staging: comedi: ni_tio: export and fix ni_tio_get_soft_copy()

Move the inline function from the header and export it instead.

For the checkpatch.pl issues:
WARNING: Prefer 'unsigned int' to bare use of 'unsigned'
CHECK: Avoid crashing the kernel - try using WARN_ON & recovery code
       rather than BUG() or BUG_ON()

The 'unsigned' vars can safely be changed to 'unsigned int'.

The BUG_ON() is overkill. All the drivers that call this function pass
'register_index' values that are valid. Just check the 'register_index'
and return 0 if it's not valid.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/ni_tio.c

@@ -228,6 +228,31 @@ static uint64_t ni_tio_clock_period_ps(const struct ni_gpct *counter,
 	return clock_period_ps;
 }
 
+/**
+ * ni_tio_get_soft_copy() - Safely read the software copy of a counter register.
+ * @counter: struct ni_gpct counter.
+ * @reg: the register to read.
+ *
+ * Used to get the software copy of a register whose bits might be modified
+ * in interrupt context, or whose software copy might need to be read in
+ * interrupt context.
+ */
+unsigned int ni_tio_get_soft_copy(const struct ni_gpct *counter,
+				  enum ni_gpct_register reg)
+{
+	struct ni_gpct_device *counter_dev = counter->counter_dev;
+	unsigned int value = 0;
+	unsigned long flags;
+
+	if (reg < NITIO_NUM_REGS) {
+		spin_lock_irqsave(&counter_dev->regs_lock, flags);
+		value = counter_dev->regs[reg];
+		spin_unlock_irqrestore(&counter_dev->regs_lock, flags);
+	}
+	return value;
+}
+EXPORT_SYMBOL_GPL(ni_tio_get_soft_copy);
+
 static unsigned ni_tio_clock_src_modifiers(const struct ni_gpct *counter)
 {
 	struct ni_gpct_device *counter_dev = counter->counter_dev;

drivers/staging/comedi/drivers/ni_tio_internal.h

@@ -224,25 +224,8 @@ static inline void ni_tio_set_bits(struct ni_gpct *counter,
 				  0x0);
 }
 
-/*
- * ni_tio_get_soft_copy( ) is for safely reading the software copy of a
- * register whose bits might be modified in interrupt context, or whose
- * software copy might need to be read in interrupt context.
- */
-static inline unsigned ni_tio_get_soft_copy(const struct ni_gpct *counter,
-					    enum ni_gpct_register
-					    register_index)
-{
-	struct ni_gpct_device *counter_dev = counter->counter_dev;
-	unsigned long flags;
-	unsigned value;
-
-	BUG_ON(register_index >= NITIO_NUM_REGS);
-	spin_lock_irqsave(&counter_dev->regs_lock, flags);
-	value = counter_dev->regs[register_index];
-	spin_unlock_irqrestore(&counter_dev->regs_lock, flags);
-	return value;
-}
+unsigned int ni_tio_get_soft_copy(const struct ni_gpct *,
+				  enum ni_gpct_register reg);
 
 int ni_tio_arm(struct ni_gpct *, bool arm, unsigned int start_trigger);
 int ni_tio_set_gate_src(struct ni_gpct *, unsigned int gate, unsigned int src);