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staging: comedi: refactor pcmuio driver to remove forward declarations

PATCH New H Hartley Sweeten 1 participant 1 message Apr 27, 2012 Staging

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PATCH 1/1 staging: comedi: refactor pcmuio driver to remove forward declarations

Refactor the switch_page and pcmuio_stop_intr functions to avoid needing the forward declarations.

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

Cc Ian Abbott <[email protected]>
Cc Mori Hess <[email protected]>
Cc Greg Kroah-Hartman <[email protected]>

---

drivers/staging/comedi/drivers/pcmuio.c +240 -309
index 661ba2e..de4f486 100644
@@ -155,19 +155,6 @@ struct pcmuio_board {
 	const int num_ports;
 };
 
-static const struct pcmuio_board pcmuio_boards[] = {
-	{
-	 .name = "pcmuio48",
-	 .num_asics = 1,
-	 .num_ports = 6,
-	 },
-	{
-	 .name = "pcmuio96",
-	 .num_asics = 2,
-	 .num_ports = 12,
-	 },
-};
-
 /*
  * Useful for shorthand access to the particular board structure
  */
@@ -218,262 +205,6 @@ struct pcmuio_private {
  */
 #define devpriv ((struct pcmuio_private *)dev->private)
 #define subpriv ((struct pcmuio_subdev_private *)s->private)
-/*
- * The struct comedi_driver structure tells the Comedi core module
- * which functions to call to configure/deconfigure (attach/detach)
- * the board, and also about the kernel module that contains
- * the device code.
- */
-static int pcmuio_attach(struct comedi_device *dev,
-			 struct comedi_devconfig *it);
-static int pcmuio_detach(struct comedi_device *dev);
-
-static struct comedi_driver driver = {
-	.driver_name = "pcmuio",
-	.module = THIS_MODULE,
-	.attach = pcmuio_attach,
-	.detach = pcmuio_detach,
-/* It is not necessary to implement the following members if you are
- * writing a driver for a ISA PnP or PCI card */
-	/* Most drivers will support multiple types of boards by
-	 * having an array of board structures.  These were defined
-	 * in pcmuio_boards[] above.  Note that the element 'name'
-	 * was first in the structure -- Comedi uses this fact to
-	 * extract the name of the board without knowing any details
-	 * about the structure except for its length.
-	 * When a device is attached (by comedi_config), the name
-	 * of the device is given to Comedi, and Comedi tries to
-	 * match it by going through the list of board names.  If
-	 * there is a match, the address of the pointer is put
-	 * into dev->board_ptr and driver->attach() is called.
-	 *
-	 * Note that these are not necessary if you can determine
-	 * the type of board in software.  ISA PnP, PCI, and PCMCIA
-	 * devices are such boards.
-	 */
-	.board_name = &pcmuio_boards[0].name,
-	.offset = sizeof(struct pcmuio_board),
-	.num_names = ARRAY_SIZE(pcmuio_boards),
-};
-
-static int pcmuio_dio_insn_bits(struct comedi_device *dev,
-				struct comedi_subdevice *s,
-				struct comedi_insn *insn, unsigned int *data);
-static int pcmuio_dio_insn_config(struct comedi_device *dev,
-				  struct comedi_subdevice *s,
-				  struct comedi_insn *insn, unsigned int *data);
-
-static irqreturn_t interrupt_pcmuio(int irq, void *d);
-static void pcmuio_stop_intr(struct comedi_device *, struct comedi_subdevice *);
