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 static ulong timestamp;
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)
50 tick *= CONFIG_SYS_HZ;
51 do_div(tick, CONFIG_MX31_CLK32);
55 static inline unsigned long long time_to_tick(unsigned long long time)
57 time *= CONFIG_MX31_CLK32;
58 do_div(time, CONFIG_SYS_HZ);
62 static inline unsigned long long us_to_tick(unsigned long long us)
64 us = us * CONFIG_MX31_CLK32 + 999999;
70 #define TICK_PER_TIME ((CONFIG_MX31_CLK32 + CONFIG_SYS_HZ / 2) / CONFIG_SYS_HZ)
71 #define US_PER_TICK (1000000 / CONFIG_MX31_CLK32)
73 static inline unsigned long long tick_to_time(unsigned long long tick)
75 do_div(tick, TICK_PER_TIME);
79 static inline unsigned long long time_to_tick(unsigned long long time)
81 return time * TICK_PER_TIME;
84 static inline unsigned long long us_to_tick(unsigned long long us)
86 us += US_PER_TICK - 1;
87 do_div(us, US_PER_TICK);
92 /* nothing really to do with interrupts, just starts up a counter. */
93 /* The 32768Hz 32-bit timer overruns in 131072 seconds */
94 int interrupt_init (void)
98 /* setup GP Timer 1 */
100 for (i = 0; i < 100; i++)
101 GPTCR = 0; /* We have no udelay by now */
102 GPTPR = 0; /* 32Khz */
103 /* Freerun Mode, PERCLK1 input */
104 GPTCR |= GPTCR_CLKSOURCE_32 | GPTCR_TEN;
109 void reset_timer_masked (void)
112 lastinc = GPTCNT; /* capture current incrementer value time */
113 timestamp = 0; /* start "advancing" time stamp from 0 */
116 void reset_timer(void)
118 reset_timer_masked();
121 unsigned long long get_ticks (void)
123 ulong now = GPTCNT; /* current tick value */
125 if (now >= lastinc) /* normal mode (non roll) */
126 /* move stamp forward with absolut diff ticks */
127 timestamp += (now - lastinc);
128 else /* we have rollover of incrementer */
129 timestamp += (0xFFFFFFFF - lastinc) + now;
134 ulong get_timer_masked (void)
137 * get_ticks() returns a long long (64 bit), it wraps in
138 * 2^64 / CONFIG_MX31_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
139 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
140 * 5 * 10^6 days - long enough.
142 return tick_to_time(get_ticks());
145 ulong get_timer (ulong base)
147 return get_timer_masked () - base;
150 void set_timer (ulong t)
152 timestamp = time_to_tick(t);
155 /* delay x useconds AND perserve advance timstamp value */
156 void udelay (unsigned long usec)
158 unsigned long long tmp;
161 tmo = us_to_tick(usec);
162 tmp = get_ticks() + tmo; /* get current timestamp */
164 while (get_ticks() < tmp) /* loop till event */
168 void reset_cpu (ulong addr)
170 __REG16(WDOG_BASE) = 4;