On Sun, 2025-01-12 at 16:11 +0000, Jonathan Cameron wrote:

On Fri, 10 Jan 2025 09:42:53 +0200
Robert Budai [off-list ref] wrote:

quoted

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 <ramona.gradinariu@analog.com>
Signed-off-by: Ramona Gradinariu <ramona.gradinariu@analog.com>
Co-developed-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Robert Budai <robert.budai@analog.com>
---

4:
- reorganized channels to match the order in the datasheet
- removed extra checks and goto statements
- for buffer memory allocation used only kfree, since adis library already
takes care of freeing the buffer

That last bit makes for a mess wrt to who owns the buffer and lifetime
management. Suggestions inline.

Jonathan

quoted

diff --git a/drivers/iio/imu/adis16550.c b/drivers/iio/imu/adis16550.c
new file mode 100644
index 000000000000..49c3ff9ef1e2
--- /dev/null
+++ b/drivers/iio/imu/adis16550.c

@@ -0,0 +1,1202 @@

...

quoted

+static int adis16550_set_accl_filter_freq(struct adis16550 *st, int
freq_hz)
+{
+	bool en = false;
+
+	if (freq_hz)
+		en = true;
+
+	return __adis_update_bits(&st->adis, ADIS16550_REG_CONFIG,
+				  ADIS16550_ACCL_FIR_EN_MASK,
+				 
(u32)FIELD_PREP(ADIS16550_ACCL_FIR_EN_MASK, en));

Why is the cast needed? Only bit 3 is set.

Typically this is needed for the cases where we want to write in 2 byte
registers and we want to make sure sizeof(val) (on the macro evaluation) gives
us the proper size. But yes, for this case as we want 4 bytes, it should not be
needed. Hmm but I think we might get 'unsigned long' from FIELD_PREP() since
mask is also of that type?

- Nuno Sá