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>
14 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
16 * See file CREDITS for list of people who contributed to this
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.
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.
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,
37 #include <configs/omap1510.h>
40 #define TIMER_LOAD_VAL 0xffffffff
42 static uint32_t timestamp;
43 static uint32_t lastdec;
45 /* nothing really to do with interrupts, just starts up a counter. */
46 int interrupt_init (void)
48 /* Start the decrementer ticking down from 0xffffffff */
49 __raw_writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + LOAD_TIM);
50 __raw_writel(MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE |
51 (CONFIG_SYS_PTV << MPUTIM_PTV_BIT),
52 CONFIG_SYS_TIMERBASE + CNTL_TIMER);
54 /* init the timestamp and lastdec value */
61 * timer without interrupts
64 void reset_timer (void)
66 reset_timer_masked ();
69 ulong get_timer (ulong base)
71 return get_timer_masked () - base;
74 void set_timer (ulong t)
79 /* delay x useconds AND preserve advance timestamp value */
80 void udelay (unsigned long usec)
84 if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
85 tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
86 tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
87 tmo /= 1000; /* finish normalize. */
88 } else { /* else small number, don't kill it prior to HZ multiply */
89 tmo = usec * CONFIG_SYS_HZ;
93 tmp = get_timer (0); /* get current timestamp */
94 if ((tmo + tmp + 1) < tmp) /* if setting this fordward will roll time stamp */
95 reset_timer_masked (); /* reset "advancing" timestamp to 0, set lastdec value */
97 tmo += tmp; /* else, set advancing stamp wake up time */
99 while (get_timer_masked () < tmo) /* loop till event */
103 void reset_timer_masked (void)
106 lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
107 timestamp = 0; /* start "advancing" time stamp from 0 */
110 ulong get_timer_masked (void)
112 uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
114 if (lastdec >= now) { /* normal mode (non roll) */
116 timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
117 } else { /* we have overflow of the count down timer */
118 /* nts = ts + ld + (TLV - now)
119 * ts=old stamp, ld=time that passed before passing through -1
120 * (TLV-now) amount of time after passing though -1
121 * nts = new "advancing time stamp"...it could also roll and cause problems.
123 timestamp += lastdec + TIMER_LOAD_VAL - now;
130 /* waits specified delay value and resets timestamp */
131 void udelay_masked (unsigned long usec)
133 #ifdef CONFIG_INNOVATOROMAP1510
134 #define LOOPS_PER_MSEC 60 /* tuned on omap1510 */
135 volatile int i, time_remaining = LOOPS_PER_MSEC*usec;
136 for (i=time_remaining; i>0; i--) { }
143 if (usec >= 1000) { /* if "big" number, spread normalization to seconds */
144 tmo = usec / 1000; /* start to normalize for usec to ticks per sec */
145 tmo *= CONFIG_SYS_HZ; /* find number of "ticks" to wait to achieve target */
146 tmo /= 1000; /* finish normalize. */
147 } else { /* else small number, don't kill it prior to HZ multiply */
148 tmo = usec * CONFIG_SYS_HZ;
152 endtime = get_timer_masked () + tmo;
155 ulong now = get_timer_masked ();
156 diff = endtime - now;
162 * This function is derived from PowerPC code (read timebase as long long).
163 * On ARM it just returns the timer value.
165 unsigned long long get_ticks(void)
171 * This function is derived from PowerPC code (timebase clock frequency).
172 * On ARM it returns the number of timer ticks per second.
174 ulong get_tbclk (void)
176 return CONFIG_SYS_HZ;