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

Alistair Delva
2021-10-20T21:41:13Z

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>
---
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