mpc85xx: pcie: Implement workaround for Erratum A007815
The read-only-write-enable bit is set by default and must be cleared
to prevent overwriting read-only registers. This should be done
immediately after resetting the PCI Express controller.
Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Tony O'Brien <tony.obrien@alliedtelesis.co.nz>
[York S: Move SYS_FSL_ERRATUM_A007815 to Kconfig]
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/drivers/pci/fsl_pci_init.c b/drivers/pci/fsl_pci_init.c
index 52792dc..af20cf0 100644
--- a/drivers/pci/fsl_pci_init.c
+++ b/drivers/pci/fsl_pci_init.c
@@ -543,6 +543,13 @@
pciauto_prescan_setup_bridge(hose, dev, hose->current_busno);
}
+#ifdef CONFIG_SYS_FSL_ERRATUM_A007815
+ /* The Read-Only Write Enable bit defaults to 1 instead of 0.
+ * Set to 0 to protect the read-only registers.
+ */
+ clrbits_be32(&pci->dbi_ro_wr_en, 0x01);
+#endif
+
/* Use generic setup_device to initialize standard pci regs,
* but do not allocate any windows since any BAR found (such
* as PCSRBAR) is not in this cpu's memory space.