xref: /openbmc/u-boot/arch/microblaze/cpu/timer.c (revision 00a2749d)
1 /*
2  * (C) Copyright 2007 Michal Simek
3  *
4  * Michal  SIMEK <monstr@monstr.eu>
5  *
6  * See file CREDITS for list of people who contributed to this
7  * project.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License as
11  * published by the Free Software Foundation; either version 2 of
12  * the License, or (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
22  * MA 02111-1307 USA
23  */
24 
25 #include <common.h>
26 #include <asm/microblaze_timer.h>
27 #include <asm/microblaze_intc.h>
28 
29 volatile int timestamp = 0;
30 
31 #ifdef CONFIG_SYS_TIMER_0
32 ulong get_timer (ulong base)
33 {
34 	return (timestamp - base);
35 }
36 #else
37 ulong get_timer (ulong base)
38 {
39 	return (timestamp++ - base);
40 }
41 #endif
42 
43 #ifdef CONFIG_SYS_TIMER_0
44 void __udelay(unsigned long usec)
45 {
46 	int i;
47 
48 	i = get_timer(0);
49 	while ((get_timer(0) - i) < (usec / 1000))
50 		;
51 }
52 #else
53 void __udelay(unsigned long usec)
54 {
55 	unsigned int i;
56 
57 	for (i = 0; i < (usec * CONFIG_XILINX_CLOCK_FREQ / 10000000); i++)
58 		;
59 }
60 #endif
61 
62 #ifdef CONFIG_SYS_TIMER_0
63 microblaze_timer_t *tmr = (microblaze_timer_t *) (CONFIG_SYS_TIMER_0_ADDR);
64 
65 void timer_isr (void *arg)
66 {
67 	timestamp++;
68 	tmr->control = tmr->control | TIMER_INTERRUPT;
69 }
70 
71 int timer_init (void)
72 {
73 	tmr->loadreg = CONFIG_SYS_TIMER_0_PRELOAD;
74 	tmr->control = TIMER_INTERRUPT | TIMER_RESET;
75 	tmr->control =
76 	    TIMER_ENABLE | TIMER_ENABLE_INTR | TIMER_RELOAD | TIMER_DOWN_COUNT;
77 	timestamp = 0;
78 	install_interrupt_handler (CONFIG_SYS_TIMER_0_IRQ, timer_isr, (void *)tmr);
79 	return 0;
80 }
81 #endif
82 
83 /*
84  * This function is derived from PowerPC code (read timebase as long long).
85  * On Microblaze it just returns the timer value.
86  */
87 unsigned long long get_ticks(void)
88 {
89 	return get_timer(0);
90 }
91 
92 /*
93  * This function is derived from PowerPC code (timebase clock frequency).
94  * On Microblaze it returns the number of timer ticks per second.
95  */
96 ulong get_tbclk(void)
97 {
98 	return CONFIG_SYS_HZ;
99 }
100