1 /* 2 * (C) Copyright 2007 3 * Sascha Hauer, Pengutronix 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/arch/mx31-regs.h> 26 #include <div64.h> 27 28 #define TIMER_BASE 0x53f90000 /* General purpose timer 1 */ 29 30 /* General purpose timers registers */ 31 #define GPTCR __REG(TIMER_BASE) /* Control register */ 32 #define GPTPR __REG(TIMER_BASE + 0x4) /* Prescaler register */ 33 #define GPTSR __REG(TIMER_BASE + 0x8) /* Status register */ 34 #define GPTCNT __REG(TIMER_BASE + 0x24) /* Counter register */ 35 36 /* General purpose timers bitfields */ 37 #define GPTCR_SWR (1 << 15) /* Software reset */ 38 #define GPTCR_FRR (1 << 9) /* Freerun / restart */ 39 #define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */ 40 #define GPTCR_TEN 1 /* Timer enable */ 41 42 DECLARE_GLOBAL_DATA_PTR; 43 44 /* "time" is measured in 1 / CONFIG_SYS_HZ seconds, "tick" is internal timer period */ 45 #ifdef CONFIG_MX31_TIMER_HIGH_PRECISION 46 /* ~0.4% error - measured with stop-watch on 100s boot-delay */ 47 static inline unsigned long long tick_to_time(unsigned long long tick) 48 { 49 tick *= CONFIG_SYS_HZ; 50 do_div(tick, CONFIG_MX31_CLK32); 51 return tick; 52 } 53 54 static inline unsigned long long time_to_tick(unsigned long long time) 55 { 56 time *= CONFIG_MX31_CLK32; 57 do_div(time, CONFIG_SYS_HZ); 58 return time; 59 } 60 61 static inline unsigned long long us_to_tick(unsigned long long us) 62 { 63 us = us * CONFIG_MX31_CLK32 + 999999; 64 do_div(us, 1000000); 65 return us; 66 } 67 #else 68 /* ~2% error */ 69 #define TICK_PER_TIME ((CONFIG_MX31_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ) 70 #define US_PER_TICK (1000000 / CONFIG_MX31_CLK32) 71 72 static inline unsigned long long tick_to_time(unsigned long long tick) 73 { 74 do_div(tick, TICK_PER_TIME); 75 return tick; 76 } 77 78 static inline unsigned long long time_to_tick(unsigned long long time) 79 { 80 return time * TICK_PER_TIME; 81 } 82 83 static inline unsigned long long us_to_tick(unsigned long long us) 84 { 85 us += US_PER_TICK - 1; 86 do_div(us, US_PER_TICK); 87 return us; 88 } 89 #endif 90 91 /* The 32768Hz 32-bit timer overruns in 131072 seconds */ 92 int timer_init (void) 93 { 94 int i; 95 96 /* setup GP Timer 1 */ 97 GPTCR = GPTCR_SWR; 98 for (i = 0; i < 100; i++) 99 GPTCR = 0; /* We have no udelay by now */ 100 GPTPR = 0; /* 32Khz */ 101 /* Freerun Mode, PERCLK1 input */ 102 GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; 103 104 return 0; 105 } 106 107 void reset_timer_masked (void) 108 { 109 /* reset time */ 110 gd->lastinc = GPTCNT; /* capture current incrementer value time */ 111 gd->tbl = 0; /* start "advancing" time stamp from 0 */ 112 } 113 114 void reset_timer(void) 115 { 116 reset_timer_masked(); 117 } 118 119 unsigned long long get_ticks (void) 120 { 121 ulong now = GPTCNT; /* current tick value */ 122 123 if (now >= gd->lastinc) /* normal mode (non roll) */ 124 /* move stamp forward with absolut diff ticks */ 125 gd->tbl += (now - gd->lastinc); 126 else /* we have rollover of incrementer */ 127 gd->tbl += (0xFFFFFFFF - gd->lastinc) + now; 128 gd->lastinc = now; 129 return gd->tbl; 130 } 131 132 ulong get_timer_masked (void) 133 { 134 /* 135 * get_ticks() returns a long long (64 bit), it wraps in 136 * 2^64 / CONFIG_MX31_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~ 137 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in 138 * 5 * 10^6 days - long enough. 139 */ 140 return tick_to_time(get_ticks()); 141 } 142 143 ulong get_timer (ulong base) 144 { 145 return get_timer_masked () - base; 146 } 147 148 void set_timer (ulong t) 149 { 150 gd->tbl = time_to_tick(t); 151 } 152 153 /* delay x useconds AND preserve advance timestamp value */ 154 void __udelay (unsigned long usec) 155 { 156 unsigned long long tmp; 157 ulong tmo; 158 159 tmo = us_to_tick(usec); 160 tmp = get_ticks() + tmo; /* get current timestamp */ 161 162 while (get_ticks() < tmp) /* loop till event */ 163 /*NOP*/; 164 } 165 166 void reset_cpu (ulong addr) 167 { 168 __REG16(WDOG_BASE) = 4; 169 } 170