| Michal Simek | ecc6dfc | 2009-03-27 14:25:24 +0100 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007-2009 Michal Simek <monstr@monstr.eu> |
| 3 | * Copyright (C) 2007-2009 PetaLogix |
| 4 | * Copyright (C) 2006 Atmark Techno, Inc. |
| 5 | * |
| 6 | * This file is subject to the terms and conditions of the GNU General Public |
| 7 | * License. See the file "COPYING" in the main directory of this archive |
| 8 | * for more details. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/sched.h> |
| 12 | #include <linux/io.h> |
| 13 | |
| 14 | #include <asm/setup.h> |
| 15 | #include <asm/page.h> |
| 16 | #include <asm/prom.h> |
| 17 | |
| 18 | static unsigned int base_addr; |
| 19 | |
| 20 | void heartbeat(void) |
| 21 | { |
| 22 | static unsigned int cnt, period, dist; |
| 23 | |
| 24 | if (base_addr) { |
| 25 | if (cnt == 0 || cnt == dist) |
| 26 | out_be32(base_addr, 1); |
| 27 | else if (cnt == 7 || cnt == dist + 7) |
| 28 | out_be32(base_addr, 0); |
| 29 | |
| 30 | if (++cnt > period) { |
| 31 | cnt = 0; |
| 32 | /* |
| 33 | * The hyperbolic function below modifies the heartbeat |
| 34 | * period length in dependency of the current (5min) |
| 35 | * load. It goes through the points f(0)=126, f(1)=86, |
| 36 | * f(5)=51, f(inf)->30. |
| 37 | */ |
| 38 | period = ((672 << FSHIFT) / (5 * avenrun[0] + |
| 39 | (7 << FSHIFT))) + 30; |
| 40 | dist = period / 4; |
| 41 | } |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | void setup_heartbeat(void) |
| 46 | { |
| 47 | struct device_node *gpio = NULL; |
| 48 | int j; |
| 49 | char *gpio_list[] = { |
| 50 | "xlnx,xps-gpio-1.00.a", |
| 51 | "xlnx,opb-gpio-1.00.a", |
| 52 | NULL |
| 53 | }; |
| 54 | |
| 55 | for (j = 0; gpio_list[j] != NULL; j++) { |
| 56 | gpio = of_find_compatible_node(NULL, NULL, gpio_list[j]); |
| 57 | if (gpio) |
| 58 | break; |
| 59 | } |
| 60 | |
| 61 | base_addr = *(int *) of_get_property(gpio, "reg", NULL); |
| 62 | base_addr = (unsigned long) ioremap(base_addr, PAGE_SIZE); |
| 63 | printk(KERN_NOTICE "Heartbeat GPIO at 0x%x\n", base_addr); |
| 64 | |
| 65 | if (*(int *) of_get_property(gpio, "xlnx,is-bidir", NULL)) |
| 66 | out_be32(base_addr + 4, 0); /* GPIO is configured as output */ |
| 67 | } |