turn peripherals into scoped singletons

.gitignore

@@ -1,4 +1,5 @@
 *.org
 *.rs.bk
+.#*
 Cargo.lock
 target

.travis.yml

@@ -16,10 +16,10 @@ matrix:
 before_install: set -e
 
 install:
-  - sh ci/install.sh
+  - bash ci/install.sh
 
 script:
-  - sh ci/script.sh
+  - bash ci/script.sh
 
 after_script: set +e
 

ci/install.sh

@@ -1,4 +1,4 @@
-set -ex
+set -euxo pipefail
 
 main() {
     case $TARGET in

ci/script.sh

@@ -1,4 +1,4 @@
-set -ex
+set -euxo pipefail
 
 main() {
     case $TARGET in

src/exception.rs

@@ -31,8 +31,8 @@ impl Exception {
     ///
     /// Returns `None` if no exception is currently active
     pub fn active() -> Option<Exception> {
-        // NOTE(safe) atomic read
-        let icsr = unsafe { (*::peripheral::SCB.get()).icsr.read() };
+        // NOTE(safe) atomic read with no side effects
+        let icsr = unsafe { (*::peripheral::SCB::ptr()).icsr.read() };
 
         Some(match icsr as u8 {
             0 => return None,

src/itm.rs

@@ -4,7 +4,7 @@ use core::{fmt, mem, ptr, slice};
 
 use aligned::Aligned;
 
-use peripheral::Stim;
+use peripheral::itm::Stim;
 
 // NOTE assumes that `bytes` is 32-bit aligned
 unsafe fn write_words(stim: &Stim, bytes: &[u32]) {

src/peripheral/cbp.rs

@@ -0,0 +1,142 @@
+//! Cache and branch predictor maintenance operations
+
+use volatile_register::WO;
+
+/// Register block
+#[repr(C)]
+pub struct RegisterBlock {
+    /// I-cache invalidate all to PoU
+    pub iciallu: WO<u32>,
+    reserved0: u32,
+    /// I-cache invalidate by MVA to PoU
+    pub icimvau: WO<u32>,
+    /// D-cache invalidate by MVA to PoC
+    pub dcimvac: WO<u32>,
+    /// D-cache invalidate by set-way
+    pub dcisw: WO<u32>,
+    /// D-cache clean by MVA to PoU
+    pub dccmvau: WO<u32>,
+    /// D-cache clean by MVA to PoC
+    pub dccmvac: WO<u32>,
+    /// D-cache clean by set-way
+    pub dccsw: WO<u32>,
+    /// D-cache clean and invalidate by MVA to PoC
+    pub dccimvac: WO<u32>,
+    /// D-cache clean and invalidate by set-way
+    pub dccisw: WO<u32>,
+    /// Branch predictor invalidate all
+    pub bpiall: WO<u32>,
+}
+
+const CBP_SW_WAY_POS: u32 = 30;
+const CBP_SW_WAY_MASK: u32 = 0x3 << CBP_SW_WAY_POS;
+const CBP_SW_SET_POS: u32 = 5;
+const CBP_SW_SET_MASK: u32 = 0x1FF << CBP_SW_SET_POS;
+
+impl RegisterBlock {
+    /// I-cache invalidate all to PoU
+    #[inline(always)]
+    pub fn iciallu(&self) {
+        unsafe {
+            self.iciallu.write(0);
+        }
+    }
+
+    /// I-cache invalidate by MVA to PoU
+    #[inline(always)]
+    pub fn icimvau(&self, mva: u32) {
+        unsafe {
+            self.icimvau.write(mva);
+        }
+    }
+
+    /// D-cache invalidate by MVA to PoC
+    #[inline(always)]
+    pub fn dcimvac(&self, mva: u32) {
+        unsafe {
+            self.dcimvac.write(mva);
+        }
+    }
+
+    /// D-cache invalidate by set-way
+    ///
+    /// `set` is masked to be between 0 and 3, and `way` between 0 and 511.
+    #[inline(always)]
+    pub fn dcisw(&self, set: u16, way: u16) {
+        // The ARMv7-M Architecture Reference Manual, as of Revision E.b, says these set/way
+        // operations have a register data format which depends on the implementation's
+        // associativity and number of sets. Specifically the 'way' and 'set' fields have
+        // offsets 32-log2(ASSOCIATIVITY) and log2(LINELEN) respectively.
+        //
+        // However, in Cortex-M7 devices, these offsets are fixed at 30 and 5, as per the Cortex-M7
+        // Generic User Guide section 4.8.3. Since no other ARMv7-M implementations except the
+        // Cortex-M7 have a DCACHE or ICACHE at all, it seems safe to do the same thing as the
+        // CMSIS-Core implementation and use fixed values.
+        unsafe {
+            self.dcisw.write(
+                (((way as u32) & (CBP_SW_WAY_MASK >> CBP_SW_WAY_POS)) << CBP_SW_WAY_POS)
+                    | (((set as u32) & (CBP_SW_SET_MASK >> CBP_SW_SET_POS)) << CBP_SW_SET_POS),
+            );
+        }
+    }
+
+    /// D-cache clean by MVA to PoU
+    #[inline(always)]
+    pub fn dccmvau(&self, mva: u32) {
+        unsafe {
+            self.dccmvau.write(mva);
+        }
+    }
+
+    /// D-cache clean by MVA to PoC
+    #[inline(always)]
+    pub fn dccmvac(&self, mva: u32) {
+        unsafe {
+            self.dccmvac.write(mva);
+        }
+    }
+
+    /// D-cache clean by set-way
+    ///
+    /// `set` is masked to be between 0 and 3, and `way` between 0 and 511.
+    #[inline(always)]
+    pub fn dccsw(&self, set: u16, way: u16) {
+        // See comment for dcisw() about the format here
+        unsafe {
+            self.dccsw.write(
+                (((way as u32) & (CBP_SW_WAY_MASK >> CBP_SW_WAY_POS)) << CBP_SW_WAY_POS)
+                    | (((set as u32) & (CBP_SW_SET_MASK >> CBP_SW_SET_POS)) << CBP_SW_SET_POS),
+            );
+        }
+    }
+
+    /// D-cache clean and invalidate by MVA to PoC
+    #[inline(always)]
+    pub fn dccimvac(&self, mva: u32) {
+        unsafe {
+            self.dccimvac.write(mva);
+        }
+    }
+
+    /// D-cache clean and invalidate by set-way
+    ///
+    /// `set` is masked to be between 0 and 3, and `way` between 0 and 511.
+    #[inline(always)]
+    pub fn dccisw(&self, set: u16, way: u16) {
+        // See comment for dcisw() about the format here
+        unsafe {
+            self.dccisw.write(
+                (((way as u32) & (CBP_SW_WAY_MASK >> CBP_SW_WAY_POS)) << CBP_SW_WAY_POS)
+                    | (((set as u32) & (CBP_SW_SET_MASK >> CBP_SW_SET_POS)) << CBP_SW_SET_POS),
+            );
+        }
+    }
+
+    /// Branch predictor invalidate all
+    #[inline(always)]
+    pub fn bpiall(&self) {
+        unsafe {
+            self.bpiall.write(0);
+        }
+    }
+}

