aarch64: move function delay() into mod timer in crate bcm2837

crate/bcm2837/src/asm.rs

@@ -1,10 +0,0 @@
-//! utility assembly instructions
-
-/// delay for some clocks
-#[inline]
-pub unsafe fn delay(_clock: u32) {
-    #[cfg(target_arch = "aarch64")]
-    asm!("mov x1, x0; 1: subs x1, x1, #1; bne 1b;"
-        :: "{x0}"(_clock)
-        :: "volatile");
-}

crate/bcm2837/src/gpio.rs

@@ -1,5 +1,5 @@
-use super::IO_BASE;
-use super::asm::delay;
+use IO_BASE;
+use timer::delay;
 use core::marker::PhantomData;
 use volatile::{ReadOnly, Volatile, WriteOnly};
 
@@ -84,16 +84,14 @@ impl<T> Gpio<T> {
     /// Set the Gpio pull-up/pull-down state for values in `pin_value`
     /// (ref: peripherals 6.1, page 101)
     pub fn set_gpio_pd(&mut self, pud_value: u8) {
-        unsafe {
-            let index = if self.pin >= 32 { 1 } else { 0 };
-
-            self.registers.PUD.write(pud_value as u32);
-            delay(150);
-            self.registers.PUDCLK[index as usize].write((1 << self.pin) as u32);
-            delay(150);
-            self.registers.PUD.write(0);
-            self.registers.PUDCLK[index as usize].write(0);
-        }
+        let index = if self.pin >= 32 { 1 } else { 0 };
+
+        self.registers.PUD.write(pud_value as u32);
+        delay(150);
+        self.registers.PUDCLK[index as usize].write((1 << self.pin) as u32);
+        delay(150);
+        self.registers.PUD.write(0);
+        self.registers.PUDCLK[index as usize].write(0);
     }
 }
 

crate/bcm2837/src/interrupt.rs

@@ -1,4 +1,4 @@
-use super::IO_BASE;
+use IO_BASE;
 use volatile::{ReadOnly, Volatile};
 
 const INT_BASE: usize = IO_BASE + 0xB000 + 0x200;

crate/bcm2837/src/lib.rs

@@ -3,8 +3,6 @@
 
 extern crate volatile;
 
-mod asm;
-
 pub mod gpio;
 pub mod timer;
 pub mod mini_uart;

crate/bcm2837/src/mini_uart.rs

@@ -1,4 +1,4 @@
-use super::IO_BASE;
+use IO_BASE;
 use gpio::{Function, Gpio};
 use volatile::{ReadOnly, Volatile};
 

crate/bcm2837/src/timer/mod.rs

@@ -24,3 +24,11 @@ pub fn current_time() -> u64 {
 pub fn tick_in(us: u32) {
     Timer::new().tick_in(us);
 }
+
+/// wait for `cycle` CPU cycles
+#[inline(always)]
+pub fn delay(cycle: u32) {
+    for _ in 0..cycle {
+        unsafe { asm!("nop") }
+    }
+}