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2 * Copyright (C) 2004-2006 Atmel Corporation
4 * See file CREDITS for list of people who contributed to this
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.
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.
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,
25 #include <asm/errno.h>
27 #include <asm/processor.h>
28 #include <asm/sysreg.h>
30 #include <asm/arch/memory-map.h>
32 #define HANDLER_MASK 0x00ffffff
33 #define INTLEV_SHIFT 30
34 #define INTLEV_MASK 0x00000003
36 DECLARE_GLOBAL_DATA_PTR
;
38 /* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */
39 volatile unsigned long timer_overflow
;
42 * Instead of dividing by get_tbclk(), multiply by this constant and
43 * right-shift the result by 32 bits.
45 static unsigned long tb_factor
;
47 unsigned long get_tbclk(void)
52 unsigned long long get_ticks(void)
54 unsigned long lo
, hi_now
, hi_prev
;
57 hi_prev
= timer_overflow
;
58 lo
= sysreg_read(COUNT
);
59 hi_now
= timer_overflow
;
60 } while (hi_prev
!= hi_now
);
62 return ((unsigned long long)hi_now
<< 32) | lo
;
65 void reset_timer(void)
67 sysreg_write(COUNT
, 0);
68 cpu_sync_pipeline(); /* process any pending interrupts */
72 unsigned long get_timer(unsigned long base
)
74 u64 now
= get_ticks();
77 return (unsigned long)(now
>> 32) - base
;
80 void set_timer(unsigned long t
)
82 unsigned long long ticks
= t
;
83 unsigned long lo
, hi
, hi_new
;
85 ticks
= (ticks
* get_tbclk()) / CONFIG_SYS_HZ
;
87 lo
= ticks
& 0xffffffffUL
;
91 sysreg_write(COUNT
, lo
);
92 hi_new
= timer_overflow
;
93 } while (hi_new
!= hi
);
97 * For short delays only. It will overflow after a few seconds.
99 void udelay(unsigned long usec
)
101 unsigned long cycles
;
105 base
= sysreg_read(COUNT
);
106 cycles
= ((usec
* (get_tbclk() / 10000)) + 50) / 100;
109 now
= sysreg_read(COUNT
);
110 } while ((now
- base
) < cycles
);
113 static int set_interrupt_handler(unsigned int nr
, void (*handler
)(void),
114 unsigned int priority
)
116 extern void _evba(void);
118 unsigned long handler_addr
= (unsigned long)handler
;
120 handler_addr
-= (unsigned long)&_evba
;
122 if ((handler_addr
& HANDLER_MASK
) != handler_addr
123 || (priority
& INTLEV_MASK
) != priority
)
126 intpr
= (handler_addr
& HANDLER_MASK
);
127 intpr
|= (priority
& INTLEV_MASK
) << INTLEV_SHIFT
;
128 writel(intpr
, (void *)INTC_BASE
+ 4 * nr
);
133 void timer_init(void)
135 extern void timer_interrupt_handler(void);
138 sysreg_write(COUNT
, 0);
140 tmp
= (u64
)CONFIG_SYS_HZ
<< 32;
141 tmp
+= gd
->cpu_hz
/ 2;
142 do_div(tmp
, gd
->cpu_hz
);
143 tb_factor
= (u32
)tmp
;
145 if (set_interrupt_handler(0, &timer_interrupt_handler
, 3))
148 /* For all practical purposes, this gives us an overflow interrupt */
149 sysreg_write(COMPARE
, 0xffffffff);