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PMIC busy for I2C read

Tim Tan
Prodigy 200 points

Hi,

I am using a 8148 EVM without the expansion board. When trying to read from PMIC with address 0x2D, I was told that the I2C device is busy.

root@dm814x:/opt/dvr_rdk/ti814x# i2cget 1 0x2d 0 b

Error: Could not set address to 0x2d: Device or resource busy

I couldn't access anything from Linux, but they work fine in uboot

TI8148_EVM#i2c md 2d 17 1

0017: 08

 

What is the possible reason for this?

Thanks,

Tim

  • 0
    TI__Genius 11470 points

    Hello,

    I just tried that on EZSDK and the result was the same: Device or resource busy from the Linux shell and it is OK from u-boot. So it seems that is normal.

    I will check why the default behaviour is like this and is there something that could be modified to change that. I'll let you know if I have something. Thank you.

    BR

    Vladimir

  • 0
    Guru 31670 points

    Tim,

    I'm not sure about the exact issue here. But is the I2C bus getting shared between M3? To confirm this try the i2cget command before loading the M3 binaries and see whether it works.

  • 0 in reply to Renjith Thomas
    Prodigy 200 points

    Hi,

    I browsed around the net for some answers after posing the question. I think the PMIC driver claimed ownership for that i2c device (address) so user space access is not granted permission.

    but when i used the 'force' option on the tool. It will perform the i2c read. i.e.

    # i2cget -f 1 0x2d 0 b

    So I have decided not to screw up the linux i2c device management and just do what I want from kernel space through PMIC driver.

    Thanks for all your help!

    Tim