drivers: wifi: Add WiFi drivers for ESP hosted firmware.

This is a host driver for ESP32 chips running the esp-hosted
firmware, which turns ESP32s into a WLAN/BT co-processor.

Signed-off-by: Ibrahim Abdalkader <[email protected]>

Author: iabdalkader

drivers/wifi/CMakeLists.txt

@@ -20,6 +20,7 @@ endif() # CONFIG_BUILD_ONLY_NO_BLOBS
 
 add_subdirectory_ifdef(CONFIG_WIFI_ESP_AT       esp_at)
 add_subdirectory_ifdef(CONFIG_WIFI_ESP32        esp32)
+add_subdirectory_ifdef(CONFIG_WIFI_ESP_HOSTED   esp_hosted)
 add_subdirectory_ifdef(CONFIG_WIFI_ESWIFI       eswifi)
 add_subdirectory_ifdef(CONFIG_WIFI_SIMPLELINK   simplelink)
 add_subdirectory_ifdef(CONFIG_WIFI_WINC1500     winc1500)

drivers/wifi/Kconfig

@@ -40,6 +40,7 @@ source "drivers/wifi/simplelink/Kconfig.simplelink"
 source "drivers/wifi/eswifi/Kconfig.eswifi"
 source "drivers/wifi/esp_at/Kconfig.esp_at"
 source "drivers/wifi/esp32/Kconfig.esp32"
+source "drivers/wifi/esp_hosted/Kconfig.esp_hosted"
 source "drivers/wifi/nxp/Kconfig.nxp"
 source "drivers/wifi/infineon/Kconfig.airoc"
 source "drivers/wifi/nrf_wifi/Kconfig.nrfwifi"

drivers/wifi/esp_hosted/CMakeLists.txt

@@ -0,0 +1,27 @@
+# Copyright (c) 2025 Arduino SA
+# SPDX-License-Identifier: Apache-2.0
+
+if (CONFIG_WIFI_ESP_HOSTED)
+
+zephyr_library_named(esp_hosted)
+
+list(APPEND CMAKE_MODULE_PATH ${ZEPHYR_BASE}/modules/nanopb)
+include(nanopb)
+
+zephyr_library_sources(
+  esp_hosted_hal.c
+  esp_hosted_wifi.c
+)
+
+zephyr_nanopb_sources(esp_hosted
+  esp_hosted_proto.pb
+)
+
+zephyr_include_directories(
+  ./
+)
+
+zephyr_compile_definitions(
+    PB_ENABLE_MALLOC=1
+)
+endif()

drivers/wifi/esp_hosted/Kconfig.esp_hosted

@@ -0,0 +1,42 @@
+# ESP Hosted WiFi driver options
+
+# Copyright (c) 2025 Arduino SA
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig WIFI_ESP_HOSTED
+	bool "ESP_HOSTED driver support"
+	depends on DT_HAS_ESPRESSIF_ESP_HOSTED_ENABLED
+	default y
+	select GPIO
+	select SPI
+	select WIFI_OFFLOAD
+	select WIFI_NM
+	select NANOPB
+	select NET_L2_ETHERNET
+	select NET_L2_WIFI_MGMT
+	select WIFI_USE_NATIVE_NETWORKING
+
+if WIFI_ESP_HOSTED
+
+config WIFI_ESP_HOSTED_DEBUG
+	bool "Enable extra debugging messages"
+	help
+	  Enable stack debugging messages.
+
+config WIFI_ESP_HOSTED_EVENT_TASK_PRIORITY
+	int "Event Task priority"
+	default 4
+
+config WIFI_ESP_HOSTED_EVENT_TASK_STACK_SIZE
+	int "Event Task Stack Size"
+	default 16384
+
+config WIFI_ESP_HOSTED_AP_CLIENTS_MAX
+	int "Max number of AP clients"
+	default 5
+
+config WIFI_ESP_HOSTED_AP_CHANNEL_DEF
+	int "Default AP channel"
+	default 9
+
+endif

