I am using the wp7608 with mangOH evaluation board. When I toggle the gpio40 from linux, i get the following warnings.
[ 610.795386] i2c-msm-v2 78b8000.i2c: NACK: slave not responding, ensure its powered: msgs(n:1 cur:0 tx) bc(rx:0 tx:18) mode:FIFO slv_addr:0x3a MSTR_STS:0x0c1300c8 OPER:0x00000090
Though the gpio40 state changes to 1.8 volts for high and 0 volts for low, but what is the warning from the system trying to indicate ?
Below is the current state of the gpio’s