abstract timer driver

main
Clyne 3 months ago
parent 294cf13209
commit 07fdd6c1dd
Signed by: clyne
GPG Key ID: 3267C8EBF3F9AFC7

@ -6,12 +6,13 @@ const timer = @import("timer.zig");
const rcc: *[39]u32 = @ptrFromInt(0x40021000); const rcc: *[39]u32 = @ptrFromInt(0x40021000);
const gpioa = gpio.gpioa; const gpioa = gpio.gpioa;
const gpioc = gpio.gpioc; const gpioc = gpio.gpioc;
const tick = timer.systick;
export fn _start() callconv(.C) noreturn { export fn _start() callconv(.C) noreturn {
cpu.interrupt_disable(); cpu.interrupt_disable();
interrupt.initialize(); interrupt.initialize();
interrupt.register(.SVCall, svcall); interrupt.register(.SVCall, svcall);
timer.initialize(1000); tick.initialize(1000);
cpu.interrupt_enable(); cpu.interrupt_enable();
rcc[19] |= 5; // gpio a and c rcc[19] |= 5; // gpio a and c
@ -21,8 +22,8 @@ export fn _start() callconv(.C) noreturn {
while (true) { while (true) {
//asm volatile("svc 0"); //asm volatile("svc 0");
gpioa.toggle(5); gpioa.toggle(5);
const next = timer.ticks() + 1000; const next = tick.ticks() + 1000;
while (timer.ticks() < next) { while (tick.ticks() < next) {
asm volatile("nop"); asm volatile("nop");
} }
} }

@ -1,6 +1,6 @@
const interrupt = @import("interrupt.zig"); const interrupt = @import("interrupt.zig");
const sys_tick_type = packed struct { const driver_armcortex = packed struct {
enable: u1, enable: u1,
tickint: u1, tickint: u1,
unused: u30, unused: u30,
@ -8,24 +8,36 @@ const sys_tick_type = packed struct {
rvr: u32, rvr: u32,
cvr: u32, cvr: u32,
calib: u32, calib: u32,
};
var sys_tick: *volatile sys_tick_type = @ptrFromInt(0xE000E010); pub fn initialize(self: *driver_armcortex, freq: u32) void {
self.rvr = 4000000 / 8 / freq;
self.tickint = 1;
self.enable = 1;
}
pub var ticks_raw: u32 = 0; };
pub fn initialize(freq: u32) void { var ticks_raw: u32 = 0;
interrupt.register(.SysTick, tick);
sys_tick.rvr = 4000000 / 8 / freq;
sys_tick.tickint = 1;
sys_tick.enable = 1;
}
fn tick() void { fn tick() void {
ticks_raw += 1; ticks_raw += 1;
} }
pub fn ticks() u32 { const driver = struct {
const lld_type = driver_armcortex;
lld: *driver_armcortex,
pub fn initialize(self: driver, freq: u32) void {
interrupt.register(.SysTick, tick);
self.lld.initialize(freq);
}
pub fn ticks(self: driver) u32 {
_ = self;
return @atomicLoad(u32, &ticks_raw, .acquire); return @atomicLoad(u32, &ticks_raw, .acquire);
} }
};
pub const systick = driver { .lld = @ptrFromInt(0xE000E010) };

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