[PATCH v2 1/2] coresight: core: Add device name support

[Mao Jinlong]

For some coresight components like CTI and TPDM, there could be
numerous of them. From the node name, we can only get the type and
register address of the component. We can't identify the HW or the
system the component belongs to. Add the device-name support for
adding the intuitive name of the device.

Signed-off-by: Mao Jinlong <quic_jinlmao@xxxxxxxxxxx>
---
 drivers/hwtracing/coresight/coresight-core.c  | 33 ++++++++++---------
 .../hwtracing/coresight/coresight-platform.c  | 31 +++++++++++++++++
 include/linux/coresight.h                     |  1 +
 3 files changed, 50 insertions(+), 15 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 9fabe00a40d6..b85fc5cc3807 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -1772,24 +1772,27 @@ char *coresight_alloc_device_name(struct coresight_dev_list *dict,
 
 	mutex_lock(&coresight_mutex);
 
-	idx = coresight_search_device_idx(dict, dev_fwnode(dev));
-	if (idx < 0) {
-		/* Make space for the new entry */
-		idx = dict->nr_idx;
-		list = krealloc_array(dict->fwnode_list,
-				      idx + 1, sizeof(*dict->fwnode_list),
-				      GFP_KERNEL);
-		if (ZERO_OR_NULL_PTR(list)) {
-			idx = -ENOMEM;
-			goto done;
+	name = coresight_get_device_name(dev);
+	if (!name) {
+		idx = coresight_search_device_idx(dict, dev_fwnode(dev));
+		if (idx < 0) {
+			/* Make space for the new entry */
+			idx = dict->nr_idx;
+			list = krealloc_array(dict->fwnode_list,
+					      idx + 1, sizeof(*dict->fwnode_list),
+					      GFP_KERNEL);
+			if (ZERO_OR_NULL_PTR(list)) {
+				idx = -ENOMEM;
+				goto done;
+			}
+
+			list[idx] = dev_fwnode(dev);
+			dict->fwnode_list = list;
+			dict->nr_idx = idx + 1;
 		}
 
-		list[idx] = dev_fwnode(dev);
-		dict->fwnode_list = list;
-		dict->nr_idx = idx + 1;
+		name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
 	}
-
-	name = devm_kasprintf(dev, GFP_KERNEL, "%s%d", dict->pfx, idx);
 done:
 	mutex_unlock(&coresight_mutex);
 	return name;
diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
index 9d550f5697fa..c6c68fc9f787 100644
--- a/drivers/hwtracing/coresight/coresight-platform.c
+++ b/drivers/hwtracing/coresight/coresight-platform.c
@@ -183,6 +183,22 @@ static int of_coresight_get_cpu(struct device *dev)
 	return cpu;
 }
 
+static const char *of_coresight_get_device_name(struct device *dev)
+{
+	const char *name = NULL;
+
+	if (!dev->of_node)
+		return NULL;
+
+	/*
+	 * Get the device name from DT. The name describes the HW or
+	 * system the device is for.
+	 */
+	of_property_read_string(dev->of_node, "device-name", &name);
+
+	return name;
+}
+
 /*
  * of_coresight_parse_endpoint : Parse the given output endpoint @ep
  * and fill the connection information in @pdata->out_conns
@@ -315,6 +331,12 @@ static inline int of_coresight_get_cpu(struct device *dev)
 {
 	return -ENODEV;
 }
+
+static inline const char *of_coresight_get_device_name(struct device *dev)
+{
+	return NULL;
+}
+
 #endif
 
 #ifdef CONFIG_ACPI
@@ -794,6 +816,15 @@ int coresight_get_cpu(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(coresight_get_cpu);
 
+const char *coresight_get_device_name(struct device *dev)
+{
+	if (is_of_node(dev->fwnode))
+		return of_coresight_get_device_name(dev);
+	else
+		return NULL;
+}
+EXPORT_SYMBOL_GPL(coresight_get_device_name);
+
 struct coresight_platform_data *
 coresight_get_platform_data(struct device *dev)
 {
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index a269fffaf991..caa17c8af865 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -675,6 +675,7 @@ static inline void coresight_write64(struct coresight_device *csdev, u64 val, u3
 #endif		/* IS_ENABLED(CONFIG_CORESIGHT) */
 
 extern int coresight_get_cpu(struct device *dev);
+extern const char *coresight_get_device_name(struct device *dev);
 
 struct coresight_platform_data *coresight_get_platform_data(struct device *dev);
 struct coresight_connection *
-- 
2.41.0