--- /dev/null
+/*
+ * mv64x60_wdt.c - MV64X60 (Marvell Discovery) watchdog userspace interface
+ *
+ * Author: James Chapman <jchapman@katalix.com>
+ *
+ * Platform-specific setup code should configure the dog to generate
+ * interrupt or reset as required. This code only enables/disables
+ * and services the watchdog.
+ *
+ * Derived from mpc8xx_wdt.c, with the following copyright.
+ *
+ * 2002 (c) Florian Schirmer <jolt@tuxbox.org> This file is licensed under
+ * the terms of the GNU General Public License version 2. This program
+ * is licensed "as is" without any warranty of any kind, whether express
+ * or implied.
+ */
+
+#include <linux/config.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+
+#include <asm/mv64x60.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+/* MV64x60 WDC (config) register access definitions */
+#define MV64x60_WDC_CTL1_MASK (3 << 24)
+#define MV64x60_WDC_CTL1(val) ((val & 3) << 24)
+#define MV64x60_WDC_CTL2_MASK (3 << 26)
+#define MV64x60_WDC_CTL2(val) ((val & 3) << 26)
+
+/* Flags bits */
+#define MV64x60_WDOG_FLAG_OPENED 0
+#define MV64x60_WDOG_FLAG_ENABLED 1
+
+static unsigned long wdt_flags;
+static int wdt_status;
+static void __iomem *mv64x60_regs;
+static int mv64x60_wdt_timeout;
+
+static void mv64x60_wdt_reg_write(u32 val)
+{
+ /* Allow write only to CTL1 / CTL2 fields, retaining values in
+ * other fields.
+ */
+ u32 data = readl(mv64x60_regs + MV64x60_WDT_WDC);
+ data &= ~(MV64x60_WDC_CTL1_MASK | MV64x60_WDC_CTL2_MASK);
+ data |= val;
+ writel(data, mv64x60_regs + MV64x60_WDT_WDC);
+}
+
+static void mv64x60_wdt_service(void)
+{
+ /* Write 01 followed by 10 to CTL2 */
+ mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x01));
+ mv64x60_wdt_reg_write(MV64x60_WDC_CTL2(0x02));
+}
+
+static void mv64x60_wdt_handler_disable(void)
+{
+ if (test_and_clear_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
+ /* Write 01 followed by 10 to CTL1 */
+ mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
+ mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
+ printk(KERN_NOTICE "mv64x60_wdt: watchdog deactivated\n");
+ }
+}
+
+static void mv64x60_wdt_handler_enable(void)
+{
+ if (!test_and_set_bit(MV64x60_WDOG_FLAG_ENABLED, &wdt_flags)) {
+ /* Write 01 followed by 10 to CTL1 */
+ mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x01));
+ mv64x60_wdt_reg_write(MV64x60_WDC_CTL1(0x02));
+ printk(KERN_NOTICE "mv64x60_wdt: watchdog activated\n");
+ }
+}
+
+static int mv64x60_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags))
+ return -EBUSY;
+
+ mv64x60_wdt_service();
+ mv64x60_wdt_handler_enable();
+
+ nonseekable_open(inode, file);
+
+ return 0;
+}
+
+static int mv64x60_wdt_release(struct inode *inode, struct file *file)
+{
+ mv64x60_wdt_service();
+
+#if !defined(CONFIG_WATCHDOG_NOWAYOUT)
+ mv64x60_wdt_handler_disable();
+#endif
+
+ clear_bit(MV64x60_WDOG_FLAG_OPENED, &wdt_flags);
+
+ return 0;
+}
+
+static ssize_t mv64x60_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t * ppos)
+{
+ if (len)
+ mv64x60_wdt_service();
+
+ return len;
+}
+
+static int mv64x60_wdt_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ int timeout;
+ void __user *argp = (void __user *)arg;
+ static struct watchdog_info info = {
+ .options = WDIOF_KEEPALIVEPING,
+ .firmware_version = 0,
+ .identity = "MV64x60 watchdog",
+ };
+
+ 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(wdt_status, (int __user *)argp))
+ return -EFAULT;
+ wdt_status &= ~WDIOF_KEEPALIVEPING;
+ break;
+
+ case WDIOC_GETTEMP:
+ return -EOPNOTSUPP;
+
+ case WDIOC_SETOPTIONS:
+ return -EOPNOTSUPP;
+
+ case WDIOC_KEEPALIVE:
+ mv64x60_wdt_service();
+ wdt_status |= WDIOF_KEEPALIVEPING;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ return -EOPNOTSUPP;
+
+ case WDIOC_GETTIMEOUT:
+ timeout = mv64x60_wdt_timeout * HZ;
+ if (put_user(timeout, (int __user *)argp))
+ return -EFAULT;
+ break;
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ return 0;
+}
+
+static struct file_operations mv64x60_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = mv64x60_wdt_write,
+ .ioctl = mv64x60_wdt_ioctl,
+ .open = mv64x60_wdt_open,
+ .release = mv64x60_wdt_release,
+};
+
+static struct miscdevice mv64x60_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &mv64x60_wdt_fops,
+};
+
+static int __devinit mv64x60_wdt_probe(struct platform_device *dev)
+{
+ struct mv64x60_wdt_pdata *pdata = dev->dev.platform_data;
+ int bus_clk = 133;
+
+ mv64x60_wdt_timeout = 10;
+ if (pdata) {
+ mv64x60_wdt_timeout = pdata->timeout;
+ bus_clk = pdata->bus_clk;
+ }
+
+ mv64x60_regs = mv64x60_get_bridge_vbase();
+
+ writel((mv64x60_wdt_timeout * (bus_clk * 1000000)) >> 8,
+ mv64x60_regs + MV64x60_WDT_WDC);
+
+ return misc_register(&mv64x60_wdt_miscdev);
+}
+
+static int __devexit mv64x60_wdt_remove(struct platform_device *dev)
+{
+ misc_deregister(&mv64x60_wdt_miscdev);
+
+ mv64x60_wdt_service();
+ mv64x60_wdt_handler_disable();
+
+ return 0;
+}
+
+static struct platform_driver mv64x60_wdt_driver = {
+ .probe = mv64x60_wdt_probe,
+ .remove = __devexit_p(mv64x60_wdt_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = MV64x60_WDT_NAME,
+ },
+};
+
+static struct platform_device *mv64x60_wdt_dev;
+
+static int __init mv64x60_wdt_init(void)
+{
+ int ret;
+
+ printk(KERN_INFO "MV64x60 watchdog driver\n");
+
+ mv64x60_wdt_dev = platform_device_alloc(MV64x60_WDT_NAME, -1);
+ if (!mv64x60_wdt_dev) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = platform_device_add(mv64x60_wdt_dev);
+ if (ret) {
+ platform_device_put(mv64x60_wdt_dev);
+ goto out;
+ }
+
+ ret = platform_driver_register(&mv64x60_wdt_driver);
+ if (ret) {
+ platform_device_unregister(mv64x60_wdt_dev);
+ goto out;
+ }
+
+ out:
+ return ret;
+}
+
+static void __exit mv64x60_wdt_exit(void)
+{
+ platform_driver_unregister(&mv64x60_wdt_driver);
+ platform_device_unregister(mv64x60_wdt_dev);
+}
+
+module_init(mv64x60_wdt_init);
+module_exit(mv64x60_wdt_exit);
+
+MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
+MODULE_DESCRIPTION("MV64x60 watchdog driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
git://git.onelab.eu / linux-2.6.git / blobdiff