ARM: OMAP2+: Fix module address for modules using mpu_rt_idx

If we use device tree data for a module interconnect target we want
to map the control registers from the module start. Legacy hwmod platform
data however is using child IP offsets for cpsw module with mpu_rt_idx.

In cases where we have the interconnect target module already using device
tree data with legacy hwmod platform data still around, the sysc register
area is not adjusted for mpu_rt_idx causing wrong registers being accessed.

Let's fix the issue for mixed dts and platform data mode by ioremapping
the module registers using child IP offset if mpu_rt_idx is set. For
device tree only data there's no reason to use mpu_rt_idx.

Fixes: 6c72b3550672 ("ARM: OMAP2+: Parse module IO range from dts for legacy
"ti,hwmods" support")
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/omap_hwmod.c

@@ -2160,6 +2160,37 @@ static int of_dev_hwmod_lookup(struct device_node *np,
 	return -ENODEV;
 }
 
+/**
+ * omap_hwmod_fix_mpu_rt_idx - fix up mpu_rt_idx register offsets
+ *
+ * @oh: struct omap_hwmod *
+ * @np: struct device_node *
+ *
+ * Fix up module register offsets for modules with mpu_rt_idx.
+ * Only needed for cpsw with interconnect target module defined
+ * in device tree while still using legacy hwmod platform data
+ * for rev, sysc and syss registers.
+ *
+ * Can be removed when all cpsw hwmod platform data has been
+ * dropped.
+ */
+static void omap_hwmod_fix_mpu_rt_idx(struct omap_hwmod *oh,
+				      struct device_node *np,
+				      struct resource *res)
+{
+	struct device_node *child = NULL;
+	int error;
+
+	child = of_get_next_child(np, child);
+	if (!child)
+		return;
+
+	error = of_address_to_resource(child, oh->mpu_rt_idx, res);
+	if (error)
+		pr_err("%s: error mapping mpu_rt_idx: %i\n",
+		       __func__, error);
+}
+
 /**
  * omap_hwmod_parse_module_range - map module IO range from device tree
  * @oh: struct omap_hwmod *
@@ -2222,6 +2253,12 @@ int omap_hwmod_parse_module_range(struct omap_hwmod *oh,
 	pr_debug("omap_hwmod: %s %s at 0x%llx size 0x%llx\n",
 		 oh ? oh->name : "", np->name, base, size);
 
+	if (oh && oh->mpu_rt_idx) {
+		omap_hwmod_fix_mpu_rt_idx(oh, np, res);
+
+		return 0;
+	}
+
 	res->start = base;
 	res->end = base + size - 1;
 	res->flags = IORESOURCE_MEM;