I am trying to add the 3-axis compass data channels to the simple_dummy_channel. I have mounted configfs and am able to load the modules correctly. Is this the right approach? printk is not printing anything to syslogs. This is part of the iio_tasks in (I have finished the first 2 tasks): https://kernelnewbies.org/IIO_tasks output of lsmod | grep dummy: iio_dummy 20480 2 iio_dummy_evgen 16384 1 iio_dummy output of ls /sys/bus/iio/devices/iio:device0/: buffer in_sampling_frequency in_voltage-voltage_scale current_timestamp_clock in_steps_calibheight name dev in_steps_en out_voltage0_raw events in_steps_input power in_accel_x_calibbias in_voltage0_offset scan_elements in_accel_x_calibscale in_voltage0_raw subsystem in_accel_x_raw in_voltage0_scale trigger in_activity_running_input in_voltage1-voltage2_raw uevent in_activity_walking_input in_voltage3-voltage4_raw I have also put the diff.Added channel to iio_dummy_channels and added element to enum simple_dummy_scan_elements. Thank you, Bharath --- drivers/iio/dummy/iio_simple_dummy.c | 43 ++++++++++++++++++++++++++++++++++++ drivers/iio/dummy/iio_simple_dummy.h | 3 +++ 2 files changed, 46 insertions(+) diff --git a/drivers/iio/dummy/iio_simple_dummy.c b/drivers/iio/dummy/iio_simple_dummy.c index 6205247..306e0cd 100644 --- a/drivers/iio/dummy/iio_simple_dummy.c +++ b/drivers/iio/dummy/iio_simple_dummy.c @@ -268,6 +268,48 @@ static const struct iio_chan_spec iio_dummy_channels[] = { .num_event_specs = 1, #endif /* CONFIG_IIO_SIMPLE_DUMMY_EVENTS */ }, + { + .type = IIO_MAGN, + .modified = 1, + .channel2 = IIO_MOD_X, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), + .scan_index = DUMMY_INDEX_MAGNX, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + .shift = 0, + }, + }, + { + .type = IIO_MAGN, + .modified = 1, + .channel2 = IIO_MOD_Y, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), + .scan_index = DUMMY_INDEX_MAGNY, + .scan_type = { + .sign = 'u', + .realbits= 16, + .storagebits = 16, + .shift = 0, + }, + }, + { + .type = IIO_MAGN, + .modified = 1, + .channel2 = IIO_MOD_Z, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), + .scan_index = DUMMY_INDEX_MAGNZ, + .scan_type = { + .sign = 'u', + .realbits = 16, + .storagebits = 16, + .shift = 0, + }, + }, }; /** @@ -621,6 +663,7 @@ static struct iio_sw_device *iio_dummy_probe(const char *name) /* Provide description of available channels */ indio_dev->channels = iio_dummy_channels; indio_dev->num_channels = ARRAY_SIZE(iio_dummy_channels); + printk(KERN_DEBUG "No of channels are %d\n",indio_dev -> num_channels); /* * Provide device type specific interface functions and diff --git a/drivers/iio/dummy/iio_simple_dummy.h b/drivers/iio/dummy/iio_simple_dummy.h index f7005c3..be6eff0 100644 --- a/drivers/iio/dummy/iio_simple_dummy.h +++ b/drivers/iio/dummy/iio_simple_dummy.h @@ -110,6 +110,9 @@ enum iio_simple_dummy_scan_elements { DUMMY_INDEX_DIFFVOLTAGE_1M2, DUMMY_INDEX_DIFFVOLTAGE_3M4, DUMMY_INDEX_ACCELX, + DUMMY_INDEX_MAGNX, + DUMMY_INDEX_MAGNY, + DUMMY_INDEX_MAGNZ, }; #ifdef CONFIG_IIO_SIMPLE_DUMMY_BUFFER -- 2.7.4