2 * Copyright (C) 2012 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2011-2012 Xilinx, Inc. All rights reserved.
6 * Guennadi Liakhovetki, DENX Software Engineering, <lg@denx.de>
9 * Philippe Robin, ARM Ltd. <philippe.robin@arm.com>
11 * (C) Copyright 2002-2004
12 * Gary Jennejohn, DENX Software Engineering, <gj@denx.de>
15 * Texas Instruments <www.ti.com>
18 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
19 * Marius Groeger <mgroeger@sysgo.de>
22 * Sysgo Real-Time Solutions, GmbH <www.elinos.com>
23 * Alex Zuepke <azu@sysgo.de>
25 * See file CREDITS for list of people who contributed to this
28 * This program is free software; you can redistribute it and/or
29 * modify it under the terms of the GNU General Public License as
30 * published by the Free Software Foundation; either version 2 of
31 * the License, or (at your option) any later version.
33 * This program is distributed in the hope that it will be useful,
34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
36 * GNU General Public License for more details.
38 * You should have received a copy of the GNU General Public License
39 * along with this program; if not, write to the Free Software
40 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
48 DECLARE_GLOBAL_DATA_PTR;
51 u32 load; /* Timer Load Register */
52 u32 counter; /* Timer Counter Register */
53 u32 control; /* Timer Control Register */
56 static struct scu_timer *timer_base =
57 (struct scu_timer *) CONFIG_SCUTIMER_BASEADDR;
59 #define SCUTIMER_CONTROL_PRESCALER_MASK 0x0000FF00 /* Prescaler */
60 #define SCUTIMER_CONTROL_PRESCALER_SHIFT 8
61 #define SCUTIMER_CONTROL_AUTO_RELOAD_MASK 0x00000002 /* Auto-reload */
62 #define SCUTIMER_CONTROL_ENABLE_MASK 0x00000001 /* Timer enable */
64 #define TIMER_LOAD_VAL 0xFFFFFFFF
65 #define TIMER_PRESCALE 255
66 #define TIMER_TICK_HZ (CONFIG_CPU_FREQ_HZ / 2 / TIMER_PRESCALE)
70 const u32 emask = SCUTIMER_CONTROL_AUTO_RELOAD_MASK |
71 (TIMER_PRESCALE << SCUTIMER_CONTROL_PRESCALER_SHIFT) |
72 SCUTIMER_CONTROL_ENABLE_MASK;
74 /* Load the timer counter register */
75 writel(0xFFFFFFFF, &timer_base->counter);
78 * Start the A9Timer device
79 * Enable Auto reload mode, Clear prescaler control bits
80 * Set prescaler value, Enable the decrementer
82 clrsetbits_le32(&timer_base->control, SCUTIMER_CONTROL_PRESCALER_MASK,
86 gd->lastinc = readl(&timer_base->counter) /
87 (TIMER_TICK_HZ / CONFIG_SYS_HZ);
94 * This function is derived from PowerPC code (read timebase as long long).
95 * On ARM it just returns the timer value.
97 ulong get_timer_masked(void)
101 now = readl(&timer_base->counter) / (TIMER_TICK_HZ / CONFIG_SYS_HZ);
103 if (gd->lastinc >= now) {
105 gd->tbl += gd->lastinc - now;
107 /* We have an overflow ... */
108 gd->tbl += gd->lastinc + TIMER_LOAD_VAL - now;
115 void __udelay(unsigned long usec)
117 unsigned long long tmp;
120 tmo = usec / (1000000 / CONFIG_SYS_HZ);
121 tmp = get_ticks() + tmo; /* Get current timestamp */
123 while (get_ticks() < tmp) { /* Loop till event */
128 /* Timer without interrupts */
129 ulong get_timer(ulong base)
131 return get_timer_masked() - base;
135 * This function is derived from PowerPC code (read timebase as long long).
136 * On ARM it just returns the timer value.
138 unsigned long long get_ticks(void)
144 * This function is derived from PowerPC code (timebase clock frequency).
145 * On ARM it returns the number of timer ticks per second.
147 ulong get_tbclk(void)
149 return CONFIG_SYS_HZ;