I am working on iPod Authentication Coprocessor 2.0C (MFI337S3959).
With source code in 'i2c-imx.c', I2C probe and writes are working fine but I2C read is failing. 'i2c_imx_read' is returning after checking for ACK in the function 'i2c_imx_acked'.
We have observed on the scope that for SCL bit-8 (acknowledge), SDA remains low for the read operation and thus there is no acknowledge. Bit-8 for write operation remains low for ACK, which is the correct.
What could be causing read not to be acknowledged? Is there a work around?
Thanks and Regards,
Solved! Go to Solution.
i am also having the apple authentication module trying to use it on imx6qp board ,
but the module is not at all detected . can someone tell how to proceed (#imx6qp) further.
Got the patch from nxp for mfi drivers but no use.:(
For this same chip I have got the acknowledgement for the slave address but I found NACK for first time i2c_writes & for every i2c_reads.As you said I retried with 500ms delay then I received ACK(for the 2nd retry) for both i2c_reads & i2c_writes.
I have few queries here,please clarify:
Is this retrying model a fix or only a work around?If there exists a solution kindly let me know.
How many retries were done in your case to get the ACK?