4 * Richard Woodruff <r-woodruff2@ti.com>
7 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
8 * Marius Groeger <mgroeger@sysgo.de>
9 * Alex Zuepke <azu@sysgo.de>
12 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
14 * See file CREDITS for list of people who contributed to this
17 * This program is free software; you can redistribute it and/or
18 * modify it under the terms of the GNU General Public License as
19 * published by the Free Software Foundation; either version 2 of
20 * the License, or (at your option) any later version.
22 * This program is distributed in the hope that it will be useful,
23 * but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU General Public License for more details.
27 * You should have received a copy of the GNU General Public License
28 * along with this program; if not, write to the Free Software
29 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
34 #include <asm/arch/bits.h>
35 #include <asm/arch/omap2420.h>
37 #define TIMER_LOAD_VAL 0
39 /* macro to read the 32 bit timer */
40 #define READ_TIMER (*((volatile ulong*)(CFG_TIMERBASE+TCRR)))
42 static ulong timestamp;
46 * nothing really to do with interrupts, just starts up a counter.
48 int interrupt_init(void)
52 /* Start the counter ticking up */
53 /* reload value on overflow*/
54 *((int32_t *) (CFG_TIMERBASE + TLDR)) = TIMER_LOAD_VAL;
55 /* mask to enable timer*/
56 val = (CFG_PVT << 2) | BIT5 | BIT1 | BIT0;
57 *((int32_t *) (CFG_TIMERBASE + TCLR)) = val; /* start timer */
59 reset_timer_masked(); /* init the timestamp and lastinc value */
64 * timer without interrupts
66 void reset_timer(void)
71 ulong get_timer(ulong base)
73 return get_timer_masked() - base;
76 void set_timer(ulong t)
81 /* delay x useconds AND perserve advance timstamp value */
82 void udelay(unsigned long usec)
86 /* if "big" number, spread normalization to seconds */
88 /* start to normalize for usec to ticks per sec */
90 /* find number of "ticks" to wait to achieve target */
92 /* finish normalize. */
95 /* else small number, don't kill it prior to HZ multiply */
99 /* get current timestamp */
101 if ((tmo + tmp + 1) < tmp)
102 /* setting this forward will roll time stamp */
103 /* reset "advancing" timestamp to 0, set lastinc value */
104 reset_timer_masked();
106 /* else, set advancing stamp wake up time */
108 while (get_timer_masked() < tmo)/* loop till event */
112 void reset_timer_masked(void)
115 /* capture current incrementer value time */
116 lastinc = READ_TIMER;
117 /* start "advancing" time stamp from 0 */
121 ulong get_timer_masked(void)
123 ulong now = READ_TIMER; /* current tick value */
125 /* normal mode (non roll) */
127 /* move stamp forward with absolute diff ticks */
128 timestamp += (now - lastinc);
130 /* we have rollover of incrementer */
131 timestamp += (0xFFFFFFFF - lastinc) + now;
136 /* waits specified delay value and resets timestamp */
137 void udelay_masked(unsigned long usec)
144 /* "big" number, spread normalization to seconds */
145 /* start to normalize for usec to ticks per sec */
147 /* find number of "ticks" to wait to achieve target */
149 tmo /= 1000;/* finish normalize. */
151 /* else small number, don't kill it prior to HZ multiply */
155 endtime = get_timer_masked() + tmo;
158 ulong now = get_timer_masked();
159 diff = endtime - now;
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)
172 * This function is derived from PowerPC code (timebase clock frequency).
173 * On ARM it returns the number of timer ticks per second.
175 ulong get_tbclk(void)