On Tue, Mar 23, 2021 at 01:27:35PM +0100, Arnaud Pouliquen wrote:
> 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.pouliquen@xxxxxxxxxxx>
> ---
> drivers/rpmsg/rpmsg_char.c | 58 +++++++++++++++++++++++++++++++++++++-
> 1 file changed, 57 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/rpmsg/rpmsg_char.c b/drivers/rpmsg/rpmsg_char.c
> index 7f6d46078179..69e774edb74b 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 DEFINE_IDA(rpmsg_ept_ida);
> @@ -405,13 +407,67 @@ 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;
> +
> + if (!rpdev->ept)
> + return -EINVAL;
> +
> + 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, NULL);
> + if (IS_ERR(eptdev))
> + 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_destroy_eptdev);
> + 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;
>
> ret = alloc_chrdev_region(&rpmsg_major, 0, RPMSG_DEV_MAX, "rpmsg");
> - if (ret < 0)
> + if (ret < 0) {
> pr_err("rpmsg: failed to allocate char dev region\n");
> + return ret;
> + }
> +
> + ret = register_rpmsg_driver(&rpmsg_chrdev_driver);
> + if (ret < 0) {
> + pr_err("rpmsg: failed to register rpmsg raw driver\n");
> + unregister_chrdev_region(rpmsg_major, RPMSG_DEV_MAX);
> + }
Function unregister_rpmsg_driver() has to be called in rpmsg_chrdev_exit().
>
> return ret;
> }
> --
> 2.17.1
>
