staging: comedi: das08: Support multiple PCI card types in future

Rename the existing board entry named "das08" for the PCI-DAS08 board to
"pci-das08".  Add a new wildcard board entry called "das08" that will
match any supported PCI board.  If 'dev->board_ptr' points to the
wildcard board entry in the ->attach() routine, it will be replaced with
a supported PCI board entry if there are any (taking into account the
bus and slot specified by the device config options passed in to the
function).

Split the code that finds a matching PCI device into a new function
das08_find_pci().
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/das08.c

@@ -32,7 +32,7 @@
  *   [ComputerBoards] DAS08 (isa-das08), DAS08-PGM (das08-pgm),
  *   DAS08-PGH (das08-pgh), DAS08-PGL (das08-pgl), DAS08-AOH (das08-aoh),
  *   DAS08-AOL (das08-aol), DAS08-AOM (das08-aom), DAS08/JR-AO (das08/jr-ao),
- *   DAS08/JR-16-AO (das08jr-16-ao), PCI-DAS08 (das08),
+ *   DAS08/JR-16-AO (das08jr-16-ao), PCI-DAS08 (pci-das08 or das08),
  *   PC104-DAS08 (pc104-das08), DAS08/JR/16 (das08jr/16)
  * Status: works
  *
@@ -765,7 +765,7 @@ static const struct das08_board_struct das08_boards[] = {
 #endif /* IS_ENABLED(CONFIG_COMEDI_DAS08_ISA) */
 #if IS_ENABLED(CONFIG_COMEDI_DAS08_PCI)
 	{
-		.name = "das08",	/*  pci-das08 */
+		.name = "pci-das08",	/*  pci-das08 */
 		.id = PCI_DEVICE_ID_PCIDAS08,
 		.bustype = pci,
 		.ai = das08_ai_rinsn,
@@ -781,6 +781,11 @@ static const struct das08_board_struct das08_boards[] = {
 		.i8254_offset = 4,
 		.iosize = 8,
 	},
+	{ /* wildcard entry matches any supported PCI device */
+		.name = DRV_NAME,
+		.id = PCI_ANY_ID,
+		.bustype = pci,
+	},
 #endif /* IS_ENABLED(CONFIG_COMEDI_DAS08_PCI) */
 };
 #endif /* DO_COMEDI_DRIVER_REGISTER */
@@ -938,6 +943,66 @@ int das08_common_attach(struct comedi_device *dev, unsigned long iobase)
 }
 EXPORT_SYMBOL_GPL(das08_common_attach);
 
+#if IS_ENABLED(CONFIG_COMEDI_DAS08_PCI)
+static struct pci_dev *das08_find_pci(struct comedi_device *dev,
+				      int bus, int slot)
+{
+	const struct das08_board_struct *thisboard = comedi_board(dev);
+	struct pci_dev *pdev;
+	unsigned int matchid;
+
+	if (bus || slot)
+		dev_dbg(dev->class_dev, "Looking for %s at PCI %02X:%02X\n",
+			thisboard->name, bus, slot);
+	else
+		dev_dbg(dev->class_dev, "Looking for %s on PCI buses\n",
+			thisboard->name);
+
+	matchid = thisboard->id;
+	pdev = NULL;
+	for_each_pci_dev(pdev) {
+		if ((bus || slot) &&
+		    (bus != pdev->bus->number || slot != PCI_SLOT(pdev->devfn)))
+			continue;
+		if (pdev->vendor != PCI_VENDOR_ID_COMPUTERBOARDS)
+			continue;
+		if (matchid == PCI_ANY_ID) {
+			/* wildcard board matches any supported PCI board */
+			unsigned int i;
+			for (i = 0; i < ARRAY_SIZE(das08_boards); i++) {
+				if (das08_boards[i].bustype != pci)
+					continue;
+				if (pdev->device == das08_boards[i].id) {
+					/* replace wildcard board_ptr */
+					dev->board_ptr = &das08_boards[i];
+					thisboard = comedi_board(dev);
+					break;
+				}
+			}
+			if (i == ARRAY_SIZE(das08_boards))
+				continue;
+		} else {
+			/* match specific PCI board */
+			if (pdev->device != matchid)
+				continue;
+		}
+		/* found a match */
+		dev_info(dev->class_dev, "Found %s at PCI %s\n",
+			 thisboard->name, pci_name(pdev));
+		return pdev;
+	}
+	/* no match found */
+	if (bus || slot)
+		dev_err(dev->class_dev,
+			"No %s cards found at PCI %02X:%02X\n",
+			thisboard->name, bus, slot);
+	else
+		dev_err(dev->class_dev, "No %s cards found on PCI buses\n",
+			thisboard->name);
+	return NULL;
+}
+#endif
+
 #ifdef DO_COMEDI_DRIVER_REGISTER
 static int das08_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 {
@@ -954,30 +1019,11 @@ static int das08_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 	dev_info(dev->class_dev, "attach\n");
 	if (IS_ENABLED(CONFIG_COMEDI_DAS08_PCI) && thisboard->bustype == pci) {
 		unsigned long pci_iobase = 0;
-		struct pci_dev *pdev = NULL;
-		if (it->options[0] || it->options[1]) {
-			dev_info(dev->class_dev, "pci bus %i slot %i\n",
-			       it->options[0], it->options[1]);
-		}
-		/*  find card */
-		for_each_pci_dev(pdev) {
-			if (pdev->vendor == PCI_VENDOR_ID_COMPUTERBOARDS
-			    && pdev->device == PCI_DEVICE_ID_PCIDAS08) {
-				if (it->options[0] || it->options[1]) {
-					if (pdev->bus->number == it->options[0]
-					    && PCI_SLOT(pdev->devfn) ==
-					    it->options[1]) {
-						break;
-					}
-				} else {
-					break;
-				}
-			}
-		}
-		if (!pdev) {
-			dev_err(dev->class_dev, "No pci das08 cards found\n");
+		struct pci_dev *pdev;
+		pdev = das08_find_pci(dev, it->options[0], it->options[1]);
+		if (pdev == NULL)
 			return -EIO;
-		}
+		thisboard = comedi_board(dev);	/* replaced wildcard board */
 		devpriv->pdev = pdev;
 		/*  enable PCI device and reserve I/O spaces */
 		if (comedi_pci_enable(pdev, DRV_NAME)) {