-static int pcmuio_cancel(struct comedi_device *dev, struct comedi_subdevice *s);
-static int pcmuio_cmd(struct comedi_device *dev, struct comedi_subdevice *s);
-static int pcmuio_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
-			  struct comedi_cmd *cmd);
-
-/* some helper functions to deal with specifics of this device's registers */
-static void init_asics(struct comedi_device *dev);	/* sets up/clears ASIC chips to defaults */
-static void switch_page(struct comedi_device *dev, int asic, int page);
-#ifdef notused
-static void lock_port(struct comedi_device *dev, int asic, int port);
-static void unlock_port(struct comedi_device *dev, int asic, int port);
-#endif
-
-/*
- * Attach is called by the Comedi core to configure the driver
- * for a particular board.  If you specified a board_name array
- * in the driver structure, dev->board_ptr contains that
- * address.
- */
-static int pcmuio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
-{
-	struct comedi_subdevice *s;
-	int sdev_no, chans_left, n_subdevs, port, asic, thisasic_chanct = 0;
-	unsigned long iobase;
-	unsigned int irq[MAX_ASICS];
-
-	iobase = it->options[0];
-	irq[0] = it->options[1];
-	irq[1] = it->options[2];
-
-	dev_dbg(dev->hw_dev, "comedi%d: %s: io: %lx attached\n", dev->minor,
-		driver.driver_name, iobase);
-
-	dev->iobase = iobase;
-
-	if (!iobase || !request_region(iobase,
-				       thisboard->num_asics * ASIC_IOSIZE,
-				       driver.driver_name)) {
-		dev_err(dev->hw_dev, "I/O port conflict\n");
-		return -EIO;
-	}
-
-/*
- * Initialize dev->board_name.  Note that we can use the "thisboard"
- * macro now, since we just initialized it in the last line.
- */
-	dev->board_name = thisboard->name;
-
-/*
- * Allocate the private structure area.  alloc_private() is a
- * convenient macro defined in comedidev.h.
- */
-	if (alloc_private(dev, sizeof(struct pcmuio_private)) < 0) {
-		dev_warn(dev->hw_dev, "cannot allocate private data structure\n");
-		return -ENOMEM;
-	}
-
-	for (asic = 0; asic < MAX_ASICS; ++asic) {
-		devpriv->asics[asic].num = asic;
-		devpriv->asics[asic].iobase = dev->iobase + asic * ASIC_IOSIZE;
-		devpriv->asics[asic].irq = 0;	/* this gets actually set at the end of
-						   this function when we
-						   request_irqs */
-		spin_lock_init(&devpriv->asics[asic].spinlock);
-	}
-
-	chans_left = CHANS_PER_ASIC * thisboard->num_asics;
-	n_subdevs = CALC_N_SUBDEVS(chans_left);
-	devpriv->sprivs =
-	    kcalloc(n_subdevs, sizeof(struct pcmuio_subdev_private),
-		    GFP_KERNEL);
-	if (!devpriv->sprivs) {
-		dev_warn(dev->hw_dev, "cannot allocate subdevice private data structures\n");
-		return -ENOMEM;
-	}
-	/*
-	 * Allocate the subdevice structures.  alloc_subdevice() is a
-	 * convenient macro defined in comedidev.h.
-	 *
-	 * Allocate 2 subdevs (32 + 16 DIO lines) or 3 32 DIO subdevs for the
-	 * 96-channel version of the board.
-	 */
-	if (alloc_subdevices(dev, n_subdevs) < 0) {
-		dev_dbg(dev->hw_dev, "cannot allocate subdevice data structures\n");
-		return -ENOMEM;
-	}
-
-	port = 0;
-	asic = 0;
-	for (sdev_no = 0; sdev_no < (int)dev->n_subdevices; ++sdev_no) {
-		int byte_no;
-
-		s = dev->subdevices + sdev_no;
-		s->private = devpriv->sprivs + sdev_no;
-		s->maxdata = 1;
-		s->range_table = &range_digital;
