2008-08-23 03:52:58

by Sean MacLennan

[permalink] [raw]
Subject: [PATCH] Pika Warp appliance watchdog timer

The FPGA based watchdog timer used by the Pika Warp appliance.

Signed-off-by: Sean MacLennan <[email protected]>
---
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index db20542..2bbb607 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -719,6 +719,14 @@ config BOOKE_WDT
Please see Documentation/watchdog/watchdog-api.txt for
more information.

+config PIKA_WDT
+ tristate "PIKA FPGA Watchdog"
+ depends on WARP
+ default y
+ help
+ This enables the watchdog in the PIKA FPGA. Currently used on
+ the Warp platform.
+
# PPC64 Architecture

config WATCHDOG_RTAS
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index ca3dc04..3527290 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -109,6 +109,7 @@ obj-$(CONFIG_MPC5200_WDT) += mpc5200_wdt.o
obj-$(CONFIG_8xxx_WDT) += mpc8xxx_wdt.o
obj-$(CONFIG_MV64X60_WDT) += mv64x60_wdt.o
obj-$(CONFIG_BOOKE_WDT) += booke_wdt.o
+obj-$(CONFIG_PIKA_WDT) += pika_wdt.o

# PPC64 Architecture
obj-$(CONFIG_WATCHDOG_RTAS) += wdrtas.o
diff --git a/drivers/watchdog/pika_wdt.c b/drivers/watchdog/pika_wdt.c
new file mode 100644
index 0000000..32e11f7
--- /dev/null
+++ b/drivers/watchdog/pika_wdt.c
@@ -0,0 +1,113 @@
+/*
+ * PIKA FPGA based Watchdog Timer
+ *
+ * Copyright (c) 2008 PIKA Technologies
+ * Sean MacLennan <[email protected]>
+ */
+
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/reboot.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+#include <linux/watchdog.h>
+
+
+static void __iomem *pikawdt_fpga;
+
+
+static inline void pikawdt_ping(void)
+{
+ unsigned reset = in_be32(pikawdt_fpga + 0x14);
+ reset |= 0xf80; /* enable with max timeout - 15 seconds */
+ out_be32(pikawdt_fpga + 0x14, reset);
+}
+
+static int pikawdt_open(struct inode *inode, struct file *file)
+{
+ printk(KERN_INFO "PIKA WDT started...\n");
+
+ pikawdt_ping();
+
+ return 0;
+}
+
+static int pikawdt_release(struct inode *inode, struct file *file)
+{
+ pikawdt_ping(); /* one last time */
+ return 0;
+}
+
+static ssize_t pikawdt_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ pikawdt_ping();
+ return count;
+}
+
+/* We support the bare minimum to be conformant. */
+static int pikawdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ if (cmd == WDIOC_KEEPALIVE) {
+ pikawdt_ping();
+ return 0;
+ } else
+ return -EINVAL;
+}
+
+static const struct file_operations pikawdt_fops = {
+ .owner = THIS_MODULE,
+ .open = pikawdt_open,
+ .release = pikawdt_release,
+ .write = pikawdt_write,
+ .ioctl = pikawdt_ioctl,
+};
+
+static struct miscdevice pikawdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &pikawdt_fops,
+};
+
+static int __init pikawdt_init(void)
+{
+ struct device_node *np;
+ int ret;
+
+ np = of_find_compatible_node(NULL, NULL, "pika,fpga");
+ if (np == NULL) {
+ printk(KERN_ERR "pikawdt: Unable to find fpga.\n");
+ return -ENOENT;
+ }
+
+ pikawdt_fpga = of_iomap(np, 0);
+
+ of_node_put(np);
+
+ if (pikawdt_fpga == NULL) {
+ printk(KERN_ERR "pikawdt: Unable to map fpga.\n");
+ return -ENOENT;
+ }
+
+ ret = misc_register(&pikawdt_miscdev);
+ if (ret) {
+ iounmap(pikawdt_fpga);
+ printk(KERN_ERR "pikawdt: Unable to register miscdev.\n");
+ return ret;
+ }
+
+ return 0;
+}
+module_init(pikawdt_init);
+
+
+static void __exit pikawdt_exit(void)
+{
+ misc_deregister(&pikawdt_miscdev);
+
+ iounmap(pikawdt_fpga);
+}
+module_exit(pikawdt_exit);