rpmsg: remote_dev: add API to check if remote is ready

Add an API to check if the remote is ready.

Signed-off-by: Wendy Liang <jliang@xilinx.com>

2 files changed, 24 insertions, 0 deletions

diff --git a/lib/include/openamp/rpmsg_core.h b/lib/include/openamp/rpmsg_core.h
index 62a410b..118a1b7 100644
--- a/lib/include/openamp/rpmsg_core.h
+++ b/lib/include/openamp/rpmsg_core.h
@@ -172,6 +172,7 @@ int rpmsg_rdev_init(struct hil_proc *proc,
                     rpmsg_chnl_cb_t channel_destroyed,
                     rpmsg_rx_cb_t default_cb);
 void rpmsg_rdev_deinit(struct remote_device *rdev);
+int rpmsg_rdev_remote_ready(struct remote_device *rdev);
 struct rpmsg_channel *rpmsg_rdev_get_chnl_from_id(struct remote_device *rdev,
                                                char *rp_chnl_id);
 struct rpmsg_endpoint *rpmsg_rdev_get_endpoint_from_addr(
diff --git a/lib/rpmsg/remote_device.c b/lib/rpmsg/remote_device.c
index 3d6a916..223e3cc 100644
--- a/lib/rpmsg/remote_device.c
+++ b/lib/rpmsg/remote_device.c
@@ -52,6 +52,7 @@
 #include "metal/utilities.h"
 #include "metal/alloc.h"
 #include "metal/atomic.h"
+#include "metal/cpu.h"
 
 /* Macro to initialize vring HW info */
 #define INIT_VRING_ALLOC_INFO(ring_info,vring_hw)                             \
@@ -368,6 +369,28 @@ int rpmsg_rdev_init_channels(struct remote_device *rdev)
         return RPMSG_SUCCESS;
 }
 
+/**
+ * check if the remote is ready to start RPMsg communication
+ */
+int rpmsg_rdev_remote_ready(struct remote_device *rdev)
+{
+        struct virtio_device *vdev = &rdev->virt_dev;
+        uint8_t status;
+        if (rdev->role == RPMSG_MASTER) {
+                while (1) {
+                        /* Busy wait until the remote is ready */
+                        status = vdev->func->get_status(vdev);
+                        if (status & VIRTIO_CONFIG_STATUS_DRIVER_OK)
+                                return true;
+                        metal_cpu_yield();
+                }
+        } else {
+                return true;
+        }
+        /* Never come here */
+        return false;
+}
+
 static void rpmsg_memset_io(struct metal_io_region *io, void *dst, int c, size_t count)
 {
         if ((io->mem_flags & METAL_IO_MAPPED)) {