I'm trying to debug an I2C problem I've found in my old-style driver: sound/soc/codecs/cs4270.c. My I2C probe function is working, but the I2C subsystem cannot find my device. I know it's there, because U-Boot can probe it just fine.
At first, I thought my problem was this: static struct i2c_driver cs4270_i2c_driver = { .driver = { .name = "CS4270 I2C", .owner = THIS_MODULE, }, .id = I2C_DRIVERID_CS4270, .attach_adapter = cs4270_i2c_attach, .detach_client = cs4270_i2c_detach, }; In a slightly older kernel (still 2.6.27), I had to change "CS4270 I2C" to "cs4270" to get it to work. However, that change no longer makes a difference. I turned on debugging and this is what I see: i2c-core: driver [CS4270 I2C] registered i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x48 i2c-adapter i2c-0: master_xfer[0] W, addr=0x48, len=0 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x49 i2c-adapter i2c-0: master_xfer[0] W, addr=0x49, len=0 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x4a i2c-adapter i2c-0: master_xfer[0] W, addr=0x4a, len=0 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x4b i2c-adapter i2c-0: master_xfer[0] W, addr=0x4b, len=0 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x4c i2c-adapter i2c-0: master_xfer[0] W, addr=0x4c, len=0 i2c-adapter i2c-0: master_xfer[0] W, addr=0x4c, len=1 i2c-adapter i2c-0: master_xfer[1] R, addr=0x4c, len=1 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x4d i2c-adapter i2c-0: master_xfer[0] W, addr=0x4d, len=0 i2c-adapter i2c-0: master_xfer[0] W, addr=0x4d, len=1 i2c-adapter i2c-0: master_xfer[1] R, addr=0x4d, len=1 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x4e i2c-adapter i2c-0: master_xfer[0] W, addr=0x4e, len=0 i2c-adapter i2c-0: found normal entry for adapter 0, addr 0x4f My device is at address 4F. The device tree defines a node for this device. You can see it in arch/powerpc/boot/dts/mpc8610_hpcd.dts. When I change the device tree so that it lists the device at an address other than 4F, (e.g. "reg = <0x48>"), then my driver works. So my conclusion is that specifying an I2C node in the device tree *requires* that the driver be new-style. Is there any way we can fix this? I'm not going to have time to update the CS4270 driver to a new-style interface before the 2.6.27 window closes. -- Timur Tabi Linux kernel developer at Freescale _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev