Kernel: Update PATAChannel implementation to use the PIT class

Also, update the class implementation to use PCI::Device class
accordingly.
The create() helper will now search for an IDE controller in the
PCI bus, allowing to simplify the initialize() method.

Kernel/Devices/PATAChannel.cpp

@@ -27,6 +27,7 @@
 #include "PATADiskDevice.h"
 #include <AK/ByteBuffer.h>
 #include <Kernel/Devices/PATAChannel.h>
+#include <Kernel/Devices/PIT.h>
 #include <Kernel/FileSystem/ProcFS.h>
 #include <Kernel/Process.h>
 #include <Kernel/VM/MemoryManager.h>
@@ -116,11 +117,18 @@ static Lock& s_lock()
 
 OwnPtr<PATAChannel> PATAChannel::create(ChannelType type, bool force_pio)
 {
-    return make<PATAChannel>(type, force_pio);
+    PCI::Address pci_address;
+    PCI::enumerate_all([&](const PCI::Address& address, PCI::ID id) {
+        if (PCI::get_class(address) == PCI_Mass_Storage_Class && PCI::get_subclass(address) == PCI_IDE_Controller_Subclass) {
+            pci_address = address;
+            kprintf("PATAChannel: PATA Controller found! id=%w:%w\n", id.vendor_id, id.device_id);
+        }
+    });
+    return make<PATAChannel>(pci_address, type, force_pio);
 }
 
-PATAChannel::PATAChannel(ChannelType type, bool force_pio)
-    : IRQHandler((type == ChannelType::Primary ? PATA_PRIMARY_IRQ : PATA_SECONDARY_IRQ))
+PATAChannel::PATAChannel(PCI::Address address, ChannelType type, bool force_pio)
+    : PCI::Device(address, (type == ChannelType::Primary ? PATA_PRIMARY_IRQ : PATA_SECONDARY_IRQ))
     , m_channel_number((type == ChannelType::Primary ? 0 : 1))
     , m_io_base((type == ChannelType::Primary ? 0x1F0 : 0x170))
     , m_control_base((type == ChannelType::Primary ? 0x3f6 : 0x376))
@@ -142,17 +150,6 @@ PATAChannel::~PATAChannel()
 
 void PATAChannel::initialize(bool force_pio)
 {
-    PCI::enumerate_all([this](const PCI::Address& address, PCI::ID id) {
-        if (PCI::get_class(address) == PCI_Mass_Storage_Class && PCI::get_subclass(address) == PCI_IDE_Controller_Subclass) {
-            m_pci_address = address;
-            kprintf("PATAChannel: PATA Controller found! id=%w:%w\n", id.vendor_id, id.device_id);
-        }
-    });
-
-    if (m_pci_address.is_null()) {
-        kprintf("PATAChannel: PCI address was null; can not set up DMA\n");
-        return;
-    }
 
     if (force_pio) {
         kprintf("PATAChannel: Requested to force PIO mode; not setting up DMA\n");
@@ -160,9 +157,9 @@ void PATAChannel::initialize(bool force_pio)
     }
 
     // Let's try to set up DMA transfers.
-    PCI::enable_bus_mastering(m_pci_address);
+    PCI::enable_bus_mastering(get_pci_address());
     prdt().end_of_table = 0x8000;
-    m_bus_master_base = PCI::get_BAR4(m_pci_address) & 0xfffc;
+    m_bus_master_base = PCI::get_BAR4(get_pci_address()) & 0xfffc;
     m_dma_buffer_page = MM.allocate_supervisor_physical_page();
     kprintf("PATAChannel: Bus master IDE: I/O @ %x\n", m_bus_master_base);
 }
@@ -188,7 +185,7 @@ void PATAChannel::wait_for_irq()
     disable_irq();
 }
 
-void PATAChannel::handle_irq()
+void PATAChannel::handle_irq(RegisterState&)
 {
     u8 status = IO::in8(m_io_base + ATA_REG_STATUS);
     if (status & ATA_SR_ERR) {