TCA8424设备地址是0x3b，但是在linux下读写i2c一直没有ACK，i2c log如下：
[ 96.845939] i2c i2c-2: master_xfer[0] W, addr=0x3b, len=2 [ 96.851355] i2c i2c-2: <i2c_imx_xfer> [ 96.855028] i2c i2c-2: <i2c_imx_start> [ 96.858847] i2c i2c-2: <i2c_imx_bus_busy> [ 96.862869] i2c i2c-2: <i2c_imx_xfer> transfer message: 0 [ 96.868282] i2c i2c-2: <i2c_imx_xfer> CONTROL: IEN=1, IIEN=1, MSTA=1, MTX=1, TXAK=1, RSTA=0 [ 96.876649] i2c i2c-2: <i2c_imx_xfer> STATUS: ICF=1, IAAS=0, IBB=1, IAL=0, SRW=0, IIF=0, RXAK=1 [ 96.885360] i2c i2c-2: <i2c_imx_write> write slave address: addr=0x76 [ 96.892331] i2c i2c-2: <i2c_imx_trx_complete> TRX complete [ 96.897831] i2c i2c-2: <i2c_imx_acked> No ACK [ 96.902198] i2c i2c-2: <i2c_imx_stop> [ 96.905869] i2c i2c-2: <i2c_imx_bus_busy> [ 96.909891] i2c i2c-2: <i2c_imx_xfer> exit with: error: -5 [ 96.915395] tca8424_keypad 2-003b: tca8424_write_byte failed, reg: 1536, val: 27, error: -5
驱动是按照TCA8418的驱动来写的。
