[PATCH v5 0/5] iio: ad3552r-hs: add support for internal ramp generator

[Angelo Dureghello]

Add support to enable the HDL IP core internal ramp generator,
actually managed by the adi-axi-dac backend. 

It works this way:

/sys/bus/iio/devices/iio:device0# echo 1 > buffer0/out_voltage0_en 
/sys/bus/iio/devices/iio:device0# echo 1 > buffer0/out_voltage1_en                                           
/sys/bus/iio/devices/iio:device0# echo 1 > buffer0/enable 

Activating ramp generator:

/sys/kernel/debug/iio/iio:device0# echo -n backend-ramp-generator > data_source

Deactivating:

/sys/kernel/debug/iio/iio:device0# echo -n iio-buffer > data_source

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
Changes in v5:
- remove kmalloc, use a small buffer in the stack,
- change debugfs data_source names.
- Link to v4: https://lore.kernel.org/r/20250408-wip-bl-ad3552r-fixes-v4-0-b33c0264bd78@xxxxxxxxxxxx

Changes in v4:
- set data source based on hw channels available (model_data),
- use a string array for data_source debugfs attribute,
- modify debugfs accessors to use the string array,
- add new "data_source_available" debugfs attr,
- fix documentation accordingly.
- Link to v3: https://lore.kernel.org/r/20250407-wip-bl-ad3552r-fixes-v3-0-61874065b60f@xxxxxxxxxxxx

Changes in v3:
- add mutex description,
- use devm_mutex_init and check for return value.
- Link to v2: https://lore.kernel.org/r/20250331-wip-bl-ad3552r-fixes-v2-0-cdedb430497e@xxxxxxxxxxxx

Changes in v2:
- doc, add few words for generic spi driver version,
- axi-dac, add a separate patch to check cntrl chan validity,
- axi-dac, return EIO on a wrong source on get, 
- add a lock on debugfs file access,
- use const strings and strlen on file access.
- Link to v1: https://lore.kernel.org/r/20250321-wip-bl-ad3552r-fixes-v1-0-3c1aa249d163@xxxxxxxxxxxx

---
Angelo Dureghello (5):
      iio: dac: adi-axi-dac: add cntrl chan check
      docs: iio: add documentation for ad3552r driver
      iio: backend: add support for data source get
      iio: dac: adi-axi-dac: add data source get
      iio: dac: ad3552r-hs: add support for internal ramp

 Documentation/iio/ad3552r.rst      |  73 +++++++++++++++++
 Documentation/iio/index.rst        |   1 +
 MAINTAINERS                        |   1 +
 drivers/iio/dac/ad3552r-hs.c       | 162 +++++++++++++++++++++++++++++++++++--
 drivers/iio/dac/adi-axi-dac.c      |  54 +++++++++++++
 drivers/iio/industrialio-backend.c |  28 +++++++
 include/linux/iio/backend.h        |   5 ++
 7 files changed, 318 insertions(+), 6 deletions(-)
---
base-commit: 3677b089b9739b69c8e1c1eb99092230cbcf741f
change-id: 20250321-wip-bl-ad3552r-fixes-4a386944c170

Best regards,
-- 
Angelo Dureghello <adureghello@xxxxxxxxxxxx>