esp32: add esp32 wifi driver

add support for esp32 wifi

Signed-off-by: Shubham Kulkarni <shubham.kulkarni@espressif.com>

drivers/wifi/CMakeLists.txt

@@ -4,3 +4,4 @@ add_subdirectory_ifdef(CONFIG_WIFI_WINC1500	winc1500)
 add_subdirectory_ifdef(CONFIG_WIFI_SIMPLELINK	simplelink)
 add_subdirectory_ifdef(CONFIG_WIFI_ESWIFI	eswifi)
 add_subdirectory_ifdef(CONFIG_WIFI_ESP		esp)
+add_subdirectory_ifdef(CONFIG_WIFI_ESP32        esp32)

drivers/wifi/Kconfig

@@ -33,5 +33,6 @@ source "drivers/wifi/winc1500/Kconfig.winc1500"
 source "drivers/wifi/simplelink/Kconfig.simplelink"
 source "drivers/wifi/eswifi/Kconfig.eswifi"
 source "drivers/wifi/esp/Kconfig.esp"
+source "drivers/wifi/esp32/Kconfig.esp32"
 
 endif # WIFI

drivers/wifi/esp32/CMakeLists.txt

@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_sources_ifdef(CONFIG_WIFI_ESP32
+  src/esp_wifi_drv.c
+  )

