staging: comedi: refactor das16m1 driver and use module_comedi_driver

Move the module_init/module_exit routines and the associated
struct comedi_drive to the end of the source. This is more
typical of how other drivers are written and removes the need
for the forward declarations.

Refactor some of the other functions to remove the remaining
forward declarations.

Convert the driver to use the module_comedi_driver() macro
which makes the code smaller and a bit simpler.
Signed-off-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Cc: Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/das16m1.c

@@ -132,57 +132,11 @@ static const struct comedi_lrange range_das16m1 = { 9,
 	 }
 };
 
-static int das16m1_do_wbits(struct comedi_device *dev,
-			    struct comedi_subdevice *s,
-			    struct comedi_insn *insn, unsigned int *data);
-static int das16m1_di_rbits(struct comedi_device *dev,
-			    struct comedi_subdevice *s,
-			    struct comedi_insn *insn, unsigned int *data);
-static int das16m1_ai_rinsn(struct comedi_device *dev,
-			    struct comedi_subdevice *s,
-			    struct comedi_insn *insn, unsigned int *data);
-
-static int das16m1_cmd_test(struct comedi_device *dev,
-			    struct comedi_subdevice *s, struct comedi_cmd *cmd);
-static int das16m1_cmd_exec(struct comedi_device *dev,
-			    struct comedi_subdevice *s);
-static int das16m1_cancel(struct comedi_device *dev,
-			  struct comedi_subdevice *s);
-
-static int das16m1_poll(struct comedi_device *dev, struct comedi_subdevice *s);
-static irqreturn_t das16m1_interrupt(int irq, void *d);
-static void das16m1_handler(struct comedi_device *dev, unsigned int status);
-
-static unsigned int das16m1_set_pacer(struct comedi_device *dev,
-				      unsigned int ns, int round_flag);
-
-static int das16m1_irq_bits(unsigned int irq);
-
 struct das16m1_board {
 	const char *name;
 	unsigned int ai_speed;
 };
 
-static const struct das16m1_board das16m1_boards[] = {
-	{
-	 .name = "cio-das16/m1",	/*  CIO-DAS16_M1.pdf */
-	 .ai_speed = 1000,	/*  1MHz max speed */
-	 },
-};
-
-static int das16m1_attach(struct comedi_device *dev,
-			  struct comedi_devconfig *it);
-static int das16m1_detach(struct comedi_device *dev);
-static struct comedi_driver driver_das16m1 = {
-	.driver_name = "das16m1",
-	.module = THIS_MODULE,
-	.attach = das16m1_attach,
-	.detach = das16m1_detach,
-	.board_name = &das16m1_boards[0].name,
-	.num_names = ARRAY_SIZE(das16m1_boards),
-	.offset = sizeof(das16m1_boards[0]),
-};
-
 struct das16m1_private_struct {
 	unsigned int control_state;
 	volatile unsigned int adc_count;	/*  number of samples completed */
@@ -198,22 +152,17 @@ struct das16m1_private_struct {
 #define devpriv ((struct das16m1_private_struct *)(dev->private))
 #define thisboard ((const struct das16m1_board *)(dev->board_ptr))
 
-static int __init driver_das16m1_init_module(void)
+static inline short munge_sample(short data)
 {
-	return comedi_driver_register(&driver_das16m1);
+	return (data >> 4) & 0xfff;
 }
 
-static void __exit driver_das16m1_cleanup_module(void)
+static void munge_sample_array(short *array, unsigned int num_elements)
 {
-	comedi_driver_unregister(&driver_das16m1);
-}
-
-module_init(driver_das16m1_init_module);
-module_exit(driver_das16m1_cleanup_module);
+	unsigned int i;
 
-static inline short munge_sample(short data)
-{
-	return (data >> 4) & 0xfff;
+	for (i = 0; i < num_elements; i++)
+		array[i] = munge_sample(array[i]);
 }
 
 static int das16m1_cmd_test(struct comedi_device *dev,
@@ -340,6 +289,25 @@ static int das16m1_cmd_test(struct comedi_device *dev,
 	return 0;
 }
 
