powerpc/scom: Add support for "reg" property

When devices are direct children of a scom controller node, they
should be able to use the normal "reg" property instead of "scom-reg".

In that case, they also use #address-cells rather than #scom-cells
to indicate the size of an entry.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/arch/powerpc/sysdev/scom.c b/arch/powerpc/sysdev/scom.c
index 10f1d9e56612cfce1f284dc39c04d16cfd677ce9..413622d54395405a597bf9836f29ffb63719a827 100644 (file)
--- a/arch/powerpc/sysdev/scom.c
+++ b/arch/powerpc/sysdev/scom.c
@@ -53,7 +53,7 @@ scom_map_t scom_map_device(struct device_node *dev, int index)
 {
        struct device_node *parent;
        unsigned int cells, size;
-       const u32 *prop;
+       const __be32 *prop, *sprop;
        u64 reg, cnt;
        scom_map_t ret;
 
@@ -62,12 +62,24 @@ scom_map_t scom_map_device(struct device_node *dev, int index)
        if (parent == NULL)
                return 0;
 
-       prop = of_get_property(parent, "#scom-cells", NULL);
-       cells = prop ? *prop : 1;
-
+       /*
+        * We support "scom-reg" properties for adding scom registers
+        * to a random device-tree node with an explicit scom-parent
+        *
+        * We also support the simple "reg" property if the device is
+        * a direct child of a scom controller.
+        *
+        * In case both exist, "scom-reg" takes precedence.
+        */
        prop = of_get_property(dev, "scom-reg", &size);
+       sprop = of_get_property(parent, "#scom-cells", NULL);
+       if (!prop && parent == dev->parent) {
+               prop = of_get_property(dev, "reg", &size);
+               sprop = of_get_property(parent, "#address-cells", NULL);
+       }
        if (!prop)
-               return 0;
+               return NULL;
+       cells = sprop ? be32_to_cpup(sprop) : 1;
        size >>= 2;
 
        if (index >= (size / (2*cells)))