blob: d720cfa942b32edc9622326aa7ae5fa8421de009 [file] [log] [blame]
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
30#include <asm/arch/platform.h>
31
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
47static const struct device *intc_dev;
48
49unsigned long get_tbclk(void)
50{
51 return gd->cpu_hz;
52}
53
54unsigned long long get_ticks(void)
55{
56 unsigned long lo, hi_now, hi_prev;
57
58 do {
59 hi_prev = timer_overflow;
60 lo = sysreg_read(COUNT);
61 hi_now = timer_overflow;
62 } while (hi_prev != hi_now);
63
64 return ((unsigned long long)hi_now << 32) | lo;
65}
66
67void reset_timer(void)
68{
69 sysreg_write(COUNT, 0);
70 cpu_sync_pipeline(); /* process any pending interrupts */
71 timer_overflow = 0;
72}
73
74unsigned long get_timer(unsigned long base)
75{
76 u64 now = get_ticks();
77
78 now *= tb_factor;
79 return (unsigned long)(now >> 32) - base;
80}
81
82void set_timer(unsigned long t)
83{
84 unsigned long long ticks = t;
85 unsigned long lo, hi, hi_new;
86
87 ticks = (ticks * get_tbclk()) / CFG_HZ;
88 hi = ticks >> 32;
89 lo = ticks & 0xffffffffUL;
90
91 do {
92 timer_overflow = hi;
93 sysreg_write(COUNT, lo);
94 hi_new = timer_overflow;
95 } while (hi_new != hi);
96}
97
98/*
99 * For short delays only. It will overflow after a few seconds.
100 */
101void udelay(unsigned long usec)
102{
103 unsigned long now, end;
104
105 now = sysreg_read(COUNT);
106
107 end = ((usec * (get_tbclk() / 10000)) + 50) / 100;
108 end += now;
109
110 while (now > end)
111 now = sysreg_read(COUNT);
112
113 while (now < end)
114 now = sysreg_read(COUNT);
115}
116
117static int set_interrupt_handler(unsigned int nr, void (*handler)(void),
118 unsigned int priority)
119{
120 unsigned long intpr;
121 unsigned long handler_addr = (unsigned long)handler;
122
123 if ((handler_addr & HANDLER_MASK) != handler_addr
124 || (priority & INTLEV_MASK) != priority)
125 return -EINVAL;
126
127 intpr = (handler_addr & HANDLER_MASK);
128 intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT;
129 writel(intpr, intc_dev->regs + 4 * nr);
130
131 return 0;
132}
133
134void timer_init(void)
135{
136 extern void timer_interrupt_handler(void);
137 u64 tmp;
138
139 sysreg_write(COUNT, 0);
140
141 tmp = (u64)CFG_HZ << 32;
142 tmp += gd->cpu_hz / 2;
143 do_div(tmp, gd->cpu_hz);
144 tb_factor = (u32)tmp;
145
146 intc_dev = get_device(DEVICE_INTC);
147
148 if (!intc_dev
149 || set_interrupt_handler(0, &timer_interrupt_handler, 3))
150 return;
151
152 /* For all practical purposes, this gives us an overflow interrupt */
153 sysreg_write(COMPARE, 0xffffffff);
154}