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/imx-regs.h> 26 #include <asm/arch/clock.h> 27 #include <div64.h> 28 #include <watchdog.h> 29 #include <asm/io.h> 30 31 #define TIMER_BASE 0x53f90000 /* General purpose timer 1 */ 32 33 /* General purpose timers registers */ 34 #define GPTCR __REG(TIMER_BASE) /* Control register */ 35 #define GPTPR __REG(TIMER_BASE + 0x4) /* Prescaler register */ 36 #define GPTSR __REG(TIMER_BASE + 0x8) /* Status register */ 37 #define GPTCNT __REG(TIMER_BASE + 0x24) /* Counter register */ 38 39 /* General purpose timers bitfields */ 40 #define GPTCR_SWR (1 << 15) /* Software reset */ 41 #define GPTCR_FRR (1 << 9) /* Freerun / restart */ 42 #define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */ 43 #define GPTCR_TEN 1 /* Timer enable */ 44 45 DECLARE_GLOBAL_DATA_PTR; 46 47 /* 48 * "time" is measured in 1 / CONFIG_SYS_HZ seconds, 49 * "tick" is internal timer period 50 */ 51 52 #ifdef CONFIG_MX31_TIMER_HIGH_PRECISION 53 /* ~0.4% error - measured with stop-watch on 100s boot-delay */ 54 static inline unsigned long long tick_to_time(unsigned long long tick) 55 { 56 tick *= CONFIG_SYS_HZ; 57 do_div(tick, MXC_CLK32); 58 return tick; 59 } 60 61 static inline unsigned long long time_to_tick(unsigned long long time) 62 { 63 time *= MXC_CLK32; 64 do_div(time, CONFIG_SYS_HZ); 65 return time; 66 } 67 68 static inline unsigned long long us_to_tick(unsigned long long us) 69 { 70 us = us * MXC_CLK32 + 999999; 71 do_div(us, 1000000); 72 return us; 73 } 74 #else 75 /* ~2% error */ 76 #define TICK_PER_TIME ((MXC_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ) 77 #define US_PER_TICK (1000000 / MXC_CLK32) 78 79 static inline unsigned long long tick_to_time(unsigned long long tick) 80 { 81 do_div(tick, TICK_PER_TIME); 82 return tick; 83 } 84 85 static inline unsigned long long time_to_tick(unsigned long long time) 86 { 87 return time * TICK_PER_TIME; 88 } 89 90 static inline unsigned long long us_to_tick(unsigned long long us) 91 { 92 us += US_PER_TICK - 1; 93 do_div(us, US_PER_TICK); 94 return us; 95 } 96 #endif 97 98 /* The 32768Hz 32-bit timer overruns in 131072 seconds */ 99 int timer_init(void) 100 { 101 int i; 102 103 /* setup GP Timer 1 */ 104 GPTCR = GPTCR_SWR; 105 for (i = 0; i < 100; i++) 106 GPTCR = 0; /* We have no udelay by now */ 107 GPTPR = 0; /* 32Khz */ 108 /* Freerun Mode, PERCLK1 input */ 109 GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN; 110 111 return 0; 112 } 113 114 unsigned long long get_ticks(void) 115 { 116 ulong now = GPTCNT; /* current tick value */ 117 118 if (now >= gd->lastinc) /* normal mode (non roll) */ 119 /* move stamp forward with absolut diff ticks */ 120 gd->tbl += (now - gd->lastinc); 121 else /* we have rollover of incrementer */ 122 gd->tbl += (0xFFFFFFFF - gd->lastinc) + now; 123 gd->lastinc = now; 124 return gd->tbl; 125 } 126 127 ulong get_timer_masked(void) 128 { 129 /* 130 * get_ticks() returns a long long (64 bit), it wraps in 131 * 2^64 / MXC_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~ 132 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in 133 * 5 * 10^6 days - long enough. 134 */ 135 return tick_to_time(get_ticks()); 136 } 137 138 ulong get_timer(ulong base) 139 { 140 return get_timer_masked() - base; 141 } 142 143 /* delay x useconds AND preserve advance timestamp value */ 144 void __udelay(unsigned long usec) 145 { 146 unsigned long long tmp; 147 ulong tmo; 148 149 tmo = us_to_tick(usec); 150 tmp = get_ticks() + tmo; /* get current timestamp */ 151 152 while (get_ticks() < tmp) /* loop till event */ 153 /*NOP*/; 154 } 155 156 /* 157 * This function is derived from PowerPC code (timebase clock frequency). 158 * On ARM it returns the number of timer ticks per second. 159 */ 160 ulong get_tbclk(void) 161 { 162 return MXC_CLK32; 163 } 164 165 void reset_cpu(ulong addr) 166 { 167 struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE; 168 wdog->wcr = WDOG_ENABLE; 169 while (1) 170 ; 171 } 172 173 #ifdef CONFIG_HW_WATCHDOG 174 void mxc_hw_watchdog_enable(void) 175 { 176 struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE; 177 u16 secs; 178 179 /* 180 * The timer watchdog can be set between 181 * 0.5 and 128 Seconds. If not defined 182 * in configuration file, sets 64 Seconds 183 */ 184 #ifdef CONFIG_SYS_WD_TIMER_SECS 185 secs = (CONFIG_SYS_WD_TIMER_SECS << 1) & 0xFF; 186 if (!secs) secs = 1; 187 #else 188 secs = 64; 189 #endif 190 setbits_le16(&wdog->wcr, (secs << WDOG_WT_SHIFT) | WDOG_ENABLE 191 | WDOG_WDZST); 192 } 193 194 195 void mxc_hw_watchdog_reset(void) 196 { 197 struct wdog_regs *wdog = (struct wdog_regs *)WDOG_BASE; 198 199 writew(0x5555, &wdog->wsr); 200 writew(0xAAAA, &wdog->wsr); 201 } 202 #endif 203