feat(openthread): support bus_latency for dual-chip BR solution

Author: tanyanquan

components/openthread/Kconfig

@@ -379,6 +379,12 @@ menu "OpenThread"
                 help
                     The device's XTAL accuracy, in ppm.
 
+            config OPENTHREAD_BUS_LATENCY
+                int "The bus latency between host and radio chip"
+                default 4000
+                help
+                    The device's bus latency, in us.
+
             config OPENTHREAD_MLE_MAX_CHILDREN
                 int "The size of max MLE children entries"
                 default 10

components/openthread/src/port/esp_openthread_radio_spinel.cpp

@@ -516,3 +516,27 @@ uint32_t otPlatRadioGetSupportedChannelMask(otInstance *aInstance)
     // Refer to `GetRadioChannelMask(bool aPreferred)`: FALSE to get supported channel mask
     return s_radio.GetRadioChannelMask(false);
 }
+
+uint32_t otPlatRadioGetBusSpeed(otInstance *aInstance)
+{
+    OT_UNUSED_VARIABLE(aInstance);
+
+#if CONFIG_OPENTHREAD_RADIO_SPINEL_UART
+    return s_esp_openthread_radio_config->radio_uart_config.uart_config.baud_rate;
+#elif CONFIG_OPENTHREAD_RADIO_SPINEL_SPI
+    return s_esp_openthread_radio_config->radio_spi_config.spi_device.clock_speed_hz;
+#else
+    return 0;
+#endif
+}
+
+uint32_t otPlatRadioGetBusLatency(otInstance *aInstance)
+{
+    OT_UNUSED_VARIABLE(aInstance);
+
+#if CONFIG_OPENTHREAD_RADIO_SPINEL_UART || CONFIG_OPENTHREAD_RADIO_SPINEL_SPI
+    return CONFIG_OPENTHREAD_BUS_LATENCY;
+#else
+    return 0;
+#endif
+}