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,
47 #include <asm/arch/hardware.h>
49 DECLARE_GLOBAL_DATA_PTR;
52 u32 load; /* Timer Load Register */
53 u32 counter; /* Timer Counter Register */
54 u32 control; /* Timer Control Register */
57 static struct scu_timer *timer_base =
58 (struct scu_timer *)ZYNQ_SCUTIMER_BASEADDR;
60 #define SCUTIMER_CONTROL_PRESCALER_MASK 0x0000FF00 /* Prescaler */
61 #define SCUTIMER_CONTROL_PRESCALER_SHIFT 8
62 #define SCUTIMER_CONTROL_AUTO_RELOAD_MASK 0x00000002 /* Auto-reload */
63 #define SCUTIMER_CONTROL_ENABLE_MASK 0x00000001 /* Timer enable */
65 #define TIMER_LOAD_VAL 0xFFFFFFFF
66 #define TIMER_PRESCALE 255
67 #define TIMER_TICK_HZ (CONFIG_CPU_FREQ_HZ / 2 / TIMER_PRESCALE)
71 const u32 emask = SCUTIMER_CONTROL_AUTO_RELOAD_MASK |
72 (TIMER_PRESCALE << SCUTIMER_CONTROL_PRESCALER_SHIFT) |
73 SCUTIMER_CONTROL_ENABLE_MASK;
75 /* Load the timer counter register */
76 writel(0xFFFFFFFF, &timer_base->counter);
79 * Start the A9Timer device
80 * Enable Auto reload mode, Clear prescaler control bits
81 * Set prescaler value, Enable the decrementer
83 clrsetbits_le32(&timer_base->control, SCUTIMER_CONTROL_PRESCALER_MASK,
87 gd->arch.lastinc = readl(&timer_base->counter) /
88 (TIMER_TICK_HZ / CONFIG_SYS_HZ);
95 * This function is derived from PowerPC code (read timebase as long long).
96 * On ARM it just returns the timer value.
98 ulong get_timer_masked(void)
102 now = readl(&timer_base->counter) / (TIMER_TICK_HZ / CONFIG_SYS_HZ);
104 if (gd->arch.lastinc >= now) {
106 gd->arch.tbl += gd->arch.lastinc - now;
108 /* We have an overflow ... */
109 gd->arch.tbl += gd->arch.lastinc + TIMER_LOAD_VAL - now;
111 gd->arch.lastinc = now;
116 void __udelay(unsigned long usec)
126 countticks = (u32) (((unsigned long long) TIMER_TICK_HZ * usec) /
129 /* decrementing timer */
130 timeend = readl(&timer_base->counter) - countticks;
132 #if TIMER_LOAD_VAL != 0xFFFFFFFF
133 /* do not manage multiple overflow */
134 if (countticks >= TIMER_LOAD_VAL)
135 countticks = TIMER_LOAD_VAL - 1;
139 timenow = readl(&timer_base->counter);
141 if (timenow >= timeend) {
143 timediff = timenow - timeend;
145 if ((TIMER_LOAD_VAL - timeend + timenow) <=
148 timediff = TIMER_LOAD_VAL - timeend + timenow;
150 /* missed the exact match */
154 } while (timediff > 0);
157 /* Timer without interrupts */
158 ulong get_timer(ulong base)
160 return get_timer_masked() - base;
164 * This function is derived from PowerPC code (read timebase as long long).
165 * On ARM it just returns the timer value.
167 unsigned long long get_ticks(void)
173 * This function is derived from PowerPC code (timebase clock frequency).
174 * On ARM it returns the number of timer ticks per second.
176 ulong get_tbclk(void)
178 return CONFIG_SYS_HZ;