1 /* 2 * (C) Copyright 2009 3 * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> 4 * 5 * (C) Copyright 2007-2010 6 * Nobobuhiro Iwamatsu <iwamatsu@nigauri.org> 7 * 8 * (C) Copyright 2003 9 * Wolfgang Denk, DENX Software Engineering, wd@denx.de. 10 * 11 * See file CREDITS for list of people who contributed to this 12 * project. 13 * 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License as 16 * published by the Free Software Foundation; either version 2 of 17 * the License, or (at your option) any later version. 18 * 19 * This program is distributed in the hope that it will be useful, 20 * but WITHOUT ANY WARRANTY; without even the implied warranty of 21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 22 * GNU General Public License for more details. 23 * 24 * You should have received a copy of the GNU General Public License 25 * along with this program; if not, write to the Free Software 26 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 27 * MA 02111-1307 USA 28 */ 29 30 #include <common.h> 31 #include <div64.h> 32 #include <asm/processor.h> 33 #include <asm/clk.h> 34 #include <asm/io.h> 35 36 #define TMU_MAX_COUNTER (~0UL) 37 38 static ulong timer_freq; 39 static unsigned long last_tcnt; 40 static unsigned long long overflow_ticks; 41 42 static inline unsigned long long tick_to_time(unsigned long long tick) 43 { 44 tick *= CONFIG_SYS_HZ; 45 do_div(tick, timer_freq); 46 47 return tick; 48 } 49 50 static inline unsigned long long usec_to_tick(unsigned long long usec) 51 { 52 usec *= timer_freq; 53 do_div(usec, 1000000); 54 55 return usec; 56 } 57 58 static void tmu_timer_start (unsigned int timer) 59 { 60 if (timer > 2) 61 return; 62 writeb(readb(TSTR) | (1 << timer), TSTR); 63 } 64 65 static void tmu_timer_stop (unsigned int timer) 66 { 67 if (timer > 2) 68 return; 69 writeb(readb(TSTR) & ~(1 << timer), TSTR); 70 } 71 72 int timer_init (void) 73 { 74 /* Divide clock by CONFIG_SYS_TMU_CLK_DIV */ 75 u16 bit = 0; 76 77 switch (CONFIG_SYS_TMU_CLK_DIV) { 78 case 1024: 79 bit = 4; 80 break; 81 case 256: 82 bit = 3; 83 break; 84 case 64: 85 bit = 2; 86 break; 87 case 16: 88 bit = 1; 89 break; 90 case 4: 91 default: 92 break; 93 } 94 writew(readw(TCR0) | bit, TCR0); 95 96 /* Calc clock rate */ 97 timer_freq = get_tmu0_clk_rate() >> ((bit + 1) * 2); 98 99 tmu_timer_stop(0); 100 tmu_timer_start(0); 101 102 last_tcnt = 0; 103 overflow_ticks = 0; 104 105 return 0; 106 } 107 108 unsigned long long get_ticks (void) 109 { 110 unsigned long tcnt = 0 - readl(TCNT0); 111 unsigned long ticks; 112 113 if (last_tcnt > tcnt) { /* overflow */ 114 overflow_ticks++; 115 ticks = (0xffffffff - last_tcnt) + tcnt; 116 } else { 117 ticks = tcnt; 118 } 119 last_tcnt = tcnt; 120 121 return (overflow_ticks << 32) | tcnt; 122 } 123 124 void __udelay (unsigned long usec) 125 { 126 unsigned long long tmp; 127 ulong tmo; 128 129 tmo = usec_to_tick(usec); 130 tmp = get_ticks() + tmo; /* get current timestamp */ 131 132 while (get_ticks() < tmp) /* loop till event */ 133 /*NOP*/; 134 } 135 136 unsigned long get_timer (unsigned long base) 137 { 138 /* return msec */ 139 return tick_to_time(get_ticks()) - base; 140 } 141 142 unsigned long get_tbclk (void) 143 { 144 return timer_freq; 145 } 146