src/peripheral/cpuid.rs

@@ -0,0 +1,84 @@
+//! CPUID
+
+use volatile_register::RO;
+#[cfg(any(armv7m, test))]
+use volatile_register::RW;
+
+/// Register block
+#[repr(C)]
+pub struct RegisterBlock {
+    /// CPUID base
+    pub base: RO<u32>,
+    reserved0: [u32; 15],
+    /// Processor Feature
+    pub pfr: [RO<u32>; 2],
+    /// Debug Feature
+    pub dfr: RO<u32>,
+    /// Auxiliary Feature
+    pub afr: RO<u32>,
+    /// Memory Model Feature
+    pub mmfr: [RO<u32>; 4],
+    /// Instruction Set Attribute
+    pub isar: [RO<u32>; 5],
+    reserved1: u32,
+    /// Cache Level ID
+    #[cfg(any(armv7m, test))]
+    pub clidr: RO<u32>,
+    /// Cache Type
+    #[cfg(any(armv7m, test))]
+    pub ctr: RO<u32>,
+    /// Cache Size ID
+    #[cfg(any(armv7m, test))]
+    pub ccsidr: RO<u32>,
+    /// Cache Size Selection
+    #[cfg(any(armv7m, test))]
+    pub csselr: RW<u32>,
+}
+
+/// Type of cache to select on CSSELR writes.
+#[cfg(armv7m)]
+pub enum CsselrCacheType {
+    /// Select DCache or unified cache
+    DataOrUnified = 0,
+    /// Select ICache
+    Instruction = 1,
+}
+
+#[cfg(armv7m)]
+impl RegisterBlock {
+    /// Selects the current CCSIDR
+    ///
+    /// * `level`: the required cache level minus 1, e.g. 0 for L1, 1 for L2
+    /// * `ind`: select instruction cache or data/unified cache
+    ///
+    /// `level` is masked to be between 0 and 7.
+    pub fn select_cache(&self, level: u8, ind: CsselrCacheType) {
+        const CSSELR_IND_POS: u32 = 0;
+        const CSSELR_IND_MASK: u32 = 1 << CSSELR_IND_POS;
+        const CSSELR_LEVEL_POS: u32 = 1;
+        const CSSELR_LEVEL_MASK: u32 = 0x7 << CSSELR_LEVEL_POS;
+
+        unsafe {
+            self.csselr.write(
+                (((level as u32) << CSSELR_LEVEL_POS) & CSSELR_LEVEL_MASK)
+                    | (((ind as u32) << CSSELR_IND_POS) & CSSELR_IND_MASK),
+            )
+        }
+    }
+
+    /// Returns the number of sets and ways in the selected cache
+    pub fn cache_num_sets_ways(&self, level: u8, ind: CsselrCacheType) -> (u16, u16) {
+        const CCSIDR_NUMSETS_POS: u32 = 13;
+        const CCSIDR_NUMSETS_MASK: u32 = 0x7FFF << CCSIDR_NUMSETS_POS;
+        const CCSIDR_ASSOCIATIVITY_POS: u32 = 3;
+        const CCSIDR_ASSOCIATIVITY_MASK: u32 = 0x3FF << CCSIDR_ASSOCIATIVITY_POS;
+
+        self.select_cache(level, ind);
+        ::asm::dsb();
+        let ccsidr = self.ccsidr.read();
+        (
+            (1 + ((ccsidr & CCSIDR_NUMSETS_MASK) >> CCSIDR_NUMSETS_POS)) as u16,
+            (1 + ((ccsidr & CCSIDR_ASSOCIATIVITY_MASK) >> CCSIDR_ASSOCIATIVITY_POS)) as u16,
+        )
+    }
+}

