The Multifunction I/O Device features I/O with varying channels, sample rates, output rates, and other features to meet many common measurement requirements. You can use the device for industry applications such as laboratory automation, research, and design verification. The Color imageRUNNER C1335iF delivers high quality color output at a speed of up to 36 ppm (BK/Color/Letter). The Color imageRUNNER C1335iF model is a full-color digital multifunctional device that meets the requirements of small office/workgroup settings to corporate fleet/MPS environments. Unknown devices would be listed as such and marked out with a yellow question mark. Select the unknown device or other device for which you need drivers and right click to access Properties. In the Properties window click on Details tab and select Device Instance Id or Hardware ID from the drop down.

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A multifunction device is a single adapter card that incorporates two or more separate functions (or subdevices). A multifunction device can contain two or more audio subdevices. It may also span device classes. A device containing audio and modem subdevices, for instance, belongs to both the media class and the modem class. For more information, see Supporting Multifunction Devices.

The WavePci port driver in PortCls places special requirements on multifunction devices. In particular, an adapter driver must provide a way to configure each subdevice so that it can be controlled independently of the other subdevices in a multifunction device. This can be accomplished by setting up the PCI configuration space for your multifunction device in one of two ways:

The preferred method is to assign a separate device ID to each logically distinct subdevice on your multifunction device. If your multifunction device contains modem, audio, and joystick subdevices, for example, the system should be able to represent each subdevice as an independent devnode in the device tree. The subdevice represented by each device ID has its own set of PCI configuration registers and is orthogonal to and independent of the other subdevices. For instance, enabling or disabling one subdevice (the audio subdevice, for example) should have no effect on any other subdevice (the modem, for example). This type of multifunction device requires no special hardware-specific driver support apart from the proprietary drivers for the subdevices themselves.
A second way to design a multifunction device is to assign a single device ID to the device as a whole and to provide separate PCI base-address registers (BARs) for the individual subdevices. In this scheme, the subdevices share a common set of configuration registers but each subdevice has its own BAR or BARs. The system multifunction driver (for example, Mf.sys on Microsoft Windows 2000 and later; see Using the System-Supplied Multifunction Bus Driver) can configure the base address for each subdevice's status, command, and data registers independently of the registers for the other functions. If your device's BARs are not logically separable by subdevice, you cannot use PortCls to manage your device.

The remainder of this section describes the steps necessary to implement approach (2) in the preceding list. The following topics are discussed:

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December 17, 2020

This article was contributed by Marta Rybczyńska

Device drivers usually live within a single kernel subsystem. Sometimes,however, developers need to handle functionalities outside of this model.Consider, for example, a network interface card (NIC) exposing both Ethernet andRDMA functionalities. There is one hardware block, but two drivers for thetwo functions. Those drivers need to work within their respectivesubsystems, but they must also share access to the same hardware. There isno standard way in current kernels to connect those drivers together, sodevelopers invent ad-hoc methods to handle the interaction betweenthem. Recently, Dave Ertman posteda patch set introducing a new type of a bus, called the 'auxiliary bus', toaddress this problem.

Complex devices

Linux already includes a number of drivers for multi-functiondevices. One of the ways to support them is the Multi-FunctionDevices (MFD) subsystem. It handles independent devices 'glued'together into one hardware block which may contain some sharedresources. MFD allows access to device registers either directly, or usinga common bus. In this second case, it conveniently multiplexes accesses onInter-Integrated Circuit(I2C) or SerialPeripheral Interface (SPI) buses. As the MFD sub-devices are separate,MFD drivers do not share a common state.

The devices Ertman addresses do not fit well into the MFD model.Devices using the auxiliary bus provide subsets of the capabilities of asingle hardware device. They do not expose separate register sets for eachfunction; thus they cannot be described by devicetrees or discovered byACPI. Their drivers need to share access to the hardware. Events concerning allsub-functionalities (like power management) need to be properly handled byall drivers. These devices will often be specialized processors runningfirmware and communicating with the host system (and the Linux drivers) bymessaging. The available functions may not be known in advance, and thusmust be discovered at run time.

The documentationpatch in the auxiliary bus series cites a number of examples. The SoundOpen Firmware (SOF) driver interacts with a single device exposinginterfaces like HDMI output, microphones, speakers, testing, and debughooks. NICs implementing both Ethernet and RDMA may need a driversupporting a common part of the functionalities, and then the specificEthernet and RDMA drivers can implement specific parts on top of that.

Current kernels do not have a generic way to describe dependenciesbetween drivers for this kind of device. A solution to the problem could beto have a way to attach secondary drivers to the primaryone; this is exactly what the auxiliary bus implements.

Auxiliary devices and drivers

The patch set introduces two main concepts: The 'auxiliary device' and'auxiliary driver'. These implement the relationship between the main andthe secondary drivers. The main driver maintains the device state, allocating and managing all shared data. It also unregisters all secondarydrivers when shutting down. Secondary drivers, instead, handle theinteractions with the specific subsystem they are implementing a devicefor.

Each main driver may expose a number of functionalities (devices) forsecondary drivers. Only one secondary driver can attach to each of thosefunctionalities.

The main driver creates an auxiliary device, represented by structauxiliary_device:

The combination of name and id must be unique; thecomplete device name is a combination of the module name and those twofields, connected by dots (.). That yields a result likemodname.device_name.id. Tora driver download for windows 10.

The developer embeds this structure in the device structure ofthe main driver, with all shared data necessary for the communicationbetween the main driver and secondary drivers. They may also addsupplementary callbacks.

The sequence to initialize the main driver contains two steps. The firstone is to call auxiliary_device_init():

It verifies the arguments and returns anerror code if need be; in such case the initialization of the deviceshould be aborted.If the first call succeeds, the second step is to call the macroauxiliary_device_add() with the initialized device; this willset up the device name and register the deviceitself.

The unregistration procedure also has two steps, consisting of calls toauxiliary_device_uninit() (necessary from the point whenauxiliary_device_init() has succeeded) andauxiliary_device_delete(). Those functions have the followingprototypes:

Drivers Welding Multifunction Devices