The adxl345 sensor offers several features. Most of them are based on using the hardware FIFO and reacting on events coming in on an interrupt line. Add access to configure and read out the FIFO, handling of interrupts and configuration and application of the watermark feature on that FIFO. Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx> --- Although I tried to implement most of the requested changes, now the code is simplified and clearer, I still encounter some issues. 1) Unsure if my way reading out the FIFO elements with a regmap_noinc_read() is supposed to be like that. TBH, isn't there a better way, say, to configure the channel correctly and this is handled by the iio API internally? As I understood from v2 there might be a way using available data, also in iio_info I see now as buffer attributes an available data field. Where can I find information how to use it or did I get this wrong? 2) Overrun handling: I'm trying to reset the FIFO and registers. Unsure, if this is the correct dealing here. 3) I can see the IRQs coming in, and with a `watch -n 0.1 iio_info` I can see the correct fields changing. I tried the follwoing down below, but the iio_readdev shows me the following result. I don't quite understand if I still have an issue here, or if this is a calibration thing? # iio_info Library version: 0.23 (git tag: v0.23) Compiled with backends: local xml ip usb IIO context created with local backend. Backend version: 0.23 (git tag: v0.23) Backend description string: Linux dut1138 6.6.21-lothar02 #3 SMP PREEMPT Wed Nov 6 21:21:14 UTC 2024 aarch64 IIO context has 2 attributes: local,kernel: 6.6.21-lothar02 uri: local: IIO context has 1 devices: iio:device0: adxl345 (buffer capable) 3 channels found: accel_x: (input, index: 0, format: le:s13/16>>0) 4 channel-specific attributes found: attr 0: calibbias value: 0 attr 1: raw value: -14 <--- CHANGES attr 2: sampling_frequency value: 100.000000000 attr 3: scale value: 0.038300 accel_y: (input, index: 1, format: le:s13/16>>0) 4 channel-specific attributes found: attr 0: calibbias value: 0 attr 1: raw value: 6 <--- CHANGES attr 2: sampling_frequency value: 100.000000000 attr 3: scale value: 0.038300 accel_z: (input, index: 2, format: le:s13/16>>0) 4 channel-specific attributes found: attr 0: calibbias value: 0 attr 1: raw value: 247 <--- CHANGES attr 2: sampling_frequency value: 100.000000000 attr 3: scale value: 0.038300 2 device-specific attributes found: attr 0: sampling_frequency_available value: 0.09765625 0.1953125 0.390625 0.78125 1.5625 3.125 6.25 12.5 25 50 100 200 400 800 1600 3200 attr 1: waiting_for_supplier value: 0 3 buffer-specific attributes found: attr 0: data_available value: 13 attr 1: direction value: in attr 2: watermark value: 15 No trigger on this device Above I marked what keeps changing with "CHANGES", that's what I expect. Then with readdev I obtain the following result. # iio_attr -c adxl345 dev 'adxl345', channel 'accel_x' (input, index: 0, format: le:s13/16>>0), found 4 channel-specific attributes dev 'adxl345', channel 'accel_y' (input, index: 1, format: le:s13/16>>0), found 4 channel-specific attributes dev 'adxl345', channel 'accel_z' (input, index: 2, format: le:s13/16>>0), found 4 channel-specific attributes # echo 1 > ./scan_elements/in_accel_x_en # echo 1 > ./scan_elements/in_accel_y_en # echo 1 > ./scan_elements/in_accel_z_en # echo 32 > ./buffer0/length # echo 15 > ./buffer0/watermark # echo 1 > ./buffer0/enable # iio_readdev -b 16 -s 21 adxl345 > samples.dat # hexdump -d ./samples.dat 0000000 65523 00006 00248 65523 00005 00235 65522 00006 0000010 00248 65522 00006 00248 65521 00005 00247 65522 0000020 00007 00249 65523 00005 00249 65521 00006 00248 0000030 65522 00006 00248 65522 00006 00250 65522 00006 0000040 00249 65522 00005 00248 65523 00005 00248 65521 0000050 00007 00248 65521 00006 00250 65522 00005 00248 0000060 65521 00006 00248 65522 00007 00247 65522 00006 0000070 00248 65522 00006 00248 65521 00004 00250 000007e Am I doing this actually correctly? --- v4 -> v5: - fix dt-binding for enum array of INT1 and INT2 v3 -> v4: - fix dt-binding indention v2 -> v3: - reorganize commits, merge the watermark handling - INT lines are defined by binding - kfifo is prepared by devm_iio_kfifo_buffer_setup() - event handler is registered w/ devm_request_threaded_irq() v1 -> v2: Fix comments according to Documentation/doc-guide/kernel-doc.rst and missing static declaration of function. --- Lothar Rubusch (10): iio: accel: adxl345: refrase comment on probe iio: accel: adxl345: rename variable data to st iio: accel: adxl345: measure right-justified iio: accel: adxl345: add function to switch measuring mode iio: accel: adxl345: complete list of defines dt-bindings: iio: accel: add interrupt-names iio: accel: adxl345: introduce interrupt handling iio: accel: adxl345: initialize FIFO delay value for SPI iio: accel: adxl345: prepare channel for scan_index iio: accel: adxl345: add FIFO with watermark events .../bindings/iio/accel/adi,adxl345.yaml | 7 + drivers/iio/accel/adxl345.h | 90 +++- drivers/iio/accel/adxl345_core.c | 427 ++++++++++++++++-- drivers/iio/accel/adxl345_i2c.c | 2 +- drivers/iio/accel/adxl345_spi.c | 7 +- 5 files changed, 478 insertions(+), 55 deletions(-) -- 2.39.2
