Qualcomm Universal serial (QUP) on msm7x30 overview.

The Qualcomm Universal serial engine provides a common data path that supports multiple mini cores like i2c , spi etc.
On 7x30 The QUP core has only i2c mini core in it.
Gpio numbers are 16, 17
The output FIFO size is 512 bytes while the input FIFO size is 64 bytes.
The QUP supports 3 I/o modes FIFO, block and data mover mode.
In FIFO mode interrupt is triggered whenever output fifo is empty, or when input fifo has some data.
In Block mode software periodically reads or writes a block of data
In Dmov mode , the DM engine communicates with FIFO to read or write data.


Software currrently has no support for dmov mode.


The data provided to the QUP FIFO, should be "tagged". A tag is a special control byte that is interpreted by QUP to understand what control signals to send the mini core.


For read transactions , the QUp appends a tag to every incoming byte.


For greater detail on How the QUP operaters refer to DCN 80-N0411-1 A