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Diffstat (limited to 'arch/microblaze/kernel/heartbeat.c')
-rw-r--r--arch/microblaze/kernel/heartbeat.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/heartbeat.c b/arch/microblaze/kernel/heartbeat.c
new file mode 100644
index 000000000..4643e3ab9
--- /dev/null
+++ b/arch/microblaze/kernel/heartbeat.c
@@ -0,0 +1,71 @@
+/*
+ * 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 microblaze_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 microblaze_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);
+ pr_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);
+ }
+}