[PATCH v4 4/6] mips: cdmm: Add mti,mips-cdmm dtb node support

[Serge Semin]

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@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx

---

Changelog prev:
- Use alphabetical order for the include pre-processor operator.
---
 drivers/bus/mips_cdmm.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/bus/mips_cdmm.c b/drivers/bus/mips_cdmm.c
index 1b14256376d2..9f7ed1fcd428 100644
--- 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;
 }
 
-- 
2.26.2