Merge pull request #626 from tier4/feat/rtc_driver_first

feat(rtc): rtc driver implementation initial setup

Author: veqcc

awkernel_drivers/src/lib.rs

@@ -21,3 +21,6 @@ pub mod pcie;
 
 #[cfg(feature = "mii")]
 pub mod mii;
+
+#[cfg(feature = "x86")]
+pub mod rtc;

awkernel_drivers/src/rtc.rs

@@ -0,0 +1,30 @@
+//! Real-Time Clock (RTC) driver support
+
+#[cfg(any(target_arch = "x86_64", feature = "x86"))]
+pub mod mc146818;
+
+#[cfg(any(target_arch = "x86_64", feature = "x86"))]
+pub use mc146818::Mc146818Rtc;
+
+#[derive(Debug, Clone, Copy)]
+pub struct DateTime {
+    pub year: u16,  // Full year (e.g., 2024)
+    pub month: u8,  // 1-12
+    pub day: u8,    // 1-31
+    pub hour: u8,   // 0-23 (24-hour format)
+    pub minute: u8, // 0-59
+    pub second: u8, // 0-59
+}
+
+impl DateTime {
+    pub fn new(year: u16, month: u8, day: u8, hour: u8, minute: u8, second: u8) -> Self {
+        Self {
+            year,
+            month,
+            day,
+            hour,
+            minute,
+            second,
+        }
+    }
+}

awkernel_drivers/src/rtc/mc146818.rs

@@ -0,0 +1,107 @@
+//! MC146818-compatible CMOS RTC driver for x86_64, x86
+
+use core::arch::asm;
+
+const _IO_RTC: u16 = 0x070;
+
+// The registers, and the bits within each register.
+
+const _MC_SEC: u8 = 0x00; // Time of year: seconds (0-59)
+const _MC_MIN: u8 = 0x02; // Time of year: minutes (0-59)
+const _MC_HOUR: u8 = 0x04; // Time of year: hour (see above)
+const _MC_DOW: u8 = 0x06; // Time of year: day of week (1-7)
+const _MC_DOM: u8 = 0x07; // Time of year: day of month (1-31)
+const _MC_MONTH: u8 = 0x08; // Time of year: month (1-12)
+const _MC_YEAR: u8 = 0x09; // Time of year: year in century (0-99)
+
+const _MC_REGA: u8 = 0x0a; // Control register A
+
+const _MC_REGA_RSMASK: u8 = 0x0f; // Interrupt rate select mask
+const _MC_REGA_DVMASK: u8 = 0x70; // Divisor select mask
+const _MC_REGA_UIP: u8 = 0x80; // Update in progress; read only
+
+const _MC_REGB: u8 = 0x0b; // Control register B
+
+const _MC_REGB_DSE: u8 = 0x01; // Daylight Saving Enable
+const _MC_REGB_24HR: u8 = 0x02; // 24-hour mode (AM/PM mode when clear)
+const _MC_REGB_DM: u8 = 0x04; // Binary mode (BCD mode when clear)
+const _MC_REGB_SQWE: u8 = 0x08; // Square wave enable, ONLY in BQ3285E
+const _MC_REGB_UIE: u8 = 0x10; // Update End interrupt enable
+const _MC_REGB_AIE: u8 = 0x20; // Alarm interrupt enable
+const _MC_REGB_PIE: u8 = 0x40; // Periodic interrupt enable
+const _MC_REGB_SET: u8 = 0x80; // Allow time to be set; stops updates
+
+const _MC_REGC: u8 = 0x0c; // Control register C
+
+const _MC_REGC_UF: u8 = 0x10; // Update End interrupt flag
+const _MC_REGC_AF: u8 = 0x20; // Alarm interrupt flag
+const _MC_REGC_PF: u8 = 0x40; // Periodic interrupt flag
+const _MC_REGC_IRQF: u8 = 0x80; // Interrupt request pending flag
+
+const _MC_REGD: u8 = 0x0d; // Control register D
+
+// MC_REGD_UNUSED 0x7f UNUSED
+const _MC_REGD_VRT: u8 = 0x80; // Valid RAM and Time bit
+
+// Number of TOD registers
+const _MC_NREGS: usize = 0xe; // 14 registers; CMOS follows
+const _MC_NTODREGS: usize = 0xa; // 10 of those are for TOD and alarm
+
+pub struct Mc146818Rtc;
+
+impl Mc146818Rtc {
+    pub fn new() -> Self {
+        Self
+    }
+}
+
+impl Default for Mc146818Rtc {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+impl Mc146818Rtc {
+    fn _mc146818_read(reg: u8) -> u8 {
+        unsafe {
+            asm!(
+                "out dx, al",
+                in("dx") _IO_RTC,
+                in("al") reg,
+                options(nostack, preserves_flags)
+            );
+
+            awkernel_lib::delay::wait_microsec(1);
+
+            let value: u8;
+            asm!(
+                "in al, dx",
+                in("dx") _IO_RTC + 1,
+                out("al") value,
+                options(nostack, preserves_flags)
+            );
+            value
+        }
+    }
+
+    fn _mc146818_write(reg: u8, value: u8) {
+        unsafe {
+            asm!(
+                "out dx, al",
+                in("dx") _IO_RTC,
+                in("al") reg,
+                options(nostack, preserves_flags)
+            );
+
+            awkernel_lib::delay::wait_microsec(1);
+
+            asm!(
+                "out dx, al",
+                in("dx") _IO_RTC + 1,
+                in("al") value,
+                options(nostack, preserves_flags)
+            );
+
+            awkernel_lib::delay::wait_microsec(1);
+        }
+    }
+}