diff options
Diffstat (limited to 'arch/microblaze/kernel/heartbeat.c')
| -rw-r--r-- | arch/microblaze/kernel/heartbeat.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/heartbeat.c b/arch/microblaze/kernel/heartbeat.c new file mode 100644 index 000000000000..1bdf20222b92 --- /dev/null +++ b/arch/microblaze/kernel/heartbeat.c @@ -0,0 +1,67 @@ +/* + * 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 j; + char *gpio_list[] = { + "xlnx,xps-gpio-1.00.a", + "xlnx,opb-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; + } + + base_addr = *(int *) 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); + + if (*(int *) of_get_property(gpio, "xlnx,is-bidir", NULL)) + out_be32(base_addr + 4, 0); /* GPIO is configured as output */ +} |