3 * Sascha Hauer, Pengutronix
5 * (C) Copyright 2008-2009 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 DECLARE_GLOBAL_DATA_PTR;
34 #define timestamp (gd->tbl)
35 #define lastinc (gd->lastinc)
37 /* General purpose timers bitfields */
38 #define GPTCR_SWR (1<<15) /* Software reset */
39 #define GPTCR_FRR (1<<9) /* Freerun / restart */
40 #define GPTCR_CLKSOURCE_32 (0x100<<6) /* Clock source */
41 #define GPTCR_CLKSOURCE_IPG (0x001<<6) /* Clock source */
42 #define GPTCR_TEN (1) /* Timer enable */
44 #define TIMER_FREQ_HZ mxc_get_clock(MXC_IPG_CLK)
46 static inline unsigned long long tick_to_time(unsigned long long tick)
48 tick *= CONFIG_SYS_HZ;
49 do_div(tick, TIMER_FREQ_HZ);
54 static inline unsigned long long us_to_tick(unsigned long long usec)
56 usec *= TIMER_FREQ_HZ;
57 do_div(usec, 1000000);
65 struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
67 /* setup GP Timer 1 */
68 writel(GPTCR_SWR, &gpt->ctrl);
69 for (i = 0; i < 100; i++)
70 writel(0, &gpt->ctrl); /* We have no udelay by now */
73 /* Freerun Mode, PERCLK1 input */
74 writel(readl(&gpt->ctrl) |
75 GPTCR_CLKSOURCE_IPG | GPTCR_TEN,
81 unsigned long long get_ticks(void)
83 struct gpt_regs *gpt = (struct gpt_regs *)GPT1_BASE_ADDR;
84 ulong now = readl(&gpt->counter); /* current tick value */
88 * normal mode (non roll)
89 * move stamp forward with absolut diff ticks
91 timestamp += (now - lastinc);
93 /* we have rollover of incrementer */
94 timestamp += (0xFFFFFFFF - lastinc) + now;
100 ulong get_timer_masked(void)
103 * get_ticks() returns a long long (64 bit), it wraps in
104 * 2^64 / CONFIG_MX25_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
105 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
106 * 5 * 10^6 days - long enough.
108 return tick_to_time(get_ticks());
111 ulong get_timer(ulong base)
113 return get_timer_masked() - base;
116 /* delay x useconds AND preserve advance timstamp value */
117 void __udelay(unsigned long usec)
119 unsigned long long tmp;
122 tmo = us_to_tick(usec);
123 tmp = get_ticks() + tmo; /* get current timestamp */
125 while (get_ticks() < tmp) /* loop till event */
130 * This function is derived from PowerPC code (timebase clock frequency).
131 * On ARM it returns the number of timer ticks per second.
133 ulong get_tbclk(void)
135 return TIMER_FREQ_HZ;