watchdog: Add WDIOC_GETTIMELEFT ioctl support to w83627 watchdog driver

Add WDIOC_GETTIMELEFT ioctl allowing you to check how much time is left
on the watchdog counter before a reset occurs.

Signed-off-by: Greg Lee <glee [at] swspec.com>
Signed-off-by: Padraig Brady <P@draigbrady.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@google.com>

diff --git a/drivers/watchdog/w83627hf_wdt.c b/drivers/watchdog/w83627hf_wdt.c
index e5c91d4404edfdb244e6a70c3e87edf63b163a63..dd5d675487583254caaf679609b2ca310f5edb7a 100644 (file)
--- a/drivers/watchdog/w83627hf_wdt.c
+++ b/drivers/watchdog/w83627hf_wdt.c
@@ -142,7 +142,7 @@ static void w83627hf_init(void)
        w83627hf_unselect_wd_register();
 }
 
-static void wdt_ctrl(int timeout)
+static void wdt_set_time(int timeout)
 {
        spin_lock(&io_lock);
 
@@ -158,13 +158,13 @@ static void wdt_ctrl(int timeout)
 
 static int wdt_ping(void)
 {
-       wdt_ctrl(timeout);
+       wdt_set_time(timeout);
        return 0;
 }
 
 static int wdt_disable(void)
 {
-       wdt_ctrl(0);
+       wdt_set_time(0);
        return 0;
 }
 
@@ -176,6 +176,24 @@ static int wdt_set_heartbeat(int t)
        return 0;
 }
 
+static int wdt_get_time(void)
+{
+       int timeleft;
+
+       spin_lock(&io_lock);
+
+       w83627hf_select_wd_register();
+
+       outb_p(0xF6, WDT_EFER);    /* Select CRF6 */
+       timeleft = inb_p(WDT_EFDR); /* Read Timeout counter to CRF6 */
+
+       w83627hf_unselect_wd_register();
+
+       spin_unlock(&io_lock);
+
+       return timeleft;
+}
+
 static ssize_t wdt_write(struct file *file, const char __user *buf,
                                                size_t count, loff_t *ppos)
 {
@@ -202,7 +220,7 @@ static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
        void __user *argp = (void __user *)arg;
        int __user *p = argp;
-       int new_timeout;
+       int timeval;
        static const struct watchdog_info ident = {
                .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT |
                                                        WDIOF_MAGICCLOSE,
@@ -238,14 +256,17 @@ static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                wdt_ping();
                break;
        case WDIOC_SETTIMEOUT:
-               if (get_user(new_timeout, p))
+               if (get_user(timeval, p))
                        return -EFAULT;
-               if (wdt_set_heartbeat(new_timeout))
+               if (wdt_set_heartbeat(timeval))
                        return -EINVAL;
                wdt_ping();
                /* Fall */
        case WDIOC_GETTIMEOUT:
                return put_user(timeout, p);
+       case WDIOC_GETTIMELEFT:
+               timeval = wdt_get_time();
+               return put_user(timeval, p);
        default:
                return -ENOTTY;
        }