src/peripheral/dcb.rs

@@ -0,0 +1,16 @@
+//! Debug Control Block
+
+use volatile_register::{RW, WO};
+
+/// Register block
+#[repr(C)]
+pub struct RegisterBlock {
+    /// Debug Halting Control and Status
+    pub dhcsr: RW<u32>,
+    /// Debug Core Register Selector
+    pub dcrsr: WO<u32>,
+    /// Debug Core Register Data
+    pub dcrdr: RW<u32>,
+    /// Debug Exception and Monitor Control
+    pub demcr: RW<u32>,
+}

src/peripheral/dwt.rs

@@ -0,0 +1,50 @@
+//! Data Watchpoint and Trace unit
+
+use volatile_register::{RO, RW, WO};
+
+/// Register block
+#[repr(C)]
+pub struct RegisterBlock {
+    /// Control
+    pub ctrl: RW<u32>,
+    /// Cycle Count
+    pub cyccnt: RW<u32>,
+    /// CPI Count
+    pub cpicnt: RW<u32>,
+    /// Exception Overhead Count
+    pub exccnt: RW<u32>,
+    /// Sleep Count
+    pub sleepcnt: RW<u32>,
+    /// LSU Count
+    pub lsucnt: RW<u32>,
+    /// Folded-instruction Count
+    pub foldcnt: RW<u32>,
+    /// Program Counter Sample
+    pub pcsr: RO<u32>,
+    /// Comparators
+    pub c: [Comparator; 16],
+    reserved: [u32; 932],
+    /// Lock Access
+    pub lar: WO<u32>,
+    /// Lock Status
+    pub lsr: RO<u32>,
+}
+
+impl RegisterBlock {
+    /// Enables the cycle counter
+    pub fn enable_cycle_counter(&self) {
+        unsafe { self.ctrl.modify(|r| r | 1) }
+    }
+}
+
+/// Comparator
+#[repr(C)]
+pub struct Comparator {
+    /// Comparator
+    pub comp: RW<u32>,
+    /// Comparator Mask
+    pub mask: RW<u32>,
+    /// Comparator Function
+    pub function: RW<u32>,
+    reserved: u32,
+}

src/peripheral/fpb.rs

@@ -0,0 +1,19 @@
+//! Flash Patch and Breakpoint unit
+
+use volatile_register::{RO, RW, WO};
+
+/// Register block
+#[repr(C)]
+pub struct RegisterBlock {
+    /// Control
+    pub ctrl: RW<u32>,
+    /// Remap
+    pub remap: RW<u32>,
+    /// Comparator
+    pub comp: [RW<u32>; 127],
+    reserved: [u32; 875],
+    /// Lock Access
+    pub lar: WO<u32>,
+    /// Lock Status
+    pub lsr: RO<u32>,
+}

src/peripheral/fpu.rs

@@ -0,0 +1,22 @@
+//! Floating Point Unit
+
+#[cfg(any(has_fpu, test))]
+use volatile_register::{RO, RW};
+
+/// Register block
+#[repr(C)]
+pub struct RegisterBlock {
+    reserved: u32,
+    /// Floating Point Context Control
+    #[cfg(any(has_fpu, test))]
+    pub fpccr: RW<u32>,
+    /// Floating Point Context Address
+    #[cfg(any(has_fpu, test))]
+    pub fpcar: RW<u32>,
+    /// Floating Point Default Status Control
+    #[cfg(any(has_fpu, test))]
+    pub fpdscr: RW<u32>,
+    /// Media and FP Feature
+    #[cfg(any(has_fpu, test))]
+    pub mvfr: [RO<u32>; 3],
+}