-		s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
-		s->type = COMEDI_SUBD_DIO;
-		s->insn_bits = pcmuio_dio_insn_bits;
-		s->insn_config = pcmuio_dio_insn_config;
-		s->n_chan = min(chans_left, MAX_CHANS_PER_SUBDEV);
-		subpriv->intr.asic = -1;
-		subpriv->intr.first_chan = -1;
-		subpriv->intr.asic_chan = -1;
-		subpriv->intr.num_asic_chans = -1;
-		subpriv->intr.active = 0;
-		s->len_chanlist = 1;
-
-		/* save the ioport address for each 'port' of 8 channels in the
-		   subdevice */
-		for (byte_no = 0; byte_no < PORTS_PER_SUBDEV; ++byte_no, ++port) {
-			if (port >= PORTS_PER_ASIC) {
-				port = 0;
-				++asic;
-				thisasic_chanct = 0;
-			}
-			subpriv->iobases[byte_no] =
-			    devpriv->asics[asic].iobase + port;
-
-			if (thisasic_chanct <
-			    CHANS_PER_PORT * INTR_PORTS_PER_ASIC
-			    && subpriv->intr.asic < 0) {
-				/* this is an interrupt subdevice, so setup the struct */
-				subpriv->intr.asic = asic;
-				subpriv->intr.active = 0;
-				subpriv->intr.stop_count = 0;
-				subpriv->intr.first_chan = byte_no * 8;
-				subpriv->intr.asic_chan = thisasic_chanct;
-				subpriv->intr.num_asic_chans =
-				    s->n_chan - subpriv->intr.first_chan;
-				dev->read_subdev = s;
-				s->subdev_flags |= SDF_CMD_READ;
-				s->cancel = pcmuio_cancel;
-				s->do_cmd = pcmuio_cmd;
-				s->do_cmdtest = pcmuio_cmdtest;
-				s->len_chanlist = subpriv->intr.num_asic_chans;
-			}
-			thisasic_chanct += CHANS_PER_PORT;
-		}
-		spin_lock_init(&subpriv->intr.spinlock);
-
-		chans_left -= s->n_chan;
-
-		if (!chans_left) {
-			asic = 0;	/* reset the asic to our first asic, to do intr subdevs */
-			port = 0;
-		}
-
-	}
-
-	init_asics(dev);	/* clear out all the registers, basically */
-
-	for (asic = 0; irq[0] && asic < MAX_ASICS; ++asic) {
-		if (irq[asic]
-		    && request_irq(irq[asic], interrupt_pcmuio,
-				   IRQF_SHARED, thisboard->name, dev)) {
-			int i;
-			/* unroll the allocated irqs.. */
-			for (i = asic - 1; i >= 0; --i) {
-				free_irq(irq[i], dev);
-				devpriv->asics[i].irq = irq[i] = 0;
-			}
-			irq[asic] = 0;
-		}
-		devpriv->asics[asic].irq = irq[asic];
-	}
-
-	dev->irq = irq[0];	/* grr.. wish comedi dev struct supported multiple
-				   irqs.. */
-
-	if (irq[0]) {
-		dev_dbg(dev->hw_dev, "irq: %u\n", irq[0]);
-		if (irq[1] && thisboard->num_asics == 2)
-			dev_dbg(dev->hw_dev, "second ASIC irq: %u\n", irq[1]);
-	} else {
-		dev_dbg(dev->hw_dev, "(IRQ mode disabled)\n");
-	}
-
-
-	return 1;
-}
-
-/*
- * _detach is called to deconfigure a device.  It should deallocate
- * resources.
- * This function is also called when _attach() fails, so it should be
- * careful not to release resources that were not necessarily
- * allocated by _attach().  dev->private and dev->subdevices are
- * deallocated automatically by the core.
- */
-static int pcmuio_detach(struct comedi_device *dev)
-{
-	int i;
-
-	dev_dbg(dev->hw_dev, "comedi%d: %s: remove\n", dev->minor,
-		driver.driver_name);
-	if (dev->iobase)
-		release_region(dev->iobase, ASIC_IOSIZE * thisboard->num_asics);
-
-	for (i = 0; i < MAX_ASICS; ++i) {
-		if (devpriv->asics[i].irq)
-			free_irq(devpriv->asics[i].irq, dev);
-	}
-
-	if (devpriv && devpriv->sprivs)
-		kfree(devpriv->sprivs);
-
-	return 0;
-}
 
