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 /* General purpose timers registers */
35 unsigned int prescaler;
37 unsigned int nouse[6];
41 static struct mxc_gpt *cur_gpt = (struct mxc_gpt *)GPT1_BASE_ADDR;
43 /* General purpose timers bitfields */
44 #define GPTCR_SWR (1 << 15) /* Software reset */
45 #define GPTCR_FRR (1 << 9) /* Freerun / restart */
46 #define GPTCR_CLKSOURCE_32 (4 << 6) /* Clock source */
47 #define GPTCR_TEN 1 /* Timer enable */
49 DECLARE_GLOBAL_DATA_PTR;
51 #define timestamp (gd->arch.tbl)
52 #define lastinc (gd->arch.lastinc)
54 static inline unsigned long long tick_to_time(unsigned long long tick)
56 tick *= CONFIG_SYS_HZ;
57 do_div(tick, MXC_CLK32);
62 static inline unsigned long long us_to_tick(unsigned long long usec)
64 usec = usec * MXC_CLK32 + 999999;
65 do_div(usec, 1000000);
75 /* setup GP Timer 1 */
76 __raw_writel(GPTCR_SWR, &cur_gpt->control);
78 /* We have no udelay by now */
79 for (i = 0; i < 100; i++)
80 __raw_writel(0, &cur_gpt->control);
82 __raw_writel(0, &cur_gpt->prescaler); /* 32Khz */
84 /* Freerun Mode, PERCLK1 input */
85 i = __raw_readl(&cur_gpt->control);
86 __raw_writel(i | GPTCR_CLKSOURCE_32 | GPTCR_TEN, &cur_gpt->control);
88 val = __raw_readl(&cur_gpt->counter);
89 lastinc = val / (MXC_CLK32 / CONFIG_SYS_HZ);
95 unsigned long long get_ticks(void)
97 ulong now = __raw_readl(&cur_gpt->counter); /* current tick value */
101 * normal mode (non roll)
102 * move stamp forward with absolut diff ticks
104 timestamp += (now - lastinc);
106 /* we have rollover of incrementer */
107 timestamp += (0xFFFFFFFF - lastinc) + now;
113 ulong get_timer_masked(void)
116 * get_ticks() returns a long long (64 bit), it wraps in
117 * 2^64 / MXC_CLK32 = 2^64 / 2^15 = 2^49 ~ 5 * 10^14 (s) ~
118 * 5 * 10^9 days... and get_ticks() * CONFIG_SYS_HZ wraps in
119 * 5 * 10^6 days - long enough.
121 return tick_to_time(get_ticks());
124 ulong get_timer(ulong base)
126 return get_timer_masked() - base;
129 /* delay x useconds AND preserve advance timstamp value */
130 void __udelay(unsigned long usec)
132 unsigned long long tmp;
135 tmo = us_to_tick(usec);
136 tmp = get_ticks() + tmo; /* get current timestamp */
138 while (get_ticks() < tmp) /* loop till event */
143 * This function is derived from PowerPC code (timebase clock frequency).
144 * On ARM it returns the number of timer ticks per second.
146 ulong get_tbclk(void)