gpiolib: move validation of line handle flags into helper function

Move validation of line handle flags into helper function.
This reduces the size and complexity of linehandle_create and allows the
validation to be reused elsewhere.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index be159f56ff45281c3cc87ea6029ccc2248844d00..a9826627f3475c7af0fbed149839fa49d7a0dc10 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -428,6 +428,54 @@ struct linehandle_state {
        GPIOHANDLE_REQUEST_OPEN_DRAIN | \
        GPIOHANDLE_REQUEST_OPEN_SOURCE)
 
+static int linehandle_validate_flags(u32 flags)
+{
+       /* Return an error if an unknown flag is set */
+       if (flags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
+               return -EINVAL;
+
+       /*
+        * Do not allow both INPUT & OUTPUT flags to be set as they are
+        * contradictory.
+        */
+       if ((flags & GPIOHANDLE_REQUEST_INPUT) &&
+           (flags & GPIOHANDLE_REQUEST_OUTPUT))
+               return -EINVAL;
+
+       /*
+        * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
+        * the hardware actually supports enabling both at the same time the
+        * electrical result would be disastrous.
+        */
+       if ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
+           (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
+               return -EINVAL;
+
+       /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
+       if (!(flags & GPIOHANDLE_REQUEST_OUTPUT) &&
+           ((flags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
+            (flags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
+               return -EINVAL;
+
+       /* Bias flags only allowed for input or output mode. */
+       if (!((flags & GPIOHANDLE_REQUEST_INPUT) ||
+             (flags & GPIOHANDLE_REQUEST_OUTPUT)) &&
+           ((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
+            (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
+            (flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
+               return -EINVAL;
+
+       /* Only one bias flag can be set. */
+       if (((flags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
+            (flags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
+                       GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
+           ((flags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
+            (flags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
+               return -EINVAL;
+
+       return 0;
+}
+
 static long linehandle_ioctl(struct file *filep, unsigned int cmd,
                             unsigned long arg)
 {
@@ -529,48 +577,9 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
 
        lflags = handlereq.flags;
 
-       /* Return an error if an unknown flag is set */
-       if (lflags & ~GPIOHANDLE_REQUEST_VALID_FLAGS)
-               return -EINVAL;
-
-       /*
-        * Do not allow both INPUT & OUTPUT flags to be set as they are
-        * contradictory.
-        */
-       if ((lflags & GPIOHANDLE_REQUEST_INPUT) &&
-           (lflags & GPIOHANDLE_REQUEST_OUTPUT))
-               return -EINVAL;
-
-       /*
-        * Do not allow OPEN_SOURCE & OPEN_DRAIN flags in a single request. If
-        * the hardware actually supports enabling both at the same time the
-        * electrical result would be disastrous.
-        */
-       if ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) &&
-           (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE))
-               return -EINVAL;
-
-       /* OPEN_DRAIN and OPEN_SOURCE flags only make sense for output mode. */
-       if (!(lflags & GPIOHANDLE_REQUEST_OUTPUT) &&
-           ((lflags & GPIOHANDLE_REQUEST_OPEN_DRAIN) ||
-            (lflags & GPIOHANDLE_REQUEST_OPEN_SOURCE)))
-               return -EINVAL;
-
-       /* Bias flags only allowed for input or output mode. */
-       if (!((lflags & GPIOHANDLE_REQUEST_INPUT) ||
-             (lflags & GPIOHANDLE_REQUEST_OUTPUT)) &&
-           ((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) ||
-            (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP) ||
-            (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN)))
-               return -EINVAL;
-
-       /* Only one bias flag can be set. */
-       if (((lflags & GPIOHANDLE_REQUEST_BIAS_DISABLE) &&
-            (lflags & (GPIOHANDLE_REQUEST_BIAS_PULL_DOWN |
-                       GPIOHANDLE_REQUEST_BIAS_PULL_UP))) ||
-           ((lflags & GPIOHANDLE_REQUEST_BIAS_PULL_DOWN) &&
-            (lflags & GPIOHANDLE_REQUEST_BIAS_PULL_UP)))
-               return -EINVAL;
+       ret = linehandle_validate_flags(lflags);
+       if (ret)
+               return ret;
 
        lh = kzalloc(sizeof(*lh), GFP_KERNEL);
        if (!lh)