u-boot/arch/arm/cpu/arm1176/bcm2835/timer.c
Stephen Warren efad6cf881 ARM: add basic support for the Broadcom BCM2835 SoC
This SoC is used in the Raspberry Pi, for example.

For more details, see:
http://www.broadcom.com/products/BCM2835
http://www.raspberrypi.org/wp-content/uploads/2012/02/BCM2835-ARM-Peripherals.pdf.

Initial support is enough to boot to a serial console, execute a minimal
set of U-Boot commands, download data over a serial port, and boot a
Linux kernel. No storage or network drivers are implemented.

GPIO driver originally by Vikram Narayanan <vikram186@gmail.com>
with many fixes from myself.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
2012-09-01 14:58:21 +02:00

55 lines
1.1 KiB
C

/*
* (C) Copyright 2012 Stephen Warren
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <common.h>
#include <asm/io.h>
#include <asm/arch/timer.h>
int timer_init(void)
{
return 0;
}
ulong get_timer(ulong base)
{
struct bcm2835_timer_regs *regs =
(struct bcm2835_timer_regs *)BCM2835_TIMER_PHYSADDR;
return readl(&regs->clo) - base;
}
unsigned long long get_ticks(void)
{
return get_timer(0);
}
ulong get_tbclk(void)
{
return CONFIG_SYS_HZ;
}
void __udelay(unsigned long usec)
{
ulong endtime;
signed long diff;
endtime = get_timer(0) + usec;
do {
ulong now = get_timer(0);
diff = endtime - now;
} while (diff >= 0);
}