esp: hal: i2c (#500)

Author: Grazfather

examples/espressif/esp/build.zig

@@ -21,6 +21,7 @@ pub fn build(b: *std.Build) void {
         .{ .name = "blinky", .file = "src/blinky.zig" },
         .{ .name = "custom_clock_config", .file = "src/custom_clock_config.zig" },
         .{ .name = "gpio_input", .file = "src/gpio_input.zig" },
+        .{ .name = "i2c_bus_scan", .file = "src/i2c_bus_scan.zig" },
         .{ .name = "stepper_driver", .file = "src/stepper_driver.zig" },
         .{ .name = "stepper_driver_dumb", .file = "src/stepper_driver_dumb.zig" },
         .{ .name = "systimer", .file = "src/systimer.zig" },

examples/espressif/esp/src/i2c_bus_scan.zig

@@ -0,0 +1,42 @@
+const std = @import("std");
+const microzig = @import("microzig");
+const time = microzig.drivers.time;
+
+const esp = microzig.hal;
+const i2c = esp.i2c;
+const gpio = esp.gpio;
+const peripherals = microzig.chip.peripherals;
+
+const i2c0 = i2c.instance.num(0);
+
+const usb_serial_jtag = esp.usb_serial_jtag;
+
+pub const microzig_options = microzig.Options{
+    .logFn = usb_serial_jtag.logger.logFn,
+};
+
+pub fn main() !void {
+    const sda_pin = gpio.num(6);
+    const scl_pin = gpio.num(5);
+
+    // TODO: Should this be done in apply?
+    // Enable I2C peripheral clock
+    peripherals.SYSTEM.PERIP_CLK_EN0.modify(.{ .I2C_EXT0_CLK_EN = 1 });
+    // Take I2C out of reset
+    peripherals.SYSTEM.PERIP_RST_EN0.modify(.{ .I2C_EXT0_RST = 0 });
+
+    try i2c0.apply(
+        .{ .sda = sda_pin, .scl = scl_pin },
+        100_000,
+    );
+
+    // for (0x20..0x21) |addr| {
+    for (0..std.math.maxInt(u7)) |addr| {
+        const a: i2c.Address = @enumFromInt(addr);
+
+        var rx_data: [1]u8 = undefined;
+        _ = i2c0.read_blocking(a, &rx_data, time.Duration.from_ms(250)) catch continue;
+
+        std.log.info("I2C device found at address {X}.", .{addr});
+    }
+}

examples/raspberrypi/rp2xxx/src/i2c_bus_scan.zig

@@ -42,9 +42,6 @@ pub fn main() !void {
     for (0..std.math.maxInt(u7)) |addr| {
         const a: i2c.Address = @enumFromInt(addr);
 
-        // Skip over any reserved addresses.
-        if (a.is_reserved()) continue;
-
         var rx_data: [1]u8 = undefined;
         _ = i2c0.read_blocking(a, &rx_data, time.Duration.from_ms(100)) catch continue;
 

port/espressif/esp/src/hal.zig

@@ -4,6 +4,7 @@ pub const clocks = @import("hal/clocks.zig");
 pub const compatibility = @import("hal/compatibility.zig");
 pub const drivers = @import("hal/drivers.zig");
 pub const gpio = @import("hal/gpio.zig");
+pub const i2c = @import("hal/i2c.zig");
 pub const rom = @import("hal/rom.zig");
 pub const system = @import("hal/system.zig");
 pub const systimer = @import("hal/systimer.zig");