[PATCH v4 14/16] rpmsg: char: introduce a RPMsg driver for the RPMsg char device

[Arnaud Pouliquen]

A RPMsg char device allows to probe the endpoint device on a remote name
service announcement. With this patch the /dev/rpmsgX interface is created
either by a user application or by the remote firmware.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliq...@foss.st.com>
---
 drivers/rpmsg/rpmsg_char.c | 63 +++++++++++++++++++++++++++++++++++++-
 1 file changed, 62 insertions(+), 1 deletion(-)

diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
index 66dcb8845d6c..d5aa874865f7 100644
--- a/drivers/rpmsg/rpmsg_char.c
+++ b/drivers/rpmsg/rpmsg_char.c
@@ -28,6 +28,8 @@
 
 #define RPMSG_DEV_MAX  (MINORMASK + 1)
 
+#define RPMSG_CHAR_DEVNAME "rpmsg-raw"
+
 static dev_t rpmsg_major;
 static struct class *rpmsg_class;
 
@@ -408,6 +410,51 @@ int rpmsg_chrdev_create_eptdev(struct rpmsg_device *rpdev, 
struct device *parent
 }
 EXPORT_SYMBOL(rpmsg_chrdev_create_eptdev);
 
+static int rpmsg_chrdev_probe(struct rpmsg_device *rpdev)
+{
+       struct rpmsg_channel_info chinfo;
+       struct rpmsg_eptdev *eptdev;
+
+       memcpy(chinfo.name, RPMSG_CHAR_DEVNAME, sizeof(RPMSG_CHAR_DEVNAME));
+       chinfo.src = rpdev->src;
+       chinfo.dst = rpdev->dst;
+
+       eptdev = __rpmsg_chrdev_create_eptdev(rpdev, &rpdev->dev, chinfo);
+       if (IS_ERR(eptdev) && rpdev->ept) {
+               rpmsg_destroy_ept(rpdev->ept);
+               return PTR_ERR(eptdev);
+       }
+
+       /* Set the private field of the default endpoint to retrieve context on 
callback. */
+       rpdev->ept->priv = eptdev;
+
+       return 0;
+}
+
+static void rpmsg_chrdev_remove(struct rpmsg_device *rpdev)
+{
+       int ret;
+
+       ret = device_for_each_child(&rpdev->dev, NULL, 
rpmsg_chrdev_eptdev_destroy);
+       if (ret)
+               dev_warn(&rpdev->dev, "failed to destroy endpoints: %d\n", ret);
+}
+
+static struct rpmsg_device_id rpmsg_chrdev_id_table[] = {
+       { .name = RPMSG_CHAR_DEVNAME },
+       { },
+};
+
+static struct rpmsg_driver rpmsg_chrdev_driver = {
+       .probe = rpmsg_chrdev_probe,
+       .remove = rpmsg_chrdev_remove,
+       .id_table = rpmsg_chrdev_id_table,
+       .callback = rpmsg_ept_cb,
+       .drv = {
+               .name = "rpmsg_chrdev",
+       },
+};
+
 static int rpmsg_chrdev_init(void)
 {
        int ret;
@@ -422,9 +469,23 @@ static int rpmsg_chrdev_init(void)
        if (IS_ERR(rpmsg_class)) {
                pr_err("failed to create rpmsg class\n");
                unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
-               return PTR_ERR(rpmsg_class);
+               ret = PTR_ERR(rpmsg_class);
+               goto free_region;
        }
 
+       ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
+       if (ret < 0) {
+               pr_err("rpmsg raw: failed to register rpmsg driver\n");
+               goto free_class;
+       }
+
+       return 0;
+
+free_class:
+       class_destroy(rpmsg_class);
+free_region:
+       unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
+
        return ret;
 }
 postcore_initcall(rpmsg_chrdev_init);
-- 
2.17.1