Add polling_interval and its usage to ethernet.rst

components/ethernet.rst

@@ -90,11 +90,30 @@ SPI configuration variables:
 - **miso_pin** (**Required**, :ref:`config-pin`): The SPI MISO pin.
 - **cs_pin** (**Required**, :ref:`config-pin`): The SPI chip select pin.
 - **interrupt_pin** (*Optional*, :ref:`config-pin`): The interrupt pin.
+  This variable is **required** for older frameworks. See below.
 - **reset_pin** (*Optional*, :ref:`config-pin`): The reset pin.
 - **clock_speed** (*Optional*, float): The SPI clock speed.
   Any frequency between `8Mhz` and `80Mhz` is allowed, but the nearest integer division
   of `80Mhz` is used, i.e. `16Mhz` (`80Mhz` / 5) is used when `15Mhz` is configured.
   Default: `26.67Mhz`.
+- **polling_interval** (*Optional*, :ref:`config-time`): If ``interrupt_pin`` is not set,
+  set the time interval for periodic polling. Minimum is 1ms, Defaults to 10ms.
+  Older frameworks may not support this variable. See below for details.
+
+If you are using a framework with the latest version, ESPHome provides
+an SPI-based Ethernet module without interrupt pin.
+Support for SPI polling mode (no interrupt pin) is provided by the following frameworks:
+
+- ESP-IDF 5.3 or later
+- ESP-IDF 5.2.1 and later 5.2.x versions
+- ESP-IDF 5.1.4
+- Arduino-ESP32 3.0.0 or later (**Caution**: PlatformIO does not support these Arduino-ESP32 versions)
+
+When building with frameworks that support SPI polling mode, either ``interrupt_pin``
+or ``polling_interval`` can be set. If you set both, ESPHome will throw an error.
+
+If you are using a framework that does not support SPI-based ethernet modules without interrupt pin,
+``interrupt_pin`` is **required** and you cannot set ``polling_interval``.
 
 Advanced common configuration variables:
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^