[PATCH v3 2/3] libnvdimm/of_pmem: handle memory-region in DT

[Alistair Delva <adelva@google.com>]

From: Kenny Root <kroot@google.com>

Add support for parsing the 'memory-region' DT property in addition to
the 'reg' DT property. This enables use cases where the pmem region is
not in I/O address space or dedicated memory (e.g. a bootloader
carveout).

Signed-off-by: Kenny Root <kroot@google.com>
Signed-off-by: Alistair Delva <adelva@google.com>
Reviewed-by: "Oliver O'Halloran" <oohall@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: devicetree@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Cc: kernel-team@android.com
---
[v3: adelva: remove duplicate "From:"]
 drivers/nvdimm/of_pmem.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/nvdimm/of_pmem.c b/drivers/nvdimm/of_pmem.c
index fdf54494e8c9..cff47cc5fc4a 100644
--- a/drivers/nvdimm/of_pmem.c
+++ b/drivers/nvdimm/of_pmem.c
@@ -49,11 +49,12 @@ static void of_pmem_register_region(struct platform_device *pdev,
 
 static int of_pmem_region_probe(struct platform_device *pdev)
 {
+	struct device_node *mr_np, *np;
 	struct of_pmem_private *priv;
-	struct device_node *np;
 	struct nvdimm_bus *bus;
+	struct resource res;
 	bool is_volatile;
-	int i;
+	int i, ret;
 
 	np = dev_of_node(&pdev->dev);
 	if (!np)
@@ -83,6 +84,21 @@ static int of_pmem_region_probe(struct platform_device *pdev)
 					is_volatile);
 	}
 
+	i = 0;
+	while ((mr_np = of_parse_phandle(np, "memory-region", i++))) {
+		ret = of_address_to_resource(mr_np, 0, &res);
+		if (ret) {
+			dev_warn(
+				&pdev->dev,
+				"Unable to acquire memory-region from %pOF: %d\n",
+				mr_np, ret);
+		} else {
+			of_pmem_register_region(pdev, bus, np, &res,
+						is_volatile);
+		}
+		of_node_put(mr_np);
+	}
+
 	return 0;
 }
 
-- 
2.25.0.265.gbab2e86ba0-goog