xref: /openbmc/u-boot/arch/arm/cpu/pxa/timer.c (revision 15855700)
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  * See file CREDITS for list of people who contributed to this
11  * project.
12  *
13  * This program is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU General Public License as
15  * published by the Free Software Foundation; either version 2 of
16  * the License, or (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
26  * MA 02111-1307 USA
27  */
28 
29 #include <common.h>
30 #include <asm/arch/pxa-regs.h>
31 #include <div64.h>
32 
33 #ifdef CONFIG_USE_IRQ
34 #error: interrupts not implemented yet
35 #endif
36 
37 #if defined(CONFIG_PXA27X) || defined(CONFIG_CPU_MONAHANS)
38 #define TIMER_FREQ_HZ 3250000
39 #elif defined(CONFIG_PXA250)
40 #define TIMER_FREQ_HZ 3686400
41 #else
42 #error "Timer frequency unknown - please config PXA CPU type"
43 #endif
44 
45 static inline unsigned long long tick_to_time(unsigned long long tick)
46 {
47 	tick *= CONFIG_SYS_HZ;
48 	do_div(tick, TIMER_FREQ_HZ);
49 	return tick;
50 }
51 
52 static inline unsigned long long us_to_tick(unsigned long long us)
53 {
54 	us = us * TIMER_FREQ_HZ + 999999;
55 	do_div(us, 1000000);
56 	return us;
57 }
58 
59 int timer_init (void)
60 {
61 	reset_timer();
62 
63 	return 0;
64 }
65 
66 void reset_timer (void)
67 {
68 	reset_timer_masked ();
69 }
70 
71 ulong get_timer (ulong base)
72 {
73 	return get_timer_masked () - base;
74 }
75 
76 void set_timer (ulong t)
77 {
78 	/* nop */
79 }
80 
81 void __udelay (unsigned long usec)
82 {
83 	udelay_masked (usec);
84 }
85 
86 
87 void reset_timer_masked (void)
88 {
89 	OSCR = 0;
90 }
91 
92 ulong get_timer_masked (void)
93 {
94 	return tick_to_time(get_ticks());
95 }
96 
97 void udelay_masked (unsigned long usec)
98 {
99 	unsigned long long tmp;
100 	ulong tmo;
101 
102 	tmo = us_to_tick(usec);
103 	tmp = get_ticks() + tmo;	/* get current timestamp */
104 
105 	while (get_ticks() < tmp)	/* loop till event */
106 		 /*NOP*/;
107 
108 }
109 
110 /*
111  * This function is derived from PowerPC code (read timebase as long long).
112  * On ARM it just returns the timer value.
113  */
114 unsigned long long get_ticks(void)
115 {
116 	return OSCR;
117 }
118 
119 /*
120  * This function is derived from PowerPC code (timebase clock frequency).
121  * On ARM it returns the number of timer ticks per second.
122  */
123 ulong get_tbclk (void)
124 {
125 	ulong tbclk;
126 	tbclk = TIMER_FREQ_HZ;
127 	return tbclk;
128 }
129