+/* This function takes a time in nanoseconds and sets the     *
+ * 2 pacer clocks to the closest frequency possible. It also  *
+ * returns the actual sampling period.                        */
+static unsigned int das16m1_set_pacer(struct comedi_device *dev,
+				      unsigned int ns, int rounding_flags)
+{
+	i8253_cascade_ns_to_timer_2div(DAS16M1_XTAL, &(devpriv->divisor1),
+				       &(devpriv->divisor2), &ns,
+				       rounding_flags & TRIG_ROUND_MASK);
+
+	/* Write the values of ctr1 and ctr2 into counters 1 and 2 */
+	i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 1, devpriv->divisor1,
+		   2);
+	i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 2, devpriv->divisor2,
+		   2);
+
+	return ns;
+}
+
 static int das16m1_cmd_exec(struct comedi_device *dev,
 			    struct comedi_subdevice *s)
 {
@@ -484,57 +452,6 @@ static int das16m1_do_wbits(struct comedi_device *dev,
 	return 2;
 }
 
-static int das16m1_poll(struct comedi_device *dev, struct comedi_subdevice *s)
-{
-	unsigned long flags;
-	unsigned int status;
-
-	/*  prevent race with interrupt handler */
-	spin_lock_irqsave(&dev->spinlock, flags);
-	status = inb(dev->iobase + DAS16M1_CS);
-	das16m1_handler(dev, status);
-	spin_unlock_irqrestore(&dev->spinlock, flags);
-
-	return s->async->buf_write_count - s->async->buf_read_count;
-}
-
-static irqreturn_t das16m1_interrupt(int irq, void *d)
-{
-	int status;
-	struct comedi_device *dev = d;
-
-	if (dev->attached == 0) {
-		comedi_error(dev, "premature interrupt");
-		return IRQ_HANDLED;
-	}
-	/*  prevent race with comedi_poll() */
-	spin_lock(&dev->spinlock);
-
-	status = inb(dev->iobase + DAS16M1_CS);
-
-	if ((status & (IRQDATA | OVRUN)) == 0) {
-		comedi_error(dev, "spurious interrupt");
-		spin_unlock(&dev->spinlock);
-		return IRQ_NONE;
-	}
-
-	das16m1_handler(dev, status);
-
-	/* clear interrupt */
-	outb(0, dev->iobase + DAS16M1_CLEAR_INTR);
-
-	spin_unlock(&dev->spinlock);
-	return IRQ_HANDLED;
-}
-
-static void munge_sample_array(short *array, unsigned int num_elements)
-{
-	unsigned int i;
-
-	for (i = 0; i < num_elements; i++)
-		array[i] = munge_sample(array[i]);
-}
-
 static void das16m1_handler(struct comedi_device *dev, unsigned int status)
 {
 	struct comedi_subdevice *s;
@@ -596,23 +513,47 @@ static void das16m1_handler(struct comedi_device *dev, unsigned int status)
 
 }
 
-/* This function takes a time in nanoseconds and sets the     *
- * 2 pacer clocks to the closest frequency possible. It also  *
- * returns the actual sampling period.                        */
-static unsigned int das16m1_set_pacer(struct comedi_device *dev,
-				      unsigned int ns, int rounding_flags)
+static int das16m1_poll(struct comedi_device *dev, struct comedi_subdevice *s)
 {
-	i8253_cascade_ns_to_timer_2div(DAS16M1_XTAL, &(devpriv->divisor1),
-				       &(devpriv->divisor2), &ns,
-				       rounding_flags & TRIG_ROUND_MASK);
+	unsigned long flags;
+	unsigned int status;
 
