[PATCH v2 15/20] mips: cdmm: Add mti,mips-cdmm dtb node support

Sergey.Semin
2020-05-06T17:44:27Z

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

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>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: devicetree@vger.kernel.org
---
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..7faa8c049f07 100644
--- a/drivers/bus/mips_cdmm.c
+++ b/drivers/bus/mips_cdmm.c
@@ -16,6 +16,8 @@
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/smp.h>
+#include <linux/of_address.h>
+#include <linux/of.h>
#include <asm/cdmm.h>
#include <asm/hazards.h>
#include <asm/mipsregs.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;
}

--
2.25.1