[PATCH 00/10] hwmon: Drop unused platform data support and max197 driver

[Guenter Roeck <linux@roeck-us.net>]

Several drivers in drivers/hwmon still support configuration through
platform data structures even though no in-tree platform or board code
ever instantiates or supplies that platform data.

Audit all hwmon drivers using dev_get_platdata(), dev->platform_data, or
headers under include/linux/platform_data/ and drop dead platform data
support where it is never provided in-tree:

- ads7828, emc2305, g762, gsc-hwmon, ltc4245, mcp3021, and shtc1 already
  support configuring the respective parameters via devicetree / fwnode
  properties (and/or hardware registers). Drop platform data support,
  remove the unused platform data headers, and update documentation and
  MAINTAINERS entries accordingly.

- f75375s already initializes PWM mode and enable state from chip
  registers during probe and exposes pwm and pwm_enable via standard
  hwmon sysfs attributes. Drop platform data support and remove
  include/linux/f75375s.h.

- ds620 clears PO2 by default when no platform data is provided, keeping
  the thermostat output pin low as a valid default configuration. Drop
  platform data support and remove include/linux/platform_data/ds620.h.

- max197 requires platform data supplying a convert() callback function
  pointer and fails to probe without it. Since no in-tree user ever
  instantiates the device or provides max197_platform_data, remove the
  unused driver along with its platform data header, Kconfig/Makefile
  entries, and documentation.

Tooling and Testing Notes
-------------------------
Per Documentation/process/generated-content.rst:
- Tool used: Jetski AI coding assistant (Gemini).
- Prompt summary: Identify all drivers in drivers/hwmon whose platform
  data is never supplied in-tree; remove platform data support and
  unused platform data headers where an alternate configuration means
  exists (including ds620's default PO2 configuration), and remove both
  the driver and header where platform data is mandatory.
- Scope of generated content: Code changes, documentation/Kconfig/
  MAINTAINERS updates, commit descriptions, and this cover letter.
- Testing: Verified with out-of-tree W=1 builds of drivers/hwmon/ under
  both allmodconfig (CONFIG_OF=y) and CONFIG_OF=n, as well as
  scripts/checkpatch.pl --strict. Not runtime-tested on hardware.

Cc: Tim Harvey <tharvey@gateworks.com>
Cc: Nuno Sá <nuno.sa@analog.com>
Cc: Riku Voipio <riku.voipio@iki.fi>

Guenter Roeck (10):
  hwmon: (ads7828) Drop platform data support
  hwmon: (emc2305) Drop platform data support
  hwmon: (g762) Drop platform data support
  hwmon: (gsc-hwmon) Drop platform data support
  hwmon: (ltc4245) Drop platform data support
  hwmon: (mcp3021) Drop platform data support
  hwmon: (shtc1) Drop platform data support
  hwmon: (max197) Remove driver
  hwmon: (f75375s) Drop platform data support
  hwmon: (ds620) Drop platform data support

 Documentation/hwmon/ads7828.rst         |  21 --
 Documentation/hwmon/ds620.rst           |  12 +-
 Documentation/hwmon/g762.rst            |   4 +-
 Documentation/hwmon/index.rst           |   1 -
 Documentation/hwmon/ltc4245.rst         |   6 +-
 Documentation/hwmon/max197.rst          |  70 -----
 Documentation/hwmon/shtc1.rst           |   3 +-
 MAINTAINERS                             |   2 -
 drivers/hwmon/Kconfig                   |   9 -
 drivers/hwmon/Makefile                  |   1 -
 drivers/hwmon/ads7828.c                 |  13 +-
 drivers/hwmon/ds620.c                   |  13 +-
 drivers/hwmon/emc2305.c                 |  44 +--
 drivers/hwmon/f75375s.c                 | 100 +++----
 drivers/hwmon/g762.c                    |  50 +---
 drivers/hwmon/gsc-hwmon.c               |  72 +++--
 drivers/hwmon/ltc4245.c                 |  21 +-
 drivers/hwmon/max197.c                  | 341 ------------------------
 drivers/hwmon/mcp3021.c                 |  18 +-
 drivers/hwmon/shtc1.c                   |  23 +-
 include/linux/f75375s.h                 |  21 --
 include/linux/platform_data/ads7828.h   |  26 --
 include/linux/platform_data/ds620.h     |  22 --
 include/linux/platform_data/emc2305.h   |  28 --
 include/linux/platform_data/g762.h      |  24 --
 include/linux/platform_data/gsc_hwmon.h |  45 ----
 include/linux/platform_data/ltc4245.h   |  17 --
 include/linux/platform_data/max197.h    |  23 --
 include/linux/platform_data/shtc1.h     |  14 -
 29 files changed, 121 insertions(+), 923 deletions(-)
 delete mode 100644 Documentation/hwmon/max197.rst
 delete mode 100644 drivers/hwmon/max197.c
 delete mode 100644 include/linux/f75375s.h
 delete mode 100644 include/linux/platform_data/ads7828.h
 delete mode 100644 include/linux/platform_data/ds620.h
 delete mode 100644 include/linux/platform_data/emc2305.h
 delete mode 100644 include/linux/platform_data/g762.h
 delete mode 100644 include/linux/platform_data/gsc_hwmon.h
 delete mode 100644 include/linux/platform_data/ltc4245.h
 delete mode 100644 include/linux/platform_data/max197.h
 delete mode 100644 include/linux/platform_data/shtc1.h

-- 
2.56.0