3 * Sascha Hauer, Pengutronix
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
25 #include <asm/arch/mx31-regs.h>
28 #define TIMER_BASE 0x53f90000 /* General purpose timer 1 */
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 */
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 */
42 DECLARE_GLOBAL_DATA_PTR;
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)
49 tick *= CONFIG_SYS_HZ;
50 do_div(tick, CONFIG_MX31_CLK32);
54 static inline unsigned long long time_to_tick(unsigned long long time)
56 time *= CONFIG_MX31_CLK32;
57 do_div(time, CONFIG_SYS_HZ);
61 static inline unsigned long long us_to_tick(unsigned long long us)
63 us = us * CONFIG_MX31_CLK32 + 999999;
69 #define TICK_PER_TIME ((CONFIG_MX31_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ)
70 #define US_PER_TICK (1000000 / CONFIG_MX31_CLK32)
72 static inline unsigned long long tick_to_time(unsigned long long tick)
74 do_div(tick, TICK_PER_TIME);
78 static inline unsigned long long time_to_tick(unsigned long long time)
80 return time * TICK_PER_TIME;
83 static inline unsigned long long us_to_tick(unsigned long long us)
85 us += US_PER_TICK - 1;
86 do_div(us, US_PER_TICK);
91 /* The 32768Hz 32-bit timer overruns in 131072 seconds */
96 /* setup GP Timer 1 */
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;
107 void reset_timer_masked (void)
110 gd->lastinc = GPTCNT; /* capture current incrementer value time */
111 gd->tbl = 0; /* start "advancing" time stamp from 0 */
114 void reset_timer(void)
116 reset_timer_masked();
119 unsigned long long get_ticks (void)
121 ulong now = GPTCNT; /* current tick value */
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;
132 ulong get_timer_masked (void)
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.
140 return tick_to_time(get_ticks());
143 ulong get_timer (ulong base)
145 return get_timer_masked () - base;
148 void set_timer (ulong t)
150 gd->tbl = time_to_tick(t);
153 /* delay x useconds AND preserve advance timestamp value */
154 void __udelay (unsigned long usec)
156 unsigned long long tmp;
159 tmo = us_to_tick(usec);
160 tmp = get_ticks() + tmo; /* get current timestamp */
162 while (get_ticks() < tmp) /* loop till event */
166 void reset_cpu (ulong addr)
168 __REG16(WDOG_BASE) = 4;