This patch series introduces support for the AAEON SRG-IMX8P embedded
controller (MCU). The MCU is connected via I2C and provides GPIO and
watchdog functionality for the SRG-IMX8P board.

The series includes:
- Device tree binding for the MFD driver
- MFD driver that serves as the core driver for the MCU
- GPIO driver implementing the GPIO functionality
- Watchdog driver for system monitoring
- MAINTAINERS entry for the new drivers

The drivers follow the standard Linux kernel subsystem patterns, with
the MFD driver registering the sub-devices (GPIO and watchdog) which
are then handled by their respective subsystem drivers.

Signed-off-by: Thomas Perrot (Schneider Electric) <thomas.perrot@bootlin.com>
---
Changes in v4:
- mfd: switch to a custom regmap bus; remove aaeon_mcu_i2c_xfer() and the aaeon_mcu_dev struct
- mfd: locking delegated to regmap's built-in mutex; drop explicit mutex
- mfd: remove firmware version reading at probe time
- gpio, watchdog: use regmap_read()/regmap_write() via dev_get_regmap()
- include: replace aaeon_mcu_i2c_xfer() declaration with AAEON_MCU_REG() macro
- dt-bindings: remove unused label from example node
- Link to v3: https://lore.kernel.org/r/20260203-dev-b4-aaeon-mcu-driver-v3-0-0a19432076ac@bootlin.com

Changes in v3:
- Renamed SRG-IMX8PL to SRG-IMX8P
- dt-bindings: add gpio-controller properties as required
- mfd: move struct aaeon_mcu_dev from header to .c file (private)
- mfd: use guard(mutex) and devm_mutex_init() for cleanup
- mfd: firmware version log changed to dev_dbg()
- mfd: add select MFD_CORE to Kconfig
- Kconfig: add || COMPILE_TEST to all three drivers
- watchdog: add comments explaining hardware timeout and WDOG_HW_RUNNING
- watchdog: remove unused platform_set_drvdata()
- watchdog: add a function to query the status
- Link to v2: https://lore.kernel.org/r/20260123-dev-b4-aaeon-mcu-driver-v2-0-9f4c00bfb5cb@bootlin.com

Changes in v2:
- Fold GPIO and watchdog bindings into MFD binding
- Drop OF_GPIO dependency in GPIO Kconfig
- Use __set_bit/__clear_bit/__assign_bit instead of atomic variants
- Various driver cleanups and improvements
- Link to v1: https://lore.kernel.org/r/20251212-dev-b4-aaeon-mcu-driver-v1-0-6bd65bc8ef12@bootlin.com

---
Thomas Perrot (Schneider Electric) (5):
      dt-bindings: vendor-prefixes: Add AAEON vendor prefix
      dt-bindings: mfd: Add AAEON embedded controller
      mfd: aaeon: Add SRG-IMX8P MCU driver
      gpio: aaeon: Add GPIO driver for SRG-IMX8P MCU
      watchdog: aaeon: Add watchdog driver for SRG-IMX8P MCU

 .../bindings/mfd/aaeon,srg-imx8p-mcu.yaml          |  67 +++++++
 .../devicetree/bindings/vendor-prefixes.yaml       |   2 +
 MAINTAINERS                                        |  10 +
 drivers/gpio/Kconfig                               |  10 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-aaeon-mcu.c                      | 221 +++++++++++++++++++++
 drivers/mfd/Kconfig                                |  10 +
 drivers/mfd/Makefile                               |   1 +
 drivers/mfd/aaeon-mcu.c                            | 155 +++++++++++++++
 drivers/watchdog/Kconfig                           |  10 +
 drivers/watchdog/Makefile                          |   1 +
 drivers/watchdog/aaeon_mcu_wdt.c                   | 134 +++++++++++++
 include/linux/mfd/aaeon-mcu.h                      |  20 ++
 13 files changed, 642 insertions(+)
---
base-commit: d358e5254674b70f34c847715ca509e46eb81e6f
change-id: 20251211-dev-b4-aaeon-mcu-driver-e0e89ebf4afb

Best regards,
-- 
Thomas Perrot (Schneider Electric) <thomas.perrot@bootlin.com>

Hi,

On 3/24/26 12:24, Thomas Perrot (Schneider Electric) wrote:
> This patch series introduces support for the AAEON SRG-IMX8P embedded
> controller (MCU). The MCU is connected via I2C and provides GPIO and
> watchdog functionality for the SRG-IMX8P board.
> 
> The series includes:
> - Device tree binding for the MFD driver
> - MFD driver that serves as the core driver for the MCU
> - GPIO driver implementing the GPIO functionality
> - Watchdog driver for system monitoring
> - MAINTAINERS entry for the new drivers
> 
> The drivers follow the standard Linux kernel subsystem patterns, with
> the MFD driver registering the sub-devices (GPIO and watchdog) which
> are then handled by their respective subsystem drivers.
> 
> Signed-off-by: Thomas Perrot (Schneider Electric) <thomas.perrot@bootlin.com>

Sashiko reports a number of issues with this series.

https://sashiko.dev/#/patchset/20260324-dev-b4-aaeon-mcu-driver-v4-0-afb011df4794%40bootlin.com

I can not comment on the non-watchdog concerns, even though the ones I looked at
seem to be valid. However, please address the watchdog subsystem related comments.
If functionality such as CONFIG_WATCHDOG_NOWAYOUT is explicitly not supported,
please add the rationale as comment into the driver.

Thanks,
Guenter