Support esp_wifi_remote for esp32p4.

CHANGELOG.md

@@ -62,7 +62,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - NVS: Implemented `RawHandle` for `EspNvs<NvsDefault>`
 - NVS: Added `EspNvs::erase_all` to remove all data stored in an nvs namespace
 - NVS: Added `EspNvs::keys` to iterate over all stored keys
-- esp32p4: This chip has no radio, so wifi has been disabled for this
+- esp32p4: This chip has no radio, but can use wifi via esp_wifi_remote. Support for esp_wifi_remote has been added.
 - HTTP: added `keep_alive_*` option into configuration
 
 ## [0.51.0] - 2025-01-15

src/lib.rs

@@ -105,9 +105,9 @@ pub mod thread;
 pub mod timer;
 pub mod tls;
 #[cfg(all(
-    not(any(esp32h2, esp32p4)),
+    not(esp32h2),
     feature = "alloc",
-    esp_idf_comp_esp_wifi_enabled,
+    any(esp_idf_comp_esp_wifi_enabled, esp_idf_comp_esp_wifi_remote_enabled),
     esp_idf_comp_esp_event_enabled,
 ))]
 pub mod wifi;

src/netif.rs

@@ -80,9 +80,26 @@ impl NetifStack {
     fn default_mac(&self) -> Result<Option<[u8; 6]>, EspError> {
         if let Some(mac_type) = self.default_mac_raw_type() {
             let mut mac = [0; 6];
-            esp!(unsafe { esp_read_mac(mac.as_mut_ptr() as *mut _, mac_type) })?;
 
-            Ok(Some(mac))
+            // On SoCs without native WiFi hardware (e.g., ESP32-P4 using
+            // esp_wifi_remote), the eFuse has no WiFi MAC address.
+            // esp_read_mac will fail for WiFi MAC types. Return None and let
+            // esp_wifi_start() set the real MAC from the companion chip later.
+            #[cfg(not(esp_idf_soc_wifi_supported))]
+            {
+                let err = unsafe { esp_read_mac(mac.as_mut_ptr() as *mut _, mac_type) };
+                if err == ESP_OK {
+                    return Ok(Some(mac));
+                } else {
+                    return Ok(None);
+                }
+            }
+
+            #[cfg(esp_idf_soc_wifi_supported)]
+            {
+                esp!(unsafe { esp_read_mac(mac.as_mut_ptr() as *mut _, mac_type) })?;
+                Ok(Some(mac))
+            }
         } else {
             Ok(None)
         }

src/wifi.rs

@@ -2373,18 +2373,39 @@ impl EspEventDeserializer for WifiEvent<'_> {
                 ),
             )))]
             wifi_event_t_WIFI_EVENT_HOME_CHANNEL_CHANGE => {
-                let payload = unsafe {
-                    (data.payload.unwrap() as *const _ as *const wifi_event_home_channel_change_t)
-                        .as_ref()
+                #[cfg(esp_idf_soc_wifi_supported)]
+                {
+                    let payload = unsafe {
+                        (data.payload.unwrap() as *const _
+                            as *const wifi_event_home_channel_change_t)
+                            .as_ref()
+                    }
+                    .unwrap();
+
+                    WifiEvent::HomeChannelChange(HomeChannelChange {
+                        old_chan: payload.old_chan,
+                        old_snd: payload.old_snd.try_into().ok(),
+                        new_chan: payload.new_chan,
+                        new_snd: payload.new_snd.try_into().ok(),
+                    })
+                }
+
+                // On SoCs without native WiFi (using esp_wifi_remote), this
+                // event may fire without a payload.
+                #[cfg(not(esp_idf_soc_wifi_supported))]
+                {
+                    let payload = data
+                        .payload
+                        .map(|p| p as *const _ as *const wifi_event_home_channel_change_t)
+                        .and_then(|p| unsafe { p.as_ref() });
+
+                    WifiEvent::HomeChannelChange(HomeChannelChange {
+                        old_chan: payload.map_or(0, |p| p.old_chan),
+                        old_snd: payload.and_then(|p| p.old_snd.try_into().ok()),
+                        new_chan: payload.map_or(0, |p| p.new_chan),
+                        new_snd: payload.and_then(|p| p.new_snd.try_into().ok()),
+                    })
                 }
-                .unwrap();
-
-                WifiEvent::HomeChannelChange(HomeChannelChange {
-                    old_chan: payload.old_chan,
-                    old_snd: payload.old_snd.try_into().ok(),
-                    new_chan: payload.new_chan,
-                    new_snd: payload.new_snd.try_into().ok(),
-                })
             }
             _ => panic!("unknown event ID: {event_id}"),
         }