[PATCH v2 0/3] i2c: Add Novatek NT726xx SoC I2C controller

[Nina_Kuo]

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From: Ben Huang <Ben_Huang@xxxxxxxxxxxxxx>


These patch series adds support for the I2C bus controllers on
Novatek NT726xx SoCs.

The controller driver implements the fundamental I2C read/write
operations and supports Standard-mode and Fast-mode.

Some I2C bus controllers on Novatek NT726xx SoCs are controllable by
stbc (Standby controller) and named as `stbc-i2c`s. These `stbc-i2c`s
are driven by stbc clock (12 MHz) and require the authentication to
stbc before any control.

The patch is tested with concurrent read/write operations on
2 different I2C busses for 1000000 times on Novatek NT72676 SoC.
Neither error nor data corruption is detected under this test.

---
v2:
  From Krzysztof's review of novatek,nt726xx-i2c.yaml:
  - Explicitly specify the unique compatibles "novatek,nt72600-i2c" for
    Novatek NT726xx SoCs
  - Modify `maxItems` as 1 for both `reg` and `interrupts` properties
  - Modify description and allowed values for `clock-frequency`
    property
  - Remove `minItems` for `novatek,hwmods` custom property
  - Rename, fix wrong type definition and add more description for
    `novatek,stbc-controllable` custom property
  - Remove `bus-enable` custom property
  - Add an example for dtsi declaration

  From Sashiko AI's review of i2c-nt726xx.c:
  - Remove flows related to `bus-enable` custom property
  - Add default value 100000 (100 kHz) of `clock-frequency` property
    to prevent from devide-by-zero panic
  - Add flows for handling ioremap() in nvt_i2c_use_case_feature()
  - Remove I2C_FUNC_SMBUS_QUICK functionality due to unsupported handling
    of 0-byte messages
  - Add flows of disabling IRQs in nvt_i2c_suspend() and nvt_i2c_remove()
  - Add of_node_get() to release the reference to device tree node in
    nvt_i2c_remove()

v1:
  https://lore.kernel.org/lkml/20260604060411.355675-1-SP_ISW1_AT@xxxxxxxxxxxxxx/T/#t

Signed-off-by: Ben Huang <Ben_Huang@xxxxxxxxxxxxxx>
Signed-off-by: Nina Kuo <Nina_Kuo@xxxxxxxxxxxxxx>


Ben Huang (3):
  MAINTAINERS: Add entry for Novatek NT726xx SoC I2C controller driver
  dt-bindings: i2c: Add Novatek NT726xx SoC I2C controller
  i2c: Add i2c-nt726xx.c I2C driver for Novatek NT726xx SoCs

 .../bindings/i2c/novatek,nt726xx-i2c.yaml     |  74 ++
 MAINTAINERS                                   |   7 +
 drivers/i2c/busses/Kconfig                    |  10 +
 drivers/i2c/busses/Makefile                   |   1 +
 drivers/i2c/busses/i2c-nt726xx.c              | 698 ++++++++++++++++++
 5 files changed, 790 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/i2c/novatek,nt726xx-i2c.yaml
 create mode 100644 drivers/i2c/busses/i2c-nt726xx.c

-- 
2.40.1