[PATCH v3 2/4] remoteproc: imx_rpoc: fix carveout name parsing

[Laurentiu Mihalcea <laurentiumihalcea111@gmail.com>]

From: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>

The imx remoteproc driver assumes that the names of the reserved memory
regions reflect their usage (e.g. "vdevbuffer", "vdev0vring0", etc.). This
conflicts with the devicetree specification's recommendation, which states
that the names of the devicetree nodes should be generic.

Therefore, instead of relying on the node names, use the names passed via
the "memory-region-names" property if present. Otherwise, keep the old
behavior.

The definition of imx_rproc_rmem_to_resource() is added to a common place
as imx_dsp_rproc.c can also use it given that it suffers from the same
aforementioned problem.

Signed-off-by: Laurentiu Mihalcea <laurentiu.mihalcea@nxp.com>
---
 drivers/remoteproc/imx_rproc.c | 13 +++++++++++--
 drivers/remoteproc/imx_rproc.h | 21 +++++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/imx_rproc.c b/drivers/remoteproc/imx_rproc.c
index 745ce52cd822..ce9bdfc1fa98 100644
--- a/drivers/remoteproc/imx_rproc.c
+++ b/drivers/remoteproc/imx_rproc.c
@@ -643,7 +643,7 @@ static int imx_rproc_prepare(struct rproc *rproc)
 		int err;
 		struct resource res;
 
-		err = of_reserved_mem_region_to_resource(np, i++, &res);
+		err = imx_rproc_rmem_to_resource(np, i++, &res);
 		if (err)
 			break;
 
@@ -818,11 +818,20 @@ static int imx_rproc_addr_init(struct imx_rproc *priv,
 	if (nph <= 0)
 		return 0;
 
+	if (!of_property_present(np, "memory-region-names")) {
+		dev_warn(dev, "using node names for carveouts should be avoided\n");
+	} else {
+		if (nph != of_property_count_strings(np, "memory-region-names")) {
+			dev_err(dev, "invalid reserved memory name count\n");
+			return -EINVAL;
+		}
+	}
+
 	/* remap optional addresses */
 	for (a = 0; a < nph; a++) {
 		struct resource res;
 
-		err = of_reserved_mem_region_to_resource(np, a, &res);
+		err = imx_rproc_rmem_to_resource(np, a, &res);
 		if (err) {
 			dev_err(dev, "unable to resolve memory region\n");
 			return err;
diff --git a/drivers/remoteproc/imx_rproc.h b/drivers/remoteproc/imx_rproc.h
index 0d7d48352a10..3632bc375c71 100644
--- a/drivers/remoteproc/imx_rproc.h
+++ b/drivers/remoteproc/imx_rproc.h
@@ -7,6 +7,8 @@
 #ifndef _IMX_RPROC_H
 #define _IMX_RPROC_H
 
+#include <linux/of_reserved_mem.h>
+
 /* address translation table */
 struct imx_rproc_att {
 	u32 da;	/* device address (From Cortex M4 view)*/
@@ -45,4 +47,23 @@ struct imx_rproc_dcfg {
 	u32				reset_vector_mask;
 };
 
+static inline int imx_rproc_rmem_to_resource(struct device_node *np,
+					     int index,
+					     struct resource *res)
+{
+	int ret;
+
+	ret = of_reserved_mem_region_to_resource(np, index, res);
+	if (ret)
+		return ret;
+
+	/* "memory-region-names" is optional */
+	ret = of_property_read_string_index(np, "memory-region-names",
+					    index, &res->name);
+	if (ret == -EINVAL)
+		return 0;
+
+	return ret;
+}
+
 #endif /* _IMX_RPROC_H */
-- 
2.53.0