serial: ns16550: Support ns16550 compatible pci uart devices

There are many pci uart devices which are ns16550 compatible. We can
describe them in the board dts file and use it as the U-Boot serial
console as specified in the chosen node 'stdout-path' property.

Those pci uart devices can have their register be memory-mapped, or
i/o-mapped. The driver will try to use the memory-mapped register if
the reg property in the node has an entry to describe the memory-mapped
register, otherwise i/o-mapped register will be used.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index af5beba..70c9462 100644 (file)
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -289,7 +289,38 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
        struct ns16550_platdata *plat = dev->platdata;
        fdt_addr_t addr;
 
+       /* try Processor Local Bus device first */
        addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
+#ifdef CONFIG_PCI
+       if (addr == FDT_ADDR_T_NONE) {
+               /* then try pci device */
+               struct fdt_pci_addr pci_addr;
+               u32 bar;
+               int ret;
+
+               /* we prefer to use a memory-mapped register */
+               ret = fdtdec_get_pci_addr(gd->fdt_blob, dev->of_offset,
+                                         FDT_PCI_SPACE_MEM32, "reg",
+                                         &pci_addr);
+               if (ret) {
+                       /* try if there is any i/o-mapped register */
+                       ret = fdtdec_get_pci_addr(gd->fdt_blob,
+                                                 dev->of_offset,
+                                                 FDT_PCI_SPACE_IO,
+                                                 "reg", &pci_addr);
+                       if (ret)
+                               return ret;
+               }
+
+               ret = fdtdec_get_pci_bar32(gd->fdt_blob, dev->of_offset,
+                                          &pci_addr, &bar);
+               if (ret)
+                       return ret;
+
+               addr = bar;
+       }
+#endif
+
        if (addr == FDT_ADDR_T_NONE)
                return -EINVAL;