xref: /openbmc/u-boot/arch/arm/cpu/arm920t/imx/timer.c (revision ed56fb1d)
1 /*
2  * (C) Copyright 2002
3  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
4  * Marius Groeger <mgroeger@sysgo.de>
5  *
6  * (C) Copyright 2002
7  * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
8  * Alex Zuepke <azu@sysgo.de>
9  *
10  * (C) Copyright 2002
11  * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
12  *
13  * See file CREDITS for list of people who contributed to this
14  * project.
15  *
16  * This program is free software; you can redistribute it and/or
17  * modify it under the terms of the GNU General Public License as
18  * published by the Free Software Foundation; either version 2 of
19  * the License, or (at your option) any later version.
20  *
21  * This program is distributed in the hope that it will be useful,
22  * but WITHOUT ANY WARRANTY; without even the implied warranty of
23  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
24  * GNU General Public License for more details.
25  *
26  * You should have received a copy of the GNU General Public License
27  * along with this program; if not, write to the Free Software
28  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29  * MA 02111-1307 USA
30  */
31 
32 #include <common.h>
33 #if defined (CONFIG_IMX)
34 
35 #include <asm/arch/imx-regs.h>
36 
37 int timer_init (void)
38 {
39 	int i;
40 	/* setup GP Timer 1 */
41 	TCTL1 = TCTL_SWR;
42 	for ( i=0; i<100; i++) TCTL1 = 0; /* We have no udelay by now */
43 	TPRER1 = get_PERCLK1() / 1000000; /* 1 MHz */
44 	TCTL1 |= TCTL_FRR | (1<<1); /* Freerun Mode, PERCLK1 input */
45 
46 	reset_timer_masked();
47 
48 	return (0);
49 }
50 
51 /*
52  * timer without interrupts
53  */
54 
55 void reset_timer (void)
56 {
57 	reset_timer_masked ();
58 }
59 
60 ulong get_timer (ulong base)
61 {
62 	return get_timer_masked() - base;
63 }
64 
65 void set_timer (ulong t)
66 {
67 	/* nop */
68 }
69 
70 void reset_timer_masked (void)
71 {
72 	TCTL1 &= ~TCTL_TEN;
73 	TCTL1 |= TCTL_TEN; /* Enable timer */
74 }
75 
76 ulong get_timer_masked (void)
77 {
78 	return TCN1;
79 }
80 
81 void udelay_masked (unsigned long usec)
82 {
83 	ulong endtime = get_timer_masked() + usec;
84 	signed long diff;
85 
86 	do {
87 		ulong now = get_timer_masked ();
88 		diff = endtime - now;
89 	} while (diff >= 0);
90 }
91 
92 void __udelay (unsigned long usec)
93 {
94 	udelay_masked(usec);
95 }
96 
97 /*
98  * This function is derived from PowerPC code (read timebase as long long).
99  * On ARM it just returns the timer value.
100  */
101 unsigned long long get_ticks(void)
102 {
103 	return get_timer(0);
104 }
105 
106 /*
107  * This function is derived from PowerPC code (timebase clock frequency).
108  * On ARM it returns the number of timer ticks per second.
109  */
110 ulong get_tbclk (void)
111 {
112 	ulong tbclk;
113 
114 	tbclk = CONFIG_SYS_HZ;
115 
116 	return tbclk;
117 }
118 
119 /*
120  * Reset the cpu by setting up the watchdog timer and let him time out
121  */
122 void reset_cpu (ulong ignored)
123 {
124 	/* Disable watchdog and set Time-Out field to 0 */
125 	WCR = 0x00000000;
126 
127 	/* Write Service Sequence */
128 	WSR = 0x00005555;
129 	WSR = 0x0000AAAA;
130 
131 	/* Enable watchdog */
132 	WCR = 0x00000001;
133 
134 	while (1);
135 	/*NOTREACHED*/
136 }
137 
138 #endif /* defined (CONFIG_IMX) */
139