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191 | with Cortex_M.Systick;
with System.Machine_Code; use System.Machine_Code;
package body PyGamer.Time is
package Systick renames Cortex_M.Systick;
Clock_Ms : Time_Ms := 0 with Volatile;
Period_Ms : constant Time_Ms := 1;
Subscribers : array (1 .. 10) of Tick_Callback := (others => null);
procedure Initialize;
procedure SysTick_Handler;
pragma Export (C, SysTick_Handler, "__gnat_sys_tick_trap");
----------------
-- Initialize --
----------------
procedure Initialize is
Reload : constant := 120_000_000 / 1_000;
begin
-- Configure for 1kH tick
Systick.Configure (Source => Systick.CPU_Clock,
Generate_Interrupt => True,
Reload_Value => Reload);
Systick.Enable;
end Initialize;
---------------------
-- SysTick_Handler --
---------------------
procedure SysTick_Handler is
begin
Clock_Ms := Clock_Ms + Period_Ms;
for Subs of Subscribers loop
if Subs /= null then
-- Call the subscriber
Subs.all;
end if;
end loop;
end SysTick_Handler;
-----------
-- Clock --
-----------
function Clock return Time_Ms
is (Clock_Ms);
--------------
-- Delay_Ms --
--------------
procedure Delay_Ms (Milliseconds : UInt64) is
begin
Delay_Until (Clock + Milliseconds);
end Delay_Ms;
-----------------
-- Delay_Until --
-----------------
procedure Delay_Until (Wakeup_Time : Time_Ms) is
begin
while Wakeup_Time > Clock loop
Asm (Template => "wfi", -- Wait for interrupt
Volatile => True);
end loop;
end Delay_Until;
-----------------
-- Tick_Period --
-----------------
function Tick_Period return Time_Ms is
begin
return Period_Ms;
end Tick_Period;
---------------------
-- Tick_Subscriber --
---------------------
function Tick_Subscriber (Callback : not null Tick_Callback) return Boolean
is
begin
for Subs of Subscribers loop
if Subs = Callback then
return True;
end if;
end loop;
return False;
end Tick_Subscriber;
--------------------
-- Tick_Subscribe --
--------------------
function Tick_Subscribe (Callback : not null Tick_Callback) return Boolean
is
begin
for Subs of Subscribers loop
if Subs = null then
Subs := Callback;
return True;
end if;
end loop;
return False;
end Tick_Subscribe;
----------------------
-- Tick_Unsubscribe --
----------------------
function Tick_Unsubscribe (Callback : not null Tick_Callback) return Boolean
is
begin
for Subs of Subscribers loop
if Subs = Callback then
Subs := null;
return True;
end if;
end loop;
return False;
end Tick_Unsubscribe;
---------------
-- HAL_Delay --
---------------
Delay_Instance : aliased PG_Delays;
function HAL_Delay return not null HAL.Time.Any_Delays is
begin
return Delay_Instance'Access;
end HAL_Delay;
------------------------
-- Delay_Microseconds --
------------------------
overriding
procedure Delay_Microseconds
(This : in out PG_Delays;
Us : Integer)
is
pragma Unreferenced (This);
begin
Delay_Ms (UInt64 (Us / 1000));
end Delay_Microseconds;
------------------------
-- Delay_Milliseconds --
------------------------
overriding
procedure Delay_Milliseconds
(This : in out PG_Delays;
Ms : Integer)
is
pragma Unreferenced (This);
begin
Delay_Ms (UInt64 (Ms));
end Delay_Milliseconds;
-------------------
-- Delay_Seconds --
-------------------
overriding
procedure Delay_Seconds (This : in out PG_Delays;
S : Integer)
is
pragma Unreferenced (This);
begin
Delay_Ms (UInt64 (S * 1000));
end Delay_Seconds;
begin
Initialize;
end PyGamer.Time;
|