This is going to be used in the incoming MIPI DSI support.
Signed-off-by: Ahmad Fatoum <a.fat...@barebox.org>
---
drivers/of/base.c | 31 +++++++++++++++++++++++++++++++
include/of.h | 1 +
2 files changed, 32 insertions(+)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 1439e55a0aac..eb1f0b44f22d 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -3569,6 +3569,37 @@ int of_graph_port_is_available(struct device_node *node)
}
EXPORT_SYMBOL(of_graph_port_is_available);
+/**
+ * of_alias_from_compatible - Lookup appropriate alias for a device node
+ * depending on compatible
+ * @node: pointer to a device tree node
+ * @alias: Pointer to buffer that alias value will be copied into
+ * @len: Length of alias value
+ *
+ * Based on the value of the compatible property, this routine will attempt
+ * to choose an appropriate alias value for a particular device tree node.
+ * It does this by stripping the manufacturer prefix (as delimited by a ',')
+ * from the first entry in the compatible list property.
+ *
+ * Note: The matching on just the "product" side of the compatible is a relic
+ * from I2C and SPI. Please do not add any new user.
+ *
+ * Return: This routine returns 0 on success, <0 on failure.
+ */
+int of_alias_from_compatible(const struct device_node *node, char *alias, int
len)
+{
+ const char *compatible, *p;
+ int cplen;
+
+ compatible = of_get_property(node, "compatible", &cplen);
+ if (!compatible || strlen(compatible) > cplen)
+ return -ENODEV;
+ p = strchr(compatible, ',');
+ strscpy(alias, p ? p + 1 : compatible, len);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(of_alias_from_compatible);
+
/**
* of_get_machine_compatible - get first compatible string from the root node.
*
diff --git a/include/of.h b/include/of.h
index 2258cd501b72..fa2401fc8ded 100644
--- a/include/of.h
+++ b/include/of.h
@@ -196,6 +196,7 @@ extern struct device_node *of_copy_node(struct device_node
*parent,
extern struct device_node *of_dup(const struct device_node *root);
extern void of_delete_node(struct device_node *node);
+extern int of_alias_from_compatible(const struct device_node *node, char
*alias, int len);
extern const char *of_get_machine_compatible(void);
extern int of_machine_is_compatible(const char *compat);
extern int of_device_is_compatible(const struct device_node *device,
--
2.39.5
