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,
40 #define TIMER_LOAD_VAL 0xffffffff
42 /* macro to read the 32 bit timer */
43 #define READ_TIMER (*(volatile ulong *)(CONFIG_SYS_TIMERBASE+8))
45 static ulong timestamp;
52 /* Start the decrementer ticking down from 0xffffffff */
53 *((int32_t *) (CONFIG_SYS_TIMERBASE + LOAD_TIM)) = TIMER_LOAD_VAL;
54 val = MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | (CONFIG_SYS_PTV << MPUTIM_PTV_BIT);
55 *((int32_t *) (CONFIG_SYS_TIMERBASE + CNTL_TIMER)) = val;
57 /* init the timestamp and lastdec value */
64 * timer without interrupts
67 void reset_timer (void)
69 reset_timer_masked ();
72 ulong get_timer (ulong base)
74 return get_timer_masked () - base;
77 void set_timer (ulong t)
82 /* delay x useconds AND preserve advance timestamp value */
83 void __udelay (unsigned long usec)
87 if(usec >= 1000){ /* if "big" number, spread normalization to seconds */
88 tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
89 tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
90 tmo /= 1000; /* finish normalize. */
91 }else{ /* else small number, don't kill it prior to HZ multiply */
92 tmo = usec * CONFIG_SYS_HZ;
96 tmp = get_timer (0); /* get current timestamp */
97 if( (tmo + tmp + 1) < tmp ) /* if setting this fordward will roll time stamp */
98 reset_timer_masked (); /* reset "advancing" timestamp to 0, set lastdec value */
100 tmo += tmp; /* else, set advancing stamp wake up time */
102 while (get_timer_masked () < tmo)/* loop till event */
106 void reset_timer_masked (void)
109 lastdec = READ_TIMER; /* capure current decrementer value time */
110 timestamp = 0; /* start "advancing" time stamp from 0 */
113 ulong get_timer_masked (void)
115 ulong now = READ_TIMER; /* current tick value */
117 if (lastdec >= now) { /* normal mode (non roll) */
119 timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
120 } else { /* we have overflow of the count down timer */
121 /* nts = ts + ld + (TLV - now)
122 * ts=old stamp, ld=time that passed before passing through -1
123 * (TLV-now) amount of time after passing though -1
124 * nts = new "advancing time stamp"...it could also roll and cause problems.
126 timestamp += lastdec + TIMER_LOAD_VAL - now;
133 /* waits specified delay value and resets timestamp */
134 void udelay_masked (unsigned long usec)
140 if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
141 tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
142 tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
143 tmo /= 1000; /* finish normalize. */
144 } else { /* else small number, don't kill it prior to HZ multiply */
145 tmo = usec * CONFIG_SYS_HZ;
149 endtime = get_timer_masked () + tmo;
152 ulong now = get_timer_masked ();
153 diff = endtime - now;
158 * This function is derived from PowerPC code (read timebase as long long).
159 * On ARM it just returns the timer value.
161 unsigned long long get_ticks(void)
167 * This function is derived from PowerPC code (timebase clock frequency).
168 * On ARM it returns the number of timer ticks per second.
170 ulong get_tbclk (void)
174 tbclk = CONFIG_SYS_HZ;