drivers/wifi/esp32/Kconfig.esp32

@@ -0,0 +1,232 @@
+# Copyright 2020 Espressif Systems (Shanghai) PTE LTD
+
+menuconfig WIFI_ESP32
+	bool "ESP32 SoC WiFi support"
+	select POSIX_API
+	select THREAD_CUSTOM_DATA
+	select DYNAMIC_INTERRUPTS
+	help
+	  Enable ESP32 SoC WiFi support.
+
+	  Note: POSIX_API is required by Wifi library. It shall be removed
+	  once NEWLIB gets supported.
+
+if WIFI_ESP32
+
+config ESP32_WIFI_SSID
+	string "SSID of WiFi network"
+	help
+	  SSID (network name) for the application to connect to.
+
+config ESP32_WIFI_PASSWORD
+	string "Password (WPA or WPA2) of WiFi network"
+	help
+	  WiFi password (WPA or WPA2) for the example to use.
+
+config ESP32_WIFI_STA_AUTO
+	bool "Automatically connect to configured WiFi SSID"
+	help
+	  WiFi driver will automatically connect to SSID.
+
+config ESP32_WIFI_STA_RECONNECT
+	bool "WiFi connection retry"
+	default y
+	help
+	  Set auto WiFI reconnection when disconnected.
+
+config ESP32_WIFI_EVENT_TASK_STACK_SIZE
+	int "Event Task Stack Size"
+	default 4096
+
+config ESP32_WIFI_EVENT_TASK_PRIO
+	int "Event Task Priority"
+	default 4
+
+config ESP32_WIFI_STATIC_RX_BUFFER_NUM
+	int "Max number of WiFi static RX buffers"
+	range 2 25
+	default 10
+	help
+	  Set the number of WiFi static RX buffers. Each buffer takes approximately
+	  1.6KB of RAM. The static rx buffers are allocated when esp_wifi_init is
+	  called, they are not freed until esp_wifi_deinit is called.
+
+	  WiFi hardware use these buffers to receive all 802.11 frames. A higher
+	  number may allow higher throughput but increases memory use.
+	  If ESP32_WIFI_AMPDU_RX_ENABLED is enabled, this value is recommended to
+	  set equal or bigger than ESP32_WIFI_RX_BA_WIN in order to achieve better
+	  throughput and compatibility with both stations and APs.
+
+config ESP32_WIFI_DYNAMIC_RX_BUFFER_NUM
+	int "Max number of WiFi dynamic RX buffers"
+	range 0 128
+	default 32
+	help
+	  Set the number of WiFi dynamic RX buffers, 0 means unlimited RX buffers
+	  will be allocated (provided sufficient free RAM). The size of each dynamic
+	  RX buffer depends on the size of the received data frame.
+
+	  For each received data frame, the WiFi driver makes a copy to an RX buffer
+	  and then delivers it to the high layer TCP/IP stack. The dynamic RX buffer
+	  is freed after the higher layer has successfully received the data frame.
+
+	  For some applications, WiFi data frames may be received faster than the
+	  application can process them. In these cases we may run out of memory if
+	  RX buffer number is unlimited (0). If a dynamic RX buffer limit is set,
+	  it should be at least the number of static RX buffers.
+
+choice ESP32_WIFI_TX_BUFFER
+	prompt "Type of WiFi TX buffers"
+	default ESP32_WIFI_DYNAMIC_TX_BUFFER
+	help
+	  Select type of WiFi TX buffers:
+
+	  If "Static" is selected, WiFi TX buffers are allocated when WiFi is
+	  initialized and released when WiFi is de-initialized. The size of each
+	  static TX buffer is fixed to about 1.6KB.
+
+	  If "Dynamic" is selected, each WiFi TX buffer is allocated as needed
+	  when a data frame is delivered to the Wifi driver from the TCP/IP stack.
+	  The buffer is freed after the data frame has been sent by the WiFi driver.
+	  The size of each dynamic TX buffer depends on the length of each data
+	  frame sent by the TCP/IP layer.
+
+	  If PSRAM is enabled, "Static" should be selected to guarantee enough
+	  WiFi TX buffers. If PSRAM is disabled, "Dynamic" should be selected
+	  to improve the utilization of RAM.
+
+	config ESP32_WIFI_STATIC_TX_BUFFER
+		bool "Static"
+	config ESP32_WIFI_DYNAMIC_TX_BUFFER
+		bool "Dynamic"
+endchoice
+
+config ESP32_WIFI_TX_BUFFER_TYPE
+	int
+	default 0 if ESP32_WIFI_STATIC_TX_BUFFER
+	default 1 if ESP32_WIFI_DYNAMIC_TX_BUFFER
+
+config ESP32_WIFI_STATIC_TX_BUFFER_NUM
+	int "Max number of WiFi static TX buffers"
+	depends on ESP32_WIFI_STATIC_TX_BUFFER
+	range 1 64
+	default 16
+	help
+	  Set the number of WiFi static TX buffers. Each buffer takes approximately
+	  1.6KB of RAM. The static RX buffers are allocated when esp_wifi_init() is
+	  called, they are not released until esp_wifi_deinit() is called.
+
