remarkable-linux/arch/microblaze/kernel/heartbeat.c
Michal Simek 02b08045a0 microblaze: Add support for little-endian Microblaze
Microblaze little-endian toolchain exports __MICROBLAZEEL__
which is used in the kernel to identify little/big endian.

The most of the changes are in loading values from DTB which
is always big endian.

Little endian platforms are based on new AXI bus which has
impact to early uartlite initialization.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2010-10-21 15:51:59 +10:00

72 lines
1.6 KiB
C

/*
* Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2007-2009 PetaLogix
* Copyright (C) 2006 Atmark Techno, Inc.
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/sched.h>
#include <linux/io.h>
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/prom.h>
static unsigned int base_addr;
void heartbeat(void)
{
static unsigned int cnt, period, dist;
if (base_addr) {
if (cnt == 0 || cnt == dist)
out_be32(base_addr, 1);
else if (cnt == 7 || cnt == dist + 7)
out_be32(base_addr, 0);
if (++cnt > period) {
cnt = 0;
/*
* The hyperbolic function below modifies the heartbeat
* period length in dependency of the current (5min)
* load. It goes through the points f(0)=126, f(1)=86,
* f(5)=51, f(inf)->30.
*/
period = ((672 << FSHIFT) / (5 * avenrun[0] +
(7 << FSHIFT))) + 30;
dist = period / 4;
}
}
}
void setup_heartbeat(void)
{
struct device_node *gpio = NULL;
int *prop;
int j;
const char * const gpio_list[] = {
"xlnx,xps-gpio-1.00.a",
NULL
};
for (j = 0; gpio_list[j] != NULL; j++) {
gpio = of_find_compatible_node(NULL, NULL, gpio_list[j]);
if (gpio)
break;
}
if (gpio) {
base_addr = be32_to_cpup(of_get_property(gpio, "reg", NULL));
base_addr = (unsigned long) ioremap(base_addr, PAGE_SIZE);
printk(KERN_NOTICE "Heartbeat GPIO at 0x%x\n", base_addr);
/* GPIO is configured as output */
prop = (int *) of_get_property(gpio, "xlnx,is-bidir", NULL);
if (prop)
out_be32(base_addr + 4, 0);
}
}