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Wolfgang Denk72a087e2006-10-24 14:27:35 +02001/*
2 * Copyright (C) 2004-2006 Atmel Corporation
3 *
4 * See file CREDITS for list of people who contributed to this
5 * project.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
20 * MA 02111-1307 USA
21 */
22#include <common.h>
23
24#include <asm/div64.h>
25#include <asm/errno.h>
26#include <asm/io.h>
27#include <asm/processor.h>
28#include <asm/sysreg.h>
29
Haavard Skinnemoendf548d32006-11-19 18:06:53 +010030#include <asm/arch/memory-map.h>
Wolfgang Denk72a087e2006-10-24 14:27:35 +020031
32#define HANDLER_MASK 0x00ffffff
33#define INTLEV_SHIFT 30
34#define INTLEV_MASK 0x00000003
35
36DECLARE_GLOBAL_DATA_PTR;
37
38/* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */
39volatile unsigned long timer_overflow;
40
41/*
42 * Instead of dividing by get_tbclk(), multiply by this constant and
43 * right-shift the result by 32 bits.
44 */
45static unsigned long tb_factor;
46
Wolfgang Denk72a087e2006-10-24 14:27:35 +020047unsigned long get_tbclk(void)
48{
49 return gd->cpu_hz;
50}
51
52unsigned long long get_ticks(void)
53{
54 unsigned long lo, hi_now, hi_prev;
55
56 do {
57 hi_prev = timer_overflow;
58 lo = sysreg_read(COUNT);
59 hi_now = timer_overflow;
60 } while (hi_prev != hi_now);
61
62 return ((unsigned long long)hi_now << 32) | lo;
63}
64
65void reset_timer(void)
66{
67 sysreg_write(COUNT, 0);
68 cpu_sync_pipeline(); /* process any pending interrupts */
69 timer_overflow = 0;
70}
71
72unsigned long get_timer(unsigned long base)
73{
74 u64 now = get_ticks();
75
76 now *= tb_factor;
77 return (unsigned long)(now >> 32) - base;
78}
79
80void set_timer(unsigned long t)
81{
82 unsigned long long ticks = t;
83 unsigned long lo, hi, hi_new;
84
85 ticks = (ticks * get_tbclk()) / CFG_HZ;
86 hi = ticks >> 32;
87 lo = ticks & 0xffffffffUL;
88
89 do {
90 timer_overflow = hi;
91 sysreg_write(COUNT, lo);
92 hi_new = timer_overflow;
93 } while (hi_new != hi);
94}
95
96/*
97 * For short delays only. It will overflow after a few seconds.
98 */
99void udelay(unsigned long usec)
100{
101 unsigned long now, end;
102
103 now = sysreg_read(COUNT);
104
105 end = ((usec * (get_tbclk() / 10000)) + 50) / 100;
106 end += now;
107
108 while (now > end)
109 now = sysreg_read(COUNT);
110
111 while (now < end)
112 now = sysreg_read(COUNT);
113}
114
115static int set_interrupt_handler(unsigned int nr, void (*handler)(void),
116 unsigned int priority)
117{
Haavard Skinnemoen1f4f2122006-11-20 15:53:10 +0100118 extern void _evba(void);
Wolfgang Denk72a087e2006-10-24 14:27:35 +0200119 unsigned long intpr;
120 unsigned long handler_addr = (unsigned long)handler;
121
Haavard Skinnemoen1f4f2122006-11-20 15:53:10 +0100122 handler_addr -= (unsigned long)&_evba;
123
Wolfgang Denk72a087e2006-10-24 14:27:35 +0200124 if ((handler_addr & HANDLER_MASK) != handler_addr
125 || (priority & INTLEV_MASK) != priority)
126 return -EINVAL;
127
128 intpr = (handler_addr & HANDLER_MASK);
129 intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT;
Haavard Skinnemoendf548d32006-11-19 18:06:53 +0100130 writel(intpr, (void *)INTC_BASE + 4 * nr);
Wolfgang Denk72a087e2006-10-24 14:27:35 +0200131
132 return 0;
133}
134
135void timer_init(void)
136{
137 extern void timer_interrupt_handler(void);
138 u64 tmp;
139
140 sysreg_write(COUNT, 0);
141
142 tmp = (u64)CFG_HZ << 32;
143 tmp += gd->cpu_hz / 2;
144 do_div(tmp, gd->cpu_hz);
145 tb_factor = (u32)tmp;
146
Haavard Skinnemoendf548d32006-11-19 18:06:53 +0100147 if (set_interrupt_handler(0, &timer_interrupt_handler, 3))
Wolfgang Denk72a087e2006-10-24 14:27:35 +0200148 return;
149
150 /* For all practical purposes, this gives us an overflow interrupt */
151 sysreg_write(COMPARE, 0xffffffff);
152}