+	  For each transmitted data frame from the higher layer TCP/IP stack,
+	  the WiFi driver makes a copy of it in a TX buffer.  For some applications
+	  especially UDP applications, the upper layer can deliver frames faster
+	  than WiFi layer can transmit.
+	  In these cases, we may run out of TX buffers.
+
+config ESP32_WIFI_CACHE_TX_BUFFER_NUM
+	int "Max number of WiFi cache TX buffers"
+	range 16 128
+	default 32
+	help
+	  Set the number of WiFi cache TX buffer number.
+
+	  For each TX packet from uplayer, such as LWIP etc, WiFi driver needs to
+	  allocate a static TX buffer and makes a copy of uplayer packet. If WiFi
+	  driver fails to allocate the static TX buffer, it caches the uplayer
+	  packets to a dedicated buffer queue, this option is used to configure the
+	  size of the cached TX queue.
+
+config ESP32_WIFI_DYNAMIC_TX_BUFFER_NUM
+	int "Max number of WiFi dynamic TX buffers"
+	depends on ESP32_WIFI_DYNAMIC_TX_BUFFER
+	range 1 128
+	default 32
+	help
+	  Set the number of WiFi dynamic TX buffers. The size of each
+	  dynamic TXbuffer is not fixed, it depends on the size of each
+	  transmitted data frame.
+
+	  For each transmitted frame from the higher layer TCP/IP stack,
+	  the WiFi driver makes a copy of it in a TX buffer. For some applications,
+	  especially UDP applications, the upper layer can deliver frames faster
+	  than WiFi layer can transmit. In these cases, we may run out of TX
+	  buffers.
+
+config ESP32_WIFI_CSI_ENABLED
+	bool "WiFi CSI(Channel State Information)"
+	help
+	  Select this option to enable CSI(Channel State Information) feature.
+	  CSI takes about CONFIG_ESP32_WIFI_STATIC_RX_BUFFER_NUM KB of RAM.
+	  If CSI is not used, it is better to disable this feature in order
+	  to save memory.
+
+config ESP32_WIFI_AMPDU_TX_ENABLED
+	bool "WiFi AMPDU TX"
+	default y
+	help
+	  Select this option to enable AMPDU TX feature. It improves transmission
+	  error checking and overall network performance with the cost of processing
+	  speed. Helpful when the device is operating in crowded wireless area.
+
+config ESP32_WIFI_TX_BA_WIN
+	int "WiFi AMPDU TX BA window size"
+	depends on ESP32_WIFI_AMPDU_TX_ENABLED
+	range 2 32
+	default 6
+	help
+	  Set the size of WiFi Block Ack TX window. Generally a bigger value means
+	  higher throughput but more memory. Most of time we should NOT change the
+	  default value unless special reason, e.g. test the maximum
+	  UDP TX throughput with iperf etc. For iperf test in shieldbox,
+	  the recommended value is 9~12.
+
+config ESP32_WIFI_AMPDU_RX_ENABLED
+	bool "WiFi AMPDU RX"
+	default y
+	help
+	  Select this option to enable AMPDU RX feature. It improves transmission
+	  error checking and overall network performance with the cost of processing
+	  speed. Helpful when the device is operating in crowded wireless area.
+
+config ESP32_WIFI_RX_BA_WIN
+	int "WiFi AMPDU RX BA window size"
+	depends on ESP32_WIFI_AMPDU_RX_ENABLED
+	range 2 32
+	default 6
+	help
+	  Set the size of WiFi Block Ack RX window. Generally a bigger value means
+	  higher throughput and better compatibility but more memory. Most of time
+	  we should NOT change the default value unless special reason,
+	  e.g. test the maximum UDP RX throughput with iperf etc. For iperf test in
+	  shieldbox, the recommended value is 9~12. If PSRAM is used and WiFi memory
+	  is preferred to allocat in PSRAM first, the default and minimum value
+	  should be 16 to achieve better throughput and compatibility with both
+	  stations and APs.
+
+choice ESP32_WIFI_TASK_CORE_ID
+	prompt "WiFi Task Core ID"
+	default ESP32_WIFI_TASK_PINNED_TO_CORE_0
+	help
+	  Pinned WiFi task to core 0 (core 1 not supported yet)
+
+	config ESP32_WIFI_TASK_PINNED_TO_CORE_0
+		bool "Core 0"
+endchoice
+
+config ESP32_PHY_MAX_WIFI_TX_POWER
+	int "Max WiFi TX power (dBm)"
+	range 10 20
+	default 20
+	help
+	  Set maximum transmit power for WiFi radio. Actual transmit power for high
+	  data rates may be lower than this setting.
+
+config ESP32_PHY_MAX_TX_POWER
+	int
+	default ESP32_PHY_MAX_WIFI_TX_POWER
+
+config ESP32_WIFI_SW_COEXIST_ENABLE
+	bool
+	help
+	  Software controls WiFi/Bluetooth coexistence. Not supported yet.
+
+endif # WIFI_ESP32

