3 * Texas Instruments <www.ti.com>
6 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
7 * Marius Groeger <mgroeger@sysgo.de>
10 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
11 * Alex Zuepke <azu@sysgo.de>
13 * (C) Copyright 2002-2004
14 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
17 * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
19 * See file CREDITS for list of people who contributed to this
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.
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.
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,
41 #define TIMER_LOAD_VAL 0xffffffff
43 /* macro to read the 32 bit timer */
44 #define READ_TIMER readl(CONFIG_SYS_TIMERBASE + 20)
46 static ulong timestamp;
49 /* nothing really to do with interrupts, just starts up a counter. */
52 /* Load timer with initial value */
53 writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + 16);
56 * Set timer to be enabled, free-running, no interrupts, 256 divider,
59 writel(0x8a, CONFIG_SYS_TIMERBASE + 24);
61 /* init the timestamp and lastdec value */
68 * timer without interrupts
70 void reset_timer(void)
75 ulong get_timer(ulong base)
77 return get_timer_masked() - base;
80 void set_timer(ulong t)
85 /* delay x useconds AND perserve advance timstamp value */
86 void udelay(unsigned long usec)
91 /* if "big" number, spread normalization to seconds */
92 tmo = usec / 1000; /* start to normalize */
93 tmo *= CONFIG_SYS_HZ; /* find number of "ticks" */
94 tmo /= 1000; /* finish normalize. */
96 /* small number, don't kill it prior to HZ multiply */
97 tmo = usec * CONFIG_SYS_HZ;
101 tmp = get_timer(0); /* get current timestamp */
102 if ((tmo + tmp + 1) < tmp) /* will roll time stamp? */
103 reset_timer_masked(); /* reset to 0, set lastdec value */
107 while (get_timer_masked() < tmo)
111 void reset_timer_masked(void)
114 lastdec = READ_TIMER; /* capure current decrementer value time */
115 timestamp = 0; /* start "advancing" time stamp from 0 */
118 ulong get_timer_masked(void)
120 ulong now = READ_TIMER; /* current tick value */
122 if (lastdec >= now) { /* normal mode (non roll) */
123 /* move stamp fordward */
124 timestamp += lastdec - now;
127 * An overflow is expected.
128 * nts = ts + ld + (TLV - now)
129 * ts=old stamp, ld=time that passed before passing through -1
130 * (TLV-now) amount of time after passing though -1
131 * nts = new "advancing time stamp"...it could also roll
133 timestamp += lastdec + TIMER_LOAD_VAL - now;
140 /* waits specified delay value and resets timestamp */
141 void udelay_masked(unsigned long usec)
146 /* if "big" number, spread normalization to seconds */
147 tmo = usec / 1000; /* start to normalize */
148 tmo *= CONFIG_SYS_HZ; /* find number of "ticks" */
149 tmo /= 1000; /* finish normalize. */
151 /* else small number, don't kill it prior to HZ multiply */
152 tmo = usec * CONFIG_SYS_HZ;
156 reset_timer_masked();
157 /* set "advancing" timestamp to 0, set lastdec vaule */
159 while (get_timer_masked() < tmo)
164 * This function is derived from PowerPC code (read timebase as long long).
165 * On ARM it just returns the timer value.
167 unsigned long long get_ticks(void)
173 * This function is derived from PowerPC code (timebase clock frequency).
174 * On ARM it returns the number of timer ticks per second.
176 ulong get_tbclk(void)
180 tbclk = CONFIG_SYS_HZ;