From 8de86dd647e16bb90397fc0b65a17a0eb5fdbf4c Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Wed, 7 Jun 2023 16:49:54 -0400
Subject: [PATCH] Add Pci.init_device() skeleton

---
 src/hulk/pci.d | 50 ++++++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/src/hulk/pci.d b/src/hulk/pci.d
index 53e889c..eff3b28 100644
--- a/src/hulk/pci.d
+++ b/src/hulk/pci.d
@@ -11,6 +11,21 @@ struct Pci
     /* IO address for PCI configuration data. */
     enum IO_ADDR_CONFIG_DATA = 0xCFCu;
 
+    struct SerialBusController
+    {
+        enum ID = 0x0Cu;
+
+        struct USBController
+        {
+            enum ID = 0x03u;
+
+            struct XHCIController
+            {
+                enum ID = 0x30u;
+            }
+        }
+    }
+
     private static ulong read_config_register(ulong bus_id, ulong device_idx, ulong register_id)
     {
         ulong addr = 0x8000_0000u | (bus_id << 16u) | (device_idx << 11u) | (register_id << 2u);
@@ -18,6 +33,32 @@ struct Pci
         return in32(IO_ADDR_CONFIG_DATA);
     }
 
+    private static void init_device(ubyte class_id, ubyte subclass_id, ubyte if_id)
+    {
+        switch (class_id)
+        {
+        case SerialBusController.ID:
+            switch (subclass_id)
+            {
+            case SerialBusController.USBController.ID:
+                switch (if_id)
+                {
+                case SerialBusController.USBController.XHCIController.ID:
+                    /* TODO */
+                    break;
+
+                default: break;
+                }
+                break;
+
+            default: break;
+            }
+            break;
+
+        default: break;
+        }
+    }
+
     private static void scan(ulong bus_id, ulong device_idx)
     {
         ulong reg0 = read_config_register(bus_id, device_idx, 0u);
@@ -26,13 +67,14 @@ struct Pci
             ulong reg2 = read_config_register(bus_id, device_idx, 2u);
             ushort vendor_id = reg0 & 0xFFFFu;
             ushort device_id = (reg0 >> 16u) & 0xFFFFu;
-            ubyte class_code = (reg2 >> 24u) & 0xFFu;
-            ubyte subclass = (reg2 >> 16u) & 0xFFu;
-            ubyte prog_if = (reg2 >> 8u) & 0xFFu;
+            ubyte class_id = (reg2 >> 24u) & 0xFFu;
+            ubyte subclass_id = (reg2 >> 16u) & 0xFFu;
+            ubyte if_id = (reg2 >> 8u) & 0xFFu;
             Klog.writefln("Found PCI device %04x:%04x (%02x:%02x:%02x) at %02u:%02u",
                     vendor_id, device_id,
-                    class_code, subclass, prog_if,
+                    class_id, subclass_id, if_id,
                     bus_id, device_idx);
+            init_device(class_id, subclass_id, if_id);
         }
     }