Re: [PATCH v6 5/8] iio: imu: Add driver for the ADI ADIS16607

[Jonathan Cameron <jic23@kernel.org>]

On Fri, 13 Nov 2026 14:33:35 +0200
Radu Sabau via B4 Relay <devnull+radu.sabau.analog.com@kernel.org> wrote:

> From: Radu Sabau <radu.sabau@analog.com>
> 
> The ADIS16607 is a Precision MEMS IMU from Analog Devices with
> triaxial gyroscope and accelerometer, delta angle/velocity, and
> temperature channels, communicating over a custom SPI Half-Duplex
> protocol. ADIS16607-2 has a ±450°/s gyroscope range, ADIS16607-3
> ±2000°/s; both share a ±40g accelerometer range and an 8 kHz internal
> clock.
> 
> This is the base driver: probe, raw channel reads, sampling-frequency
> control, startup/self-test via adislib, and debugfs identity entries.
> No buffered capture, external clock sync, or calibration bias yet -
> those follow in later patches.
> 
> Self-test leaves the device's SELF_TEST register cleared on every exit
> path, not just on success, so a read failure or a failed delta check
> doesn't leave the sensor stuck in its self-test/force state until the
> next reset.
> 
> Signed-off-by: Radu Sabau <radu.sabau@analog.com>


The chan_spec in here includes buffer related stuff (scan index and
the channel type bit) + the timestamp channel in general. That should
all have been introduced in the next patch.  Thus feedback on that
patch isn't contained and I've dropped this one for now.


> diff --git a/drivers/iio/imu/adis16607.c b/drivers/iio/imu/adis16607.c
> new file mode 100644
> index 000000000000..f5dc37c54191
> --- /dev/null
> +++ b/drivers/iio/imu/adis16607.c

> +/*
> + * .address indexes adis16607_chan_regs[], .scan_index is the buffer position;
> + * both come from the same enum today but are separate fields on purpose.
> + */
> +#define ADIS16607_MOD_CHAN(_type, _mod, _idx)				       \
> +	{								       \
> +		.type = (_type),					       \
> +		.modified = 1,						       \
> +		.channel2 = (_mod),					       \
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		       \
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	       \
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
> +		.address = (_idx),					       \
> +		.scan_index = (_idx),					       \
> +		.scan_type = {						       \
> +			.sign = 's',					       \
> +			.realbits = 24,					       \
> +			.storagebits = 32,				       \
> +			.endianness = IIO_BE,				       \
> +		},							       \
> +	}
> +
> +#define ADIS16607_ACCEL_CHANNEL(_mod)					       \
> +	ADIS16607_MOD_CHAN(IIO_ACCEL, IIO_MOD_ ## _mod,			       \
> +			   ADIS16607_SCAN_ACCEL_ ## _mod)
> +
> +#define ADIS16607_GYRO_CHANNEL(_mod)					       \
> +	ADIS16607_MOD_CHAN(IIO_ANGL_VEL, IIO_MOD_ ## _mod,		       \
> +			   ADIS16607_SCAN_GYRO_ ## _mod)
> +
> +#define ADIS16607_MOD_CHAN_DELTA(_type, _mod, _idx)			       \
> +	{								       \
> +		.type = (_type),					       \
> +		.modified = 1,						       \
> +		.channel2 = (_mod),					       \
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		       \
> +		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	       \
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),       \
> +		.address = (_idx),					       \
> +		.scan_index = (_idx),					       \
> +		.scan_type = {						       \
> +			.sign = 's',					       \
> +			.realbits = 24,					       \
> +			.storagebits = 32,				       \
> +			.endianness = IIO_BE,				       \
> +		},							       \
> +	}
> +
> +#define ADIS16607_DELTANG_CHAN(_mod)					       \
> +	ADIS16607_MOD_CHAN_DELTA(IIO_DELTA_ANGL, IIO_MOD_ ## _mod,	       \
> +				 ADIS16607_SCAN_DELTANG_ ## _mod)
> +
> +#define ADIS16607_DELTVEL_CHAN(_mod)					       \
> +	ADIS16607_MOD_CHAN_DELTA(IIO_DELTA_VELOCITY, IIO_MOD_ ## _mod,	       \
> +				 ADIS16607_SCAN_DELTVEL_ ## _mod)
> +
> +static const struct iio_chan_spec adis16607_channels[] = {
> +	ADIS16607_ACCEL_CHANNEL(X),
> +	ADIS16607_ACCEL_CHANNEL(Y),
> +	ADIS16607_ACCEL_CHANNEL(Z),
> +	ADIS16607_GYRO_CHANNEL(X),
> +	ADIS16607_GYRO_CHANNEL(Y),
> +	ADIS16607_GYRO_CHANNEL(Z),
> +	ADIS16607_DELTVEL_CHAN(X),
> +	ADIS16607_DELTVEL_CHAN(Y),
> +	ADIS16607_DELTVEL_CHAN(Z),
> +	ADIS16607_DELTANG_CHAN(X),
> +	ADIS16607_DELTANG_CHAN(Y),
> +	ADIS16607_DELTANG_CHAN(Z),
> +	{
> +		.type = IIO_TEMP,
> +		.indexed = 1,
> +		.channel = 0,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_SCALE) |
> +				      BIT(IIO_CHAN_INFO_OFFSET),
> +		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> +		.address = ADIS16607_SCAN_TEMP,
> +		.scan_index = ADIS16607_SCAN_TEMP,
> +		.scan_type = {
> +			.sign = 's',
> +			.realbits = 16,
> +			.storagebits = 16,
> +			.endianness = IIO_BE,
> +		},
> +	},
> +	IIO_CHAN_SOFT_TIMESTAMP(ADIS16607_SCAN_MAX),

Should not be here and the channels above should not 'yet' hvae
scan_type or scan_index.  Those belong in the patch adding buffered support.


> +};