[PATCH v4 00/16] Add thermal management support for sama7d65

[Varshini Rajendran <varshini.rajendran@microchip.com>]

Thermal management system of sama7d65 includes:

- Temperature sensor as a part of ADC channel
- Temperature calibration data retrieved from the OTP memory for
  improved accuracy of the readings
- DVFS implementation
- Thermal system with DVFS as cooling cell.

This patch series adds support for the following:

- Tag-based packet lookup for the NVMEM OTPC driver while preserving
  backward compatibility with existing ID-based access
- Temperature calibration layout handling in the ADC driver to support
  different SoC-specific calibration data formats
- ADC driver adaptation for sama7d65
- DT nodes for OTP, ADC, temperature sensor, and thermal zones for
  sama7d65

Changes in v4:
	- Reworked cleanup.h usage: define and assign __free() variables at point
	  of use after early returns, add DEFINE_FREE(nvmem_cell_put, ...) for
	  nvmem_cell cleanup
	- Split patch 3/13 into two: refactoring (layout struct) and tag validation
	- Used struct u32_fract for p1 scaling factors
	- Return -ENODEV instead of -EINVAL when layout is missing
	- New precursor patch to remove unnecessary casts in of_device_id
	- Removed trailing comma from single-line initializer array
	- Moved emulation mode validation into a separate patch
	- Added FourCC validation for packet tags; invalid tags fall back to ID-only
	  access
	- Mentioned FourCC in commit message and comments
	- Used intermediate variable for off % 4
	- Rename tmp → mr_val, val→ tag
	- Addressed style issues: Removed comment blocks, put functions in
	  one line
	- Remove blank line after compatible in regulator node
	- Reorder properties.

Link to v3: https://lore.kernel.org/lkml/20260630093603.38663-1-varshini.rajendran@microchip.com/

Changes in v3:
    - Updated the commit message with reasoning for a new compatible
      without a fallback (sama7d65-adc)
    - Split patch 2/12 into two patches: a patch with cleanup.h changes only
      and the rework patch
    - Added comment explaining the TAG ACST
    - Fixed the holes identified in the at91_adc_platform struct by
      pahole tool
    - Dropped labels in the dt document example
    - Added temp variable in mchp_otpc_resolve_packet() to avoid % and /
      operations in the same instruction (avoiding compiler optimization)
    - Added the SoC details in the ADC driver Kconfig help section
    - Maintained reverse xmas ordering in declarations
    - Fixed node ordering (alphabetically) in the board dts file

Link to v2: https://lore.kernel.org/lkml/20260623105944.128840-1-varshini.rajendran@microchip.com/

Changes in v2:
    - Preserved backward compatibility with ID-based packet lookup to
      avoid breaking existing users
    - Removed sama7g5 DTS changes (not needed with backward compatible
      driver - will be sent later to update to the new access method)
    - Preserved the packet data structure returned not to break the
      consumers
    - Reworked ADC driver to use a calibration layout structure instead of
      hardcoded indexes, for scalability
    - Fixed kernel-doc Return section
    - Removed stray blank line in mchp_otpc_read()
    - Removed unnecessary UL suffix in writel_relaxed()
    - Dropped unused packet types
    - Fixed stray spaces before exclamation marks in error messages
    - Added ASCII representation to TAG macro definition
    - Removed odd MAX enum with trailing comma and refactored
    - Moved DTS patches to the end of series
    - Used cleanup.h helpers for NVMEM data buffer handling in ADC driver
    - Combined multiple v1 patches into logical units
    - Used correct subject prefixes for dt-bindings patches
    - Used fixed-layout NVMEM syntax for sama7d65 DTS and binding
      instead of deprecated syntax
    - Added cpu-supply linkage for proper DVFS voltage scaling
    - Updated stale stride=4 comment in dt-bindings header

Link to v1: https://lore.kernel.org/linux-arm-kernel/20250804100219.63325-1-varshini.rajendran@microchip.com/



Varshini Rajendran (16):
  dt-bindings: iio: adc: at91-sama5d2: document sama7d65
  iio: adc: at91-sama5d2_adc: use cleanup.h for NVMEM buffer
  iio: adc: at91-sama5d2_adc: rework temp calibration layout handling
  iio: adc: at91-sama5d2_adc: add condition to validate calibration data
  iio: adc: at91-sama5d2_adc: remove unnecessary casts in of_device_id
  iio: adc: at91-sama5d2_adc: adapt the driver for sama7d65
  dt-bindings: nvmem: microchip,sama7g5-otpc: add sama7d65 and dt node
    example
  nvmem: microchip-otpc: nvmem: microchip-otpc: add tag-based packet
    lookup
  nvmem: microchip-otpc: nvmem: add emulation mode and OTP access
    validation
  ARM: dts: microchip: sama7d65: add cpu opps
  ARM: dts: microchip: sama7d65: Add ADC node
  ARM: dts: microchip: sama7d65_curiosity: Enable ADC, DVFS
  ARM: dts: microchip: sama7d65: add otpc node
  ARM: dts: microchip: sama7d65: add cells for temperature calibration
  ARM: dts: microchip: sama7d65: add temperature sensor
  ARM: dts: microchip: sama7d65: add thermal zones node

 .../bindings/iio/adc/atmel,sama5d2-adc.yaml   |   1 +
 .../nvmem/microchip,sama7g5-otpc.yaml         |  28 +++-
 .../dts/microchip/at91-sama7d65_curiosity.dts |  27 ++++
 arch/arm/boot/dts/microchip/sama7d65.dtsi     | 131 +++++++++++++++++
 drivers/iio/adc/Kconfig                       |   2 +-
 drivers/iio/adc/at91-sama5d2_adc.c            | 132 ++++++++++++-----
 drivers/nvmem/microchip-otpc.c                | 133 ++++++++++++++++--
 .../nvmem/microchip,sama7g5-otpc.h            |   4 +-
 8 files changed, 404 insertions(+), 54 deletions(-)

-- 
2.34.1