3 * Sascha Hauer, Pengutronix
5 * (C) Copyright 2009 Freescale Semiconductor, Inc.
7 * See file CREDITS for list of people who contributed to this
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29 #include <asm/arch/imx-regs.h>
30 #include <asm/arch/clock.h>
32 #define DEBUG_TIMER_WRAP
34 /* General purpose timers registers */
37 unsigned int prescaler;
39 unsigned int nouse[6];
43 static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
45 /* General purpose timers bitfields */
46 #define GPTCR_SWR (1 << 15) /* Software reset */
47 #define GPTCR_FRR (1 << 9) /* Freerun / restart */
48 #define GPTCR_CLKSOURCE_IPG (1 << 6) /* Clock source */
49 #define GPTCR_CLKSOURCE_CKIH (2 << 6)
50 #define GPTCR_CLKSOURCE_32kHz (4 << 6)
52 #define GPTCR_CLKSOURCE_OSC_DIV_8 (5 << 6)
53 #define GPTCR_CLKSOURCE_OSC (7 << 6)
55 #define GPTCR_CLKSOURCE_OSC (5 << 6)
57 #define GPTCR_CLKSOURCE_MASK (7 << 6)
58 #define GPTCR_TEN 1 /* Timer enable */
61 #define GPT_CLKSOURCE GPTCR_CLKSOURCE_OSC
62 #define GPT_REFCLK 24000000
63 #define GPT_PRESCALER 24
65 #define GPT_CLKSOURCE GPTCR_CLKSOURCE_32kHz
66 #define GPT_REFCLK 32768
67 #define GPT_PRESCALER 1
69 #define GPT_CLK (GPT_REFCLK / GPT_PRESCALER)
71 #ifdef DEBUG_TIMER_WRAP
73 * Let the timer wrap 30 seconds after start to catch misbehaving
74 * timer related code early
76 #define TIMER_START (-time_to_tick(30 * CONFIG_SYS_HZ))
78 #define TIMER_START 0UL
81 DECLARE_GLOBAL_DATA_PTR;
83 static inline unsigned long tick_to_time(unsigned long tick)
85 unsigned long long t = (unsigned long long)tick * CONFIG_SYS_HZ;
90 static inline unsigned long time_to_tick(unsigned long time)
92 unsigned long long ticks = (unsigned long long)time;
95 do_div(ticks, CONFIG_SYS_HZ);
99 static inline unsigned long us_to_tick(unsigned long usec)
101 unsigned long long ticks = (unsigned long long)usec;
104 do_div(ticks, 1000 * CONFIG_SYS_HZ);
112 /* setup GP Timer 1 */
113 __raw_writel(GPTCR_SWR, &cur_gpt->control);
115 /* We have no udelay by now */
116 for (i = 0; i < 100; i++)
117 __raw_writel(0, &cur_gpt->control);
119 __raw_writel(GPT_PRESCALER - 1, &cur_gpt->prescaler);
121 /* Freerun Mode, PERCLK1 input */
122 i = __raw_readl(&cur_gpt->control);
123 i &= ~GPTCR_CLKSOURCE_MASK;
124 __raw_writel(i | GPT_CLKSOURCE | GPTCR_TEN, &cur_gpt->control);
126 gd->arch.lastinc = __raw_readl(&cur_gpt->counter);
128 gd->arch.tbl = TIMER_START;
129 gd->arch.timer_rate_hz = GPT_CLK;
134 unsigned long long get_ticks(void)
136 ulong now = __raw_readl(&cur_gpt->counter); /* current tick value */
137 ulong inc = now - gd->arch.lastinc;
140 gd->arch.lastinc = now;
144 ulong get_timer_masked(void)
147 * get_ticks() returns a long long (64 bit), it wraps in
148 * 2^64 / MXC_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
149 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
150 * 5 * 10^6 days - long enough.
153 * LW: get_ticks() returns a long long with the top 32 bits always ZERO!
154 * Thus the calculation above is not true.
155 * A 64bit timer value would only make sense if it was
156 * consistently used throughout the code. Thus also the parameter
157 * to get_timer() and its return value would need to be 64bit wide!
159 return tick_to_time(get_ticks());
162 ulong get_timer(ulong base)
164 return tick_to_time(get_ticks() - time_to_tick(base));
167 #include <asm/gpio.h>
169 /* delay x useconds AND preserve advance timstamp value */
170 void __udelay(unsigned long usec)
172 unsigned long start = __raw_readl(&cur_gpt->counter);
178 ticks = us_to_tick(usec);
182 while (__raw_readl(&cur_gpt->counter) - start < ticks)
183 /* loop till event */;
187 * This function is derived from PowerPC code (timebase clock frequency).
188 * On ARM it returns the number of timer ticks per second.
190 ulong get_tbclk(void)
192 return gd->arch.timer_rate_hz;