staging: comedi: adl_pci6208: combine PCI-6208 and PCI-6216 support

This module's PCI device table has separate PCI device IDs for PCI-6208
and PCI-6216, but in reality, both boards and their cPCI and PCIe
variants seem to have the same PCI device ID: 0x6208.  The PCI subdevice
ID doesn't seem to help either.

It shouldn't do any harm to claim 16 AO channels for all devices
supported by this driver.  The original PCI-6216 is just a PCI-6208 with
a daughter board providing the extra DACs.  The data is clocked out to
the DACs serially with no acknowledgment.  I assume this would still
happen when the DACs for the upper 8 channels are missing.  Therefore,
change the driver to support a single board type with 16 AO channels,
and remove the suspicious PCI device ID for the PCI-6216.

Evidence about lack of a separate PCI device ID for PCI-6216 follows....

1. Jesus Vasquez reports the following lspci output for a PCIe-6216 on
his Ubuntu 12.04 system:

lspci -n -vvv
07:00.0 1180: 144a:6208 (rev 02)
        Subsystem: 144a:6208
        Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop-
ParErr- Stepping- SERR- FastB2B- DisINTx-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort-
<TAbort- <MAbort- >SERR- <PERR- INTx-
        Region 0: Memory at f6000000 (32-bit, non-prefetchable)
[size=128]
        Region 1: I/O ports at c100 [size=128]
        Region 2: I/O ports at c000 [size=256]
        Kernel driver in use: adl_pci6208
        Kernel modules: adl_pci6208

That system's "adl_pci6208" module only has the single PCI device ID for
the PCI-6208, but works for his PCIe-6216 except that it only supports 8
analog output channels instead of 16.

2. ADLINK's binary Linux module "pci6208.ko" (there is no separate
module for the PCI-6216) has a single alias:

  alias: pci:v0000144Ad00006208sv*sd*bc*sc*i*

3. The MS Windows drivers include this set of hardware IDs for the
PCI-6208 series, with nothing more specific for the PCI-6216 (they are
all tied to the same name "ADLINK PCI-6208" and there is no mention of
PCI-6216):

  PCI\VEN_10B5&DEV_9050&SUBSYS_62089999
  PCI\VEN_144A&DEV_6208&SUBSYS_6208144A
  PCI\VEN_144A&DEV_6208&SUBSYS_62089999
  PCI\VEN_144A&DEV_6208&SUBSYS_C208144A
  PCI\VEN_144A&DEV_6208&SUBSYS_C20855AA
  PCI\VEN_144A&DEV_6208
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/adl_pci6208.c

@@ -19,12 +19,16 @@
 /*
  * Driver: adl_pci6208
  * Description: ADLink PCI-6208/6216 Series Multi-channel Analog Output Cards
- * Devices: [ADLink] PCI-6208 (adl_pci6208), PCI-6216 (adl_pci6216)
+ * Devices: [ADLink] PCI-6208 (adl_pci6208), PCI-6216
  * Author: nsyeow <nsyeow@pd.jaring.my>
- * Updated: Fri, 30 Jan 2004 14:44:27 +0800
+ * Updated: Wed, 11 Feb 2015 11:37:18 +0000
  * Status: untested
  *
  * Configuration Options: not applicable, uses PCI auto config
+ *
+ * All supported devices share the same PCI device ID and are treated as a
+ * PCI-6216 with 16 analog output channels.  On a PCI-6208, the upper 8
+ * channels exist in registers, but don't go to DAC chips.
  */
 
 #include <linux/module.h>
@@ -47,7 +51,6 @@
 
 enum pci6208_boardid {
 	BOARD_PCI6208,
-	BOARD_PCI6216,
 };
 
 struct pci6208_board {
@@ -58,11 +61,7 @@ struct pci6208_board {
 static const struct pci6208_board pci6208_boards[] = {
 	[BOARD_PCI6208] = {
 		.name		= "adl_pci6208",
-		.ao_chans	= 8,
-	},
-	[BOARD_PCI6216] = {
-		.name		= "adl_pci6216",
-		.ao_chans	= 16,
+		.ao_chans	= 16,	/* Only 8 usable on PCI-6208 */
 	},
 };
 
@@ -218,7 +217,6 @@ static int adl_pci6208_pci_probe(struct pci_dev *dev,
 
 static const struct pci_device_id adl_pci6208_pci_table[] = {
 	{ PCI_VDEVICE(ADLINK, 0x6208), BOARD_PCI6208 },
-	{ PCI_VDEVICE(ADLINK, 0x6216), BOARD_PCI6216 },
 	{ 0 }
 };
 MODULE_DEVICE_TABLE(pci, adl_pci6208_pci_table);