 /* DIO devices are slightly special.  Although it is possible to
  * implement the insn_read/insn_write interface, it is much more
@@ -621,6 +352,21 @@ static int pcmuio_dio_insn_config(struct comedi_device *dev,
 	return insn->n;
 }
 
+static void switch_page(struct comedi_device *dev, int asic, int page)
+{
+	if (asic < 0 || asic >= thisboard->num_asics)
+		return;		/* paranoia */
+	if (page < 0 || page >= NUM_PAGES)
+		return;		/* more paranoia */
+
+	devpriv->asics[asic].pagelock &= ~REG_PAGE_MASK;
+	devpriv->asics[asic].pagelock |= page << REG_PAGE_BITOFFSET;
+
+	/* now write out the shadow register */
+	outb(devpriv->asics[asic].pagelock,
+	     dev->iobase + ASIC_IOSIZE * asic + REG_PAGELOCK);
+}
+
 static void init_asics(struct comedi_device *dev)
 {				/* sets up an
 				   ASIC chip to defaults */
@@ -658,21 +404,6 @@ static void init_asics(struct comedi_device *dev)
 	}
 }
 
-static void switch_page(struct comedi_device *dev, int asic, int page)
-{
-	if (asic < 0 || asic >= thisboard->num_asics)
-		return;		/* paranoia */
-	if (page < 0 || page >= NUM_PAGES)
-		return;		/* more paranoia */
-
-	devpriv->asics[asic].pagelock &= ~REG_PAGE_MASK;
-	devpriv->asics[asic].pagelock |= page << REG_PAGE_BITOFFSET;
-
-	/* now write out the shadow register */
-	outb(devpriv->asics[asic].pagelock,
-	     dev->iobase + ASIC_IOSIZE * asic + REG_PAGELOCK);
-}
-
 #ifdef notused
 static void lock_port(struct comedi_device *dev, int asic, int port)
 {
@@ -700,6 +431,27 @@ static void unlock_port(struct comedi_device *dev, int asic, int port)
 }
 #endif /* notused */
 
+static void pcmuio_stop_intr(struct comedi_device *dev,
+			     struct comedi_subdevice *s)
+{
+	int nports, firstport, asic, port;
+
+	asic = subpriv->intr.asic;
+	if (asic < 0)
+		return;		/* not an interrupt subdev */
+
+	subpriv->intr.enabled_mask = 0;
+	subpriv->intr.active = 0;
+	s->async->inttrig = 0;
+	nports = subpriv->intr.num_asic_chans / CHANS_PER_PORT;
+	firstport = subpriv->intr.asic_chan / CHANS_PER_PORT;
+	switch_page(dev, asic, PAGE_ENAB);
+	for (port = firstport; port < firstport + nports; ++port) {
+		/* disable all intrs for this subdev.. */
+		outb(0, devpriv->asics[asic].iobase + REG_ENAB0 + port);
+	}
+}
+
 static irqreturn_t interrupt_pcmuio(int irq, void *d)
 {
 	int asic, got1 = 0;
@@ -852,27 +604,6 @@ static irqreturn_t interrupt_pcmuio(int irq, void *d)
 	return IRQ_HANDLED;
 }
 
-static void pcmuio_stop_intr(struct comedi_device *dev,
-			     struct comedi_subdevice *s)
-{
-	int nports, firstport, asic, port;
-
-	asic = subpriv->intr.asic;
-	if (asic < 0)
-		return;		/* not an interrupt subdev */
-
-	subpriv->intr.enabled_mask = 0;
-	subpriv->intr.active = 0;
-	s->async->inttrig = 0;
-	nports = subpriv->intr.num_asic_chans / CHANS_PER_PORT;
-	firstport = subpriv->intr.asic_chan / CHANS_PER_PORT;
-	switch_page(dev, asic, PAGE_ENAB);
-	for (port = firstport; port < firstport + nports; ++port) {
-		/* disable all intrs for this subdev.. */
-		outb(0, devpriv->asics[asic].iobase + REG_ENAB0 + port);
-	}
-}
-
 static int pcmuio_start_intr(struct comedi_device *dev,
 			     struct comedi_subdevice *s)
 {
@@ -1014,21 +745,221 @@ pcmuio_cmdtest(struct comedi_device *dev, struct comedi_subdevice *s,
 	return comedi_pcm_cmdtest(dev, s, cmd);
 }
 
