priti priti

I want to control chipselect for my spidevice from user space. i am using imax25 board.

Discussion created by priti priti on Aug 8, 2012
Latest reply on Aug 9, 2012 by Yuji Sasaki

I have a requirement for control chipselect for my spidevice.

The requirement is between two writes or reads my device should remain selected from contoller.

For example the sequence is  like :

 

Write opreation

 

1)chip select

2)send some data ( i am using ioctl(SPI_IOC_MESSAGE(1) )

3)send some more data ( means sending one more time ioctl command).

4)chip deselect

 

Now after Write operation i need to read the data.

 

Read Operation

1)chip select

2)Read data ( i am using ioctl(SPI_IOC_MESSAGE(1) )

3)Read more data ( means sending one more time ioctl command).

4)chip deselect

 

but as per my understanding whenever we call ioctl(SPI_IOC_MESSAGE(1)) the control finally goes to mxc_spi.c (which is controller driver) and for each write/read it selects the chip -> enables the clock -> write/read data then deselects the chip.

Note : i saw it wrtites to the control register which actually has the value for chip select and all.

 

Is there any way i can meet the above requirement?

i am really stuck.

 

 

 

 

 

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