From eb3460a01049cc98d2286a1f522d1f671d93ad72 Mon Sep 17 00:00:00 2001
From: Mark Poliakov <mark@alnyan.me>
Date: Thu, 7 Oct 2021 17:20:31 +0300
Subject: [PATCH] feat: orangepi3 rtc tick

---
 kernel/src/arch/aarch64/mach_orangepi3/mod.rs |   7 ++
 kernel/src/arch/aarch64/mach_orangepi3/rtc.rs | 100 ++++++++++++++++++
 2 files changed, 107 insertions(+)
 create mode 100644 kernel/src/arch/aarch64/mach_orangepi3/rtc.rs

diff --git a/kernel/src/arch/aarch64/mach_orangepi3/mod.rs b/kernel/src/arch/aarch64/mach_orangepi3/mod.rs
index f1697ec..d90c481 100644
--- a/kernel/src/arch/aarch64/mach_orangepi3/mod.rs
+++ b/kernel/src/arch/aarch64/mach_orangepi3/mod.rs
@@ -15,11 +15,13 @@ use error::Errno;
 
 mod gpio;
 mod uart;
+mod rtc;
 
 pub use gic::IrqNumber;
 pub use gpio::PinAddress;
 use gpio::Gpio;
 use uart::Uart;
+use rtc::Rtc;
 
 #[allow(missing_docs)]
 pub fn init_board() -> Result<(), Errno> {
@@ -31,11 +33,15 @@ pub fn init_board() -> Result<(), Errno> {
 
         UART0.enable()?;
         UART0.init_irqs()?;
+
+        RTC.enable()?;
+        RTC.init_irqs()?;
     }
     Ok(())
 }
 
 const UART0_BASE: usize = 0x05000000;
+const RTC_BASE: usize = 0x07000000;
 const PIO_BASE: usize = 0x0300B000;
 const GICD_BASE: usize = 0x03021000;
 const GICC_BASE: usize = 0x03022000;
@@ -61,4 +67,5 @@ pub fn intc() -> &'static impl IntController<IrqNumber = IrqNumber> {
 static UART0: Uart = unsafe { Uart::new(UART0_BASE, IrqNumber::new(32)) };
 static LOCAL_TIMER: GenericTimer = GenericTimer {};
 pub(super) static GPIO: Gpio = unsafe { Gpio::new(PIO_BASE) };
+static RTC: Rtc = unsafe { Rtc::new(RTC_BASE, IrqNumber::new(133)) };
 static GIC: Gic = unsafe { Gic::new(GICD_BASE, GICC_BASE) };
diff --git a/kernel/src/arch/aarch64/mach_orangepi3/rtc.rs b/kernel/src/arch/aarch64/mach_orangepi3/rtc.rs
new file mode 100644
index 0000000..0ee6403
--- /dev/null
+++ b/kernel/src/arch/aarch64/mach_orangepi3/rtc.rs
@@ -0,0 +1,100 @@
+use crate::dev::{Device, rtc::RtcDevice, irq::{IntController, IntSource}};
+use crate::arch::{MemoryIo, machine::{self, IrqNumber}};
+use crate::sync::IrqSafeNullLock;
+use error::Errno;
+use tock_registers::{
+    interfaces::{Readable, Writeable, ReadWriteable},
+    register_bitfields, register_structs,
+    registers::{ReadOnly, ReadWrite, WriteOnly},
+};
+
+register_bitfields! {
+    u32,
+    ALARM0_IRQ_EN [
+        ALARM0_IRQ_EN OFFSET(0) NUMBITS(1) []
+    ],
+    ALARM0_ENABLE [
+        ALM_0_EN OFFSET(0) NUMBITS(1) []
+    ],
+    ALARM0_IRQ_STA [
+        ALARM0_IRQ_PEND OFFSET(0) NUMBITS(1) []
+    ]
+}
+
+register_structs! {
+    #[allow(non_snake_case)]
+    Regs {
+        (0x00 => LOSC_CTRL: ReadWrite<u32>),
+        (0x04 => LOSC_AUTO_SWT_STA: ReadWrite<u32>),
+        (0x08 => INTOSC_CLK_PRESCAL: ReadWrite<u32>),
+        (0x0C => INTOSC_CLK_AUTO_CALI: ReadWrite<u32>),
+        (0x10 => RTC_YY_MM_DD: ReadWrite<u32>),
+        (0x14 => RTC_HH_MM_SS: ReadWrite<u32>),
+        (0x18 => _res0),
+        (0x20 => ALARM0_COUNTER: ReadWrite<u32>),
+        (0x24 => ALARM0_CUR_VLU: ReadOnly<u32>),
+        (0x28 => ALARM0_ENABLE: ReadWrite<u32, ALARM0_ENABLE::Register>),
+        (0x2C => ALARM0_IRQ_EN: ReadWrite<u32, ALARM0_IRQ_EN::Register>),
+        (0x30 => ALARM0_IRQ_STA: ReadWrite<u32, ALARM0_IRQ_STA::Register>),
+        (0x34 => @END),
+    }
+}
+
+pub struct Rtc {
+    regs: IrqSafeNullLock<MemoryIo<Regs>>,
+    irq: IrqNumber
+}
+
+impl Regs {
+    fn arm_alarm0_irq(&self, sec: u32) {
+        // Clear IRQ pending status
+        if sec == 0 {
+            return;
+        }
+        self.ALARM0_IRQ_STA.write(ALARM0_IRQ_STA::ALARM0_IRQ_PEND::SET);
+        self.ALARM0_IRQ_EN.write(ALARM0_IRQ_EN::ALARM0_IRQ_EN::SET);
+        self.ALARM0_COUNTER.set(self.ALARM0_CUR_VLU.get() + sec - 1);
+        self.ALARM0_ENABLE.write(ALARM0_ENABLE::ALM_0_EN::SET);
+    }
+}
+
+impl RtcDevice for Rtc {}
+
+impl IntSource for Rtc {
+    fn handle_irq(&self) -> Result<(), Errno> {
+        self.regs.lock().arm_alarm0_irq(1);
+        Ok(())
+    }
+
+    fn init_irqs(&'static self) -> Result<(), Errno> {
+        machine::intc().register_handler(self.irq, self)?;
+        self.regs.lock().arm_alarm0_irq(1);
+        machine::intc().enable_irq(self.irq)?;
+
+        Ok(())
+    }
+}
+
+impl Device for Rtc {
+    fn name(&self) -> &'static str {
+        "Allwinner H6 RTC"
+    }
+
+    unsafe fn enable(&self) -> Result<(), Errno> {
+        Ok(())
+    }
+}
+
+impl Rtc {
+    /// Constructs an instance of RTC device.
+    ///
+    /// # Safety
+    ///
+    /// Does not perform `base` validation.
+    pub const unsafe fn new(base: usize, irq: IrqNumber) -> Self {
+        Self {
+            regs: IrqSafeNullLock::new(MemoryIo::new(base)),
+            irq
+        }
+    }
+}