PCI: loongson: Work around LS7A incorrect Interrupt Pin registers

Several devices integrated into LS7A report 1 (which means they use
INTA) in their Interrupt Pin registers, but they actually use a different
interrupt.

Add a quirk to override the incorrect Interrupt Pin values.

This is only needed by ACPI-based systems. For DT-based systems,
pci_assign_irq() ignores the Interrupt Pin register except to learn that
the device uses INTx and the host bridge .map_irq() function
(loongson_map_irq()) learns the IRQ mapping via DT and of_irq_parse_pci().

[bhelgaas: drop PCIE_PORT_x, OHCI, GPU since they are function 0 and don't
need the quirk, squash in updates from
https://lore.kernel.org/r/CAAhV-H40_o+9KS1t67O98GusM38pDaiB4bssxd3KQZpAByfnLg@mail.gmail.com]
Link: https://lore.kernel.org/r/20220714124216.1489304-8-chenhuacai@loongson.cn
Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Author: lvjianmin-loongson

drivers/pci/controller/pci-loongson.c

@@ -20,8 +20,15 @@
 #define DEV_PCIE_PORT_2	0x7a29
 
 #define DEV_LS2K_APB	0x7a02
-#define DEV_LS7A_CONF	0x7a10
+#define DEV_LS7A_GMAC	0x7a03
+#define DEV_LS7A_DC1	0x7a06
 #define DEV_LS7A_LPC	0x7a0c
+#define DEV_LS7A_AHCI	0x7a08
+#define DEV_LS7A_CONF	0x7a10
+#define DEV_LS7A_GNET	0x7a13
+#define DEV_LS7A_EHCI	0x7a14
+#define DEV_LS7A_DC2	0x7a36
+#define DEV_LS7A_HDMI	0x7a37
 
 #define FLAG_CFG0	BIT(0)
 #define FLAG_CFG1	BIT(1)
@@ -100,6 +107,25 @@ static void loongson_mrrs_quirk(struct pci_dev *dev)
 }
 DECLARE_PCI_FIXUP_ENABLE(PCI_ANY_ID, PCI_ANY_ID, loongson_mrrs_quirk);
 
+static void loongson_pci_pin_quirk(struct pci_dev *pdev)
+{
+	pdev->pin = 1 + (PCI_FUNC(pdev->devfn) & 3);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_DC1, loongson_pci_pin_quirk);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_DC2, loongson_pci_pin_quirk);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_GMAC, loongson_pci_pin_quirk);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_AHCI, loongson_pci_pin_quirk);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_EHCI, loongson_pci_pin_quirk);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_GNET, loongson_pci_pin_quirk);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON,
+			DEV_LS7A_HDMI, loongson_pci_pin_quirk);
+
 static struct loongson_pci *pci_bus_to_loongson_pci(struct pci_bus *bus)
 {
 	struct pci_config_window *cfg;