1 /* 2 * (C) Copyright 2009 3 * Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> 4 * 5 * (C) Copyright 2007-2012 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 #include <sh_tmu.h> 36 37 static struct tmu_regs *tmu = (struct tmu_regs *)TMU_BASE; 38 39 #define TMU_MAX_COUNTER (~0UL) 40 41 static ulong timer_freq; 42 static unsigned long last_tcnt; 43 static unsigned long long overflow_ticks; 44 45 static inline unsigned long long tick_to_time(unsigned long long tick) 46 { 47 tick *= CONFIG_SYS_HZ; 48 do_div(tick, timer_freq); 49 50 return tick; 51 } 52 53 static inline unsigned long long usec_to_tick(unsigned long long usec) 54 { 55 usec *= timer_freq; 56 do_div(usec, 1000000); 57 58 return usec; 59 } 60 61 static void tmu_timer_start(unsigned int timer) 62 { 63 if (timer > 2) 64 return; 65 writeb(readb(&tmu->tstr) | (1 << timer), &tmu->tstr); 66 } 67 68 static void tmu_timer_stop(unsigned int timer) 69 { 70 if (timer > 2) 71 return; 72 writeb(readb(&tmu->tstr) & ~(1 << timer), &tmu->tstr); 73 } 74 75 int timer_init(void) 76 { 77 /* Divide clock by CONFIG_SYS_TMU_CLK_DIV */ 78 u16 bit = 0; 79 80 switch (CONFIG_SYS_TMU_CLK_DIV) { 81 case 1024: 82 bit = 4; 83 break; 84 case 256: 85 bit = 3; 86 break; 87 case 64: 88 bit = 2; 89 break; 90 case 16: 91 bit = 1; 92 break; 93 case 4: 94 default: 95 break; 96 } 97 writew(readw(&tmu->tcr0) | bit, &tmu->tcr0); 98 99 /* Calc clock rate */ 100 timer_freq = get_tmu0_clk_rate() >> ((bit + 1) * 2); 101 102 tmu_timer_stop(0); 103 tmu_timer_start(0); 104 105 last_tcnt = 0; 106 overflow_ticks = 0; 107 108 return 0; 109 } 110 111 unsigned long long get_ticks(void) 112 { 113 unsigned long tcnt = 0 - readl(&tmu->tcnt0); 114 115 if (last_tcnt > tcnt) /* overflow */ 116 overflow_ticks++; 117 last_tcnt = tcnt; 118 119 return (overflow_ticks << 32) | tcnt; 120 } 121 122 void __udelay(unsigned long usec) 123 { 124 unsigned long long tmp; 125 ulong tmo; 126 127 tmo = usec_to_tick(usec); 128 tmp = get_ticks() + tmo; /* get current timestamp */ 129 130 while (get_ticks() < tmp) /* loop till event */ 131 /*NOP*/; 132 } 133 134 unsigned long get_timer(unsigned long base) 135 { 136 /* return msec */ 137 return tick_to_time(get_ticks()) - base; 138 } 139 140 unsigned long get_tbclk(void) 141 { 142 return timer_freq; 143 } 144