5 * Richard Woodruff <r-woodruff2@ti.com>
6 * Syed Moahmmed Khasim <khasim@ti.com>
9 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
10 * Marius Groeger <mgroeger@sysgo.de>
11 * Alex Zuepke <azu@sysgo.de>
14 * Gary Jennejohn, DENX Software Engineering, <garyj@denx.de>
16 * See file CREDITS for list of people who contributed to this
19 * This program is free software; you can redistribute it and/or
20 * modify it under the terms of the GNU General Public License as
21 * published by the Free Software Foundation; either version 2 of
22 * the License, or (at your option) any later version.
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
29 * You should have received a copy of the GNU General Public License
30 * along with this program; if not, write to the Free Software
31 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
37 #include <asm/arch/cpu.h>
39 DECLARE_GLOBAL_DATA_PTR;
41 static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
44 * Nothing really to do with interrupts, just starts up a counter.
47 #define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
48 #define TIMER_OVERFLOW_VAL 0xffffffff
49 #define TIMER_LOAD_VAL 0
53 /* start the counter ticking up, reload value on overflow */
54 writel(TIMER_LOAD_VAL, &timer_base->tldr);
56 writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
59 /* reset time, capture current incrementer value time */
60 gd->arch.lastinc = readl(&timer_base->tcrr) /
61 (TIMER_CLOCK / CONFIG_SYS_HZ);
62 gd->arch.tbl = 0; /* start "advancing" time stamp from 0 */
68 * timer without interrupts
70 ulong get_timer(ulong base)
72 return get_timer_masked() - base;
75 /* delay x useconds */
76 void __udelay(unsigned long usec)
78 long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
79 unsigned long now, last = readl(&timer_base->tcrr);
82 now = readl(&timer_base->tcrr);
83 if (last > now) /* count up timer overflow */
84 tmo -= TIMER_OVERFLOW_VAL - last + now + 1;
91 ulong get_timer_masked(void)
93 /* current tick value */
94 ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
96 if (now >= gd->arch.lastinc) { /* normal mode (non roll) */
97 /* move stamp fordward with absoulte diff ticks */
98 gd->arch.tbl += (now - gd->arch.lastinc);
99 } else { /* we have rollover of incrementer */
100 gd->arch.tbl += ((TIMER_LOAD_VAL / (TIMER_CLOCK /
101 CONFIG_SYS_HZ)) - gd->arch.lastinc) + now;
103 gd->arch.lastinc = now;
108 * This function is derived from PowerPC code (read timebase as long long).
109 * On ARM it just returns the timer value.
111 unsigned long long get_ticks(void)
117 * This function is derived from PowerPC code (timebase clock frequency).
118 * On ARM it returns the number of timer ticks per second.
120 ulong get_tbclk(void)
122 return CONFIG_SYS_HZ;