rpmsg: smd: Expose edge registration functions

The edge registration functions is to be used from a remoteproc driver
to register and unregister an edge as the remote processor comes and
goes.

Signed-off-by: Bjorn Andersson <[e-mail]>

drivers/rpmsg/qcom_smd.c

···
 #include <linux/soc/qcom/smem.h>
 #include <linux/wait.h>
 #include <linux/rpmsg.h>
+#include <linux/rpmsg/qcom_smd.h>
 
 #include "rpmsg_internal.h"
 

include/linux/rpmsg/qcom_smd.h

···
+
+#ifndef _LINUX_RPMSG_QCOM_SMD_H
+#define _LINUX_RPMSG_QCOM_SMD_H
+
+#include <linux/device.h>
+
+struct qcom_smd_edge;
+
+#if IS_ENABLED(CONFIG_RPMSG_QCOM_SMD) || IS_ENABLED(CONFIG_QCOM_SMD)
+
+struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent,
+					     struct device_node *node);
+int qcom_smd_unregister_edge(struct qcom_smd_edge *edge);
+
+#else
+
+static inline struct qcom_smd_edge *
+qcom_smd_register_edge(struct device *parent,
+		       struct device_node *node)
+{
+	return ERR_PTR(-ENXIO);
+}
+
+static inline int qcom_smd_unregister_edge(struct qcom_smd_edge *edge)
+{
+	/* This shouldn't be possible */
+	WARN_ON(1);
+	return -ENXIO;
+}
+
+#endif
+
+#endif