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,
24 #include <asm/div64.h>
25 #include <asm/errno.h>
27 #include <asm/processor.h>
28 #include <asm/sysreg.h>
30 #include <asm/arch/platform.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 static const struct device *intc_dev;
49 unsigned long get_tbclk(void)
54 unsigned long long get_ticks(void)
56 unsigned long lo, hi_now, hi_prev;
59 hi_prev = timer_overflow;
60 lo = sysreg_read(COUNT);
61 hi_now = timer_overflow;
62 } while (hi_prev != hi_now);
64 return ((unsigned long long)hi_now << 32) | lo;
67 void reset_timer(void)
69 sysreg_write(COUNT, 0);
70 cpu_sync_pipeline(); /* process any pending interrupts */
74 unsigned long get_timer(unsigned long base)
76 u64 now = get_ticks();
79 return (unsigned long)(now >> 32) - base;
82 void set_timer(unsigned long t)
84 unsigned long long ticks = t;
85 unsigned long lo, hi, hi_new;
87 ticks = (ticks * get_tbclk()) / CFG_HZ;
89 lo = ticks & 0xffffffffUL;
93 sysreg_write(COUNT, lo);
94 hi_new = timer_overflow;
95 } while (hi_new != hi);
99 * For short delays only. It will overflow after a few seconds.
101 void udelay(unsigned long usec)
103 unsigned long now, end;
105 now = sysreg_read(COUNT);
107 end = ((usec * (get_tbclk() / 10000)) + 50) / 100;
111 now = sysreg_read(COUNT);
114 now = sysreg_read(COUNT);
117 static int set_interrupt_handler(unsigned int nr, void (*handler)(void),
118 unsigned int priority)
121 unsigned long handler_addr = (unsigned long)handler;
123 if ((handler_addr & HANDLER_MASK) != handler_addr
124 || (priority & INTLEV_MASK) != priority)
127 intpr = (handler_addr & HANDLER_MASK);
128 intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT;
129 writel(intpr, intc_dev->regs + 4 * nr);
134 void timer_init(void)
136 extern void timer_interrupt_handler(void);
139 sysreg_write(COUNT, 0);
141 tmp = (u64)CFG_HZ << 32;
142 tmp += gd->cpu_hz / 2;
143 do_div(tmp, gd->cpu_hz);
144 tb_factor = (u32)tmp;
146 intc_dev = get_device(DEVICE_INTC);
149 || set_interrupt_handler(0, &timer_interrupt_handler, 3))
152 /* For all practical purposes, this gives us an overflow interrupt */
153 sysreg_write(COMPARE, 0xffffffff);