[WATCHDOG] Freescale STMP: watchdog driver
Add watchdog timer support for Freescale STMP3xxx boards
Signed-off-by: Vitaly Wool <vital@embeddedalley.com>
Signed-off-by: Dmitry Pervushin <dpervushin@embeddedalley.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
diff --git a/drivers/watchdog/stmp3xxx_wdt.c b/drivers/watchdog/stmp3xxx_wdt.c
new file mode 100644
index 0000000..5dd9526
--- /dev/null
+++ b/drivers/watchdog/stmp3xxx_wdt.c
@@ -0,0 +1,296 @@
+/*
+ * Watchdog driver for Freescale STMP37XX/STMP378X
+ *
+ * Author: Vitaly Wool <vital@embeddedalley.com>
+ *
+ * Copyright 2008 Freescale Semiconductor, Inc. All Rights Reserved.
+ * Copyright 2008 Embedded Alley Solutions, Inc All Rights Reserved.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/fs.h>
+#include <linux/miscdevice.h>
+#include <linux/watchdog.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/uaccess.h>
+
+#include <mach/platform.h>
+#include <mach/regs-rtc.h>
+
+#define DEFAULT_HEARTBEAT 19
+#define MAX_HEARTBEAT (0x10000000 >> 6)
+
+/* missing bitmask in headers */
+#define BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER 0x80000000
+
+#define WDT_IN_USE 0
+#define WDT_OK_TO_CLOSE 1
+
+#define WDOG_COUNTER_RATE 1000 /* 1 kHz clock */
+
+static DEFINE_SPINLOCK(stmp3xxx_wdt_io_lock);
+static unsigned long wdt_status;
+static const int nowayout = WATCHDOG_NOWAYOUT;
+static int heartbeat = DEFAULT_HEARTBEAT;
+static unsigned long boot_status;
+
+static void wdt_enable(u32 value)
+{
+ spin_lock(&stmp3xxx_wdt_io_lock);
+ __raw_writel(value, REGS_RTC_BASE + HW_RTC_WATCHDOG);
+ stmp3xxx_setl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
+ stmp3xxx_setl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
+ REGS_RTC_BASE + HW_RTC_PERSISTENT1);
+ spin_unlock(&stmp3xxx_wdt_io_lock);
+}
+
+static void wdt_disable(void)
+{
+ spin_lock(&stmp3xxx_wdt_io_lock);
+ stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
+ REGS_RTC_BASE + HW_RTC_PERSISTENT1);
+ stmp3xxx_clearl(BM_RTC_CTRL_WATCHDOGEN, REGS_RTC_BASE + HW_RTC_CTRL);
+ spin_unlock(&stmp3xxx_wdt_io_lock);
+}
+
+static void wdt_ping(void)
+{
+ wdt_enable(heartbeat * WDOG_COUNTER_RATE);
+}
+
+static int stmp3xxx_wdt_open(struct inode *inode, struct file *file)
+{
+ if (test_and_set_bit(WDT_IN_USE, &wdt_status))
+ return -EBUSY;
+
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+ wdt_ping();
+
+ return nonseekable_open(inode, file);
+}
+
+static ssize_t stmp3xxx_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ if (len) {
+ if (!nowayout) {
+ size_t i;
+
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+
+ for (i = 0; i != len; i++) {
+ char c;
+
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V')
+ set_bit(WDT_OK_TO_CLOSE, &wdt_status);
+ }
+ }
+ wdt_ping();
+ }
+
+ return len;
+}
+
+static struct watchdog_info ident = {
+ .options = WDIOF_CARDRESET |
+ WDIOF_MAGICCLOSE |
+ WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING,
+ .identity = "STMP3XXX Watchdog",
+};
+
+static long stmp3xxx_wdt_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ int new_heartbeat, opts;
+ int ret = -ENOTTY;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ ret = copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
+ break;
+
+ case WDIOC_GETSTATUS:
+ ret = put_user(0, p);
+ break;
+
+ case WDIOC_GETBOOTSTATUS:
+ ret = put_user(boot_status, p);
+ break;
+
+ case WDIOC_SETOPTIONS:
+ if (get_user(opts, p)) {
+ ret = -EFAULT;
+ break;
+ }
+ if (opts & WDIOS_DISABLECARD)
+ wdt_disable();
+ else if (opts & WDIOS_ENABLECARD)
+ wdt_ping();
+ else {
+ pr_debug("%s: unknown option 0x%x\n", __func__, opts);
