IOATADevice

Inherits from
IOService
Availability
Available in OS X v10.0 and later.
Declared in
IOATADevice.h

Overview

This object implements a relay to an ATA Bus where a drive is attached.

IOATADevice is the superclass which represents a particular device attached to a particular IOATAController (bus). IOATADevice is the provider for ATA mass-storage device drivers.IOATADevice is the factory for all IOATACommand objects and is responsible for creating and freeing IOATACommands. IOATAControllers will create an instance of IOATADevice for each device physically connected to the ata bus. IOATADevice is virtual and specific subclass should be implemented for particular types of IOATAController. In this manner, controller-specifc IOATACommands may be paired with the proper type of controller.

Tasks

Miscellaneous

Instance Methods

allocCommand

create IOATACommands. Device drivers should allocate command objects only through this method.

virtual IOATACommand* allocCommand( void );
Return Value

null if allocation failed. Retain count is one.

executeCommand

Submit IO requests

virtual IOReturn executeCommand( IOATACommand *command);
Parameters
command

pointer to a valid IOATACommand with the command to be executed.

Return Value

kIOSuccess (0) if the command was successfully queued in the controller.

freeCommand

release a command object that is no longer needed. Do not free an object in use and do not release the object anymore times than you have retained it.

virtual void freeCommand( IOATACommand *inCommand);
Parameters
inCommand

the command to be released.

getDeviceType

Find out what kind of device this nub is (ata or atapi)

virtual ataDeviceType getDeviceType( void );
Return Value

ataDeviceType as defined in IOATATypes.h

getUnitID

Determine whether this device is number 0 or 1 (ie, master/slave)

virtual ataUnitID getUnitID( void );
Return Value

ataUnitID - 0 or 1.

matchLocation

matching stuff for IOBSDInit and so on.

virtual IOService* matchLocation( IOService *client);

matchPropertyTable(OSDictionary *)

matching stuff for IOBSDInit and so on.

virtual bool matchPropertyTable( OSDictionary *table);

matchPropertyTable(OSDictionary *, SInt32 *)

matching stuff for IOBSDInit and so on.

virtual bool matchPropertyTable( OSDictionary *table, SInt32 *score);

notifyEvent

called by controllers when they need to send a message to client (disk) drivers.

virtual void notifyEvent( UInt32 event );

provideBusInfo

Find out the bus capability so the client can choose the features to set and commands to run.

virtual IOReturn provideBusInfo( IOATABusInfo *getInfo);
Parameters
getInfo

a pointer to a valid IOATABusInfo object.

Return Value

kIOSuccess (0) and the getInfo object will be filled out by the bus controller with information about the bus.

provideConfig

Find out what speed the bus has configured for this unit.

virtual IOReturn provideConfig( IOATADevConfig *configRequest);
Parameters
configRequest

pointer to a valid IOATADevConfig object.

Return Value

kIOSuccess (0) on successful completion and configRequest will contain the configuration information.

selectConfig

Tell the bus what speed to use for your device.

virtual IOReturn selectConfig( IOATADevConfig *configRequest);
Parameters
configRequest

pointer to a valid and initialized IOATADevConfig object.

Return Value

kIOSuccess (0) if the configuration was succesfully selected.

Discussion

This should only be called once during a disk drivers start method before registering its availability, and must be called prior to issuing any data IO transactions.

ExpansionData

struct ExpansionData {
};
Discussion

This structure will be used to expand the capablilties of the IOWorkLoop in the future.

Instance Variables

reserved

ExpansionData *reserved;

Reserved for future use. (Internal use only)