zynq::ddr: wait for init

src/zynq/ddr/mod.rs

@@ -8,7 +8,9 @@ mod regs;
 const DDR_FREQ: u32 = 666_666_666;
 const DCI_FREQ: u32 = 10_000_000;
 
-pub struct DdrRam;
+pub struct DdrRam {
+    regs: &'static mut regs::RegisterBlock,
+}
 
 impl DdrRam {
     pub fn new() -> Self {
@@ -16,9 +18,11 @@ impl DdrRam {
         Self::clock_setup(&clocks);
         Self::calibrate_iob_impedance(&clocks);
         Self::configure_iob();
-        Self::reset_ddrc();
 
-        DdrRam
+        let regs = unsafe { regs::RegisterBlock::new() };
+        let mut ddr = DdrRam { regs };
+        ddr.reset_ddrc();
+        ddr
     }
 
     /// Zynq-7000 AP SoC Technical Reference Manual:
@@ -133,15 +137,20 @@ impl DdrRam {
     }
 
     /// Reset DDR controller
-    fn reset_ddrc() {
+    fn reset_ddrc(&mut self) {
-        let regs = unsafe { regs::RegisterBlock::new() };
+        self.regs.ddrc_ctrl.modify(|_, w| w
-        regs.ddrc_ctrl.modify(|_, w| w
             .soft_rstb(false)
         );
-        regs.ddrc_ctrl.modify(|_, w| w
+        self.regs.ddrc_ctrl.modify(|_, w| w
             .soft_rstb(true)
             .powerdown_en(false)
             .data_bus_width(regs::DataBusWidth::Width32bit)
         );
+
+        while self.status() == regs::ControllerStatus::Init {}
+    }
+
+    pub fn status(&self) -> regs::ControllerStatus {
+        self.regs.mode_sts_reg.read().operating_mode()
     }
 }

src/zynq/ddr/regs.rs

@@ -8,6 +8,21 @@ pub enum DataBusWidth {
     Width16bit = 0b01,
 }
 
+#[derive(Debug, Clone, PartialEq)]
+#[repr(u8)]
+pub enum ControllerStatus {
+    Init = 0,
+    Normal = 1,
+    Powerdown = 2,
+    SelfRefresh = 3,
+    Powerdown1 = 4,
+    Powerdown2 = 5,
+    Powerdown3 = 6,
+    Powerdown4 = 7,
+}
+
+
+
 #[repr(C)]
 pub struct RegisterBlock {
     pub ddrc_ctrl: DdrcCtrl,
@@ -31,7 +46,7 @@ pub struct RegisterBlock {
     pub dram_odt_reg: RW<u32>,
     pub phy_dbg_reg: RW<u32>,
     pub phy_cmd_timeout_rddata_cpt: RW<u32>,
-    pub mode_sts_reg: RW<u32>,
+    pub mode_sts_reg: ModeStsReg,
     pub dll_calib: RW<u32>,
     pub odt_delay_hold: RW<u32>,
     pub ctrl_reg1: RW<u32>,
@@ -154,3 +169,8 @@ register_bit!(ddrc_ctrl,
 register_bit!(ddrc_ctrl, powerdown_en, 1);
 register_bits_typed!(ddrc_ctrl, data_bus_width, u8, DataBusWidth, 2, 3);
 // (ddrc_ctrl) ...
+
+/// Controller operation mode status
+register!(mode_sts_reg, ModeStsReg, RO, u32);
+register_bits_typed!(mode_sts_reg, operating_mode, u8, ControllerStatus, 0, 2);
+// (mode_sts_reg) ...