[PATCH net-next v6 0/2] Add Si3474 PSE controller driver

[Piotr Kubik <piotr.kubik@adtran.com>]

From: Piotr Kubik <piotr.kubik@adtran.com>

These patch series provide support for Skyworks Si3474 I2C Power
Sourcing Equipment controller.

Based on the TPS23881 driver code.

Supported features of Si3474:
- get port status,
- get port power,
- get port voltage,
- enable/disable port power

Signed-off-by: Piotr Kubik <piotr.kubik@adtran.com>
---

Repost due to closed merge window, no changes.

Changes in v6:
  - Remove unnecessary chan id range checks.
  - Fix return value for incorrect DT channels parse.
  - Simplify bit logic for 'is_enabled' assignment.
  - Remove unnecessary init values assignment.
  - Fix code style issues (apply correct reverse xmas tree notation, remove extra brackets).
  - Link to v5: https://lore.kernel.org/netdev/be0fb368-79b6-4b99-ad6b-00d7897ca8b0@adtran.com

Changes in v5:
  - Remove inline function declarations.
  - Fix code style issues (apply reverse xmas tree notation, remove extra brackets).
  - Remove unnecessary "!= 0" check.
  - Link to v4: https://lore.kernel.org/netdev/c0c284b8-6438-4163-a627-bbf5f4bcc624@adtran.com

Changes in v4:
  - Remove parsing of pse-pis node; now relies solely on the pcdev->pi[x] provided by the framework.
  - Set the DETECT_CLASS_ENABLE register, ensuring reliable PI power-up without artificial delays.
  - Introduce helper macros for bit manipulation logic.
  - Add si3474_get_channels() and si3474_get_chan_client() helpers to reduce redundant code.
  - Kconfig: Clarify that only 4-pair PSE configurations are supported.
  - Fix second channel voltage read if the first one is inactive.
  - Avoid reading currents and computing power when PI voltage is zero.
  - Link to v3: https://lore.kernel.org/netdev/f975f23e-84a7-48e6-a2b2-18ceb9148675@adtran.com

Changes in v3:
  - Use _scoped version of for_each_child_of_node().
  - Remove redundant return value assignments in si3474_get_of_channels().
  - Change dev_info() to dev_dbg() on successful probe.
  - Rename all instances of "slave" to "secondary".
  - Register devm cleanup action for ancillary i2c, simplifying cleanup logic in si3474_i2c_probe().
  - Add explicit return 0 on successful probe.
  - Drop unnecessary .remove callback.
  - Update channel node description in device tree binding documentation.
  - Reorder reg and reg-names properties in device tree binding documentation.
  - Rename all "slave" references to "secondary" in device tree bindings documentation.
  - Link to v2: https://lore.kernel.org/netdev/bf9e5c77-512d-4efb-ad1d-f14120c4e06b@adtran.com

Changes in v2:
  - Handle both IC quads via single driver instance
  - Add architecture & terminology description comment
  - Change pi_enable, pi_disable, pi_get_admin_state to use PORT_MODE register
  - Rename power ports to 'pi'
  - Use i2c_smbus_write_byte_data() for single byte registers
  - Coding style improvements
  - Link to v1: https://lore.kernel.org/netdev/a92be603-7ad4-4dd3-b083-548658a4448a@adtran.com

---
Piotr Kubik (2):
  dt-bindings: net: pse-pd: Add bindings for Si3474 PSE controller
  net: pse-pd: Add Si3474 PSE controller driver

 .../bindings/net/pse-pd/skyworks,si3474.yaml  | 144 +++++
 drivers/net/pse-pd/Kconfig                    |  11 +
 drivers/net/pse-pd/Makefile                   |   1 +
 drivers/net/pse-pd/si3474.c                   | 568 ++++++++++++++++++
 4 files changed, 724 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/pse-pd/skyworks,si3474.yaml
 create mode 100644 drivers/net/pse-pd/si3474.c

-- 
2.43.0