From a14cbb581907cd05208705b51b953ac773abb0d5 Mon Sep 17 00:00:00 2001
From: Rudo <rudo2204@gmail.com>
Date: Sat, 29 May 2021 19:26:49 +0700
Subject: [PATCH] Hardware divide/modulo support (#40)
* Initial SIO div/mod implementation
* Implement signed/unsigned methods for HwDivider
---
rp2040-hal/src/sio.rs | 68 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 61 insertions(+), 7 deletions(-)
diff --git a/rp2040-hal/src/sio.rs b/rp2040-hal/src/sio.rs
index 111376b..063df57 100644
--- a/rp2040-hal/src/sio.rs
+++ b/rp2040-hal/src/sio.rs
@@ -12,22 +12,34 @@
//! let pins = pac.IO_BANK0.split(pac.PADS_BANK0, sio.gpio_bank0, &mut pac.RESETS);
//! ```
use super::*;
-use core::marker::PhantomData;
/// Marker struct for ownership of SIO gpio bank0
pub struct SioGpioBank0 {
- _private: PhantomData<u32>,
+ _private: (),
+}
+
+/// Marker struct for ownership of divide/modulo module
+pub struct HwDivider {
+ _private: (),
+}
+
+/// Result of divide/modulo operation
+pub struct DivResult<T> {
+ /// The remainder of divide/modulo operation
+ pub remainder: T,
+ /// The quotient of divide/modulo operation
+ pub quotient: T,
}
/// Struct containing ownership markers for managing ownership of the SIO registers.
pub struct Sio {
_sio: pac::SIO,
-
/// GPIO Bank 0 registers
pub gpio_bank0: SioGpioBank0,
+ /// 8-cycle hardware divide/modulo module
+ pub hwdivider: HwDivider,
// we can hand out other things here, for example:
// gpio_qspi
- // divider
// interp0
// interp1
}
@@ -37,9 +49,51 @@ impl Sio {
Self {
_sio: sio,
- gpio_bank0: SioGpioBank0 {
- _private: PhantomData,
- },
+ gpio_bank0: SioGpioBank0 { _private: () },
+
+ hwdivider: HwDivider { _private: () },
+ }
+ }
+}
+
+impl HwDivider {
+ /// Perform hardware unsigned divide/modulo operation
+ pub fn unsigned(&self, dividend: u32, divisor: u32) -> DivResult<u32> {
+ let sio = unsafe { &(*pac::SIO::ptr()) };
+ sio.div_sdividend.write(|w| unsafe { w.bits(dividend) });
+
+ sio.div_sdivisor.write(|w| unsafe { w.bits(divisor) });
+
+ cortex_m::asm::delay(8);
+
+ // Note: quotient must be read last
+ let remainder = sio.div_remainder.read().bits();
+ let quotient = sio.div_quotient.read().bits();
+
+ DivResult {
+ remainder,
+ quotient,
+ }
+ }
+
+ /// Perform hardware signed divide/modulo operation
+ pub fn signed(&self, dividend: i32, divisor: i32) -> DivResult<i32> {
+ let sio = unsafe { &(*pac::SIO::ptr()) };
+ sio.div_sdividend
+ .write(|w| unsafe { w.bits(dividend as u32) });
+
+ sio.div_sdivisor
+ .write(|w| unsafe { w.bits(divisor as u32) });
+
+ cortex_m::asm::delay(8);
+
+ // Note: quotient must be read last
+ let remainder = sio.div_remainder.read().bits() as i32;
+ let quotient = sio.div_quotient.read().bits() as i32;
+
+ DivResult {
+ remainder,
+ quotient,
}
}
}