staging: comedi: cb_pcidas: use attach_pci callback

Convert this PCI driver to use the comedi PCI auto config attach
mechanism by adding an 'attach_pci' callback function. Since the
driver does not require any external configuration options, and
the legacy 'attach' callback is now optional, remove it.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/cb_pcidas.c

@@ -45,11 +45,7 @@ Devices: [Measurement Computing] PCI-DAS1602/16 (cb_pcidas),
   The boards may be autocalibrated using the comedi_calibrate
   utility.
 
-Configuration options:
-  [0] - PCI bus of device (optional)
-  [1] - PCI slot of device (optional)
-  If bus/slot is not specified, the first supported
-  PCI device found will be used.
+Configuration options: not applicable, uses PCI auto config
 
 For commands, the scanned channels must be consecutive
 (i.e. 4-5-6-7, 2-3-4,...), and must all have the same
@@ -1501,69 +1497,45 @@ static irqreturn_t cb_pcidas_interrupt(int irq, void *d)
 	return IRQ_HANDLED;
 }
 
-static struct pci_dev *cb_pcidas_find_pci_device(struct comedi_device *dev,
-						 struct comedi_devconfig *it)
+static const void *cb_pcidas_find_boardinfo(struct comedi_device *dev,
+					    struct pci_dev *pcidev)
 {
 	const struct cb_pcidas_board *thisboard;
-	struct pci_dev *pcidev = NULL;
-	int bus = it->options[0];
-	int slot = it->options[1];
 	int i;
 
-	for_each_pci_dev(pcidev) {
-		/*  is it not a computer boards card? */
-		if (pcidev->vendor != PCI_VENDOR_ID_CB)
-			continue;
-		/*  loop through cards supported by this driver */
 	for (i = 0; i < ARRAY_SIZE(cb_pcidas_boards); i++) {
 		thisboard = &cb_pcidas_boards[i];
-			if (thisboard->device_id != pcidev->device)
-				continue;
-			/*  was a particular bus/slot requested? */
-			if (bus || slot) {
-				/*  are we on the wrong bus/slot? */
-				if (pcidev->bus->number != bus ||
-				    PCI_SLOT(pcidev->devfn) != slot) {
-					continue;
+		if (thisboard->device_id == pcidev->device)
+			return thisboard;
 	}
-			}
-			dev_dbg(dev->class_dev,
-				"Found %s on bus %i, slot %i\n",
-				thisboard->name,
-				pcidev->bus->number, PCI_SLOT(pcidev->devfn));
-			dev->board_ptr = thisboard;
-			return pcidev;
-		}
-	}
-	dev_err(dev->class_dev, "No supported card found\n");
 	return NULL;
 }
 
-static int cb_pcidas_attach(struct comedi_device *dev,
-			    struct comedi_devconfig *it)
+static int cb_pcidas_attach_pci(struct comedi_device *dev,
+				struct pci_dev *pcidev)
 {
 	const struct cb_pcidas_board *thisboard;
 	struct cb_pcidas_private *devpriv;
-	struct pci_dev *pcidev;
 	struct comedi_subdevice *s;
 	int i;
 	int ret;
 
-	if (alloc_private(dev, sizeof(struct cb_pcidas_private)) < 0)
-		return -ENOMEM;
-	devpriv = dev->private;
-
-	pcidev = cb_pcidas_find_pci_device(dev, it);
-	if (!pcidev)
-		return -EIO;
 	comedi_set_hw_dev(dev, &pcidev->dev);
-	thisboard = comedi_board(dev);
 
-	if (comedi_pci_enable(pcidev, dev->driver->driver_name)) {
-		dev_err(dev->class_dev,
-			"Failed to enable PCI device and request regions\n");
-		return -EIO;
-	}
+	thisboard = cb_pcidas_find_boardinfo(dev, pcidev);
+	if (!thisboard)
+		return -ENODEV;
+	dev->board_ptr  = thisboard;
+	dev->board_name = thisboard->name;
+
+	ret = alloc_private(dev, sizeof(*devpriv));
+	if (ret)
+		return ret;
+	devpriv = dev->private;
+
+	ret = comedi_pci_enable(pcidev, dev->board_name);
+	if (ret)
+		return ret;
 
 	devpriv->s5933_config = pci_resource_start(pcidev, 0);
 	devpriv->control_status = pci_resource_start(pcidev, 1);
@@ -1584,8 +1556,6 @@ static int cb_pcidas_attach(struct comedi_device *dev,
 	}
 	dev->irq = pcidev->irq;
 
-	dev->board_name = thisboard->name;
-
 	ret = comedi_alloc_subdevices(dev, 7);
 	if (ret)
 		return ret;
@@ -1698,7 +1668,10 @@ static int cb_pcidas_attach(struct comedi_device *dev,
 	outl(devpriv->s5933_intcsr_bits | INTCSR_INBOX_INTR_STATUS,
 	     devpriv->s5933_config + AMCC_OP_REG_INTCSR);
 
-	return 1;
+	dev_info(dev->class_dev, "%s: %s attached\n",
+		dev->driver->driver_name, dev->board_name);
+
+	return 0;
 }
 
 static void cb_pcidas_detach(struct comedi_device *dev)
@@ -1719,14 +1692,13 @@ static void cb_pcidas_detach(struct comedi_device *dev)
 	if (pcidev) {
 		if (devpriv->s5933_config)
 			comedi_pci_disable(pcidev);
-		pci_dev_put(pcidev);
 	}
 }
 
 static struct comedi_driver cb_pcidas_driver = {
 	.driver_name	= "cb_pcidas",
 	.module		= THIS_MODULE,
-	.attach		= cb_pcidas_attach,
+	.attach_pci	= cb_pcidas_attach_pci,
 	.detach		= cb_pcidas_detach,
 };