IOATADevice

Overview

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

Discussion

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.

Functions

allocCommand

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

executeCommand

Submit IO requests

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.

getDeviceType

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

getUnitID

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

matchLocation

matching stuff for IOBSDInit and so on.

matchPropertyTable(OSDictionary *)

matching stuff for IOBSDInit and so on.

matchPropertyTable(OSDictionary *, SInt32 *)

matching stuff for IOBSDInit and so on.

notifyEvent

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

provideBusInfo

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

provideConfig

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

selectConfig

Tell the bus what speed to use for your device.

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

public

virtual IOATACommand* allocCommand(
    void ); 

Return Value

null if allocation failed. Retain count is one.

Submit IO requests

public

virtual IOReturn executeCommand(
    IOATACommand *command); 

Parameters

Return Value

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

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.

public

virtual void freeCommand(
    IOATACommand *inCommand); 

Parameters

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

public

virtual ataDeviceType getDeviceType(
    void ); 

Return Value

ataDeviceType as defined in IOATATypes.h

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

public

virtual ataUnitID getUnitID(
    void ); 

Return Value

ataUnitID - 0 or 1.

matching stuff for IOBSDInit and so on.

public

virtual IOService* matchLocation(
    IOService *client); 

matching stuff for IOBSDInit and so on.

public

virtual bool matchPropertyTable(
    OSDictionary *table); 

matching stuff for IOBSDInit and so on.

public

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

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

public

virtual void notifyEvent(
    UInt32 event ); 

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

public

virtual IOReturn provideBusInfo(
    IOATABusInfo *getInfo); 

Parameters

Return Value

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

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

public

virtual IOReturn provideConfig(
    IOATADevConfig *configRequest); 

Parameters

Return Value

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

Tell the bus what speed to use for your device.

public

virtual IOReturn selectConfig(
    IOATADevConfig *configRequest); 

Parameters

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.

Structs and Unions

ExpansionData

protected

struct ExpansionData {
}; 

Discussion

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

Member Data

reserved

protected

ExpansionData *reserved; 

Discussion

Reserved for future use. (Internal use only)

Last Updated: 2009-10-14