| Zhi-zhou Zhang | 32afad7 | 2012-10-16 15:02:08 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * (C) Copyright 2003 |
| 3 | * Wolfgang Denk, DENX Software Engineering, wd@denx.de. |
| 4 | * |
| 5 | * See file CREDITS for list of people who contributed to this |
| 6 | * project. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or |
| 9 | * modify it under the terms of the GNU General Public License as |
| 10 | * published by the Free Software Foundation; either version 2 of |
| 11 | * the License, or (at your option) any later version. |
| 12 | * |
| 13 | * This program is distributed in the hope that it will be useful, |
| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | * GNU General Public License for more details. |
| 17 | * |
| 18 | * You should have received a copy of the GNU General Public License |
| 19 | * along with this program; if not, write to the Free Software |
| 20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| 21 | * MA 02111-1307 USA |
| 22 | */ |
| 23 | |
| 24 | #include <common.h> |
| 25 | #include <asm/mipsregs.h> |
| 26 | |
| 27 | static unsigned long timestamp; |
| 28 | |
| 29 | /* how many counter cycles in a jiffy */ |
| 30 | #define CYCLES_PER_JIFFY \ |
| 31 | (CONFIG_SYS_MIPS_TIMER_FREQ + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ |
| 32 | |
| 33 | /* |
| 34 | * timer without interrupts |
| 35 | */ |
| 36 | |
| 37 | int timer_init(void) |
| 38 | { |
| 39 | /* Set up the timer for the first expiration. */ |
| 40 | timestamp = 0; |
| 41 | write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY); |
| 42 | |
| 43 | return 0; |
| 44 | } |
| 45 | |
| 46 | ulong get_timer(ulong base) |
| 47 | { |
| 48 | unsigned int count; |
| 49 | unsigned int expirelo = read_c0_compare(); |
| 50 | |
| 51 | /* Check to see if we have missed any timestamps. */ |
| 52 | count = read_c0_count(); |
| 53 | while ((count - expirelo) < 0x7fffffff) { |
| 54 | expirelo += CYCLES_PER_JIFFY; |
| 55 | timestamp++; |
| 56 | } |
| 57 | write_c0_compare(expirelo); |
| 58 | |
| 59 | return timestamp - base; |
| 60 | } |
| 61 | |
| 62 | void __udelay(unsigned long usec) |
| 63 | { |
| 64 | unsigned int tmo; |
| 65 | |
| 66 | tmo = read_c0_count() + (usec * (CONFIG_SYS_MIPS_TIMER_FREQ / 1000000)); |
| 67 | while ((tmo - read_c0_count()) < 0x7fffffff) |
| 68 | /*NOP*/; |
| 69 | } |
| 70 | |
| 71 | /* |
| 72 | * This function is derived from PowerPC code (read timebase as long long). |
| 73 | * On MIPS it just returns the timer value. |
| 74 | */ |
| 75 | unsigned long long get_ticks(void) |
| 76 | { |
| 77 | return get_timer(0); |
| 78 | } |
| 79 | |
| 80 | /* |
| 81 | * This function is derived from PowerPC code (timebase clock frequency). |
| 82 | * On MIPS it returns the number of timer ticks per second. |
| 83 | */ |
| 84 | ulong get_tbclk(void) |
| 85 | { |
| 86 | return CONFIG_SYS_HZ; |
| 87 | } |