[PATCH v3 0/6] iio: adc: xilinx-xadc: Add I2C interface support for System Management Wizard

[Dileep Kumar Nagavarapu]

The existing driver only supported AXI memory-mapped access to the System
Management Wizard IP. This series extends the driver to support I2C-based
access, which is particularly useful for System Controller usecases.

Key Changes:
- Split the xilinx-xadc-core.c file into two files(xilinx-xadc-core.c and
  xilinx-xadc-platform.c)
- Add required helper functions and callbacks
- Add channel configuration via callback mechanism
- New I2C driver for UltraScale+ System Management Wizard for basic
  voltage and temperature monitoring
- Converted text binding to YAML schema format

Note: We are working on x86 platform support where fixed channel
configuration is used(no DT support). The .setup_channels() function
pointer introduced in patch 2/4 enables different channel configuration
approaches for various platforms.

This series was originally posted by Sai Krishna Potthuri.

Link:https://lore.kernel.org/all/20260323074505.3853353-1-sai.krishna.potthuri@xxxxxxx/

I will be maintaining the series going forward and posting updated
revisions.

Changes in v3:
-> 1/6 - Modernized the driver code with latest kernel coding styles
         and guidelines.
       - Restored one-variable-per-line declarations where no
         functional change  was intended.
       - Added unit suffixes to timing and clock-rate constants.
       - Replaced GENMASK() and FIELD_PREP() in appropriate places.
       - Added guard(spinlock_irq) helper to manage the spinlock
         automatically on scope exit.
       - Added MAINTAINERS entry for XILINX XADC driver.
-> 2/6 - Refactored the xadc_setup_buffer_and_triggers function
         with only two arguments.
       - Added xadc_device_setup() and xadc_device_configure() to handle
         device initialization and configuration separately.
-> 3/6 - Added IIO_XADC namespace to all exported symbols and
         imported the namespace in platform specific modulue.
       - Spliting the driver with modrern driver changes.
-> 4/6 - Added .setup_channels() to handle custom channel setup
         and configuration.
-> 5/6 - Replaced mutex initialization with devm_mutex_init()
       - Removed unused i2c_set_clientdata() usage.
       - Added comments describing the DRP packet layout used
         for I2C  transactions.
       - Added comment for hardware initialization check from xadc i2c
         write and read functions.
       - Wrapped Kconfig help text to conform to kernel style guidelines.
       - Switched device setup error handling to dev_err_probe().
-> 6/6 - Removed write edge default configuration in XADCIF_CFG register.
-> Dropped the binding to YAML conversion patch as this is already sent by
   Pramod Maurya and is in discussion.

Changes in v2:
-> 1/4 - Split the xilinx-xadc-core.c file into two files
         xilinx-xadc-core.c and xilinx-xadc-platform.c(comments from Andy).
-> 2/4 - Referred as .setup_channels instead of setup_channels.
-> 3/4 - Created separate functions for i2c read and write.
       - Created separate file for i2c interface handling.
-> 4/4(comments from Krzysztof)
       - Removed $defs and use it directly under xlnx,channels.
       - Documented the error information in the commit message due to
         vendor prefix properties.
       - Kept only one example as there is not much differences.


Dileep Kumar Nagavarapu (6):
  iio: adc: xilinx-xadc: Modernize driver code
  iio: adc: xilinx-xadc: Add helper functions for the device setup
  iio: adc: xilinx-xadc: Split driver into core and platform files
  iio: adc: xilinx-xadc: Add .setup_channels() to struct xadc_ops
  iio: adc: xilinx-xadc: Add I2C interface support
  iio: adc: xilinx-xadc: Correct Write edge in CFG

 MAINTAINERS                                   |    7 +
 drivers/iio/adc/Kconfig                       |   23 +-
 drivers/iio/adc/Makefile                      |    6 +-
 drivers/iio/adc/xilinx-xadc-core.c            |  886 ++------------
 drivers/iio/adc/xilinx-xadc-events.c          |   54 +-
 drivers/iio/adc/xilinx-xadc-i2c.c             |  228 ++++
 ...inx-xadc-core.c => xilinx-xadc-platform.c} | 1043 ++---------------
 drivers/iio/adc/xilinx-xadc.h                 |  108 +-
 8 files changed, 609 insertions(+), 1746 deletions(-)
 create mode 100644 drivers/iio/adc/xilinx-xadc-i2c.c
 copy drivers/iio/adc/{xilinx-xadc-core.c => xilinx-xadc-platform.c} (34%)

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2.34.1