[PATCH] RFC: arm: pci: Add PCI cam support to PCI-E ecam driver

[Alistair Delva]

When booting U-Boot in crosvm, the virtual machine emulates a PCI cam
device, not the PCI-E 'ecam' device normally seen on e.g. QEMU. This
PCI device can be supported with only trivial changes to the ecam
driver.

Instead of adding a completely new driver which is identical besides the
initialization step, add support for the PCI version to the existing
driver.

Signed-off-by: Alistair Delva <adelva at google.com>
Cc: Tuomas Tynkkynen <tuomas.tynkkynen at iki.fi>
Cc: Ram Muthiah <rammuthiah at google.com>
---
 drivers/pci/pcie_ecam_generic.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pcie_ecam_generic.c b/drivers/pci/pcie_ecam_generic.c
index e83e5aff20..c9b55b45a9 100644
--- a/drivers/pci/pcie_ecam_generic.c
+++ b/drivers/pci/pcie_ecam_generic.c
@@ -14,6 +14,8 @@
 
 #include <asm/io.h>
 
+#define TYPE_PCI 0x1
+
 /**
  * struct generic_ecam_pcie - generic_ecam PCIe controller state
  * @cfg_base: The base address of memory mapped configuration space
@@ -46,9 +48,16 @@ static int pci_generic_ecam_conf_address(const struct udevice *bus,
 	void *addr;
 
 	addr = pcie->cfg_base;
-	addr += (PCI_BUS(bdf) - pcie->first_busno) << 20;
-	addr += PCI_DEV(bdf) << 15;
-	addr += PCI_FUNC(bdf) << 12;
+
+	if (dev_get_driver_data(bus) == TYPE_PCI) {
+		addr += (PCI_BUS(bdf) - pcie->first_busno) << 16;
+		addr += PCI_DEV(bdf) << 11;
+		addr += PCI_FUNC(bdf) << 8;
+	} else {
+		addr += (PCI_BUS(bdf) - pcie->first_busno) << 20;
+		addr += PCI_DEV(bdf) << 15;
+		addr += PCI_FUNC(bdf) << 12;
+	}
 	addr += offset;
 	*paddress = addr;
 
@@ -158,7 +167,8 @@ static const struct dm_pci_ops pci_generic_ecam_ops = {
 };
 
 static const struct udevice_id pci_generic_ecam_ids[] = {
-	{ .compatible = "pci-host-ecam-generic" },
+	{ .compatible = "pci-host-ecam-generic" /* PCI-E */ },
+	{ .compatible = "pci-host-cam-generic", .data = TYPE_PCI },
 	{ }
 };
 
-- 
2.30.2