This patch introduces a custom ops struct letting users define
custom read and write functions. Some adis devices might define
a completely different spi protocol from the one used in the
default implementation.

Co-developed-by: Ramona Gradinariu <[email protected]>
Signed-off-by: Ramona Gradinariu <[email protected]>
Co-developed-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Nuno Sá <[email protected]>

Some devices may have more than 16 bits of status. This patch allows the
user to specify the size of the DIAG_STAT register. It defaults to 2 if
not specified. This is mainly for backward compatibility.

Co-developed-by: Ramona Gradinariu <[email protected]>
Signed-off-by: Ramona Gradinariu <[email protected]>
Co-developed-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Nuno Sá <[email protected]>

Document the ADIS16550 device devicetree bindings.

Co-developed-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Ramona Gradinariu <[email protected]>

The ADIS16550 is a complete inertial system that includes a triaxis
gyroscope and a triaxis accelerometer. Each inertial sensor in
the ADIS16550 combines industry leading MEMS only technology
with signal conditioning that optimizes dynamic performance. The
factory calibration characterizes each sensor for sensitivity, bias,
and alignment. As a result, each sensor has its own dynamic com-
pensation formulas that provide accurate sensor measurements

Co-developed-by: Ramona Gradinariu <[email protected]>
Signed-off-by: Ramona Gradinariu <[email protected]>
Co-developed-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Nuno Sá <[email protected]>

Add documentation for adis16550 driver which describes the driver
device files and shows how the user may use the ABI for various
scenarios (configuration, measurement, etc.).

Co-developed-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Antoniu Miclaus <[email protected]>
Signed-off-by: Ramona Gradinariu <[email protected]>

Add entry for the ADIS16550 driver.

Signed-off-by: Ramona Gradinariu <[email protected]>