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authorDavid S. Miller <davem@davemloft.net>2008-08-29 15:40:24 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-29 15:40:24 -0700
commit957183f32e136450eb9a4b8eed52dfac46834eed (patch)
tree8c0b70602f1c2043e5bab7337580ca666e70ca99 /drivers/watchdog/riowd.c
parente42311d75107ca78868ded0286b691aad2df1f29 (diff)
downloadvexpress-lsk-957183f32e136450eb9a4b8eed52dfac46834eed.tar.gz
riowatchdog: Move under drivers/watchdog
The config stuff was already in drivers/watchdog/Kconfig Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/watchdog/riowd.c')
-rw-r--r--drivers/watchdog/riowd.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/drivers/watchdog/riowd.c b/drivers/watchdog/riowd.c
new file mode 100644
index 00000000000..98bb60ff02f
--- /dev/null
+++ b/drivers/watchdog/riowd.c
@@ -0,0 +1,259 @@
+/* riowd.c - driver for hw watchdog inside Super I/O of RIO
+ *
+ * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/miscdevice.h>
+#include <linux/smp_lock.h>
+#include <linux/watchdog.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+
+/* RIO uses the NatSemi Super I/O power management logical device
+ * as its' watchdog.
+ *
+ * When the watchdog triggers, it asserts a line to the BBC (Boot Bus
+ * Controller) of the machine. The BBC can only be configured to
+ * trigger a power-on reset when the signal is asserted. The BBC
+ * can be configured to ignore the signal entirely as well.
+ *
+ * The only Super I/O device register we care about is at index
+ * 0x05 (WDTO_INDEX) which is the watchdog time-out in minutes (1-255).
+ * If set to zero, this disables the watchdog. When set, the system
+ * must periodically (before watchdog expires) clear (set to zero) and
+ * re-set the watchdog else it will trigger.
+ *
+ * There are two other indexed watchdog registers inside this Super I/O
+ * logical device, but they are unused. The first, at index 0x06 is
+ * the watchdog control and can be used to make the watchdog timer re-set
+ * when the PS/2 mouse or serial lines show activity. The second, at
+ * index 0x07 is merely a sampling of the line from the watchdog to the
+ * BBC.
+ *
+ * The watchdog device generates no interrupts.
+ */
+
+MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
+MODULE_DESCRIPTION("Hardware watchdog driver for Sun RIO");
+MODULE_SUPPORTED_DEVICE("watchdog");
+MODULE_LICENSE("GPL");
+
+#define RIOWD_NAME "pmc"
+#define PFX RIOWD_NAME ": "
+
+struct riowd {
+ void __iomem *regs;
+ spinlock_t lock;
+};
+
+static struct riowd *riowd_device;
+
+#define WDTO_INDEX 0x05
+
+static int riowd_timeout = 1; /* in minutes */
+module_param(riowd_timeout, int, 0);
+MODULE_PARM_DESC(riowd_timeout, "Watchdog timeout in minutes");
+
+static void riowd_writereg(struct riowd *p, u8 val, int index)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&p->lock, flags);
+ writeb(index, p->regs + 0);
+ writeb(val, p->regs + 1);
+ spin_unlock_irqrestore(&p->lock, flags);
+}
+
+static int riowd_open(struct inode *inode, struct file *filp)
+{
+ cycle_kernel_lock();
+ nonseekable_open(inode, filp);
+ return 0;
+}
+
+static int riowd_release(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+static int riowd_ioctl(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ static struct watchdog_info info = {
+ .options = WDIOF_SETTIMEOUT,
+ .firmware_version = 1,
+ .identity = "riowd",
+ };
+ void __user *argp = (void __user *)arg;
+ struct riowd *p = riowd_device;
+ unsigned int options;
+ int new_margin;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ if (copy_to_user(argp, &info, sizeof(info)))
+ return -EFAULT;
+ break;
+
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ if (put_user(0, (int __user *)argp))
+ return -EFAULT;
+ break;
+
+ case WDIOC_KEEPALIVE:
+ riowd_writereg(p, riowd_timeout, WDTO_INDEX);
+ break;
+
+ case WDIOC_SETOPTIONS:
+ if (copy_from_user(&options, argp, sizeof(options)))
+ return -EFAULT;
+
+ if (options & WDIOS_DISABLECARD)
+ riowd_writereg(p, 0, WDTO_INDEX);
+ else if (options & WDIOS_ENABLECARD)
+ riowd_writereg(p, riowd_timeout, WDTO_INDEX);
+ else
+ return -EINVAL;
+
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_margin, (int __user *)argp))
+ return -EFAULT;
+ if ((new_margin < 60) || (new_margin > (255 * 60)))
+ return -EINVAL;
+ riowd_timeout = (new_margin + 59) / 60;
+ riowd_writereg(p, riowd_timeout, WDTO_INDEX);
+ /* Fall */
+
+ case WDIOC_GETTIMEOUT:
+ return put_user(riowd_timeout * 60, (int __user *)argp);
+
+ default:
+ return -EINVAL;
+ };
+
+ return 0;
+}
+
+static ssize_t riowd_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+ struct riowd *p = riowd_device;
+
+ if (count) {
+ riowd_writereg(p, riowd_timeout, WDTO_INDEX);
+ return 1;
+ }
+
+ return 0;
+}
+
+static const struct file_operations riowd_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .ioctl = riowd_ioctl,
+ .open = riowd_open,
+ .write = riowd_write,
+ .release = riowd_release,
+};
+
+static struct miscdevice riowd_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &riowd_fops
+};
+
+static int __devinit riowd_probe(struct of_device *op,
+ const struct of_device_id *match)
+{
+ struct riowd *p;
+ int err = -EINVAL;
+
+ if (riowd_device)
+ goto out;
+
+ err = -ENOMEM;
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p)
+ goto out;
+
+ spin_lock_init(&p->lock);
+
+ p->regs = of_ioremap(&op->resource[0], 0, 2, "riowd");
+ if (!p->regs) {
+ printk(KERN_ERR PFX "Cannot map registers.\n");
+ goto out_free;
+ }
+
+ err = misc_register(&riowd_miscdev);
+ if (err) {
+ printk(KERN_ERR PFX "Cannot register watchdog misc device.\n");
+ goto out_iounmap;
+ }
+
+ printk(KERN_INFO PFX "Hardware watchdog [%i minutes], "
+ "regs at %p\n", riowd_timeout, p->regs);
+
+ dev_set_drvdata(&op->dev, p);
+ riowd_device = p;
+ err = 0;
+
+out_iounmap:
+ of_iounmap(&op->resource[0], p->regs, 2);
+
+out_free:
+ kfree(p);
+
+out:
+ return err;
+}
+
+static int __devexit riowd_remove(struct of_device *op)
+{
+ struct riowd *p = dev_get_drvdata(&op->dev);
+
+ misc_deregister(&riowd_miscdev);
+ of_iounmap(&op->resource[0], p->regs, 2);
+ kfree(p);
+
+ return 0;
+}
+
+static struct of_device_id riowd_match[] = {
+ {
+ .name = "pmc",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, riowd_match);
+
+static struct of_platform_driver riowd_driver = {
+ .name = "riowd",
+ .match_table = riowd_match,
+ .probe = riowd_probe,
+ .remove = __devexit_p(riowd_remove),
+};
+
+static int __init riowd_init(void)
+{
+ return of_register_driver(&riowd_driver, &of_bus_type);
+}
+
+static void __exit riowd_exit(void)
+{
+ of_unregister_driver(&riowd_driver);
+}
+
+module_init(riowd_init);
+module_exit(riowd_exit);