Better HAL for STM32F303 (#729)

* Rework STM32F303 HAL to better match other HAL and fix to support latest regz register.

* Add alternate function to GPIO

* Migrate UART for STM32F303 to its own file and add better support.

* Add logging function for STM32F303

* Initial setup for RCC.

* Add I2C and improve FPU for stm32f3 core

Author: mathk

core/src/cpus/cortex_m/m4.zig

@@ -84,6 +84,23 @@ pub const SystemControlBlock = extern struct {
     BFAR: u32,
     /// Auxilary Feature Register.
     AFSR: u32,
+    reserved0: [18]u32,
+    CPACR: mmio.Mmio(packed struct(u32) {
+        reserved0: u20,
+        CP10: Privilege,
+        CP11: Privilege,
+        reserved1: u8,
+
+        pub const Privilege = enum(u2) {
+            /// Access denied. Any attempted access generates a NOCP UsageFault.
+            access_denied = 0b00,
+            /// Privileged access only. An unprivileged access generates a NOCP UsageFault.
+            priviledged_access_only = 0b01,
+            reserved = 0b10,
+            /// Full access.
+            full_access = 0b11,
+        };
+    }),
 };
 
 pub const NestedVectorInterruptController = extern struct {
@@ -187,3 +204,39 @@ pub const MemoryProtectionUnit = extern struct {
         reserved2: u3 = 0,
     });
 };
+
+pub const FloatingPointUnit = extern struct {
+    FPCCR: mmio.Mmio(packed struct(u32) {
+        LSPACT: u1,
+        USER: u1,
+        reserved0: u1 = 0,
+        THREAD: u1,
+        HFRDY: u1,
+        MMRDY: u1,
+        BFRDY: u1,
+        reserved1: u1 = 0,
+        MONRDY: u1,
+        reserved2: u21 = 0,
+        /// Automatic state preservation enable. Enables lazy context save of
+        /// floating-point state. The possible values of this bit are:
+        /// 0 = Disable automatic lazy context save.
+        /// 1 = Enable automatic lazy state preservation for floating-point
+        /// context.
+        ///
+        /// Writes to this bit from Non-secure state are ignored if LSPENS is
+        /// set to one.
+        LSPEN: u1,
+        /// Automatic state preservation enable. Enables CONTROL.FPCA setting
+        /// on execution of a floating-point instruction. This results in
+        /// automatic hardware state preservation and restoration, for
+        /// floating-point context, on exception entry and exit. The possible
+        /// values of this bit are:
+        /// 1 = Enable CONTROL.FPCA setting on execution of a floating-point
+        /// instruction.
+        /// 0 = Disable CONTROL.FPCA setting on execution of a
+        /// floating-point instruction.
+        ASPEN: u1,
+    }),
+    FPCAR: u32,
+    FPDSCR: u32,
+};

examples/stmicro/stm32/src/blinky.zig

@@ -21,26 +21,33 @@ pub fn main() !void {
             };
             break :res .{ pins, all_leds };
         } else if (comptime microzig.config.board_name != null and std.mem.eql(u8, microzig.config.board_name.?, "STM32F3DISCOVERY")) {
-            const pins = (stm32.pins.GlobalConfiguration{ .GPIOE = .{
-                .PE8 = .{ .mode = .{ .output = .push_pull } },
-                .PE9 = .{ .mode = .{ .output = .push_pull } },
-                .PE10 = .{ .mode = .{ .output = .push_pull } },
-                .PE11 = .{ .mode = .{ .output = .push_pull } },
-                .PE12 = .{ .mode = .{ .output = .push_pull } },
-                .PE13 = .{ .mode = .{ .output = .push_pull } },
-                .PE14 = .{ .mode = .{ .output = .push_pull } },
-                .PE15 = .{ .mode = .{ .output = .push_pull } },
-            } }).apply();
+            const pins = (stm32.pins.GlobalConfiguration{
+                .GPIOC = .{
+                    .PIN4 = .{ .mode = .{ .alternate_function = .{ .afr = .AF7 } } },
+                    .PIN5 = .{ .mode = .{ .alternate_function = .{ .afr = .AF7 } } },
+                },
+                .GPIOE = .{
+                    .PIN8 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN9 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN10 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN11 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN12 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN13 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN14 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                    .PIN15 = .{ .mode = .{ .output = .{ .resistor = .Floating, .o_type = .PushPull } } },
+                },
+            }).apply();
             const all_leds = .{
-                pins.PE8,
-                pins.PE9,
-                pins.PE10,
-                pins.PE11,
-                pins.PE12,
-                pins.PE13,
-                pins.PE14,
-                pins.PE15,
+                pins.PIN8,
+                pins.PIN9,
+                pins.PIN10,
+                pins.PIN11,
+                pins.PIN12,
+                pins.PIN13,
+                pins.PIN14,
+                pins.PIN15,
             };
+
             break :res .{ pins, all_leds };
         } else {
             @compileError("blinky is not (yet?) implemented for this target");

port/stmicro/stm32/src/boards/STM32F3DISCOVERY.zig

@@ -1,6 +1,11 @@
+const std = @import("std");
+
 pub const microzig = @import("microzig");
 
-pub const cpu_frequency = 8_000_000;
+pub const hal = microzig.hal;
+pub const rcc = hal.rcc;
+pub const pins = hal.pins;
+const UART_LOG = microzig.hal.uart.Uart(.UART1);
 
 pub const pin_map = .{
     // circle of LEDs, connected to GPIOE bits 8..15
@@ -23,15 +28,29 @@ pub const pin_map = .{
     .LD6 = "PE15",
 };
 
-pub fn debug_write(string: []const u8) void {
-    const uart1 = microzig.core.experimental.Uart(1, .{}).get_or_init(.{
-        .baud_rate = 9600,
-        .data_bits = .eight,
-        .parity = null,
-        .stop_bits = .one,
-    }) catch unreachable;
+pub fn init() void {
+    hal.enable_fpu();
+    rcc.enable_hse(8_000_000);
+    rcc.enable_pll(.HSE, .Div1, .Mul5) catch {
+        @panic("PLL faile to enable");
+    };
+    rcc.select_pll_for_sysclk() catch {
+        @panic("Faile to select sysclk");
+    };
+}
+
+var uart_log: ?UART_LOG = null;
 
-    const writer = uart1.writer();
-    _ = writer.write(string) catch unreachable;
-    uart1.internal.txflush();
+// Init should come first or the baud_rate would be too fast for the default HSI.
+pub fn init_log() void {
+    _ = (pins.GlobalConfiguration{
+        .GPIOC = .{
+            .PIN4 = .{ .mode = .{ .alternate_function = .{ .afr = .AF7 } } },
+            .PIN5 = .{ .mode = .{ .alternate_function = .{ .afr = .AF7 } } },
+        },
+    }).apply();
+    uart_log = try microzig.hal.uart.Uart(.UART1).init(.{ .baud_rate = 115200 });
+    if (uart_log) |*logger| {
+        microzig.hal.uart.init_logger(logger);
+    }
 }