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i2c bus doesn't support slave address?

Ganesh Biradar
Expert 2315 points
Other Parts Discussed in Thread: DM385

Hi guys,

i'm having a custom DM385 CBB board, i was adding support for peripheral devices in board-dm385cbb.c file. i have a device EP9351(hdmi receiver) which has address of 0x78. As it is independent device so their is no driver support is needed but it is connected to our dm385 so i wanted to add device info in board-dm385cbb.c file.

{
                I2C_BOARD_INFO("ep9351", 0x78),//(i2c-0 bus)
 },

after building and  flashing uImage. In board shell prompt i have given i2cdetect -r 1

i2cdetect -r 1
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-1 using read byte commands.
I will probe address range 0x03-0x77.

As you can see it can read an i2c address till 0x77 but my device address is 0x78. can anyone suggest what i can do to sort these issue.

one more little help i'm getting an error of i2c

 omap_i2c omap_i2c.1: timeout waiting for bus ready     (at board booting time also i'm facing these error and also at i2cdetect -r 1)

can anyone suggest what can be done to avoid above error.

regards,

Ganesh

 

  • 0
    TI__Guru**** 170625 points

    Ganesh Biradar said:

    i2cdetect -r 1
    WARNING! This program can confuse your I2C bus, cause data loss and worse!
    I will probe file /dev/i2c-1 using read byte commands.
    I will probe address range 0x03-0x77.

    As you can see it can read an i2c address till 0x77 but my device address is 0x78. can anyone suggest what i can do to sort these issue.

    Refer to the i2cdetect source code (i2cdetect.c), you will see that by default the last address of the probing range is 0x77. You can increase that range from 0x03-0x77 to 0x00-0x7F using the -a option:

    root@dm814x-evm:~# i2cdetect -a -r 1
    WARNING! This program can confuse your I2C bus, cause data loss and worse!
    I will probe file /dev/i2c-1 using read byte commands.
    I will probe address range 0x00-0x7f.
    Continue? [Y/n]

    Ganesh Biradar said:

    one more little help i'm getting an error of i2c

     omap_i2c omap_i2c.1: timeout waiting for bus ready     (at board booting time also i'm facing these error and also at i2cdetect -r 1)


     

    I2C bus time out can come from any of the I2C slave devices, it would be good to identify all the drivers used in your application. This will help in eliminating the slave which can cause a bus-time out issue.

    See also if the below pointers will be in help:

    Regards,
    Pavel

  • 0
    Expert 2315 points
    Hi,

    i have changed my board with few changes and it is working. it was hardware issue.

    regards
    Ganesh