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 static ulong timestamp; 43 static ulong lastinc; 44 45 /* "time" is measured in 1 / CONFIG_SYS_HZ seconds, "tick" is internal timer period */ 46 #ifdef CONFIG_MX31_TIMER_HIGH_PRECISION 47 /* ~0.4% error - measured with stop-watch on 100s boot-delay */ 48 static inline unsigned long long tick_to_time(unsigned long long tick) 49 { 50 tick *= CONFIG_SYS_HZ; 51 do_div(tick, CONFIG_MX31_CLK32); 52 return tick; 53 } 54 55 static inline unsigned long long time_to_tick(unsigned long long time) 56 { 57 time *= CONFIG_MX31_CLK32; 58 do_div(time, CONFIG_SYS_HZ); 59 return time; 60 } 61 62 static inline unsigned long long us_to_tick(unsigned long long us) 63 { 64 us = us * CONFIG_MX31_CLK32 + 999999; 65 do_div(us, 1000000); 66 return us; 67 } 68 #else 69 /* ~2% error */ 70 #define TICK_PER_TIME ((CONFIG_MX31_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ) 71 #define US_PER_TICK (1000000 / CONFIG_MX31_CLK32) 72 73 static inline unsigned long long tick_to_time(unsigned long long tick) 74 { 75 do_div(tick, TICK_PER_TIME); 76 return tick; 77 } 78 79 static inline unsigned long long time_to_tick(unsigned long long time) 80 { 81 return time * TICK_PER_TIME; 82 } 83 84 static inline unsigned long long us_to_tick(unsigned long long us) 85 { 86 us += US_PER_TICK - 1; 87 do_div(us, US_PER_TICK); 88 return us; 89 } 90 #endif 91 92 /* The 32768Hz 32-bit timer overruns in 131072 seconds */ 93 int timer_init (void) 94 { 95 int i; 96 97 /* setup GP Timer 1 */ 98 GPTCR = GPTCR_SWR; 99 for (i = 0; i < 100; i++) 100 GPTCR = 0; /* We have no udelay by now */ 101 GPTPR = 0; /* 32Khz */ 102 /* Freerun Mode, PERCLK1 input */ 103 GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; 104 105 return 0; 106 } 107 108 void reset_timer_masked (void) 109 { 110 /* reset time */ 111 lastinc = GPTCNT; /* capture current incrementer value time */ 112 timestamp = 0; /* start "advancing" time stamp from 0 */ 113 } 114 115 void reset_timer(void) 116 { 117 reset_timer_masked(); 118 } 119 120 unsigned long long get_ticks (void) 121 { 122 ulong now = GPTCNT; /* current tick value */ 123 124 if (now >= lastinc) /* normal mode (non roll) */ 125 /* move stamp forward with absolut diff ticks */ 126 timestamp += (now - lastinc); 127 else /* we have rollover of incrementer */ 128 timestamp += (0xFFFFFFFF - lastinc) + now; 129 lastinc = now; 130 return timestamp; 131 } 132 133 ulong get_timer_masked (void) 134 { 135 /* 136 * get_ticks() returns a long long (64 bit), it wraps in 137 * 2^64 / CONFIG_MX31_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~ 138 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in 139 * 5 * 10^6 days - long enough. 140 */ 141 return tick_to_time(get_ticks()); 142 } 143 144 ulong get_timer (ulong base) 145 { 146 return get_timer_masked () - base; 147 } 148 149 void set_timer (ulong t) 150 { 151 timestamp = time_to_tick(t); 152 } 153 154 /* delay x useconds AND perserve advance timstamp value */ 155 void __udelay (unsigned long usec) 156 { 157 unsigned long long tmp; 158 ulong tmo; 159 160 tmo = us_to_tick(usec); 161 tmp = get_ticks() + tmo; /* get current timestamp */ 162 163 while (get_ticks() < tmp) /* loop till event */ 164 /*NOP*/; 165 } 166 167 void reset_cpu (ulong addr) 168 { 169 __REG16(WDOG_BASE) = 4; 170 } 171