drivers/wifi/esp32/src/esp_wifi_drv.c

@@ -0,0 +1,184 @@
+/*
+ * Copyright (c) 2020 Espressif Systems (Shanghai) Co., Ltd.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT espressif_esp32_wifi
+
+#include <logging/log.h>
+LOG_MODULE_REGISTER(esp32_wifi, CONFIG_WIFI_LOG_LEVEL);
+
+#include <net/ethernet.h>
+#include <net/net_pkt.h>
+#include <net/net_if.h>
+#include <device.h>
+#include <soc.h>
+#include <ethernet/eth_stats.h>
+#include "esp_networking_priv.h"
+#include "esp_private/wifi.h"
+#include "esp_event.h"
+#include "esp_timer.h"
+#include "esp_wifi_system.h"
+#include "esp_wpa.h"
+
+#define DEV_DATA(dev) \
+	((struct esp32_wifi_runtime *)(dev)->data)
+
+/* use global iface pointer to support any ethernet driver */
+/* necessary for wifi callback functions */
+static struct net_if *esp32_wifi_iface;
+
+struct esp32_wifi_runtime {
+	struct net_if *iface;
+	uint8_t mac_addr[6];
+	bool tx_err;
+	uint32_t tx_word;
+	int tx_pos;
+	uint8_t frame_buf[NET_ETH_MAX_FRAME_SIZE];
+#if defined(CONFIG_NET_STATISTICS_ETHERNET)
+	struct net_stats_eth stats;
+#endif
+};
+
+static int eth_esp32_send(const struct device *dev, struct net_pkt *pkt)
+{
+	const int pkt_len = net_pkt_get_len(pkt);
+
+	/* Read the packet payload */
+	if (net_pkt_read(pkt, DEV_DATA(dev)->frame_buf, pkt_len) < 0) {
+		return -EIO;
+	}
+
+	/* Enqueue packet for transmission */
+	esp_wifi_internal_tx(ESP_IF_WIFI_STA, (void *)DEV_DATA(dev)->frame_buf, pkt_len);
+
+	LOG_DBG("pkt sent %p len %d", pkt, pkt_len);
+
+	return 0;
+}
+
+static esp_err_t eth_esp32_rx(void *buffer, uint16_t len, void *eb)
+{
+	struct net_pkt *pkt;
+
+	if (esp32_wifi_iface == NULL) {
+		LOG_ERR("network interface unavailable");
+		return ESP_FAIL;
+	}
+
+	pkt = net_pkt_rx_alloc_with_buffer(esp32_wifi_iface, len,
+			AF_UNSPEC, 0, K_NO_WAIT);
+	if (!pkt) {
+		LOG_ERR("Failed to get net buffer");
+		return ESP_FAIL;
+	}
+
+	if (net_pkt_write(pkt, buffer, len) < 0) {
+		LOG_ERR("Failed to write pkt");
+		goto pkt_unref;
+	}
+
+	if (net_recv_data(esp32_wifi_iface, pkt) < 0) {
+		LOG_ERR("Failed to push received data");
+		goto pkt_unref;
+	}
+
+	esp_wifi_internal_free_rx_buffer(eb);
+	return ESP_OK;
+
+pkt_unref:
+	net_pkt_unref(pkt);
+	return ESP_FAIL;
+}
+
+/* internally used by wifi hal layer */
+void esp_wifi_set_net_state(bool state)
+{
+	if (esp32_wifi_iface == NULL) {
+		LOG_ERR("network interface unavailable");
+		return;
+	}
+
+	if (state) {
+		net_if_up(esp32_wifi_iface);
+	} else {
+		net_if_down(esp32_wifi_iface);
+	}
+}
+
+static void eth_esp32_init(struct net_if *iface)
+{
+	const struct device *dev = net_if_get_device(iface);
+	struct esp32_wifi_runtime *dev_data = DEV_DATA(dev);
+
+	dev_data->iface = iface;
+	esp32_wifi_iface = iface;
+
+	/* Start interface when we are actually connected with WiFi network */
+	net_if_flag_set(iface, NET_IF_NO_AUTO_START);
+	esp_read_mac(dev_data->mac_addr, ESP_MAC_WIFI_STA);
+
+	/* Assign link local address. */
+	net_if_set_link_addr(iface,
+			dev_data->mac_addr, 6, NET_LINK_ETHERNET);
+
+	ethernet_init(iface);
+
+	esp_wifi_internal_reg_rxcb(ESP_IF_WIFI_STA, eth_esp32_rx);
+}
+
+#if defined(CONFIG_NET_STATISTICS_ETHERNET)
+static struct net_stats_eth *eth_esp32_stats(const struct device *dev)
+{
+	return &(DEV_DATA(dev)->stats);
+}
+#endif
+
+static int eth_esp32_dev_init(const struct device *dev)
+{
+	esp_timer_init();
+	esp_event_init();
+
+	wifi_init_config_t config = WIFI_INIT_CONFIG_DEFAULT();
+	esp_err_t ret = esp_wifi_init(&config);
+
+	ret |= esp_supplicant_init();
+	ret |= esp_wifi_start();
+
+	if (IS_ENABLED(CONFIG_ESP32_WIFI_STA_AUTO)) {
+		wifi_config_t wifi_config = {
+			.sta = {
+				.ssid = CONFIG_ESP32_WIFI_SSID,
+				.password = CONFIG_ESP32_WIFI_PASSWORD,
+			},
+		};
+
+		ret = esp_wifi_set_mode(WIFI_MODE_STA);
+		ret |= esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config);
+		ret |= esp_wifi_connect();
+	}
+
+	if (ret != ESP_OK) {
+		LOG_ERR("Connect failed");
+	}
+
+	return ret;
+}
+
+
+static struct esp32_wifi_runtime eth_data;
+
+static const struct ethernet_api eth_esp32_apis = {
+	.iface_api.init	= eth_esp32_init,
+	.send =  eth_esp32_send,
+#if defined(CONFIG_NET_STATISTICS_ETHERNET)
+	.get_stats = eth_esp32_stats,
+#endif
+};
+
+NET_DEVICE_DT_INST_DEFINE(0,
+		eth_esp32_dev_init, device_pm_control_nop,
+		&eth_data, NULL, CONFIG_ETH_INIT_PRIORITY,
+		&eth_esp32_apis, ETHERNET_L2,
+		NET_L2_GET_CTX_TYPE(ETHERNET_L2), NET_ETH_MTU);

dts/xtensa/espressif/esp32.dtsi

@@ -50,6 +50,11 @@
 			status = "ok";
 		};
 
+	wifi: wifi {
+		compatible = "espressif,esp32-wifi";
+		status = "disabled";
+	};
+
 		uart0: uart@3ff40000 {
 			compatible = "espressif,esp32-uart";
 			reg = <0x3ff40000 0x400>;
@@ -161,5 +166,7 @@
 			clocks = <&rtc ESP32_SPI3_MODULE>;
 			status = "disabled";
 		};
+
 	};
+
 };

soc/xtensa/esp32/linker.ld

@@ -39,6 +39,7 @@ PROVIDE ( crc32_le = 0x4005cfec );
 PROVIDE ( Cache_Read_Disable_rom = 0x40009ab8 );
 PROVIDE ( Cache_Read_Enable_rom = 0x40009a84 );
 PROVIDE ( Cache_Read_Init_rom = 0x40009950 );
+PROVIDE ( phy_get_romfuncs = 0x40004100 );
 PROVIDE ( SPI1 = 0x3ff42fff );
 PROVIDE ( SPI2 = 0x3ff64fff );
 PROVIDE ( SPI3 = 0x3ff65fff );