powerpc/pasemi: Add PCI initialisation for Nemo board.

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 <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/platforms/pasemi/pci.c b/arch/powerpc/platforms/pasemi/pci.c
index c3c6417..116c0fe 100644 (file)
--- 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)
 {