====== Unifi Switch Lite 16 PoE ======

A fanless 16-port switch with 8 PoE+ ports and built-in power supply. Rated PoE power budget is 45W.

====== Components ======

  * SoC: RTL8382M
  * RAM: 128MiB DDR3 (Winbond W631GG8MB-15)
  * Flash: 16MiB SPI NOR (Macronix MX25L12835FMI-10G)
  * Ethernet ports:
    * 1-8: SoC's internal RTL8218B
    * 9-16: External RTL8218B
  * PoE: Broadcom platform
    * Nuvoton M0516LDN management MCU
    * 1× Broadcom BCM59121 PSE controller
  * Extra I/O
    * 2× NXP PCA9555A: 16-bit I2C GPIO expander
    * 5× 74VHC595: 8-bit latching shift register with 3-state output enable (U112, U114, U117, U118, U119)
  * Power supply: 100V-240V AC with C13 plug, internal PSU provides power for PoE and switch functions. Low voltage power is managed by an internal TPS23754 802.3at PD controller.

====== Board configuration ======

  * SoC
    * gpio 0: reset button
    * gpio 1: /INT of PCA9555 @ 25, falling edge/active low
    * gpio 2: I2C-0 SCL (bit banged)
    * gpio 3: I2C-0 SDA (bit banged)
    * gpio 12: I2C-1 SCL (bit banged). Defined in OEM, but not used.
    * gpio 13: I2C-1 SDA (bit banged). Defined in OEM, but not used.
  * I2C-0: 5 devices reported by ''i2cdetect''
    * PoE MCU @ 0x20 (U49)
    * PCA9555A @ 0x22 (U11)
      * /INT: cascaded into U469:P1_7 (gpio 15 on PCA9555A @ 25)
      * gpio 0: port 2 amber PoE status LED
      * gpio 1: port 1 amber PoE status LED
      * gpio 2: port 4 amber PoE status LED
      * gpio 3: port 3 amber PoE status LED
      * gpio 4: port 6 amber PoE status LED
      * gpio 5: port 5 amber PoE status LED
      * gpio 6: port 8 amber PoE status LED
      * gpio 7: port 7 amber PoE status LED
    * PCA9555A @ 0x25 (U469)
      * /INT: cascaded into SoC gpio 1
      * gpio 8: white LED, active high
      * gpio 9: blue LED, active high
      * gpio 10: PoE output enable, active high
      * gpio 15: /INT of PCA9555A @ 22, active low (interrupt on falling edge)
    * NCT375 (LM75A compatible) @ 0x48 (U152): SoC temperature
    * NCT375 (LM75A compatible) @ 0x49 (U153): phy temperature
  * I2C-1: no devices reported by ''i2cdetect''