Sensors driver for GPD Handhelds that expose fan reading and control via
hwmon sysfs.

Shenzhen GPD Technology Co., Ltd. manufactures a series of handheld
devices. This driver implements these functions through x86 port-mapped IO.

Tested-by: Marcin Strągowski <marcin@stragowski.com>
Tested-by: someone5678 <someone5678.dev@gmail.com>
Tested-by: Justin Weiss <justin@justinweiss.com>
Tested-by: Antheas Kapenekakis <lkml@antheas.dev>
Tested-by: command_block <mtf@ik.me>

Signed-off-by: Cryolitia PukNgae <Cryolitia@gmail.com>

---
Changes in v6:
- fix: nullptr and label followed by a declaration
- cleanup: clean up code and rename some function
- format code
- dmi: add 2025 new GPD devices
- Link to v5: https://lore.kernel.org/r/20250211-gpd_fan-v5-0-608f4255f0e1@gmail.com

Changes in v5:
- Rebase on kernel 6.13
- Remove all value-cache related code
- Clean up code
- Link to v4: https://lore.kernel.org/r/20240718-gpd_fan-v4-0-116e5431a9fe@gmail.com

Changes in v4:
- Apply suggest by Krzysztof Kozlowski, thanks!
- Link to v3: https://lore.kernel.org/r/20240717-gpd_fan-v3-0-8d7efb1263b7@gmail.com

Changes in v3:
- Re-arrange code, thanks to Krzysztof Kozlowski, Guenter Roeck, Yao Zi!
- Link to v2: https://lore.kernel.org/r/20240717-gpd_fan-v2-0-f7b7e6b9f21b@gmail.com

Changes in v2:
- Improved documentation, thanks to Randy Dunlap!
- Link to v1: https://lore.kernel.org/r/20240716-gpd_fan-v1-0-34051dd71a06@gmail.com

---
Cryolitia PukNgae (2):
      hwmon: add GPD devices sensor driver
      hwmon: document: add gpd-fan

 Documentation/hwmon/gpd-fan.rst |  71 +++++
 Documentation/hwmon/index.rst   |   1 +
 MAINTAINERS                     |   7 +
 drivers/hwmon/Kconfig           |  10 +
 drivers/hwmon/Makefile          |   1 +
 drivers/hwmon/gpd-fan.c         | 681 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 771 insertions(+)
---
base-commit: ffd294d346d185b70e28b1a28abe367bbfe53c04
change-id: 20240716-gpd_fan-57f30923c884

Best regards,
-- 
Cryolitia PukNgae <Cryolitia@gmail.com>