From 770a729e597702c0a32855b73dfc11fd8469316e Mon Sep 17 00:00:00 2001
From: Jesse Buhagiar <jooster669@gmail.com>
Date: Sun, 3 Jan 2021 00:12:54 +1100
Subject: [PATCH] Kernel/USB: Add basic root port detection/management

We can now read/write to the two root ports exposed to the
UHCI controller, and detect when a device is plugged in or
out via a kernel process that constantly scans the port
for any changes. This is very basic, but is a bit of fun to see
the kernel detecting hardware on the fly :^)
---
 Kernel/Devices/USB/UHCIController.cpp | 58 ++++++++++++++++++++++++++-
 Kernel/Devices/USB/UHCIController.h   |  7 ++++
 Kernel/init.cpp                       |  1 +
 3 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/Kernel/Devices/USB/UHCIController.cpp b/Kernel/Devices/USB/UHCIController.cpp
index 372db51729..0d82f7e702 100644
--- a/Kernel/Devices/USB/UHCIController.cpp
+++ b/Kernel/Devices/USB/UHCIController.cpp
@@ -66,6 +66,18 @@ static constexpr u8 UHCI_USBINTR_SHORT_PACKET_INTR_ENABLE = 0x08;
 static constexpr u16 UHCI_FRAMELIST_FRAME_COUNT = 1024; // Each entry is 4 bytes in our allocated page
 static constexpr u16 UHCI_FRAMELIST_FRAME_INVALID = 0x0001;
 
+// Port stuff
+static constexpr u8 UHCI_ROOT_PORT_COUNT = 2;
+static constexpr u16 UHCI_PORTSC_CURRRENT_CONNECT_STATUS = 0x0001;
+static constexpr u16 UHCI_PORTSC_CONNECT_STATUS_CHANGED = 0x0002;
+static constexpr u16 UHCI_PORTSC_PORT_ENABLED = 0x0004;
+static constexpr u16 UHCI_PORTSC_PORT_ENABLE_CHANGED = 0x0008;
+static constexpr u16 UHCI_PORTSC_LINE_STATUS = 0x0030;
+static constexpr u16 UHCI_PORTSC_RESUME_DETECT = 0x40;
+static constexpr u16 UHCI_PORTSC_LOW_SPEED_DEVICE = 0x0100;
+static constexpr u16 UHCI_PORTSC_PORT_RESET = 0x0200;
+static constexpr u16 UHCI_PORTSC_SUSPEND = 0x1000;
+
 // *BSD and a few other drivers seem to use this number
 static constexpr u8 UHCI_NUMBER_OF_ISOCHRONOUS_TDS = 128;
 static constexpr u16 UHCI_NUMBER_OF_FRAMES = 1024;
@@ -338,9 +350,53 @@ void UHCIController::start()
     klog() << "UHCI: Started!";
 }
 
+void UHCIController::spawn_port_proc()
+{
+    RefPtr<Thread> usb_hotplug_thread;
+    timespec sleep_time;
+
+    sleep_time.tv_sec = 1;
+    Process::create_kernel_process(usb_hotplug_thread, "UHCIHotplug", [sleep_time] {
+        for (;;) {
+            for (int port = 0; port < UHCI_ROOT_PORT_COUNT; port++) {
+                u16 port_data = 0;
+
+                if (port == 1) {
+                    // Let's see what's happening on port 1
+                    port_data = UHCIController::the().read_portsc1();
+                    if (port_data & UHCI_PORTSC_CONNECT_STATUS_CHANGED) {
+                        if (port_data & UHCI_PORTSC_CURRRENT_CONNECT_STATUS) {
+                            klog() << "UHCI: Device attach detected on Root Port 1!";
+                        } else {
+                            klog() << "UHCI: Device detach detected on Root Port 1!";
+                        }
+
+                        UHCIController::the().write_portsc1(
+                            UHCI_PORTSC_CONNECT_STATUS_CHANGED);
+                    }
+                } else {
+                    port_data = UHCIController::the().read_portsc2();
+                    if (port_data & UHCI_PORTSC_CONNECT_STATUS_CHANGED) {
+                        if (port_data & UHCI_PORTSC_CURRRENT_CONNECT_STATUS) {
+                            klog() << "UHCI: Device attach detected on Root Port 2!";
+                        } else {
+                            klog() << "UHCI: Device detach detected on Root Port 2!";
+                        }
+
+                        UHCIController::the().write_portsc2(
+                            UHCI_PORTSC_CONNECT_STATUS_CHANGED);
+                    }
+                }
+            }
+            Thread::current()->sleep(sleep_time);
+        }
+    });
+}
+
 void UHCIController::handle_irq(const RegisterState&)
 {
-    dbg() << "UHCI: Interrupt happened!";
+    klog() << "UHCI: Interrupt happened!";
+    klog() << "Value of USBSTS: " << read_usbsts();
 }
 
 }
diff --git a/Kernel/Devices/USB/UHCIController.h b/Kernel/Devices/USB/UHCIController.h
index 7f6cf165be..6d721f5c8e 100644
--- a/Kernel/Devices/USB/UHCIController.h
+++ b/Kernel/Devices/USB/UHCIController.h
@@ -31,6 +31,8 @@
 #include <Kernel/Devices/USB/UHCIDescriptorTypes.h>
 #include <Kernel/IO.h>
 #include <Kernel/PCI/Device.h>
+#include <Kernel/Process.h>
+#include <Kernel/Time/TimeManagement.h>
 #include <Kernel/VM/ContiguousVMObject.h>
 
 namespace Kernel::USB {
@@ -45,6 +47,7 @@ public:
     void reset();
     void stop();
     void start();
+    void spawn_port_proc();
 
 private:
     UHCIController(PCI::Address, PCI::ID);
@@ -55,6 +58,8 @@ private:
     u16 read_frnum() { return m_io_base.offset(0x6).in<u16>(); }
     u32 read_flbaseadd() { return m_io_base.offset(0x8).in<u32>(); }
     u8 read_sofmod() { return m_io_base.offset(0xc).in<u8>(); }
+    u16 read_portsc1() { return m_io_base.offset(0x10).in<u16>(); }
+    u16 read_portsc2() { return m_io_base.offset(0x12).in<u16>(); }
 
     void write_usbcmd(u16 value) { m_io_base.offset(0).out(value); }
     void write_usbsts(u16 value) { m_io_base.offset(0x2).out(value); }
@@ -62,6 +67,8 @@ private:
     void write_frnum(u16 value) { m_io_base.offset(0x6).out(value); }
     void write_flbaseadd(u32 value) { m_io_base.offset(0x8).out(value); }
     void write_sofmod(u8 value) { m_io_base.offset(0xc).out(value); }
+    void write_portsc1(u16 value) { m_io_base.offset(0x10).out(value); }
+    void write_portsc2(u16 value) { m_io_base.offset(0x12).out(value); }
 
     virtual void handle_irq(const RegisterState&) override;
 
diff --git a/Kernel/init.cpp b/Kernel/init.cpp
index 8beb09ea94..10df5abf99 100644
--- a/Kernel/init.cpp
+++ b/Kernel/init.cpp
@@ -247,6 +247,7 @@ void init_stage2(void*)
     }
 
     USB::UHCIController::detect();
+    USB::UHCIController::the().spawn_port_proc();
 
     E1000NetworkAdapter::detect();
     RTL8139NetworkAdapter::detect();