The A-Eon Amigaone X1000's Nemo motherboard has an AMD SB600
connected to one of the PCI-e root ports on its PaSemi
Pwrficient 1628M SoC. Normally the SB600 southbridge would be
connected to a hidden PCI-e port on the system's northbridge,
and as a result doesn't fully comply with the PCI-e spec.
Add code to relax the PCI-e detection in both the root port
and the Linux kernel allowing on board devices to be detected.
Signed-off-by: Darren Stevens <dar...@stevens-zone.net>
---
Changes made:
v2: Replaced sb600_bus with a define, moved iob_mapbase into
sb600_set_flag()
Created some register/Flag names (as I don't have the docs
for the PA6T-1682M)
diff --git a/arch/powerpc/platforms/pasemi/pci.c
b/arch/powerpc/platforms/pasemi/pci.c
index c3c6417..116c0fe 100644
--- a/arch/powerpc/platforms/pasemi/pci.c
+++ b/arch/powerpc/platforms/pasemi/pci.c
@@ -108,6 +108,61 @@ static int workaround_5945(struct pci_bus *bus, unsigned
int devfn,
return 1;
}
+#ifdef CONFIG_PPC_PASEMI_NEMO
+#define PXP_ERR_CFG_REG 0x4
+#define PXP_IGNORE_PCIE_ERRORS 0x800
+#define SB600_BUS 5
+
+static void sb600_set_flag(int bus)
+{
+ static void __iomem *iob_mapbase = NULL;
+ struct resource res;
+ struct device_node *dn;
+ int err;
+
+ if (iob_mapbase == NULL) {
+ dn = of_find_compatible_node(NULL, "isa", "pasemi,1682m-iob");
+ if (!dn) {
+ pr_crit("NEMO SB600 missing iob node\n");
+ return;
+ }
+
+ err = of_address_to_resource(dn, 0, &res);
+ of_node_put(dn);
+
+ if (err) {
+ pr_crit("NEMO SB600 missing resource\n");
+ return;
+ }
+
+ pr_info("NEMO SB600 IOB base %08llx\n",res.start);
+
+ iob_mapbase = ioremap(res.start + 0x100, 0x94);
+ }
+
+ if (iob_mapbase != NULL) {
+ if (bus == SB600_BUS) {
+ /*
+ * This is the SB600's bus, tell the PCI-e root port
+ * to allow non-zero devices to enumerate.
+ */
+ out_le32(iob_mapbase + PXP_ERR_CFG_REG,
in_le32(iob_mapbase + PXP_ERR_CFG_REG) | PXP_IGNORE_PCIE_ERRORS);
+ } else {
+ /*
+ * Only scan device 0 on other busses
+ */
+ out_le32(iob_mapbase + PXP_ERR_CFG_REG,
in_le32(iob_mapbase + PXP_ERR_CFG_REG) & ~PXP_IGNORE_PCIE_ERRORS);
+ }
+ }
+}
+
+#else
+
+static void sb600_set_flag(int bus)
+{
+}
+#endif
+
static int pa_pxp_read_config(struct pci_bus *bus, unsigned int devfn,
int offset, int len, u32 *val)
{