+static int pcmuio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
+{
+	struct comedi_subdevice *s;
+	int sdev_no, chans_left, n_subdevs, port, asic, thisasic_chanct = 0;
+	unsigned long iobase;
+	unsigned int irq[MAX_ASICS];
+
+	iobase = it->options[0];
+	irq[0] = it->options[1];
+	irq[1] = it->options[2];
+
+	dev_dbg(dev->hw_dev, "comedi%d: %s: io: %lx attached\n", dev->minor,
+		driver.driver_name, iobase);
+
+	dev->iobase = iobase;
+
+	if (!iobase || !request_region(iobase,
+				       thisboard->num_asics * ASIC_IOSIZE,
+				       driver.driver_name)) {
+		dev_err(dev->hw_dev, "I/O port conflict\n");
+		return -EIO;
+	}
+
 /*
- * A convenient macro that defines init_module() and cleanup_module(),
- * as necessary.
+ * Initialize dev->board_name.  Note that we can use the "thisboard"
+ * macro now, since we just initialized it in the last line.
+ */
+	dev->board_name = thisboard->name;
+
+/*
+ * Allocate the private structure area.  alloc_private() is a
+ * convenient macro defined in comedidev.h.
  */
+	if (alloc_private(dev, sizeof(struct pcmuio_private)) < 0) {
+		dev_warn(dev->hw_dev, "cannot allocate private data structure\n");
+		return -ENOMEM;
+	}
+
+	for (asic = 0; asic < MAX_ASICS; ++asic) {
+		devpriv->asics[asic].num = asic;
+		devpriv->asics[asic].iobase = dev->iobase + asic * ASIC_IOSIZE;
+		devpriv->asics[asic].irq = 0;	/* this gets actually set at the end of
+						   this function when we
+						   request_irqs */
+		spin_lock_init(&devpriv->asics[asic].spinlock);
+	}
+
+	chans_left = CHANS_PER_ASIC * thisboard->num_asics;
+	n_subdevs = CALC_N_SUBDEVS(chans_left);
+	devpriv->sprivs =
+	    kcalloc(n_subdevs, sizeof(struct pcmuio_subdev_private),
+		    GFP_KERNEL);
+	if (!devpriv->sprivs) {
+		dev_warn(dev->hw_dev, "cannot allocate subdevice private data structures\n");
+		return -ENOMEM;
+	}
+	/*
+	 * Allocate the subdevice structures.  alloc_subdevice() is a
+	 * convenient macro defined in comedidev.h.
+	 *
+	 * Allocate 2 subdevs (32 + 16 DIO lines) or 3 32 DIO subdevs for the
+	 * 96-channel version of the board.
+	 */
+	if (alloc_subdevices(dev, n_subdevs) < 0) {
+		dev_dbg(dev->hw_dev, "cannot allocate subdevice data structures\n");
+		return -ENOMEM;
+	}
+
+	port = 0;
+	asic = 0;
+	for (sdev_no = 0; sdev_no < (int)dev->n_subdevices; ++sdev_no) {
+		int byte_no;
+
+		s = dev->subdevices + sdev_no;
+		s->private = devpriv->sprivs + sdev_no;
+		s->maxdata = 1;
+		s->range_table = &range_digital;
+		s->subdev_flags = SDF_READABLE | SDF_WRITABLE;
+		s->type = COMEDI_SUBD_DIO;
+		s->insn_bits = pcmuio_dio_insn_bits;
+		s->insn_config = pcmuio_dio_insn_config;
+		s->n_chan = min(chans_left, MAX_CHANS_PER_SUBDEV);
+		subpriv->intr.asic = -1;
+		subpriv->intr.first_chan = -1;
+		subpriv->intr.asic_chan = -1;
+		subpriv->intr.num_asic_chans = -1;
+		subpriv->intr.active = 0;
+		s->len_chanlist = 1;
+
+		/* save the ioport address for each 'port' of 8 channels in the
+		   subdevice */
+		for (byte_no = 0; byte_no < PORTS_PER_SUBDEV; ++byte_no, ++port) {
+			if (port >= PORTS_PER_ASIC) {
+				port = 0;
+				++asic;
