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,
38 static ulong timestamp;
40 static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
43 * Nothing really to do with interrupts, just starts up a counter.
44 * We run the counter with 13MHz, divided by 8, resulting in timer
45 * frequency of 1.625MHz. With 32bit counter register, counter
49 /* 13MHz / 8 = 1.625MHz */
50 #define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
51 #define TIMER_LOAD_VAL 0xffffffff
55 /* start the counter ticking up, reload value on overflow */
56 writel(TIMER_LOAD_VAL, &timer_base->tldr);
58 writel((CONFIG_SYS_PTV << 2) | TCLR_PRE | TCLR_AR | TCLR_ST,
61 reset_timer_masked(); /* init the timestamp and lastinc value */
67 * timer without interrupts
69 void reset_timer(void)
74 ulong get_timer(ulong base)
76 return get_timer_masked() - base;
79 void set_timer(ulong t)
84 /* delay x useconds */
85 void __udelay(unsigned long usec)
87 #if defined(CONFIG_OMAP44XX)
88 /* TODO temporary hack until OMAP4 clock setup routines are present */
92 long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
93 unsigned long now, last = readl(&timer_base->tcrr);
96 now = readl(&timer_base->tcrr);
97 if (last > now) /* count up timer overflow */
98 tmo -= TIMER_LOAD_VAL - last + now;
105 void reset_timer_masked(void)
107 /* reset time, capture current incrementer value time */
108 lastinc = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
109 timestamp = 0; /* start "advancing" time stamp from 0 */
112 ulong get_timer_masked(void)
114 /* current tick value */
115 ulong now = readl(&timer_base->tcrr) / (TIMER_CLOCK / CONFIG_SYS_HZ);
117 if (now >= lastinc) /* normal mode (non roll) */
118 /* move stamp fordward with absoulte diff ticks */
119 timestamp += (now - lastinc);
120 else /* we have rollover of incrementer */
121 timestamp += ((TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ))
128 * This function is derived from PowerPC code (read timebase as long long).
129 * On ARM it just returns the timer value.
131 unsigned long long get_ticks(void)
137 * This function is derived from PowerPC code (timebase clock frequency).
138 * On ARM it returns the number of timer ticks per second.
140 ulong get_tbclk(void)
142 return CONFIG_SYS_HZ;