Linux support to access OMAP-L138 SOM Power Measure chips

Just an update on this question, now I've started writing a application that will try to access the INA219AIDCNR chips through the I2C bus.

I am able to open the I2C device node, but when I issue an IOCTL request (ioctl(fd, I2C_SLAVE_FORCE, 0x41)) I always get an EINVAL return code.

I've looked ath the i2c-dev.c in the kernel->drivers directory and it does not make sense why it should return an EINVAL code.

Here's the code that I wrote:

int main(void)
{
    int fd;
    char buff[10];

    if(fd = open("/dev/i2c-1", O_RDWR) < 0)
    {
        printf("Error opening I2C bus\n");
        return 1;
    }

    if(ioctl(fd, I2C_SLAVE_FORCE, 0x41) < 0)
    {   
        printf("Error setting I2C address\n");
        switch(errno)
        {
            case EBADF:
                printf("d is not a valid descriptor\n");
                break;
            case EFAULT:
                printf("argp references an inaccessible memory area\n");
                break;           
            case EINVAL:
                printf("Request or argp is not valid\n");
                break;
            case ENOTTY:
                printf("d is not associated with a character special device\n");
                break;
            default:
                printf("Error setting I2C address\n");
                break;
        }
        close(fd);
        return 1;
    }

    return 0;

}

Update:

I realize that the INA219AIDCNR ICs in the SOM board does not have any SW drivers for it.

I'm currently looking if I can enable the driver in .config.

Hi Grant,

may be this does not apply to your case, but in mine the problem is described in E0013 on  OMAP-L138 SOM-M1 Errata.

On my SOM I cannot access them with i2c-tools (i2cdump).

Hope it helps,

A.