From: Alistair Delva <adelva@google.com>
Date: Wed, 20 Oct 2021 21:31:34 +0000 (+0000)
Subject: RFC: arm: pci: Add PCI cam support to PCI-E ecam driver
X-Git-Tag: v2022.07~227^2~30^2~6
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4f2e2280862aabb22cbdb39d37d524702aa57bcc;p=platform%2Fkernel%2Fu-boot.git

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

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@google.com>
Cc: Tuomas Tynkkynen <tuomas.tynkkynen@iki.fi>
Cc: Ram Muthiah <rammuthiah@google.com>
---

diff --git a/drivers/pci/pcie_ecam_generic.c b/drivers/pci/pcie_ecam_generic.c
index 09b6fc1..1a9f9ae 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
@@ -46,8 +48,14 @@ static int pci_generic_ecam_conf_address(const struct udevice *bus,
 	void *addr;
 
 	addr = pcie->cfg_base;
-	addr += PCIE_ECAM_OFFSET(PCI_BUS(bdf) - pcie->first_busno,
-				 PCI_DEV(bdf), PCI_FUNC(bdf), offset);
+
+	if (dev_get_driver_data(bus) == TYPE_PCI) {
+		addr += ((PCI_BUS(bdf) - pcie->first_busno) << 16) |
+			 (PCI_DEV(bdf) << 11) | (PCI_FUNC(bdf) << 8) | offset;
+	} else {
+		addr += PCIE_ECAM_OFFSET(PCI_BUS(bdf) - pcie->first_busno,
+					 PCI_DEV(bdf), PCI_FUNC(bdf), offset);
+	}
 	*paddress = addr;
 
 	return 0;
@@ -156,7 +164,8 @@ 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 },
 	{ }
 };