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tom-dudleyTom Dudley
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Tom Dudley
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Add basic WiFi support for CYW43 driver (ZigEmbeddedGroup#777)
Co-authored-by: Tom Dudley <[email protected]>
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-6
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15 files changed

+1619
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lines changed

‎drivers/framework.zig‎

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@@ -69,6 +69,7 @@ pub const IO_expander = struct {
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};
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pub const wireless = struct {
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pub const cyw43 = @import("wireless/cyw43/cyw43.zig");
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pub const cyw43_bus = @import("wireless/cyw43/bus.zig");
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pub const cyw43_runner = @import("wireless/cyw43/runner.zig");
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pub const Cyw43_Spi = cyw43_bus.Cyw43_Spi;

‎drivers/wireless/cyw43/bus.zig‎

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@@ -39,6 +39,10 @@ pub const Cyw43_Bus = struct {
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internal_delay_ms: *const delayus_callback,
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backplane_window: u32 = 0xAAAA_AAAA,
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// WLAN packet buffers (u32 aligned for SPI)
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wlan_tx_buf: [512]u32 = undefined, // 2048 bytes
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wlan_rx_buf: [512]u32 = undefined, // 2048 bytes
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pub fn init_bus(self: *Self) !void {
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// Init sequence
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try self.pwr_pin.write(.low);
@@ -328,6 +332,45 @@ pub const Cyw43_Bus = struct {
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inline fn swap16(x: u32) u32 {
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return x << 16 | x >> 16;
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}
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/// Get buffer for building WLAN TX packets.
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/// Returns byte slice starting after the command word (which wlan_send will fill).
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pub fn get_wlan_tx_buffer(self: *Self) []u8 {
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return std.mem.sliceAsBytes(self.wlan_tx_buf[1..]);
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}
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/// Send WLAN packet. Caller should have written packet data to get_wlan_tx_buffer().
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/// Builds command word and performs SPI transaction.
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pub fn wlan_send(self: *Self, len: usize) void {
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const aligned_len = (len + 3) & ~@as(usize, 3);
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const cmd = Cyw43Cmd{
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.cmd = .write,
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.incr = .incremental,
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.func = .wlan,
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.addr = 0,
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.len = @intCast(aligned_len),
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};
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self.wlan_tx_buf[0] = @bitCast(cmd);
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const words = (aligned_len + 3) / 4;
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// spi_write_blocking returns chip status register, not byte count
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_ = self.spi.spi_write_blocking(self.wlan_tx_buf[0 .. words + 1]);
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}
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/// Receive WLAN packet. Returns slice of received data.
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pub fn wlan_recv(self: *Self, len: usize) []const u8 {
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const words = (len + 3) / 4;
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const cmd = Cyw43Cmd{
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.cmd = .read,
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.incr = .incremental,
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.func = .wlan,
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.addr = 0,
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.len = @intCast(len),
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};
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// spi_read_blocking returns chip status register, not byte count
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_ = self.spi.spi_read_blocking(@bitCast(cmd), self.wlan_rx_buf[0..words]);
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return std.mem.sliceAsBytes(self.wlan_rx_buf[0..words])[0..len];
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}
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};
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const CmdType = enum(u1) {

‎drivers/wireless/cyw43/cyw43.zig‎

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,28 @@
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// CYW43 WiFi Driver
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// Top-level entry point for the CYW43439 WiFi chip
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const std = @import("std");
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const bus = @import("bus.zig");
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const runner_mod = @import("runner.zig");
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const wifi_mod = @import("wifi.zig");
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pub const Runner = runner_mod.Cyw43_Runner;
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pub const Wifi = wifi_mod.CYW43_Wifi;
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pub const Bus = bus.Cyw43_Bus;
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pub const Security = wifi_mod.Security;
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pub const Event = wifi_mod.Event;
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/// Initialize CYW43 chip and return Runner
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/// Loads firmware and prepares chip for WiFi operations.
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/// Use runner.wifi() to access WiFi configuration (enable, join, etc.)
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/// Use runner.run() in your main loop to poll for packets
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/// Use runner.get_rx_frame() to retrieve received data
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pub fn init(cyw43_bus: *Bus, delay_ms: *const fn (u32) void) !Runner {
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var cyw43_runner = Runner{
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.bus = cyw43_bus,
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.internal_delay_ms = delay_ms,
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};
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try cyw43_runner.init();
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return cyw43_runner;
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}

‎drivers/wireless/cyw43/runner.zig‎

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Original file line numberDiff line numberDiff line change
@@ -2,6 +2,7 @@ const std = @import("std");
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const bus = @import("bus.zig");
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const consts = @import("consts.zig");
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const nvram = @import("nvram.zig");
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const wifi_mod = @import("wifi.zig");
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/// Callback for microsecond delays
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pub const delayus_callback = fn (delay: u32) void;
@@ -15,6 +16,17 @@ pub const Cyw43_Runner = struct {
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bus: *bus.Cyw43_Bus,
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internal_delay_ms: *const delayus_callback,
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// WiFi instance (initialized in init())
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wifi_instance: wifi_mod.CYW43_Wifi = undefined,
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// RX frame buffer (valid until next run() call)
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// NOTE: Single-frame buffer. If get_rx_frame() is not called before the next
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// run() receives data, the previous frame is lost. For high-throughput or
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// bursty traffic, we may want to replace with a ring buffer.
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rx_frame_buf: [1600]u8 = undefined,
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rx_frame_len: usize = 0,
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has_rx_frame: bool = false,
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pub fn init(self: *Self) !void {
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try self.bus.init_bus();
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@@ -99,6 +111,9 @@ pub const Cyw43_Runner = struct {
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self.log_init();
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// Initialize WiFi layer
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self.wifi_instance = wifi_mod.CYW43_Wifi.init(self.bus);
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// TODO: bluetooth setup
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log.debug("cyw43 runner init done", .{});
@@ -208,10 +223,37 @@ pub const Cyw43_Runner = struct {
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}
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}
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211-
pub fn run(self: *Self) void {
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while (true) {
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self.log_read();
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/// Run one poll cycle. Returns true if there was activity.
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/// Received data frames are buffered and can be retrieved via get_rx_frame().
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pub fn run(self: *Self) bool {
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// Clear previous frame
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self.has_rx_frame = false;
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// Poll WiFi - processes events, may return data
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if (try self.wifi_instance.poll()) |frame| {
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// Buffer the received frame
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const copy_len = @min(frame.len, self.rx_frame_buf.len);
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@memcpy(self.rx_frame_buf[0..copy_len], frame[0..copy_len]);
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self.rx_frame_len = copy_len;
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self.has_rx_frame = true;
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return true;
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}
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return false;
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}
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/// Get the last received ethernet frame, if any.
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/// Returns null if no frame was received in the last run() call.
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pub fn get_rx_frame(self: *Self) ?[]const u8 {
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if (self.has_rx_frame) {
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return self.rx_frame_buf[0..self.rx_frame_len];
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}
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return null;
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}
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/// Get pointer to WiFi instance for configuration (enable, join, etc.)
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pub fn wifi(self: *Self) *wifi_mod.CYW43_Wifi {
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return &self.wifi_instance;
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}
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};
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