Hi,
i'm trying to implement TWI using PDC. Therefor I changed the linux i2c-at91 driver.
I got correct bussignals. But the buffer seems to be rotated. Ever the last read byte (n) is on position 0 and the other bytes (0 to n-1) are on position 1 to n.
Another problem is that the last read (Minicom_output with DMA time [ 1.290000]) returns 0x00 instead of 0x11.
I tried to solve the problem by changing the bytes to read and by changing the buffersize.
At least i also tried to use functions virt_to_phys() and virt_to_bus() without any affect.
I'm stumped.
Thanks and sorry for my english

Hello,
I solved the problem by by try and error. Now I use a temp buffer (sizeof(userbuffer) + 1) and reading 1 byte more. So the order is correct from pos 1 to n in tempBuf. After reading the bus I copy the tempBuf into the userbuffer. Not fine but it works.
Best regards.