1 /*
2 * (C) Copyright 2007-2008
3 * Stelian Pop <stelian@popies.net>
4 * Lead Tech Design <www.leadtechdesign.com>
5 *
6 * (C) Copyright 2010
7 * Matthias Weisser, Graf-Syteco <weisserm@arcor.de>
8 *
9 * See file CREDITS for list of people who contributed to this
10 * project.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of
15 * the License, or (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 *
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
25 * MA 02111-1307 USA
26 */
28 #include <div64.h>
29 #include <common.h>
30 #include <asm/io.h>
31 #include <asm/arch/hardware.h>
33 #define TIMER_LOAD_VAL 0xffffffff
34 #define TIMER_FREQ (CONFIG_MB86R0x_IOCLK / 256)
36 DECLARE_GLOBAL_DATA_PTR;
38 #define timestamp gd->tbl
39 #define lastdec gd->lastinc
41 static inline unsigned long long tick_to_time(unsigned long long tick)
42 {
43 tick *= CONFIG_SYS_HZ;
44 do_div(tick, TIMER_FREQ);
46 return tick;
47 }
49 static inline unsigned long long usec_to_tick(unsigned long long usec)
50 {
51 usec *= TIMER_FREQ;
52 do_div(usec, 1000000);
54 return usec;
55 }
57 /* nothing really to do with interrupts, just starts up a counter. */
58 int timer_init(void)
59 {
60 struct mb86r0x_timer * timer = (struct mb86r0x_timer *)
61 MB86R0x_TIMER_BASE;
62 ulong ctrl = readl(&timer->control);
64 writel(TIMER_LOAD_VAL, &timer->load);
66 ctrl |= MB86R0x_TIMER_ENABLE | MB86R0x_TIMER_PRS_8S |
67 MB86R0x_TIMER_SIZE_32;
69 writel(ctrl, &timer->control);
71 /* capture current value time */
72 lastdec = readl(&timer->value);
73 timestamp = 0; /* start "advancing" time stamp from 0 */
75 return 0;
76 }
78 /*
79 * timer without interrupts
80 */
81 unsigned long long get_ticks(void)
82 {
83 struct mb86r0x_timer * timer = (struct mb86r0x_timer *)
84 MB86R0x_TIMER_BASE;
85 ulong now = readl(&timer->value);
87 if (now <= lastdec) {
88 /* normal mode (non roll) */
89 /* move stamp forward with absolut diff ticks */
90 timestamp += lastdec - now;
91 } else {
92 /* we have rollover of incrementer */
93 timestamp += lastdec + TIMER_LOAD_VAL - now;
94 }
95 lastdec = now;
96 return timestamp;
97 }
99 ulong get_timer_masked(void)
100 {
101 return tick_to_time(get_ticks());
102 }
104 void __udelay(unsigned long usec)
105 {
106 unsigned long long tmp;
107 ulong tmo;
109 tmo = usec_to_tick(usec);
110 tmp = get_ticks(); /* get current timestamp */
112 while ((get_ticks() - tmp) < tmo) /* loop till event */
113 /*NOP*/;
114 }
116 ulong get_timer(ulong base)
117 {
118 return get_timer_masked() - base;
119 }
121 /*
122 * This function is derived from PowerPC code (timebase clock frequency).
123 * On ARM it returns the number of timer ticks per second.
124 */
125 ulong get_tbclk(void)
126 {
127 ulong tbclk;
129 tbclk = TIMER_FREQ;
130 return tbclk;
131 }