Instance Property

replyTransactionType

Specifies one of four possible reply transaction types.

Declaration

IOOptionBits replyTransactionType;

Discussion

The following types of transaction are defined for the reply part of the request:

Table 1

Possible values for replyTransactionType

kIOI2CNoTransactionType

No reply transaction to perform.

kIOI2CSimpleTransactionType

Simple I2C message.

kIOI2CDDCciReplyTransactionType

DDC/ci message (with embedded length). See VESA DDC/ci specification.

kIOI2CCombinedTransactionType

Combined format I2C R/~W transaction.

See Also

Fields

__reservedA

Set to zero.

result

The result of the transaction. Common errors are kIOReturnNoDevice if there is no device responding at the given address, kIOReturnUnsupportedMode if the type of transaction is unsupported on the requested bus.

completion

A completion routine to be executed when the request completes. If NULL is passed, the request is synchronous, otherwise it may execute asynchronously.

commFlags

Flags that modify the I2C transaction type.

minReplyDelay

Minimum delay as absolute time between send and reply transactions.

sendAddress

I2C address to write.

sendSubAddress

I2C subaddress to write.

__reservedB

Set to zero.

sendTransactionType

Specifies one of three possible transaction types.

sendBuffer

Pointer to the send buffer.

sendBytes

Number of bytes to send. Set to actual bytes sent on completion of the request.

replyAddress

I2C Address from which to read.

replySubAddress

I2C Address from which to read.

__reservedC

Set to zero.

replyBuffer

Pointer to the reply buffer.

replyBytes

Max bytes to reply (size of replyBuffer). Set to actual bytes received on completion of the request.

__reservedD

Set to zero.