+				thisasic_chanct = 0;
+			}
+			subpriv->iobases[byte_no] =
+			    devpriv->asics[asic].iobase + port;
+
+			if (thisasic_chanct <
+			    CHANS_PER_PORT * INTR_PORTS_PER_ASIC
+			    && subpriv->intr.asic < 0) {
+				/* this is an interrupt subdevice, so setup the struct */
+				subpriv->intr.asic = asic;
+				subpriv->intr.active = 0;
+				subpriv->intr.stop_count = 0;
+				subpriv->intr.first_chan = byte_no * 8;
+				subpriv->intr.asic_chan = thisasic_chanct;
+				subpriv->intr.num_asic_chans =
+				    s->n_chan - subpriv->intr.first_chan;
+				dev->read_subdev = s;
+				s->subdev_flags |= SDF_CMD_READ;
+				s->cancel = pcmuio_cancel;
+				s->do_cmd = pcmuio_cmd;
+				s->do_cmdtest = pcmuio_cmdtest;
+				s->len_chanlist = subpriv->intr.num_asic_chans;
+			}
+			thisasic_chanct += CHANS_PER_PORT;
+		}
+		spin_lock_init(&subpriv->intr.spinlock);
+
+		chans_left -= s->n_chan;
+
+		if (!chans_left) {
+			asic = 0;	/* reset the asic to our first asic, to do intr subdevs */
+			port = 0;
+		}
+
+	}
+
+	init_asics(dev);	/* clear out all the registers, basically */
+
+	for (asic = 0; irq[0] && asic < MAX_ASICS; ++asic) {
+		if (irq[asic]
+		    && request_irq(irq[asic], interrupt_pcmuio,
+				   IRQF_SHARED, thisboard->name, dev)) {
+			int i;
+			/* unroll the allocated irqs.. */
+			for (i = asic - 1; i >= 0; --i) {
+				free_irq(irq[i], dev);
+				devpriv->asics[i].irq = irq[i] = 0;
+			}
+			irq[asic] = 0;
+		}
+		devpriv->asics[asic].irq = irq[asic];
+	}
+
+	dev->irq = irq[0];	/* grr.. wish comedi dev struct supported multiple
+				   irqs.. */
+
+	if (irq[0]) {
+		dev_dbg(dev->hw_dev, "irq: %u\n", irq[0]);
+		if (irq[1] && thisboard->num_asics == 2)
+			dev_dbg(dev->hw_dev, "second ASIC irq: %u\n", irq[1]);
+	} else {
+		dev_dbg(dev->hw_dev, "(IRQ mode disabled)\n");
+	}
+
+
+	return 1;
+}
+
+static int pcmuio_detach(struct comedi_device *dev)
+{
+	int i;
+
+	dev_dbg(dev->hw_dev, "comedi%d: %s: remove\n", dev->minor,
+		driver.driver_name);
+	if (dev->iobase)
+		release_region(dev->iobase, ASIC_IOSIZE * thisboard->num_asics);
+
+	for (i = 0; i < MAX_ASICS; ++i) {
+		if (devpriv->asics[i].irq)
+			free_irq(devpriv->asics[i].irq, dev);
+	}
+
+	if (devpriv && devpriv->sprivs)
+		kfree(devpriv->sprivs);
+
+	return 0;
+}
+
+static const struct pcmuio_board pcmuio_boards[] = {
+	{
+		.name		= "pcmuio48",
+		.num_asics	= 1,
+		.num_ports	= 6,
+	}, {
+		.name		= "pcmuio96",
+		.num_asics	= 2,
+		.num_ports	= 12,
+	},
+};
+
+static struct comedi_driver driver = {
+	.driver_name	= "pcmuio",
+	.module		= THIS_MODULE,
+	.attach		= pcmuio_attach,
+	.detach		= pcmuio_detach,
+	.board_name	= &pcmuio_boards[0].name,
+	.offset		= sizeof(struct pcmuio_board),
+	.num_names	= ARRAY_SIZE(pcmuio_boards),
+};
+
 static int __init driver_init_module(void)
 {
 	return comedi_driver_register(&driver);
 }
+module_init(driver_init_module);
 
 static void __exit driver_cleanup_module(void)
 {
 	comedi_driver_unregister(&driver);
 }
-
-module_init(driver_init_module);
 module_exit(driver_cleanup_module);
 
 MODULE_AUTHOR("Comedi http://www.comedi.org");