return us;
97}
98#endif
99
100/* nothing really to do with interrupts, just starts up a counter. */
101/* The 32768Hz 32-bit timer overruns in 131072 seconds */
102int timer_init(void)
103{
104 int i;
105 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
106 struct pll_regs *pll = (struct pll_regs *)IMX_PLL_BASE;
107
108 /* setup GP Timer 1 */
109 writel(GPTCR_SWR, &regs->gpt_tctl);
110
111 writel(readl(&pll->pccr0) | PCCR0_GPT1_EN, &pll->pccr0);
112 writel(readl(&pll->pccr1) | PCCR1_PERCLK1_EN, &pll->pccr1);
113
114 for (i = 0; i < 100; i++)
115 writel(0, &regs->gpt_tctl); /* We have no udelay by now */
116 writel(0, &regs->gpt_tprer); /* 32Khz */
117 /* Freerun Mode, PERCLK1 input */
118 writel(readl(&regs->gpt_tctl) | GPTCR_CLKSOURCE_32 | GPTCR_FRR,
119 &regs->gpt_tctl);
120 writel(readl(&regs->gpt_tctl) | GPTCR_TEN, &regs->gpt_tctl);
121
122 return 0;
123}
124
125void reset_timer_masked(void)
126{
127 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
128 /* reset time */
129 /* capture current incrementer value time */
130 lastinc = readl(&regs->gpt_tcn);
131 timestamp = 0; /* start "advancing" time stamp from 0 */
132}
133
134void reset_timer(void)
135{
136 reset_timer_masked();
137}
138
139unsigned long long get_ticks (void)
140{
141 struct gpt_regs *regs = (struct gpt_regs *)IMX_TIM1_BASE;
142 ulong now = readl(&regs->gpt_tcn); /* current tick value */
143
144 if (now >= lastinc) {
145 /*
146 * normal mode (non roll)
147 * move stamp forward with absolut diff ticks
148 */
149 timestamp += (now - lastinc);
150 } else {
151 /* we have rollover of incrementer */
152 timestamp += (0xFFFFFFFF - lastinc) + now;
153 }
154 lastinc = now;
155 return timestamp;
156}
157
158ulong get_timer_masked (void)
159{
160 /*
161 * get_ticks() returns a long long (64 bit), it wraps in
162 * 2^64 / CONFIG_MX27_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
163 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
164 * 5 * 10^6 days - long enough.
165 */
166 return tick_to_time(get_ticks());
167}
168
169ulong get_timer (ulong base)
170{
171 return get_timer_masked () - base;
172}
173
174void set_timer (ulong t)
175{
176 timestamp = time_to_tick(t);
177}
178
Wolfgang Denk8e5e9b92009-07-07 22:35:02 +0200179/* delay x useconds AND preserve advance timstamp value */
Ingo van Lil3eb90ba2009-11-24 14:09:21 +0100180void __udelay (unsigned long usec)
Ilya Yanok1dc4da72009-06-08 04:12:45 +0400181{
182 unsigned long long tmp;
183 ulong tmo;
184
185 tmo = us_to_tick(usec);
186 tmp = get_ticks() + tmo; /* get current timestamp */
187
188 while (get_ticks() < tmp) /* loop till event */
189 /*NOP*/;
190}