-	/* Write the values of ctr1 and ctr2 into counters 1 and 2 */
-	i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 1, devpriv->divisor1,
-		   2);
-	i8254_load(dev->iobase + DAS16M1_8254_SECOND, 0, 2, devpriv->divisor2,
-		   2);
+	/*  prevent race with interrupt handler */
+	spin_lock_irqsave(&dev->spinlock, flags);
+	status = inb(dev->iobase + DAS16M1_CS);
+	das16m1_handler(dev, status);
+	spin_unlock_irqrestore(&dev->spinlock, flags);
 
-	return ns;
+	return s->async->buf_write_count - s->async->buf_read_count;
+}
+
+static irqreturn_t das16m1_interrupt(int irq, void *d)
+{
+	int status;
+	struct comedi_device *dev = d;
+
+	if (dev->attached == 0) {
+		comedi_error(dev, "premature interrupt");
+		return IRQ_HANDLED;
+	}
+	/*  prevent race with comedi_poll() */
+	spin_lock(&dev->spinlock);
+
+	status = inb(dev->iobase + DAS16M1_CS);
+
+	if ((status & (IRQDATA | OVRUN)) == 0) {
+		comedi_error(dev, "spurious interrupt");
+		spin_unlock(&dev->spinlock);
+		return IRQ_NONE;
+	}
+
+	das16m1_handler(dev, status);
+
+	/* clear interrupt */
+	outb(0, dev->iobase + DAS16M1_CLEAR_INTR);
+
+	spin_unlock(&dev->spinlock);
+	return IRQ_HANDLED;
 }
 
 static int das16m1_irq_bits(unsigned int irq)
@@ -656,7 +597,6 @@ static int das16m1_irq_bits(unsigned int irq)
  *   0  I/O base
  *   1  IRQ
  */
-
 static int das16m1_attach(struct comedi_device *dev,
 			  struct comedi_devconfig *it)
 {
@@ -673,12 +613,12 @@ static int das16m1_attach(struct comedi_device *dev,
 
 	dev->board_name = thisboard->name;
 
-	if (!request_region(iobase, DAS16M1_SIZE, driver_das16m1.driver_name)) {
+	if (!request_region(iobase, DAS16M1_SIZE, dev->driver->driver_name)) {
 		comedi_error(dev, "I/O port conflict\n");
 		return -EIO;
 	}
 	if (!request_region(iobase + DAS16M1_82C55, DAS16M1_SIZE2,
-			    driver_das16m1.driver_name)) {
+			    dev->driver->driver_name)) {
 		release_region(iobase, DAS16M1_SIZE);
 		comedi_error(dev, "I/O port conflict\n");
 		return -EIO;
@@ -690,7 +630,7 @@ static int das16m1_attach(struct comedi_device *dev,
 	/*  make sure it is valid */
 	if (das16m1_irq_bits(irq) >= 0) {
 		ret = request_irq(irq, das16m1_interrupt, 0,
-				  driver_das16m1.driver_name, dev);
+				  dev->driver->driver_name, dev);
 		if (ret < 0)
 			return ret;
 		dev->irq = irq;
@@ -782,6 +722,24 @@ static int das16m1_detach(struct comedi_device *dev)
 	return 0;
 }
 
+static const struct das16m1_board das16m1_boards[] = {
+	{
+		.name		= "cio-das16/m1",	/*  CIO-DAS16_M1.pdf */
+		.ai_speed	= 1000,			/*  1MHz max speed */
+	},
+};
+
+static struct comedi_driver das16m1_driver = {
+	.driver_name	= "das16m1",
+	.module		= THIS_MODULE,
+	.attach		= das16m1_attach,
+	.detach		= das16m1_detach,
+	.board_name	= &das16m1_boards[0].name,
+	.num_names	= ARRAY_SIZE(das16m1_boards),
+	.offset		= sizeof(das16m1_boards[0]),
+};
+module_comedi_driver(das16m1_driver);
+
 MODULE_AUTHOR("Comedi http://www.comedi.org");
 MODULE_DESCRIPTION("Comedi low-level driver");
 MODULE_LICENSE("GPL");