blob: a2a9133ee0533b55b522e655c7dc26dbaf660eed [file] [log] [blame]
Wolfgang Denkff7fefe2006-03-13 12:37:35 +01001/*
2 * (C) Copyright 2003
3 * Texas Instruments <www.ti.com>
4 *
5 * (C) Copyright 2002
6 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Marius Groeger <mgroeger@sysgo.de>
8 *
9 * (C) Copyright 2002
10 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
11 * Alex Zuepke <azu@sysgo.de>
12 *
13 * (C) Copyright 2002-2004
14 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
15 *
16 * (C) Copyright 2004
17 * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
18 *
19 * See file CREDITS for list of people who contributed to this
20 * project.
21 *
22 * This program is free software; you can redistribute it and/or
23 * modify it under the terms of the GNU General Public License as
24 * published by the Free Software Foundation; either version 2 of
25 * the License, or (at your option) any later version.
26 *
27 * This program is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
30 * GNU General Public License for more details.
31 *
32 * You should have received a copy of the GNU General Public License
33 * along with this program; if not, write to the Free Software
34 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
35 * MA 02111-1307 USA
36 */
37
38#include <common.h>
39#include <arm926ejs.h>
40
41#define TIMER_LOAD_VAL 0xffffffff
42
43/* macro to read the 32 bit timer */
44#define READ_TIMER (*(volatile ulong *)(CFG_TIMERBASE+8))
45
46static ulong timestamp;
47static ulong lastdec;
48
49int timer_init (void)
50{
51 int32_t val;
52
53 /* Start the decrementer ticking down from 0xffffffff */
54 *((int32_t *) (CFG_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL;
55 val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | (CFG_PVT << MPUTIM_PTV_BIT);
56 *((int32_t *) (CFG_TIMERBASE + CNTL_TIMER)) = val;
57
58 /* init the timestamp and lastdec value */
59 reset_timer_masked();
60
61 return 0;
62}
63
64/*
65 * timer without interrupts
66 */
67
68void reset_timer (void)
69{
70 reset_timer_masked ();
71}
72
73ulong get_timer (ulong base)
74{
75 return get_timer_masked () - base;
76}
77
78void set_timer (ulong t)
79{
80 timestamp = t;
81}
82
83/* delay x useconds AND perserve advance timstamp value */
84void udelay (unsigned long usec)
85{
86 ulong tmo, tmp;
87
88 if(usec >= 1000){ /* if "big" number, spread normalization to seconds */
89 tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
90 tmo *= CFG_HZ; /* find number of "ticks" to wait to achieve target */
91 tmo /= 1000; /* finish normalize. */
92 }else{ /* else small number, don't kill it prior to HZ multiply */
93 tmo = usec * CFG_HZ;
94 tmo /= (1000*1000);
95 }
96
97 tmp = get_timer (0); /* get current timestamp */
98 if( (tmo + tmp + 1) < tmp ) /* if setting this fordward will roll time stamp */
99 reset_timer_masked (); /* reset "advancing" timestamp to 0, set lastdec value */
100 else
101 tmo += tmp; /* else, set advancing stamp wake up time */
102
103 while (get_timer_masked () < tmo)/* loop till event */
104 /*NOP*/;
105}
106
107void reset_timer_masked (void)
108{
109 /* reset time */
110 lastdec = READ_TIMER; /* capure current decrementer value time */
111 timestamp = 0; /* start "advancing" time stamp from 0 */
112}
113
114ulong get_timer_masked (void)
115{
116 ulong now = READ_TIMER; /* current tick value */
117
118 if (lastdec >= now) { /* normal mode (non roll) */
119 /* normal mode */
120 timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
121 } else { /* we have overflow of the count down timer */
122 /* nts = ts + ld + (TLV - now)
123 * ts=old stamp, ld=time that passed before passing through -1
124 * (TLV-now) amount of time after passing though -1
125 * nts = new "advancing time stamp"...it could also roll and cause problems.
126 */
127 timestamp += lastdec + TIMER_LOAD_VAL - now;
128 }
129 lastdec = now;
130
131 return timestamp;
132}
133
134/* waits specified delay value and resets timestamp */
135void udelay_masked (unsigned long usec)
136{
137 ulong tmo;
138 ulong endtime;
139 signed long diff;
140
141 if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
142 tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
143 tmo *= CFG_HZ; /* find number of "ticks" to wait to achieve target */
144 tmo /= 1000; /* finish normalize. */
145 } else { /* else small number, don't kill it prior to HZ multiply */
146 tmo = usec * CFG_HZ;
147 tmo /= (1000*1000);
148 }
149
150 endtime = get_timer_masked () + tmo;
151
152 do {
153 ulong now = get_timer_masked ();
154 diff = endtime - now;
155 } while (diff >= 0);
156}
157
158/*
159 * This function is derived from PowerPC code (read timebase as long long).
160 * On ARM it just returns the timer value.
161 */
162unsigned long long get_ticks(void)
163{
164 return get_timer(0);
165}
166
167/*
168 * This function is derived from PowerPC code (timebase clock frequency).
169 * On ARM it returns the number of timer ticks per second.
170 */
171ulong get_tbclk (void)
172{
173 ulong tbclk;
174
175 tbclk = CFG_HZ;
176 return tbclk;
177}