drivers/wifi/esp_hosted/esp_hosted_hal.c

@@ -0,0 +1,85 @@
+/*
+ * Copyright (c) 2025 Arduino SA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdint.h>
+#include <string.h>
+
+#include <zephyr/kernel.h>
+#include "esp_hosted_wifi.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(esp_hosted_hal, CONFIG_WIFI_LOG_LEVEL);
+
+int esp_hosted_hal_init(const struct device *dev)
+{
+	const esp_hosted_config_t *config = dev->config;
+
+	if (!spi_is_ready_dt(&config->spi_bus)) {
+		LOG_ERR("SPI device is not ready");
+		return -ENODEV;
+	}
+
+	/* Configure pins. */
+	gpio_pin_configure_dt(&config->dataready_gpio, GPIO_OUTPUT);
+	gpio_pin_configure_dt(&config->reset_gpio, GPIO_OUTPUT);
+
+	/* Perform a hard-reset */
+	gpio_pin_set_dt(&config->dataready_gpio, 1);
+	gpio_pin_set_dt(&config->reset_gpio, 0);
+	k_msleep(100);
+	gpio_pin_set_dt(&config->reset_gpio, 1);
+	k_msleep(500);
+
+	/* Configure handshake/dataready pins. */
+	gpio_pin_configure_dt(&config->dataready_gpio, GPIO_INPUT);
+	gpio_pin_configure_dt(&config->handshake_gpio, GPIO_INPUT);
+
+	return 0;
+}
+
+bool esp_hosted_hal_data_ready(const struct device *dev)
+{
+	const esp_hosted_config_t *config = dev->config;
+
+	return gpio_pin_get_dt(&config->dataready_gpio);
+}
+
+int esp_hosted_hal_spi_transfer(const struct device *dev, void *tx, void *rx, uint32_t size)
+{
+	int ret = 0;
+	esp_hosted_data_t *data = dev->data;
+	const esp_hosted_config_t *config = dev->config;
+
+	const struct spi_buf tx_buf = {.buf = tx ? tx : rx, .len = size};
+	const struct spi_buf_set tx_set = {.buffers = &tx_buf, .count = 1};
+
+	const struct spi_buf rx_buf = {.buf = rx ? rx : tx, .len = size};
+	const struct spi_buf_set rx_set = {.buffers = &rx_buf, .count = 1};
+
+	/* Wait for handshake pin to go high. */
+	for (uint64_t start = k_uptime_get();; k_msleep(1)) {
+		if (gpio_pin_get_dt(&config->handshake_gpio) &&
+		    (rx == NULL || gpio_pin_get_dt(&config->dataready_gpio))) {
+			break;
+		}
+		if ((k_uptime_get() - start) >= 100) {
+			return -ETIMEDOUT;
+		}
+	}
+
+	if (k_sem_take(&data->bus_sem, K_FOREVER) != 0) {
+		return -1;
+	}
+
+	/* Transfer SPI buffers. */
+	if (spi_transceive_dt(&config->spi_bus, &tx_set, &rx_set)) {
+		LOG_ERR("spi_transceive failed");
+		ret = -EIO;
+	}
+
+	k_sem_give(&data->bus_sem);
+	return ret;
+}

drivers/wifi/esp_hosted/esp_hosted_hal.h

@@ -0,0 +1,12 @@
+/*
+ * Copyright (c) 2025 Arduino SA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef MICROPY_INCLUDED_DRIVERS_ESP_HOSTED_HAL_H
+#define MICROPY_INCLUDED_DRIVERS_ESP_HOSTED_HAL_H
+int esp_hosted_hal_init(const struct device *dev);
+bool esp_hosted_hal_data_ready(const struct device *dev);
+int esp_hosted_hal_spi_transfer(const struct device *dev, void *tx, void *rx, uint32_t size);
+#endif /* MICROPY_INCLUDED_DRIVERS_ESP_HOSTED_HAL_H */

drivers/wifi/esp_hosted/esp_hosted_proto.options

@@ -0,0 +1,8 @@
+*.ssid max_size:32 max_length:31
+*.bssid max_size:17
+*.mac max_size:17
+*.pwd max_size:64 max_length:63
+*.entries type:FT_POINTER
+*.stations type:FT_POINTER
+*.init_data max_size:0
+esp_hosted_proto.pb max_size:256 max_count:64 anonymous_oneof:true type:FT_STATIC