mips: cdmm: Add mti,mips-cdmm dtb node support

Since having and mapping the CDMM block is platform specific, then
instead of just returning a zero-address, lets make the default CDMM
base address search method (mips_cdmm_phys_base()) to do something
useful. For instance to find the address in a dedicated dtb-node in
order to support of-based platforms by default.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

diff --git a/drivers/bus/mips_cdmm.c b/drivers/bus/mips_cdmm.c
index 1b14256..9f7ed1f 100644 (file)
--- a/drivers/bus/mips_cdmm.c
+++ b/drivers/bus/mips_cdmm.c
@@ -13,6 +13,8 @@
 #include <linux/cpu.h>
 #include <linux/cpumask.h>
 #include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/smp.h>
@@ -337,9 +339,22 @@ static phys_addr_t mips_cdmm_cur_base(void)
  * Picking a suitable physical address at which to map the CDMM region is
  * platform specific, so this weak function can be overridden by platform
  * code to pick a suitable value if none is configured by the bootloader.
+ * By default this method tries to find a CDMM-specific node in the system
+ * dtb. Note that this won't work for early serial console.
  */
 phys_addr_t __weak mips_cdmm_phys_base(void)
 {
+       struct device_node *np;
+       struct resource res;
+       int err;
+
+       np = of_find_compatible_node(NULL, NULL, "mti,mips-cdmm");
+       if (np) {
+               err = of_address_to_resource(np, 0, &res);
+               if (!err)
+                       return res.start;
+       }
+
        return 0;
 }