From 7b6173a7bdba3ccfd06c543e0d35bc5ab5c0d46c Mon Sep 17 00:00:00 2001
From: equation314 <equation618@gmail.com>
Date: Sun, 4 Nov 2018 18:27:21 +0800
Subject: [PATCH] aarch64: move function delay() into mod timer in crate
 bcm2837

---
 crate/bcm2837/src/asm.rs       | 10 ----------
 crate/bcm2837/src/gpio.rs      | 22 ++++++++++------------
 crate/bcm2837/src/interrupt.rs |  2 +-
 crate/bcm2837/src/lib.rs       |  2 --
 crate/bcm2837/src/mini_uart.rs |  2 +-
 crate/bcm2837/src/timer/mod.rs |  8 ++++++++
 6 files changed, 20 insertions(+), 26 deletions(-)
 delete mode 100644 crate/bcm2837/src/asm.rs

diff --git a/crate/bcm2837/src/asm.rs b/crate/bcm2837/src/asm.rs
deleted file mode 100644
index a496d92..0000000
--- a/crate/bcm2837/src/asm.rs
+++ /dev/null
@@ -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");
-}
diff --git a/crate/bcm2837/src/gpio.rs b/crate/bcm2837/src/gpio.rs
index 1b340c7..1fb7fec 100644
--- a/crate/bcm2837/src/gpio.rs
+++ b/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);
     }
 }
 
diff --git a/crate/bcm2837/src/interrupt.rs b/crate/bcm2837/src/interrupt.rs
index cf340ee..7324085 100644
--- a/crate/bcm2837/src/interrupt.rs
+++ b/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;
diff --git a/crate/bcm2837/src/lib.rs b/crate/bcm2837/src/lib.rs
index 13da9ff..9635fdc 100644
--- a/crate/bcm2837/src/lib.rs
+++ b/crate/bcm2837/src/lib.rs
@@ -3,8 +3,6 @@
 
 extern crate volatile;
 
-mod asm;
-
 pub mod gpio;
 pub mod timer;
 pub mod mini_uart;
diff --git a/crate/bcm2837/src/mini_uart.rs b/crate/bcm2837/src/mini_uart.rs
index 5816017..28e2c13 100644
--- a/crate/bcm2837/src/mini_uart.rs
+++ b/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};
 
diff --git a/crate/bcm2837/src/timer/mod.rs b/crate/bcm2837/src/timer/mod.rs
index da501cb..f88b33d 100644
--- a/crate/bcm2837/src/timer/mod.rs
+++ b/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") }
+    }
+}