A few days ago I asked about sample code for I2C in the U-boot sources, and was pointed to it.
I still have problems, and would like some guidance. When I take the controller out of reset, I find that the bus is busy, and the condition does not clear up even after waiting. If I go ahead and try to start a slave selection anyway, arbitration fails (not surprising).
I am using the P1010-RDB reference design board for my software development.
After system reset, I find the registers contain (as expected):
I2C_ADR = 00
I2C_FDR = 00
I2C_CR = 00
I2C_SR = 0x81 = MCF + RXAK
I2C_DR = 00
I2C_DFSRR = 0x10
In my initialization routine, I set
I2C_FDR = 0x15 (with CCB clock at 400 MHz, that should yield an I2C clock at just under 2 kHz)
I2C_CR = 0x80
I now find that
I2C_SR = 0xA1 = MCF + MBB + RXAK
Where did the MBB (Bus Busy) come from ? How do I clear it ?
Am I supposed to set MSTA then clear it at initialization time ?
Message was edited by: Lars Poulsen I have attached the source code of my failing driver.
After initialization I get:
I2C Port 0 Interface Status
Registers: Adr=00
FDR=07 factor=1024 freq=195312
CR =80 MEN
SR =B3 MCF MBB MAL MIF RXAK
DR =00
DFSRR=10
Data: State=00 RESET
I2C Port 1 Interface Status
Registers: Adr=00
FDR=07 factor=1024 freq=195312
CR =80 MEN
SR =86 MCF SRW MIF
DR =FF
DFSRR=10
Data: State=00 RESET
Anyone have ideas ?
Original Attachment has been moved to: p10_i2c.c.zip
