[PATCH 08/10] rpmsg: core: Add RPMSG byte conversion operations

[Mathieu Poirier]

Add RPMSG device specific byte conversion operations as a first
step to separate the RPMSG name space service from the virtIO
transport layer.

Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
---
 drivers/rpmsg/rpmsg_core.c     | 51 ++++++++++++++++++++++++++++++++++
 drivers/rpmsg/rpmsg_internal.h | 12 ++++++++
 2 files changed, 63 insertions(+)

diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c
index 50a835eaf1ba..66ad5b5f1e87 100644
--- a/drivers/rpmsg/rpmsg_core.c
+++ b/drivers/rpmsg/rpmsg_core.c
@@ -20,6 +20,57 @@
 
 #include "rpmsg_internal.h"
 
+/**
+ * rpmsg{16|32}_to_cpu()
+ * cpu_to_rpmsg[16|32}() - rpmsg device specific byte conversion functions to
+ *			   perform byte conversion between rpmsg device and the
+ *			   transport layer it is operating on.
+ */
+
+u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, u16 val)
+{
+	if (WARN_ON(!rpdev))
+		return -EINVAL;
+	if (!rpdev->ops || !rpdev->ops->transport16_to_cpu)
+		return -EPERM;
+
+	return rpdev->ops->transport16_to_cpu(rpdev, val);
+}
+EXPORT_SYMBOL(rpmsg16_to_cpu);
+
+u16 cpu_to_rpmsg16(struct rpmsg_device *rpdev, u16 val)
+{
+	if (WARN_ON(!rpdev))
+		return -EINVAL;
+	if (!rpdev->ops || !rpdev->ops->cpu_to_transport16)
+		return -EPERM;
+
+	return rpdev->ops->cpu_to_transport16(rpdev, val);
+}
+EXPORT_SYMBOL(cpu_to_rpmsg16);
+
+u32 rpmsg32_to_cpu(struct rpmsg_device *rpdev, u32 val)
+{
+	if (WARN_ON(!rpdev))
+		return -EINVAL;
+	if (!rpdev->ops || !rpdev->ops->transport32_to_cpu)
+		return -EPERM;
+
+	return rpdev->ops->transport32_to_cpu(rpdev, val);
+}
+EXPORT_SYMBOL(rpmsg32_to_cpu);
+
+u32 cpu_to_rpmsg32(struct rpmsg_device *rpdev, u32 val)
+{
+	if (WARN_ON(!rpdev))
+		return -EINVAL;
+	if (!rpdev->ops || !rpdev->ops->cpu_to_transport32)
+		return -EPERM;
+
+	return rpdev->ops->cpu_to_transport32(rpdev, val);
+}
+EXPORT_SYMBOL(cpu_to_rpmsg32);
+
 /**
  * rpmsg_create_channel() - create a new rpmsg channel
  * using its name and address info.
diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h
index 2e65386f191e..2f0ad1a52698 100644
--- a/drivers/rpmsg/rpmsg_internal.h
+++ b/drivers/rpmsg/rpmsg_internal.h
@@ -81,6 +81,8 @@ struct virtio_rpmsg_channel {
 
 /**
  * struct rpmsg_device_ops - indirection table for the rpmsg_device operations
+ * @transport{16|32}_to_cpu: byte conversion from rpmsg device to transport layer
+ * @cpu_to_transport{16|32}: byte conversion from transport layer to rpmsg device
  * @create_channel:	create backend-specific channel, optional
  * @release_channel:	release backend-specific channel, optional
  * @create_ept:		create backend-specific endpoint, required
@@ -92,6 +94,10 @@ struct virtio_rpmsg_channel {
  * advertise new channels implicitly by creating the endpoints.
  */
 struct rpmsg_device_ops {
+	u16 (*transport16_to_cpu)(struct rpmsg_device *rpdev, u16 val);
+	u16 (*cpu_to_transport16)(struct rpmsg_device *rpdev, u16 val);
+	u32 (*transport32_to_cpu)(struct rpmsg_device *rpdev, u32 val);
+	u32 (*cpu_to_transport32)(struct rpmsg_device *rpdev, u32 val);
 	struct rpmsg_device *(*create_channel)(struct rpmsg_device *rpdev,
 					     struct rpmsg_channel_info *chinfo);
 	int (*release_channel)(struct rpmsg_device *rpdev,
@@ -148,6 +154,12 @@ rpmsg_create_channel(struct rpmsg_device *rpdev,
 		     struct rpmsg_channel_info *chinfo);
 int rpmsg_release_channel(struct rpmsg_device *rpdev,
 			  struct rpmsg_channel_info *chinfo);
+
+u16 rpmsg16_to_cpu(struct rpmsg_device *rpdev, u16 val);
+u16 cpu_to_rpmsg16(struct rpmsg_device *rpdev, u16 val);
+u32 rpmsg32_to_cpu(struct rpmsg_device *rpdev, u32 val);
+u32 cpu_to_rpmsg32(struct rpmsg_device *rpdev, u32 val);
+
 /**
  * rpmsg_chrdev_register_device() - register chrdev device based on rpdev
  * @rpdev:	prepared rpdev to be used for creating endpoints
-- 
2.25.1