+ ret = -EINVAL;
+ break;
+ }
+ ret = 0;
+ break;
+
+ case WDIOC_KEEPALIVE:
+ wdt_ping();
+ ret = 0;
+ break;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_heartbeat, p)) {
+ ret = -EFAULT;
+ break;
+ }
+ if (new_heartbeat <= 0 || new_heartbeat > MAX_HEARTBEAT) {
+ ret = -EINVAL;
+ break;
+ }
+
+ heartbeat = new_heartbeat;
+ wdt_ping();
+ /* Fall through */
+
+ case WDIOC_GETTIMEOUT:
+ ret = put_user(heartbeat, p);
+ break;
+ }
+ return ret;
+}
+
+static int stmp3xxx_wdt_release(struct inode *inode, struct file *file)
+{
+ int ret = 0;
+
+ if (!nowayout) {
+ if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status)) {
+ wdt_ping();
+ pr_debug("%s: Device closed unexpectdly\n", __func__);
+ ret = -EINVAL;
+ } else {
+ wdt_disable();
+ clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
+ }
+ }
+ clear_bit(WDT_IN_USE, &wdt_status);
+
+ return ret;
+}
+
+static const struct file_operations stmp3xxx_wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .write = stmp3xxx_wdt_write,
+ .unlocked_ioctl = stmp3xxx_wdt_ioctl,
+ .open = stmp3xxx_wdt_open,
+ .release = stmp3xxx_wdt_release,
+};
+
+static struct miscdevice stmp3xxx_wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &stmp3xxx_wdt_fops,
+};
+
+static int __devinit stmp3xxx_wdt_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+
+ if (heartbeat < 1 || heartbeat > MAX_HEARTBEAT)
+ heartbeat = DEFAULT_HEARTBEAT;
+
+ boot_status = __raw_readl(REGS_RTC_BASE + HW_RTC_PERSISTENT1) &
+ BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER;
+ boot_status = !!boot_status;
+ stmp3xxx_clearl(BV_RTC_PERSISTENT1_GENERAL__RTC_FORCE_UPDATER,
+ REGS_RTC_BASE + HW_RTC_PERSISTENT1);
+ wdt_disable(); /* disable for now */
+
+ ret = misc_register(&stmp3xxx_wdt_miscdev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "cannot register misc device\n");
+ return ret;
+ }
+
+ printk(KERN_INFO "stmp3xxx watchdog: initialized, heartbeat %d sec\n",
+ heartbeat);
+
+ return ret;
+}
+
+static int __devexit stmp3xxx_wdt_remove(struct platform_device *pdev)
+{
+ misc_deregister(&stmp3xxx_wdt_miscdev);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int wdt_suspended;
+static u32 wdt_saved_time;
+
+static int stmp3xxx_wdt_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ if (__raw_readl(REGS_RTC_BASE + HW_RTC_CTRL) &
+ BM_RTC_CTRL_WATCHDOGEN) {
+ wdt_suspended = 1;
+ wdt_saved_time = __raw_readl(REGS_RTC_BASE + HW_RTC_WATCHDOG);
+ wdt_disable();
+ }
+ return 0;
+}
+
+static int stmp3xxx_wdt_resume(struct platform_device *pdev)
+{
+ if (wdt_suspended) {
+ wdt_enable(wdt_saved_time);
+ wdt_suspended = 0;
+ }
+ return 0;
+}
+#else
+#define stmp3xxx_wdt_suspend NULL
+#define stmp3xxx_wdt_resume NULL
+#endif
+
+static struct platform_driver platform_wdt_driver = {
+ .driver = {
+ .name = "stmp3xxx_wdt",
+ },
+ .probe = stmp3xxx_wdt_probe,
+ .remove = __devexit_p(stmp3xxx_wdt_remove),
+ .suspend = stmp3xxx_wdt_suspend,
+ .resume = stmp3xxx_wdt_resume,
+};
+
+static int __init stmp3xxx_wdt_init(void)
+{
+ return platform_driver_register(&platform_wdt_driver);
+}
+
+static void __exit stmp3xxx_wdt_exit(void)
+{
+ return platform_driver_unregister(&platform_wdt_driver);
+}
+
+module_init(stmp3xxx_wdt_init);
+module_exit(stmp3xxx_wdt_exit);
+
+MODULE_DESCRIPTION("STMP3XXX Watchdog Driver");
+MODULE_LICENSE("GPL");
+
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat,
+ "Watchdog heartbeat period in seconds from 1 to "
+ __MODULE_STRING(MAX_HEARTBEAT) ", default "
+ __MODULE_STRING(DEFAULT_HEARTBEAT));
+
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);